2274, Parts 1=5 1 OAK RIDGE NATIONAL LABORATORY LIBRARIES aec Reseagc anp | WLANEARALL 3 445k 05kLL29E 7 I Uit L2730 UATH AIRCRAFT NUCLEAR PROPULSION PROJECT TAT.E ILNITIALS QUARTERLY PROGRESS REPORT " .:U_f;.—%T_"f FOR PERIOD ENDING MARCH 31, 1957 o] DO 1979 RITIEW OB DECLASSIFIED BRPORTS e This Dooument 1s Properly Declasaifiod. 3 Roviewed by P. g, Bak ORNL Classification Qffyses ! }; 1979 =t OAK RIDGE NATIONAL LABORATORY - OPERATED BY UNION CARBIDE NUCLEAR COMPANY A Division of Union Carbide and Carbon Corporation POST OFFICE BOX X * OAK RIDGE, TENNESSEE | Features of Aircraft Reactors™ I_,!' M - ‘ ' 3 | .;I il ORNL-2274, Parts 15 C-84 — Reoctors-Special Fectures of Alrcraft Reactors This document consists of 338 poges. Copy f/f of 254 copies. Serims A, Contract No, W-7405 eng-26 AIRCRAFT NUCLEAR PROPULSION PROJECT QUARTERLY PROGRESS REPORT For Periad Ending March 31, 1957 W, H. Jordan, Director 3, J. Cromer, Co-Diractor A. J. Miller, Assistont Directar DATE ISSUED JUL 51957 whief, Declassification Branch G!EE ODAX RIDGE HATIONAL LABORATORY ” s T . Oporoted by UNION CARBIDE NUCLEAR COMPANY A Divigion of Union Corblde and Corbon Corporatien Post Qfflce Box X Dak Rldge, Tannessee ORNL-528 ORNL-629 ORNL-768 ORNL-858 ORNL-9219 ANP.60 ANP-65 ORNL-1154 ORNL-1170 ORNL-1227 ORNL-1294 ORNL-1375 ORNL-1439 ORNL-1515 ORNL-1556 ORNL-160% ORNL-1649 ORNL-1692 ORNL-1729 ORNL-1771 ORNL-1816 ORNL-1864 ORNL- 1896 ORNL-1947 ORNL-2012 ORNL-2061 ORNL-2106 ORNL-2157 ORNL-2221] Reports previously issued in this series are as follows: Period Ending November 30, 1949 Period Ending February 28, 1950 Period Ending May 31, 1950 Period Ending August 31, 1950 Period Ending December 10, 1950 Period Ending March 10, 1951 Period Ending June 10, 1951 Period Ending September 10, 1951 Period Ending December 13, 1951 Period Ending March 10, 1952 Period Ending June 10, 1952 Period Ending September 10, 1952 Period Ending December 10, 1952 Peried Ending March 10, 1953 Period Ending June 10, 1953 Period Ending September 10, 1953 Peried Ending December 10, 1953 Period Ending Mosch 10, 1954 Period Ending June 10, 1954 Period Ending September 10, 1954 Period Ending December 10, 1954 Period Ending March 10, 1955 Period Ending June 10, 1955 Period Ending September 10, 1955 Period Ending December 10, 1955 Period Ending March 10, 1956 Period Ending June 10, 1956 Period Ending September 10, 1956 Period Ending December 31, 1956 el 02 e Erd L0 B PO EMUr -0 MOV ECOITANDPTNTEMTOEOMMNOTND = - CERPIMOM> X P D INTERNAL DISTRIBUTION . G, Affel . J. Barton ., Bender . 5, Billington . F. Blankenship . P. Blizard . J. Borkowski . F. Boudreau . E. Boyd . A. Bredig . Ju Breeding . E. Browning . R. Bruce . D. Callihan . W, Cardwell . E. Center (K-25) . A, Charpie . L. Clark . E. Cliftord H. Cocbs . B. Cottrell J. Cromer . 5. Crouse . L. Culler . R. Cuneo H. DeVYon . M, Doney . A. Dougles . R. Dytke . K. Eister . B. Emlet {K-25) . E. Ferguson . P. Froas H. Frye, Jr. . T. Furgerson . J. Gray . T. Gresky. . R. Grimes . G. Grindel! ., Guth . S. Harrill . E. Hoffman . W, Hotfman . Hollgender . 5. Householder T. Howe --'F g ORNL.-2274, Ports 1=5 C-84 — Reactors-Special Features of Aircraft Reactars 47. 48. 49. 2. 52. 33+ 54-55. 56. 57. 8. 59, 61. 62. 63. 63. 67. 68. 6%, 70. 71. 72. 73. /4. 73, 76. 77. 78. 79. 8l. 82, 86. 87. 88. 89. 90. 21. Q2. 93 DAPITIZPIO-0PN DN QT -MACDPDOT-EMrMENADIDDIT - IOOXE . Jordan . Keilholtz . Keim . Keller . Kelley —Sr U =TI . Kertesz . J. Keyes A, Lane . B. Lindauer . 3. Livingston . N. Lyon . G. MocPherson . E. MacPhersen . C. Maienschein . D. Manly . R. Mann A. Mann . B. McDonald R. McNally . R. McQuilkin . V., Meghreblion . P. Milford . J. Miller . E. Moore G. Morgan . Z. Morgan . J. Murphy . P. Murray (Y-12} . L. Nelson . J. Nessle B. Oliver . G. Overholser . Patriorca K. Penny . M. Perry . Phillips C. Pigg . M. Reyling . E. Richt T. Robinson . W. Savage . W, Savelainen . D. Schultheiss . Scott o £ L. Scott D. Shipley - w 4. A. Simon 107. J, C. White @5. O. Sisman 108. G. D. Whitman Q6. J. Sites 109. E, P. Wigner (consultant) 97. M. J. Skinner 110, G, C, Williams 98. A, H. Snell 111, J. C. Wilson 9. C. D. Susano 112, C. E, Winters 100. J. A, Swartout 113. W. Zobel 101. E. H. Taylor 114-116. ORNL - Y-12 Technical Librory, 102. R. €, Thoma Document Reference Section 103. D. B. Trouger 117-124. Laboratory Records Department 104. D. K. Trubey 125. Lobeoratory Records, ORNL R.C. 105. G, M, Watsen 126—-128. Central Research Library 106. A. M. Weinberg EXTERNAL DISTRIBUTION 129, Aerojet-General Corporation 130. AF Plont Representative, Baltimore 131. AF Plant Represenfative, Burbank 132. AF Plant Representative, Clifton 133, AF Plont Representotive, Long Beoch 134-135. AF Plont Representative, Marietta 136-138. AF Plont Representative, Sonta Monico 132--140. AF Plant Representative, Seattle 141. AF Plant Representative, Wichito 142. Air Material Command 143. Air Reseorch and Development Command (RDGN) 144. Air Technical Intelligence Center 145-147. ANP Project Office, Fort Worth 148. Albuguerque Operations Office 149. Argonne Notioncl Laboratory 150. Armed Forces Special Weopons Project, Sandia 151. Armed Forces Special Weapons Project, Washington 152. Assistant Secretary of the Air Force, R&D 153—158. Atomic Energy Commission, Woshington 159, Atomics International 160. Botrelle Memorial Institute 1561-162. Bettis Plant (WAPD) 163. Bureau of Aeronautics 164. Bureau of Aeronautics (Code 24) 165. Bureau of Aeronavtics General Representative 166. Chicago Operations Office 167. Chicago Patent Group 168. Chief of Naval Research 169. Convair-General Dyromics Corporation 170. Curtiss-Wright Corporation 171. Engineer Research and Development Laboratories 172--175. General Electric Company (ANPD) 176. General Nuclear Engineering Corporation 177. 178. 179-180, 181. 182. 183. 184. 185. 186. 187. 188-190. 191. 192, 193. 194, 195. 196. 197. 198-201. 202. 203. 204, 205. 206. 207, 208. 209. 210, 211~228. 229-253. 254, i -—c. | - - Glenn L. Martin Company Hartford Area Dffice Headquarters, Air Force Special Weapons Center ldaho Qperaticns Office Knells Atomic Power LLaboratory Lockland Area Office Los Alamos Scientific Laboratory Marquardt Aircraft Company National Advisory Committee for Aeronautics, Cleveland National Advisory Committee for Aeronautics, Washington Naval Air Development and Material Center Noval Research LLoboratory New York Operations Office Narth American Aviation, lnc. (Missile Development Division) Nuclear Development Corporation of America Office of the Chief of Naval Operation (OP-351} Potent Branch, Washington Patterson-Moos Pratt & Whitney Aircraft Division (Fox Project) San Francisce Operations Office Sandia Corporation School of Aviation Medicine Sylvania Electric Product, Inc, Technical Research Group, New York LISAF Heodquarters USAF Project RAND U.S. Novol Radiological Defense Laboratory University of Californic Radiation Laboratory, Livermore Wright Air Development Center (WCOS|-3) Technical Information Service Extension, Oak Ridge Division of Research and Development, AEC, ORO FOREWORD This quarterly progress report of the Aircraft Nuclear Propulsion Project at QRNL records the technical progress of the research on circuloting-fuel reactors and other ANP research ot the Loboratory under its Contract W-7405-eng-26. The report is divided into five mojor parts: ). Aircraft Reactor Engineering, 2. Chemistry, 3. Metallurgy, 4. Redia- tion Domage and Fuel Recovery and Reprocessing, ond 5. Critical Experiments and Reactor Shielding. The ANP Project personnel are engaged in many phases of reseorch directed toward the achievement of nuclecr propulsion of circraft. A considercble portion of this research is performed in support of the work of other organizations participating in the national ANP effort. However, the bulk of the ANP research at ORNL is directed toward the development of o circuleating-fuel type of reactoer. The design, construction, and eperation of the Aircraft Reactor Test {ART), are the current objectives of the project. The ART is to be a power plant system that wiil in- clude o 60-Mw circuloting-fuel reflector-moderator reoctor ond adequate means for heat disposal. Operation of the system will be for the purpose of determining feasibility and for studying the problems associated with the design, construction, and operation of a high-power circulating-fuel reflector-moderated aircroft reactor system. k3 i i ey vii FOREWORD SUMMARY L1 1.2, 1.3. 1.4, CONTENTS PART 1, AIRCRAFT REACTOR ENGINEERING AIRCRAFT REACTOR TEST DESIGN. ... e e Applied Mechanics and Stress Analysis. ..o Tests of ART Siructural Design Criteria. oo e Thermal Stress Analyses of Shells. . e e e s Design Analysis for Creep Bending ... e Radiator Stress Analysis Problems ..., Core-Shell Thermal Shield .o e e e e et e Core HydrodyMOmigs .o i e o et e e et e et e e e s £t one e eh et e et et e e £t e ART Shi@lding oot et et et ettt et ettt ettt et et st e eb £ ekt ee et et e et e e ere e ART INSTRUMENTS AND CONTROLS .. Flow Decay in ART Primary NaK Syslem Followmg Power Loss .. Liquid-Metal-Level Transducers ..ot et e en et aene e -0 Level Probes oo e e e e e e e e e e et Fuel-Expansion-Tank Level Indicotor ... e vt cree e e e e e ean DM Cr e @ ve] T 818 (e e e s e et SO C-L Vel TBEES it et s et et eh e b e e e e e en e s e en e e en e eee e 2 e Pressure Transmitters for Use at High Temperatures oo MOgretic Flowmeters ..ot e et e e e s e e bt i s s e Remotely Adjustable Pressure Regulators. .o e e e e e e e Turbine Flowmeters for Use at High Temperatures ... e AR T Thermocouples e ettt e e COMPONENT DEVELOPMENT AND TESTING L. e e et e e e e e Pump Developmeant TeSts ..o et e e et s ee e e e e e annians Bearing and Seal Tests ... Fuel Pump Development Water Tesrs Fuel Pump High-Temperature Performance T SIS o e Fuel Pump Endurance Tests .. Sodium Pump Development Wmer Tesls : Sodium Pump Barrel Seal Test .. S0dium Pump Endurance Tests oot mnie e e et vt eevn e eas b st epe e e Primary NoK Pump Development Tests et e Auxitiary NoK Pump Development Water TeSIS .o e e e e e Reactor Component Development Tests .. Heat Exchanger and Radiator Development Tests Woter Flow Tests on Aluminum North-Head Mockup Dump Volve Development Tests i e i ers ot s et s b e ernabe s e ......................................................................................................................................... --------------------------------------------------------------------------------------------------------------------------------------------- 1.5. 1.6, Ersteritn Shall THermal SRTBIITI TBEE s s o il e o Sadiym Tircuid Water Flow TeBlE o v oo s s sass s s i i s a Auxiliory Component Development TeSts .o i i i i et s e b 2o e s o High-Frequency Thermal-Cycling Water Tests o s s, HighFigieney LhatlaCueling TESELAED wommmmnmmmemmms e s s s Cold Ticos and PLuGhing It iBBEEE ez s xooms sy om0 o sy s o i s s L gii - Matal Vopor T on B SBIE: s s s s o e oA 0 1 e S ST EAN 54 A SRS A Tivconitim - Blugride Vopol T ROPE s oo i v s s s o e s s s R S s e Tnsulotion Toms b v s S S i A S B S S B T S L S B 0 REACTOR AND FACILITY CONSTRUCTION ..o iiiiitie it e cee e e et ene ettt be ey snss e b oo ART.ETL Reaétor Canstrottion and Asaembly . . cnmmmmmimmmmmi i ki s as s sssassims s North-Head Assembly ... ....................................................................................................................... Reflactor-Modarator Aasembly:cs e o s s i s s i s S i g b s lstond and Pressore: Shell Liner.... s sm s A Fuel-to-Nal Heat Exchangers ... e e vt st s e s e e s Assembly Methods Devel OPment ..o i e e e st e e e s ETU Facility «oooovrreerre. ...................................................................................................................... Toast Toll Compoments s s s s o i s S S s e S M B B et AET Cacilityonusssmnaam Test Facility oo Disassembly Facility ... ...................................................................................................................... ...................................................................................................................... ....................................................................................................................... AR, B LU AN IRGELE R AT RS o cmmmummomnosnsmms o e s R S S AR T I DBt TN P A TR cosnccmns s o s i 8 S A S e RS O R85 ETU Operation Planning...... ...................................................................................................................... ART Disassembly ProC@dures . eieeiis et e eriesaears e stes sba s s1s st beassesren sees enssemsesneaeres sras eeee e In-Pile Experimentation ..... In-Pile Loops....cceen... Frototype In-Pile Pump ....................................................................................................................... ...................................................................................................................... iR el LaBn e ERCHOGET TaB By oo e sty sos 60 samissi e s s O B St liak thal T R PG HERIOE. DR TTEN S s issssmisints comass o o a5 S RS o R B e S B s ¢ HEAT TRANSFER STUBNES o s o o mms satos oo nssa iess Si t es e hS r emsvi i ART Fuel-to-NakK Heot Exchanger woiiiimuiii viniiitinimi i s i s inssasio sssiveivaissivsissoss ART Hydrodynamics .......... Core Hydrodynamics ... ....................................................................................................................... ...................................................................................................................... Instantaneous Velocity Profile Meusurements ................................................................................ Heat Tronsfer in Reflector-Moderated Recctor o ores . oo e et eee e et e e e ere s e e e e e e e ART Core Heat Transfer .................................................................................................................... Vortex Tube Heal TronSler uems o ms i s B s fa fa e s e i S T i ST S Thermol Cyeling Experiments csin s et oo e ien B ras sanmss some s mpmsas s sssas nsompns Physical Properties............ Enthalpy and Heat Cnpnciiy Yiscosity .. ....................................................................................................................... ------------------------------------------------------------------------------------------------------------- Thermal Canduchwty Electrical Conductivity ....................................................................................................................... ...................................................................................................................... 50 51 53 53 55 57 &0 61 62 65 635 65 65 b6 56 &7 67 69 70 /0 70 73 73 74 75 75 75 75 76 76 7 79 79 80 81 81 82 82 87 87 87 88 88 PART 2. CHEMISTRY . PHASE EQUILIBRIUM STUDIES. .. i i et e cienees s e O Modification of Apparatus for Thermal Anolysis. ..o i . 9 Visual Observation and Differentiol Thermal Anclysis of Small Quentities of Fused Solts oo e e e e e e e et e e e e e e e 91 The System LiF-UF ..o e s s G2 The System NaF-HIF o e 93 The System LiF-Cef i et s e 93 The System KE-Bef, .o s 93 The System NaF-RbF-Bef, .ot e, 96 The System NaF-LiF-UF, e 96 NaF-ZrF ,-Steuctural Metal Fluoride Systems oo 96 Opticol Properties and X-Roy Diffroction Patterns for Compounds in Fluoride Systems .............. 99 Subcontract Work of Mound Laborotory and ot Bottelle Memorial lastitute oo, 101 . CHEMICAL REACTIONS IN MOLTEN SALTS oottt et ettt e eanr e 102 Equilibrium Reduction of Niff, by Hy in NaF-ZeF e 102 Solubility of NiF, in NaF-ZrF o e 103 Stability of Chremium Flyorides in LiF-ThF, ond LiF-BeF,-ThF, Mixtures ..o 103 Reduction of UF‘1 by Structural Metals....... o et e 104 Reduction in Molten RbF-ZrF, Mixtures ... s s s 104 Reduction in ThF -Bearing Melts. ... e 103 Measurements of Solubility of Rore-Earth Fluorides in Molten NoF-ZrF -UF, Mixtures ............ 105 Solubility of CeF g i 104 Solubility of Li::F3 . VDD ORGP P UT U COR A PROPUPPOTPRURPN | Solubilities of CeF, c:-nd LaF in Combmu?lon e ettt e e e e e e senene e 100 Solubility of SmE,.... . et ettt et et e s e snennnina e 1O Etfect of BaF, or SrF on SO'UbIIITY of CeF et te ettt et 108 Solubility Relotionships Arnong Rare-Earth Fluorides in Molten NoF-ZrF -UF, .0 109 Solubility of Individual Rare Eorths ... e s et 109 Solubility of Binary Rare-Earth Mixtures..........cccciiiiiiiin s e, 109 Solukility of Xenon Gos in NuF-Zer-UF_{ .................................. e e e e e et e ke SRR Comparison of the Solubilities of Helium and Xenon Gases in NaF-ZrF -UF . 112 Selutility of HF in NaF-ZrF, e tt et £ r e r e ek he sere b e ebeb e b ene e enen sren e ene e e s e rnenne e 1 1O EMF Measurements in Molten Fluorides. .. . i i e 118 Concentration Cells with ZZeF, Eiectrodes ............................................................................... . 18 Concentration Celis with N|°|N|F Electrodes. ..ot e 118 Daniell Cells . e it s et ettt e e s e e s tees e e rieae essnen e st nes s snraesnseneecrsannices | 1P Activities from EMF Measurements of Molten and Solid Solutions of Salts oo 120 Electromigrotion in Molten Salts as a Possible Separotion Technigue for Processing Fuel . e e ettt e e e ennne e 2] . THEORY CF MOLTEN FLUQRIDE BEHAVIOR.. ... i s 123 Correlations of Molten Fluoride Behavior Based on Charge-te-lon Radius Reties ... 123 2.4, 2.8, 2.6. 2.7, xii Some Aspects of Solution Behavior of Fluoride Melts ..o, A Structure Model and an Acid-Base System for Fuel Mixtures ..., PHYSICAL PROPERTIES OF MOLTEN MATERIALS. ..o Vapor Pressures of Molten Fluorides s isi s st e it i s ssbass s Surface Tension and Density of Molten UF i PRODUCTION OF PURIFIED FLUQRIDE MIXTURES ... e Praodiatich Bl VoriBoE P ube TPl aBritles e ommrs somssensssssiio s ssosia g 9o boisss (s s essos Preporation of ¥ Fy o s s i s s s s s s e Prepcration of Fluorides of Molybdenum ... oo Erepargtion-ot Uther Molerial susmsmmmuseninsiaunssma o o s ss e s s s s ne s e lisiiss Pilot-Scale Purification Dperations . ... cieesieieiries s eersasessreorr e e snsesesns rresnenss e sreast e s e s nmnenvrme s Production=5cale Oparations ..o .o it s s e seee e et et sereeabe e seeaes seb e e bene £ ebes e hene £ ea e rmnte e Bitrhins it DitpErrsing DEePiitiie o cmommmssse i i i s s S s e 846 OB B B TG <. voviss ot s S R 3 A A S R A AN i S S i Fillihg, Droining; ondSampling Operttions cossuwiaim s s s e Filling of Pratt & Whitney High-Temperature Critical Assembly ... COMPATIBILITY OF MATERIALS AT HIGH TEMPERATURE .. ... Penetration of Graphite by Molten Fluorides.. ..o e e e Elesteglyiais Bahia NaOH I SR S o e 5 s s s s s s e s S A Physical Properties of Elastomers Exposed to Attack by Liquid Metals ...co.ovoiviiiicccinccnn e, AN A LY TH AL CHEMIST RY Lo e ettt e et e s ees Sensase s eees esb et s sn e ees e ebean smsans Crssiiatntl LEitEs ar PSS T B cnmmmsmoonieosm e i s e s S S e D e G O SR O Betérmination of Oxygen i Mebtallit L iBRTEI oo mssivemmsmiis s i mss s s i v s iiiiss soioass sivdass Apparatus for Sampling and Analyzing Alkali Metals.......ocii i e Anolyses of Lithium-Base Fluoride Salts for Metallic Impurities e AU DI o ossinse e eesuscn st ae s ae ae e ea e ases s rvmsass o e saasaes res e eae s eae s sten sam semsnt e eesee e nat s e e e aaes saes erts eemmenn e sen sres W OO UM o ittt er e e ettt es te s e et ey e e bt et e s e et ae £t s £ e et e et ran et e e e e en ettt e eeeeeeneee e ean en eaen e en eereeeeemnanes Titanium ................................................................................................................................................ Spectrophotometric Determination of Nickel in Alkali Metals.. .o Determination of Trace Amounts of Zirconium in Sulfate Solutions with Pyrocatechel Violet H R R R R R R AR R L R R L AR AR S LA by r b4 E S Lt T4 aaad eyt E e m TR PR F N R TR R A N AR R AR EE R4 AN AL EE REAMyE REALEEEE & Aad R EEa Determination of Sulfur in Fluoride Fuels oo, Oxidation of Chromium with Argentic Oxide .......................................................................................... Solvent Extraction of Molybdenum from Acidic Solutions with Tri-n-octylphosphine Oxide .................................................................................................................... Preparation of Rare-Earth Fluoride Tracers .......................................................................................... Service Laboratory ...................................................................................................................................... Vapor-Phase Polymers in Alkali-Halide Salts ........................................................................................ 3.1 B 3.3. PART 3. METALLURGY DYNAMIC CORROSION STUDIES .. Forced-Circulation Loop Tests .. Fuel Mixtures in Inconel und in Husielloy B ........................................................................ Nak in Inconel .. Sodium in I'nconen' and in Stomless Sreel ...................................................... e B, A Long-Duretion Tests of NaK and Sedium in Inconel oo e Thermal-Convection Loop Tests .. NaF-KF-LiF-UF, ond Sc:-dtum in Nlckel Mo!ybdenum AHoys .............................................. Void Migration in Inconel Exposed to NaF-ZrF -UF, NaF-KE-LiF-UF, end Sedium in Nishium . vwnnimnnms s amnins GENERAL CORROSION STUBIES ... o bk 5550 i85 ne ik mmncingms sons ammers e dhams silizsn grnn oo Tests of Inconel Tube-to-Header Joints with Recrystallized Welds .. et e Tasts of Hoviries Mo, S84 Braming BUIE8 s s s s ot s o5 i s s s S0 : Compatibility of Molybdenum and Nickel-Molybdenum Alleys in NaF-KF-LiF-UF, ... Thermel-Convection Loap Test-of Sodivm: inHedtelloy Buvsninmnnesasnnuyasea. Sodium-Berylfium-lnconel Compatibility in o Stotic System {Test No, 3} oo, Effect of Zirconium on Corrosion in on lnconel-Sodium System .............. e e e Ml ydenimes Bl gt G ammaiti b T i SOREEIN s s o cmm e s S R SRS e Titanium Carbide~Nickel Cermets in Molten Sodium. .. oo i Boron Carbide and Boron Nitride in Melten Sodium ... v, SHC S0 11 MOlt@Nn SOGTUM oot ettt e eet et e e ee et e e et s e e s rsm s saen s eteeees e BT L T A L T BT cmssssomn somnsonic s s o A R B TN N Valoti ity PrHot Plant T oRrE ST STUGTBE umeri s svms e ovieisss 10 647880880 F0E 58 S50 LR MR VR Exgerimental Studies with'Molten Lithium.cnaaianmusisasaiminsonmaiminsma g Nickel-Molybdenum Alloy Development ... i et e v e e e s General Status of Development Program ... s e Propariies OF AUEE HOREE oo mmmommonms smseses i mieinsss s o0 s s 5600 i kit S S b Proparbias Bl B ew IO umrmmummonssenmssn im0 s s b s e s Fabrication of ORNL Experimental Alloys ... Production of Commerciat-Size Heaots of Nlckel Molybdenum Alloys ................................ Phase Diagrom Studies at the University of Tennessee .. Alloy Development at Battelle Memarial Tnstitute ..o Fabrication of Composite Tubing at Superior Tube Co. oo Shield Plugs for ART Pumps ..o i it e et sty et e et e e s e et et st it e WEUTEEEE STl WG EERRE rurmommansmsinens s onsoess rosmn e i 5oy s v S PO 5 SOV Y SR A Tiubulor Control Rage e im0 s i i S S R s S A A S RS Evaluation of Arc-Cast ond Powder-Metallurgy Niobium ....ocoooiiiiiii Metal Hydrides for Use as Moderators in High-Tempercature Reactors ... vovicnnn e Capsules for InePile Tests o i e an et e saes et e sae e sees e s srere srerne HYdriding: B GUIBMBIT e msiom s svemsms s e s s s s isasis SECRET] 147 147 147 150 154 155 157 157 162 164 164 164 165 166 166 169 169 171 173 174 174 175 176 177 177 177 182 183 183 183 186 187 188 188 188 189 120 192 192 193 Xiil 3.4. 3.3, 3.6. 4.1. XY UM IV ETO ] P ro@Ue b iMoo oo oo oo e et e s ete e eeate s e oee er eere b e et e e e e e e e e aeae e et ra e mreaan G TR oo e N S S S WELDING AND BRAZING INVESTIGATIONS v s v s ivss s siais s siisass soiicassianss Heat Exchonger Fabricatioa... ART Sodium-to-NoK Heat Exchqngers lnvestigation of Rapid Heoting Cycles OB ERIIaH BF Vol e GO T SIS oo oms R s 550 55000 99 SX E0 S D030 e SRS SR e ART Fill-and-Drain Tank Fabricotion ... R S S O S S S e Welding ond Brazing of Nickel-Molybdenum Alloys ... .. o B T R Studies of Hastelloy B ond W Welds. . : Welding and Brozing Studies of Experlmenfcl Nlckel Molybdenum A]toys Hot-Ductility Tests of Experimental Nickel-Molybdenum Alloys ..o, NaK-to-Air Rodiator Fobrication ., Effects of Brazing Yariables on Broze Adherence Assistonce to Yendors .. Studies of Grain Growth in Incone]l T ubBe s ot e et et ee e reeasts eerarar tene sraeas sree smeearmranreas Influence of Brazing Temperatures... lnfluence of Time at Temperature... . Influence of Tube- Strmgh'lenmg uncl Tube F’ollshlng Opemhons Influence of Cold Work .. : Subcontract Work «ommnmims oo oo o o s S T T S S S R TR S B N S SRR MECHANICAL PROPERTIES STUDIES...o i s et e b e e Dinamie Sirain Propeities of TREBRB e rmimnissammimsanmsis o v v s w5 s B T T Festingof Beryl i v s s s s T s s s R e NONDESTRUCTIVE TESTING AND INSPECTION OF MATERIALS AND COMPONENTS ... . Eddy-Current Inspection T e hmiGuUes oo oo iee o e oeeeeer s ee e et ot e e et e e et e en e e e et s et oo oo oo T UBING I SPECIION oottt e et e e e e e et et et tees s nes e a et bt o e Clatding T hicRAsEs MeuiremBiiiel o e s b o s Radiographic Inspection Techniques .o o e et et et et e e e e e e Examination of Leok in Sump Tank of Pratt & Whitney High-Temperature Critieal Assembly ... it s e e e e e et bttt skt et Moterial In5pecfion e b Tubing... Plate .. Berylllum Hc:-f Pressmgs PART 4. RADIATION DAMAGE AND FUEL RECOVERY AND REPROCESSING RARIATION DEAMAGE oarmmrmsmnsmssosiag ssws s = Examinations of Compenents ond Materials Tested in the MTR ... iviies o1 In-Pile Loops... e Irradicted Moderutor Muiermls 'h-' 193 194 195 195 195 195 198 200 201 201 201 205 205 205 208 208 209 209 209 211 215 216 216 220 224 225 225 225 227 230 231 232 232 236 236 239 243 243 243 243 4.2. 5.1, 3.2, 3.3, Creep ond Stress-Rupture Tests of [nconel oo Apparatus for Stress-Rupture Tests of Tubing in the MTR ... Tube-Burst Tests in the LITR s e e et e s s Effect of Radiation on Corrosion of Structurel Motericls by Static Fused Salts ... .. Inconel Capsules.....ooconein Hastelloy B Capsules.. . e e e e e e In-Pile Loop Experiments.... .............. Qut-of-Pile Test of F'ump fc:-r LITR Verhcaf Loop ........................................................... Assembly of LITR Vertical Loop ... Irradiation Facilities in Cok Ridge Reseurch Rec:-ctor Investigation of Sulfur Contamination of a Dry Box by Neoprene Rubber ... .............. Effect of Radiation on Thermal-Neutron Shield Materials oo e e e Fused Solt Polaragraphy . ... i e e e e e er e et ssaeae s e eenas et et sete e stbe et et sraaaessae s ara . Neutron Flux Studies... Effects of Radiation on Electronic Components ... Mincrity Carrier Lifetime Measurements in n—Type Germunlum o Irr O OO S oo oot e oo e e e tes e e er e vensoes rre e mte e e aeeeeeaeee s eeaaneeene aeeanaeeeeaaeens Transistors.. A Safe for Removul of Samples from 1he Reucmr ............................................................................. Modifications to Hole 30 of the ORNL Graphite Reactor ..o e Dielectric Constant and Loss Tangent of lrrediated Plastics ot Microwave Frequencies FUEL RECOVERY AND REPROCESHNG ..o, e .............. P i ot P It e oo e e e e e e et e e e et et e ae e e ae ettt eea e e e, Sulfur Embrittl ement of Nickel . o e e e e e e e e Oxidotion Resistance of Alloys in Flucride Systems. ... Porosity and Density of NaF .. e e e e R U e UM o Om i ma i 0M oo ciioee et e cee ettt e eet e e e ee e e s eeee eeee sen s ser s eaes eesen te s aes eare e se s veensenssen s tnsntee vete ernennense, PART 5. CRITICAL EXPERIMENTS AND REACTOR SHIELDING CRITICAL EXPERIMENTS e s Reflector-Moderated Reactor Experiments at High Temperatures. ..o e S DING THE O RY et e et et a b e a e b eees Summary of Monte Carlo Calculations of Gamma-Ray Penetration in Multiregion Shields with Slab Geometry o oo e e e et e LID TANK SHIELDING FACILITY et e et e e e ______________ New Instrument Carriage at the LTOF L e e e e e Investigation of the Physical Properties of Lithium Borohydride—Ammonia Under Subcontract No. 300 e ST e e e by e e eyt e Pressure-Temperature- Composifion Re|ut¢onsh|ps Density Relationships ............... Survey of Shielding Materiols Under Subcontroct No. 931 .. 248 249 250 250 250 254 254 256 2537 257 257 260 260 265 265 266 268 269 269 269 274 274 274 278 279 281 285 285 286 286 290 290 290 292 292 293 M 5.4, TOWER SHIELDING REACTOR T oot e s evesasns s svsvssnn e ee 29 NUCTEor Parameter Sty ..o i et s st e e e e e e e £ sbss e ki ek e b e 294 ST R amEa ] SUUHRL s sasmmvns s s e 5 s A A B S S 299 e e o T G S G 300 ANP PROJECT QUARTERLY PROGRESS REPORT SUMMARY PART 1. AIRCRAFT REACTOR ENGINEERING 1.1, Aircraft Reactor Test Design Tests ore under way or have been proposed with which to evaluate the ART structural design criteria, since experience in the design of structures for operation af temperatures in excess of 1000°F is limited and in general not directly applicable. The high operating temperature will greatly affect the creep ond relaxation of the structure, and temperature cycling will cause strain cycling. The only test completed in this study thus far was the initial core-shell low-frequency thermol-cycling experiment. The results of this one test indicate that the strain-cycling criterion used tor the core shells is conservative. In- formatien on strain-cycling and creep character- istics of lnconel, as well as on the effects of “‘cumulative damage,'’ is to be obtained in heat exchanger tests that ore now wunder woy., An attempt to predict the life of the heat exchanger revealed the need for creep measurements of Inconel in fused sclts at the corrosion rates expected in the reactor, The distribution of stresses in the various shells that will resuvlt from design-point temperature and pressure profiles is being analyzed. Shells V and V| (shell ¥V separates the boron-tile curtain around the heot exchanger from the fuel, and shell V| is the pressure shell liner) have been studied, and final designs for the junctions of these shells have becna prepared on the basis of the onolyses. Efforts are being made to predict the stress- rupture life of tubes subjected to a bending stress on o short section., The results of this stdy indicate that the calculoted maximum stress is quickly reduced to about B0% of the predicted elostic value and remains essentially constont for the life of the member. The study alse indicoted that constant-sttess data are required for calcu- lations of this type, rather than constent-load data. An experimental attempt to verify the “reduced- stress effect’’ is being made. Detailed stress analyses of the ART fin-type NaX-to-air rodiators are under way. Several critical areas in the design hove been identified, and alterotions required by stress considerations have Studies were made of weight ond air drag loads, relative thermal expansion between fins ond header, and relotive thermal expansion between adjacent tubes in the event of flow stoppage as a result of oxide plugging. Series of tests ond experiments are under waoy in order to determine the fatigue life of Inconel under simulated ART conditions, since the core shells might be subjected to surface temperature oscillations os large as BPF ot frequencies of from l,;; to 4 cps. It it is found that lncenel does not possess adequate fatigue strength, design modifications moy be required to alleviate the temperature oscillations. One proposal being studied provides for mounting o pair of thin Inconel shells in the core to serve as '‘thermal shields™ for the structural core shells, been made. Flow studies of the full-scale 21-in. plastic model of the ART core were continved in order to investigate woll temperoture fluctuotions, which may be analogous to the fluid temperature fluctu- ctions observed in the one-half-scale volume-heot- Varicus types of probes and thermocouple arrangements are being invesfigufed for use in these studies. The fiow-guidance ex- periments continued with tests of the core entrance region alone, the core entrance and equatorial source experiment, regions simultaneously, and the core island bellows region within the center volute of the cxial-flow type of header. bution, both radiclly and circumferentially, were obtained with an inlet guide vane, a cenical baffle plate, and o slotted disk, which wos loceted & in. above the equator. Some improvements in flow distri- 1.2, Reactor Physics The gamma-ray dose rate at the outer surface of the ART neutron shield was computed as o first step in a re-evoluation of the shielding of the ART ond auxiliary equipment, Gamma-roy source strengths were obtained through the use of two- dimensional neutron-diffusion calculations. Sec- ondary gamma rays from the lead shield were neglected, since Lid Tank Shielding Fecility ‘- 3 XV (LTSF) experimenis showed that the dose varied exponentially with lead fthickness up to cbout 4.5 in.; the ART lecd is 4.3 in. thick. The LTSF data ore interpreted ta meen that the intensity of gamma rays penetrating the 4.3-in.-thick leod shield of the ART will be much greater than the intensity of gomme rays preduced in the lead, The colculated dose rate at the surface of the shield was found to be 1840 r/hr. The relotive importance of each source is indicoted by the percentfage contribution teo the total dose rate: core, 22%; outer core shell, 9%; reflector, 12%; reflector shell, 35%; heat exchanger, 22%. The fast-neutron dose rote at the shield surface was computed from LTSF data. It was found thar ot a distence of 50 ft from the center of the ART operating at 60 Mw with o 4.3-in.-lead and 31.5-in.- water shield, the calculated gamma-ray dose is 22.8 rem/hv and the fast-neutron dose rate is 0.05 rem/hr. 1.3. ART Instrumenis and Controls The ART NaK circuit flow-decay characteristics were investigated as an initial step in evaluating the significance of a pump power failure in terms of temperoture and pressure transients in the ART heat-dump system. Experimente] data were ob- tained for o loop in which an ARTY prototype NoK pump was being tested ot high temperatures. Curing shutdown tests, complete tabulations of pump shaft revolutions as a function of time were obtained from which speed vs time dota could ke obtained through numerical differentiation. The data thus obtained were correlated with computed velumes of segments of the ART primary NoK heat-dump circuit. Tests of commercially availoble resistance-type liquid-metal-level tronsducers were continued, and when the tests were terminated at 3732 hr, during which time the NgK level of the system was cycled 65,000 times, oaly one of the four instruments was in operating condition. The other three units failed because NeK seeped into the insulation threugh cracks at the U-bends. The reaction of the Nal with the insulotion caused visible deformation. ORML-designed units, which will be clemped into place rather than welded, ore being prepared for further tests. The ORNL units will hove improved temperature compensation, and the weld design has been modified. xviii All-welded resistance-type on-off level probes are being developed as replecements for con- ventional spark-plug probes, which are not suitable for pressurized systems and temperatures above 450°F. An especially fabricated spark plug with a beryllivm oxide insulator was tested in NaK as an on-off level probe, but it failed in 20 hr of operation because of short circyiting of the in- sulator. Several special plugs with insulators high in olumino ond mognesium conient were received for testing. Tests of the helium-bubbler-type tuel-level in- dicetors were continued, and tests to determine the cause of bubbler plugging were initiated. It is thought that the wmateriol which plugs the bubbler tubes is Zr0,. Special static-level tests are to be run therefore in which the oxygen content will be carefully contrelled. It is hoped that the present average life of 1100 hr in a static-level system can be increased to the specified 3000 hr. Evaluation tests of commercial pressure trans- mitters for use at high temperatures were continued. Units that employ differential transformers were found to be difficult to use becavse the field of the Calrod heaters used to maintain the operating temperature has on effect on the output readings. A unit that employs @ varioble-permeance type of pressure transducer was unsolisfactory because of lack of svitable aligning guides. Additional tests of the promising four-legged strain-goge transmitters are being maode. Also o second set of pneumatic-output fransmitters completed a suc- cessful 3000-hr life test in o NaK-filled test loop. Six of the SIé-in. magnetic flowmeters purchased for the ETU and the ART were installed in the flowmeter test loop for calibration. Preliminary indications are that ot least four of these flow- meters will be ccceptoble for ETU installation, Six 2-in. magnetic flowmeters are aveilable for calibration, and the 3%-in. models designed for plug indicotors and cold trops are being fobricated. Two prototype models of remotely adjustable pressure regulators were tested. These units were found to be stable under line-voltage, supply- pressure, and normal ambient-temperature vari- ations. Life tests are to be run on these instruments, A 1-in. turbine flowmeter ceased to operate after 340 hr of an endurance test scheduled for 3000 hr in a circulating fused salt. X-roy exomination showed that the unit was not broken, and it is thought that oxidation resulting from previous operaticn in NaK systems may have caused the unit to bind. The unit will be removed for ex- aminaticn when the loop is drained. A 31,5-En. turbine flowmeter operating in a NaK system failed some time during the first 40 hr of operation. Disassembly of the loop showed eight of the ten blades 10 be missing; the remaining two blades were bent; and both shafts were broken. The cause of this failure is being investigated. Tests of closure welds of Inconel-sheathed thermocouples in sodium and in fused salts are under way, The Heliorc welding process has been found to yield 30 to 50% acceptable welds. Bend tests were made, ond single U-bends on a 3,:’1—ir:. radius were found to have little effect on accuracy, Repeated bending caused a 2 to 3°F shift. The drift of data obteined with sheathed and with beaded Chromel-alumel thermocouples as a function of time and temperature is being studied. 1.4, Component Development and Testing Yrradiation tests of a full-scale ART fuel pump rotary assembly are to be run in a gamma-irradiation facility in the MTR cenal. The final selection of a lubricant-coolant for the reactor pumps will be based on the results of these tests. On the basis of further satisfactory test per- formance, modified Durametollic seals have been specified for use in the ART NaK pumps. Hf the irradiation tests show either UCON LB-140-X or Gultcrest 34 lubricants fo be satisfactory, buna-N- base O-rings will be specified for the reactor pump ¥ the MTR tests prove these lubricants to be uvasatisfactory, the seal material mey ogain become o problem. The development 1tests with water of an ac- ceptable impeller configuration (designated model 32) for the ART fuel pump were completed., The tests showed that flow rate, head, and pumping power remained fairly constant when the liquid level in the expansion tank was reduced from 3 to g.g in. Further reductions in the level resuited in definite decreases in flow rote, head, ond pumping power, Tests for determining degassing times were alse conducted with the liquid level in the expansion tank ot 3 in. and the pump eperating of the design speed of 2700 rpm. Degassing of an injected air sample was complete in less thon seals. 1 min. Tests of the pump at high temperatures with NaF-ZrF -UF, (50-45-4 mole %, fuel 30) as the circuloted fluid were started, The pump head is 1 to 2 ft lower than that cbtained with water, ond this discrepancy is beiny investigated. Pers- formance and cavitation dota are being obtained. A similar pump that operated with fuel 30 tn an endurance test was shut down after a total of 2587 hr of operating time and 120 thermal cycles in the temperotuee range of 1400 to 1100°F, Ex- ominaticn showed the pump to be in good condition, ond it has been clecned, reassembled with new seals, ond put back into operation., There was no trouble with the hydroulic drive during the lost 1240 hr of operation because a back pressure was mointained on the discharge side of the motor to ensure that the piston shoes were seated on the wobble plate af oll times. The ART sodium pump is now being subjected to development testing with water on the same basis as that used for the fue! pump. Tests to date hove been hampered by ingassing of the loop in which the pump is instalied. Since free move- ment between the sodium pump barrel and volute will be required in the ART to ollow for radial movement, a seal is being developed for this region to minimize leakoge of sodium between the heat exchanger inlet and the pump centrifuge outlet. Two types of multiple-ring seals are being considered, as well 0s a simpler seal with o single Fing. An ART sodium pump is also being fested in an endurance test with sodium ond has accumulated 1584 nr of operating time with 300 thermal cycles in the temperature range of 1250 te 1050°F. The oump priming difficulties encountered previously were solved by stopping the pump when transferring sodium to the pot, The off-ges line plugging problem was resclved by lowering the liguid level in the pump poft. High-temperature testing of an ART primary NoK pump was continued, and performance and efficiency curves were obtoined ot o NaK temper- ature of 1200°F. The data are in good agreement with the daofa obtained with water, An ART auxiliary NaK pump is being tested with water and an Inconel impeller in ploce of the brass impeller used previously. Cavitation performance of the Inconel impeller has been found to be entirely satisfoctory. After a vent was provided for gos trapped during filling, the pump primed satisfactorily, A specific technique for starting and siopping the pump was developed. Fuel-toNaK heot and NaK-to-air radiator test operations were continued. One test was terminated by a MNoK leck in the circulating cold-trap economizer after ¢ total of 1845 hr of operation. The heat exchanger and the radiotor exchonger in this system hod been operated noniscthermally for 1456 hr, including 552 hr ot o fuel inlet temper- afure of 1600°F and 29 thermal cycles. Dato obtained in this test are being analyzed as part of a study of mass transfer in a NaK circuit, A 20-tube semicircular heat exchaonger was de- signed ond is being fabricated thot simulates the tube geometries of the ART main heat exchangers. This heat exchonger will be subjected to o thermal cycling progrom in order te wverify the stress analysis of the ART heot exchongers, The ART twin fuel pump system was tested further as part of the water flow tests of the aluminum north-head mockup. With the improved model 32 impellers in the pumps, the liquid spraying and sloshing noted previously in the expansion tank and the resultant wetting of the tank ceiling were greatly reduced. The madel 32 impeller olso resolved the problem of liquid rising in the shoft annulus of o stopped pump if the other pump was stilt running. Tests of ART prototype dump valves were con- tinued. VYalves which have rigidly mounted plugs are now considered to be essenticl for satisfactory aoperation. The seat and plug materials which have been found to be the most saotisfactory are the Kentanium cermets K 151A vs K-152B and KM vs K-162B8. All tests to date have been made with fuel 30, but a test stand is now being modified for tests with NaK, The second of the two proposed thermal-stability tests of the outer core shell was started under conditions similar to those used previously. Di- mensions were carefully taken for later comparison with dimensions to be taken after the test, Orifice plugs were tested for controlling sodium flow through the cooling holes in the ART be- reflector in order to obtain o uniform temperature throughout the beryllium. A full-scale wooden mockup of one-half of the symmetrical sodium circuit in the reflector entrance region was The head and flow distribution measurements obtained in these tests are being used in design anclyses, A water test was also conducted on a proposed byposs slot to be cut between the sodium-to-NaK heat exchanger shell ryllium olsc fested. and the external pressure shell of the reactor. This slot will allow some sodium to byposs the present s5lots between the pressure shell and the upper-deck outer shell and will provide a more direct entrance for flow into the heat exchanger inlet. The high-frequency thermal-cycling test loop designed for studying the effect of thermal cycling The loop has operated satisfoctorily ot design specitications in water tests, and data are being taken on temper- ature amplitudes at the test section as a function on Inconel tubing was completed. of freqguency ond flow rate. The water tests will be continued wuntil thoraugh fomiliarization with the operotion is achieved. The plugging indicaters that are to be provided in sach of the eight NeX cold-trap circvits of the ART to monitor the sodium oxide level were calibrated against chemical onalyses. The coli- bration curves obtoined include most of the praciical range of plugging-indicater application, Tests were made on modified liquid-metal-vopor condensers. A satisfactory NaK cendenser is now ovailable, but further developmental effort is required to obtain o satisfactory sodium condenser, The design of an experimental prototype of the ART zirconium flucride thermal-condensation vopor trap was completed, and a unit is being fobricated. Traps poucked with A|203 have operated satis- factorily in several tests. Tests were run on three bronds of insulation being considered for use on piping corrying high- tempergture NaK, The thermal conductivifies and heat losses were obtained. 1.5. Reactor and Facility Construction The detailed design of the reactor is essentially complete, with some work remaining to be done on the design of sodium annuli surrounding the fuel overflow, off-gas, and fill-and-drain lines, MNumerous design changes haove been made based on further design studies, development component fabricatien difficulties, ond shrinkage tests. The schedule for ossembly of the ETU end ART reactors was revised on the basis of delayed delivery of compenents being produced by outside vendors. Work on the north-head assembly is awaiting delivery of the sodium-to-NaK heat ex- changers. The components for two reflector- tests, weld moderator assemblies are now available, ond the xx u assembly for the ETU is progressing satisfactorily. Work is clso progressing on the strut-load ring assembly. Most of the beron carbide tiles required for two reactors are ovailable, aad no difficulty is anticipated in obtairing the remainder. Some difficulties are being experienced by the fabricator of the stoinless-steel-clod boron-copper shielding material thot may be resoived by a relaxetion in tolerances. The fobricotion of the Inconel shells by the spinning process remains o major problem, but progress is being made. An alternate effort is being made tc fabricate the thin core shells by hot forming oversized ports and then finish machining them to final thickness. It is doubtful, however, that shells produced in this manner will have satisfactory metallurgical structure, One set of beryllivm island parts is complete, and work is under way on the pressure shell liner. The dual effort on fuel-to-NaK heat exchanger fabrication was evaluated, and Black, Sivalls & Bryson was selected as the fabricator. Extensive tests of reactor assembly methods have been performed, and the assembly procedures have been developed. The assembly area aond fixtures are olmost completed. Much installetion work on the ETU assembly has been done, and prelimincry estimotes show an expected ETU focility completion date, exclusive of the reactor and its associated equipment, of September 1, 1958. A further study of the items fo be ploced within the ETU cell that simuleotes the ART cell brought about several changes, including the elimination of the equatorial and south-head lead shielding, Design of the cell compenents {other thon the reactor) is well under way, and fabrication of many items has been initiated. Much of the outside contract work on the ART focitity has been completed. The work to be done by ORNL forces on the installation of process piping ond equipment remains, and design work on this phase of the project is well under way. Procurement was initiated on o few items, Plans for removing ond sectioning the ART after operation were studied further. A Ix‘iz-scale modef of a proposed hot cell is now avsoilable as an aid in visualizing the complex techniques that will be involved and in designing the tools and tixtures that will be required. 1.6. ART, ETU, and In-Pile Operations A critical review of the reactor system operability is being made, ond conflicts among the design, construction, and instrumentation phases of the project are being resolved. A study of manpower required for various phases of the program in- dicated thot the peok work foad during operation of the ART will require 40 engineers ond 18 technicians. As the result of o design review, additional provisions have been made for the ceontainment of octivity at the ART focility in the event of concurrent heat exchanger and radiater lecks; @ number of design and instrument changes have been incorporated into the system; ond addisional component development tests have been schedufed to demonstrate the odequacy of the system for the prescribed test program. Procedures for filling the various systems were prepared. The planning for ETU operation is paralleling that for ART operation, with the maintenance of ETU flow sheets, instrument lists, and valve tabulations being emphasized, A preliminary study of ART emergency conditions to be simulated with the ETU is under way. Procedures for disassembling the ART were studied further, Possible methods for performing the remote cutting operations that will be required within the cell were studied, and several dis- odvantoges of a proposed underwater operation have developed. Developmental work is under woy on the higher performance pump and heat exchanger that will be required for in-pile loop experiments with the new nickel-molybdenum alloys and lithium-base fuels, A pump is now availoble that will be suitable for a loop with maximum temperatures in the range of 1600 to 1650°F, which correspond to o pump temperature of 1500°F. |In on effort to increase the copacity of the heat exchonger, a vnit with machined nickel fins has been designed and is being fabricoted for testing. In-pile tests of moderctor materials continued with the preporation for insertion in the MTR of copsules conteining beryllium oxide, graphite, and zirconium hydride specimens. XX 1.7. Heat Tronster and Physical Properties Heat transfer studies with the delta-array heot exchanger were continved. Flow in the laminar region wos investigated to establish the effect of natural convection on the total heat tronsfer, No effect could be observed over the Reynolds modulus range exomined. The fluid friction choroc- teristics on the fuel side of a straighi-tube model of the ART fuel-10-NaK heat exchanger were tested further, with measurements being token down to a Reynolds modulus of 1530. The early transirion in the data indicates the effect of the turbulent spacer wokes on the system pressure drop. FPre- liminary designs have been made for an apparatus to study the heat transfer and velocity struciures in a single fuel-side channel of an ART type of heat exchanger. Additional data on the screens in reactor cores ore to be obtoined with the use of the swirl entronce system. A mathe- matical analysis indicated that even under fuel conditions reactor core screens will not reach dangerously high temperatures. FPhotogrophic records have been mode of lominar and surbulent velocity profiles i o stabilizing effect of dump number of geometries. Quantitative data on the turbulent velocity strycture of woter flowing through a circular tube were obtained by superimposing the velocity profile photograph on a grid photograph. A volume-heot-source experiment is plonned with which to establish the effect of screens on the thermal structure in the ART core. A series of vortex tube heat transfer and hydrodynomic ex- been outlined for determining quantitatively the characteristics of this system. Therma)-cycling studies of the strength and cor- resion characteristics of Inconel in a fluoride salt mixture envircnment were continued. The sig- nificonce and limits of some of the experimentol variables have been determined, There is some indication that high-frequency cycling causes greater corrosive attack thon does low- periments have thermal frequency cycling. The enthalpy and heat capacity for the mixture NaF.ZrF,-UF, (50-25-25 mole %) were determined in both the solid ond liquid states. Data on the pure compound U‘F‘t have been obtained for the solid stete only. Viscosity measurements hove been made with three mixtures in the NaF-RbF- ZrF,-UF, system. The viscosities ronged from 7.5 to 9.5 centipoises ot O00°C down to 3.3 to 3.5 centipoises at 800°C, studies have concentrated on the problems of eliminoting from the experimentol data the effects of variable heat flows. An experimental study has been initiated to determine the electrical con- ductivity of {iquid soedium and of sodium-potassium alloys. Thermal conductivity PART 2, CHEMISTRY 2.1. Phose Equilibrium Studies A simple modificatian wos mode ta the thermal analysis apporatus in order to minimize losses by wvaporization. With the modified opparatus it hos been possible to analyze samples containing up to 80% ZrF , with negligible loss in weight of the sample. A new vocuum furnace that is odaptable to microscopic observations was developed ond fabricated for use in visual observation of liquidus and solidus points and for differential thermol analyses of quantities of fused salts. indicote that accurate melt temperctures small Preliminary visual observations reasonably caon be measured with only 150 mg of material. Quenching studies of LiF-UF, systems thot contain 20 to 32 mole % UFA confirmed the liquidus ond solidus relationships previously reported. |t was found that the compound -d'L.iI:-Ui:‘1 undergoes very slow subsolidus decomposition to LiF and 7LiF-6UF4 at about 470°C. Thormal anolysis studies showed thot these mixtures undercooled readily if the melt wos first heoted to aver 800°C. results characterized the equilibrium conditicns, a seeding experiment wos conducted on g mixture contoining 24 mole % UF . accordance with in order to be sure that the quenching The results were in the results of the quenching studies, except thot the temperatures of the thermal ettects were about 10°C lower, A study of the similarities of the systems NuF-Hde and NaF-ZrF, has revealed three NaF-Hde compounds that ore onologous to NaF-ZrFi compounds. The high-temperature vsed for visuol observations of liquidys temperatures of mixfures in the LiF-CeF, system. A diogrom of the system was prepared. Examination of slowly coeled melits showed only furnace was L.iF and CeF, to be present and contirmed thermal indications of the cbhsence of complex compounds. Thermal analysis of the system KF-BeF, indi- cated on incongruent melting point aof 390°C and o peritectic composition with about 52,5 mole % Ber. The phase equilibrivm diagram for the system was prepared. Quenching studies of the system NoF-RbF-Ber were initiated. For mixtures containing 33.3 and 40 mole % NoF, the ternary compound is the primary phose, the solidus temperature is 452°C, ond RbF.BeF, is the other phase below the solidus. The phose relationships between the liquidus and solidus have not yet been established. A large number of quenching experiments were completed thot showed the tentative phose equi- librivm diagrom presented previously for the system NoF-LiF-UF to be in eror in several respects. A revised diogram was therefore prepared. Phase equilibrium studies of the systems NaF-CrF ,-ZrF ,, NaF-FeF -ZrF,, ond NaF-NiF - ZrF, were undertaken in order to determine the formyla and phase relationships of the ternary compound in eacch of these systems. Only one ternary compound wos observed in each system. Optical properties ond x-ray diffraction data ore presenfed for the following cempounds: S- KF-?Ber, QKCinFeCIZ, KCl-FeClz, INaF-HIF 2MNaF-BfF ,, NaF.CrF,.2ZrF,, NoF-.FeF,.2ZrF , and NaF.NiF _.27rF ,. 2.2, Chemical Reactions in Molten Salts The investigation of the equilibrium reduction of NiF2 by H2 in Naf-Zrf ot 550°C was con- cluded, ond the dato were combined with these previously obtained. The doto indicate that the equilibrium constant, K, is independent of the NiF, concentration over the concentration range studied, which included values not for from the concentration of NiF2 in the soturated solution at this temparoture. In o carefu! determinction of the solubility of nickel as NiF, in NaF-ZrF, (53-47 mele %) of 55(G°C, a volye of 352 + 11 ppm was obtoined. The dota indicoted that the solubility remcined constant when the omount of saturating phase changed from a trace to a total of 1310 ppm Ni T Further, the value of 352 is in substantial agree- ment with o value of 400 ppm previously reported for the solubility obtained with an oddition of 1760 ppm Ni**, Additionul experiments on the reduction of UF by Fe® in the reaction medivm RbF-ZrF (60-40 mole %) showed that equilibrium wos established in 5 hr and that the equilibrium concentration of Fe** is significantly higher at 400 than of 800°C. The concentration values obtained fell in the ronge of those obtained in other alkali Hluoride-binary mixtures, satisfoctory explanation is ovailable for the lack of elfect of the recction medium. In controst, the studies of the Cro-UF4 reaction showed that the chromium concentration increases in the order of use of RbF, KF, NaF, LiF, which is the order of decreasing ion size. Additionel data on the reaction of UFA with Cr® in the RbF-Zrf, reaction medium ot 600 ond at 800°C indicate that the fluoride increases only slightly when the RbF concentration ond no ion activity is increased from 50 to 58 mole %. Rare-earth fluorides labeled with Ce 141, [La 140, ond Sm133 were used to study the solubilities of CeF3 angd Lu:II:3 ¢lone and in combination and SmfF, clone and in combinaticn with CeF3 in NcF-Zer-UFd {50-46-4 mele %) at varicus tem- peratures. The odditien of both LaF; and SmF, decreased the solubility of CeF,. Similorly addi- tions of BoF, and 5rF, reduced the solubility of CeF,. The data indicate that the solubilities of the rare earth flyorides are sufficiently high to permit quite long-time operotion of o reactor before precipitation of these materials becomes a problem. The determination of the solubility of xenon gas in molten NoF-Zer-UFd {50-46-4 mole %) os a function of pressure and temperoture was suc- cessfully completed. As in the cose of helium, the solubility wos found to increase with in- creosing temperature. A direct equilibrotion method was used for determining the solubility of HF in NoF-ZrF (53-47 mole %) at 600°C. The dato obtained, which will be extended to higher temperatures ond pressures, indicate that the solubility is 1.25 x 10~ moles of HF per cubic centimeter of melt af 1 atm. The data of the solubility of HF will be valuable in studies of methods of salt purification, some aspects of corrosion problems, and processes for dissclution of solid fuel elements for uranivm recovery. Preliminory measurements of concentrotion celfs with l[‘»li':’/'l*lilz2 electrodes and the solvent KF-LiF (50-50 mole %) indicote the sclubility of Nin in this sclvent to be obout 10 times that in the solvent MaF-ZrF (53-47 mole %), This difference 4 can probably be oftributed to the basic noture of the KF-LiF solvent in which the weokly acid NiF, would be more soluble thon in the more acid NaF-Zer mixture. In order to obtain more infor- mation regording the chonge of solute activity coefficients with solvent composition, efforts are under way to develop more reliable types of Danieil cells and to measure a series of these cells in different media with vorying but dilute concen- trations of the metal fluorides, NEFz, FeFE, Cer, and possibly ather solutes. The possibility ef obtaining activities from emf measurements of melten and solid sclutions of salts was studied further with meosurements of the LiCl-AgCl system. The main deterrent to the application of similor techniques to fluoride fuels is the lack of o suitable substitute for a fluorine electrode. Electromigration in molten salts has been shown to be a successful means for separoting isotopes, ond therefore it is of interest to determine the usefulness of this technique for the presyumably easier problem of seporating i1ons of different elements in fuel Some preliminary experiments with LiT and Ni ** ions in a chloride melt showed that if the chloride lattice is con- sidered to be stationary, the Li ¥ ions moved about 20 times faster than the Ni** jsas. electromigration should be a very efficient means of recovering Li' from o spent fuel, but the engineering arrangements for working in fluorides rather than formidabie probiems. Even the chloride systems seem |ikely to be very awkward from an engineering standpoint. mixtures, In principle, chlerides preseat some extremetly 2.3. Theory of Molten Fluaride Behaviar An attempt hos been made to correlate the behavior of molten Hluorides on the basis of chorge- to-ion radius (Z/ R) ratios. If the Z/ R ratios of the salts in o mixture differ considerobly ond especially if the salts are of widely different valence states, the extra stobility of the mixture will be large, and the structure will be considerably distorted in comparison with the structures of the component salts, that is, the larger the difference in Z/R rotios, the more stable the mixture relative to its compenents. For components which mix without o change in coordination number and with little distortion, the negative deviation from ideal solution behavior is accounted for, in general, by o dacrease in cation repulsive energy upon mixing. It is alse convenient to correlate the behavior of the complex melten fluoride mixtures in terms of the attraction between the fluoride nelghboring cations. The ions in a selution tend I in positions of lowsest ions ond to arrange themselves energy. Accordingly, the mutucl energy value determines the positien of the fluoride ions with respect to oltarnative cations, and fluoride ions will prefer as necrest neighbors those cations which yield the largest Z/R ratios. in the difference in the Z/R raties of the cations An increase of a fluoride solution will resvit in an increase in the negative deviations from ideal solutien behavior shown by the mixture. A useful qualitative model for describing the liguid structure of fuel mixtures based on the NaF.ZrF, system was devised in which liquid ZeF , is considered to be a somewhat disorganized lottice of flucride bridges cornecting zirconium ions. The addition of NaF to ZrF4 results in the breaking of the bridges to give zirconium ions which are surrounded partially by bridging fluorides and partially by nonbridging fluorides. Since the complexing potentialities of o fluoride melt depend on the fluoride ion activity, it is very important to know how this activity, which cannot be measured, varies with composition. The fluoride ion activity con be correlated in « qualitative manner by an acid-base scheme in which catiens are rated according to their tendency to behave os fluoride donors or acceptors. If fluoride denors ore defined as bases and fluoride acceptors as acids, the cations fall into the same general pottern as thot used for the classification of oxides as acidic or basic. The NaF compound is an exomple of o sirong base and ZrF4 of a strong acid, In order to map the relative acidity of o fuel solvent, Z/R ratios are plotted vs solvent compo- sition. Such a plot permits estimates of the reletive negative deviations of solutes, and, hence, also relative solubilities in case the pure solute is the saturoting phase. An important use is the selection of which will reduce corrosion by complexing the corrosive agents rather thon the corrosion products. solvent compositions 2.4, Physical Properties of Molten Materials The wvapor pressures of the less volatile compenents in fuel mixtures are being studied. XXlv In order to determine the vopor species, the absolute vapor pressures of molten alkali fluorides were measured by a quasi-static method. A suf- ficiently wide temperature range was covered to give curvature on a log p vs 1/T plot. Equations were estoblished ond constants evaluated for the compounds LiF, NaF, KF, RbF, ond CsF. Tento- tive estimates were olso moade of the percentage of monomeric molecules in the saturated vapor of the various molten olkoli fluorides. A preliminary value for the density of mohen UF . was obtained for use in o determination of the sur‘f‘oce tension, At 1075°C, a density of 6.80 t 0.09 g/cm® was found by using graphite pycnometers. The density of the molten material being greater than that of solid UF, (6.63 g/cm?® based on x-ray data) and the behavier of the salt surface level upon freezing in the pycnometer indicate that UI:‘1 either contracts or expands only very slightly upon melting. 2,5. Production of Puritied Fluoride Mixtures The hydride of yttrium is being studied for use as a moderator in high-temperature reactors. Considerable quantities of YF, (™~1400 g} were therefore prepared for use in manufacturing the metallic yttrium from which the hydride is prepared. The product of the reduction of MoF with FeF was collected in o condenser and redlshiled uné the yellow product was found to melt at 78°C rather than the 60°C previously reported for the moterial before distilletion. |t has not yet been determined conclusively that the material is MoF .. In the pilot-scale equipment, 42 hatches were processed that totaled 1575 lb of various fluoride compositions, with o mojor portion of the material being NuF-KF-LiF-UF4 (11.2-41-45.3-2.5 mole %). Nickel storage receivers are unsatisfactory for the lithium-bose mixture becavuse of the large exponsion of the material upon melting. Incenel cans are now being used for 50-lb batches, but when inadvertent exposure of the mixture to air or water occurs in Inconel cans, extensive contami- nation of the melt with CrF, and FeF, results. Since these contominants cannot be removed economically by retreatment of the batch, the material must be discarded., In the production-scale facility 446 batches totaling approximately 11,500 Ib were processed. Some 18,000 of the 30,000 Ib of NaZrF_ ordered from a vendor was received and found to ie satis- factory. A total of 15,700 Ib of processed fluorides was dispensed in botch sizes ronging from 1 to 25¢ lb. Approximotely 4000 |b of processed fluorides and 2500 Ib of ligquid metals were charged into test units. 2.6. Compatibility of Materials ot High Temperature The study of the penetration of grophite by molten tluerides was continved. An experiment was performed in which commercial APC graphite was impregnated with NaF-ZrF, (53-47 mole %) and then subjected fo a sublimotion step in order to raise the melting temperature of the residual mixtyre to above that of the uronium-bearing mixture. The sublimation procedure increased the NnF-to-ZrF4 ratio in the graphite, with the final rotic being obout 16:1. This material will be tested in o molten uranium-bearing mixture to determine whether a sclid impregnating material will resist penetrotion. Two types of graphite (code Nos, R-28 and M-80) obtained from the National Carbon Compony were immersed in NaF- ZrF -UF | (53.5-40-6.5 mole %) ofter impregnation with Nulé ZrF (53-47 mole %). Examinations revealed that these specimens were not penetrated to ony consideroble degree by either of the salt mixtures. it hos been established through electrolytic studies of the NoOH-Ni system that in o non- isothermal system the hot nickel electrode is usvally enodic and the cold electrode is cathedic. This situation can, however, be reversed by the use of a hydrogen atmosphere. Since NeOH is o potential moderator-coolant material, ottempts are being made to balance the current in an effort to find @ way to eliminate the moss-transfer effects observed in NaOH circuloted under a temperoture grodient. In service tests of valve seat materials exposed to helium scturated with NaK vopor, G-E SE-550 and SE-450, Dow-Corning Silastic-80, and Dy Pont 5570 withstoed NaK fairly well, with SE-550 possibly being superior to the other materiols. 2.7. Analytical Chemistry The apparctys for the detection of submicrogram omounts of sodium in oir wos assembled and tested. In preliminary tests 100 ppb of sodium could be easily detected. By means of appropriate re- finements in the Iinstrument it appears that the E amounts of zirconium in desired limit of detection of 10 ppb is feasible with the present apparatus. Zirconium was found to be a suitable moterial from which to fobricote orifices for the injection of NaK inte air. These orifices will be used in the testing of the NoK leck detectors. The methancl-dissolution method for the deter- mination of oxygen in lithium was investigated. In this method the lithium oxide torms an equivalent amount of water upon dissolution in methanol. The then titrated with Korl Fischer reagent. The reliahbility of the method is dependent on the degree to which the methanol can be dried. Methano! was produced with ¢ concentration of 10 ppm of water. An improved device for sampling alkali metals wos developed which includes a Jomesbury valve modified so that it also serves as a sample holder, water is The valve is connected to the operating apparatus by means of a metal-to-glass stondard taper jeint. Methods for the determination amounts of agluminum, venadium, and titanium in lithium-base fluoride salts were modified in order to apply these methods in the presence of in- of microgram terfering metals. In the method for aluminum analysis, zirconium, iron, uranium, titanium, and vanadium are removed by extracting them with This particular ex- traction essentially isolotes the aluminum in the tri-n-octylphosphine oxide, oquecus phase. For the vonadium determination, the interfering ions, including nickel, iron, chro- mium, eond molybdenum, among other ions, were removed by deposition at the mercury cathode prior to determination of the vanadium os the benzohydroxamote complex. Titanium was separated from molybdenum by a basic carbonate precipitation and from niebivm by extraction of the thiocyonate salts with diethyl ether, A sensitive, spectrophotometric method for the determination of nickel with 4-isopropyl-1, 2- cyclohexaredionedioxime was developed. When the nickel-dioxime complex is extracted with xylene, the ultimate sensitivity is less than 0.5 ppm of nickel in a 5-g somple of alkali metal. The inter- ference of iron is masked by use of the fluoride ion, This method is also applicobie to the deter- mination of nickel in solutions of zirconium- or lithium-bose fused salt fuels. A study of interferences of vorious cations in the spectrophotometric determination of microgram xxvi sulfate solutions with pyrocateche! violet was completed, Vanadium, titanivm, and aluminum, os well as the anions that form relatively strong complexes with zir- conium, were found to interfere seriously. The methylene-blue method for the determination of sulfur in fluoride salts was improved by the substitution of a reducing mixture of stannous chloride and dehydrated phosphoric acid for the standard mixture of red phosphorys, hydriedic acid, and formic acid. As much as 1 g of the fluoride salt con be dissolved in 20 ml of the new mixture, whereas the fluoride salts are only slightly soluble in the red phosphorus mixture, The improved method is thus much more relioble, sul fur, Argentic oxide was studied as on oxidant for This oxidant is efficient in solutions particularly for low concentrations of chromiym, of all acids except hydrochloric, Excess oxidant is destroyed by heating the solution. The use of this reagent materially shortens the procedure for the spectrophotometric determination of chroemium with diphenylcorbazide with apparently no sacrifice in precision, The extraction of melybdenum from acidic solu- tions with tri-n-octylphosphine oxide was investi- goted. Under fovorable conditiens as much as 20 mg of molybdenum(Yl) can be extrocted quan- titatively in a single extraction by 0.5 mmoles of reagent. A satisfactory effusion cell was developed for use in mass-spectrometer investigations of the compositions of the wvapor phases of fused-solt fuel mixtures. Preliminary measurements were made on alkali-halide salts. PART 3. METALLURGY 3.1. Dynamic Corrosion Studies Three forced-circulation leops fabricated of Hastelloy B were examined that had circulated NuF-KF-LiF-UFd {11.2-41-45.3-2.5 mole %, {fuel 107} at a meximum fluid temperature of 1850°F. Two of the loops operated with maximum wall temperotures of obout 1750°F oand showed no svidence of mass transfer after 407 and 1000 hr, respectively. A third loep, which operated with o maximum wail temperature of 1710°F and at @ relatively low flow rate, showed slight evidence of deposits near the pump. The hot legs of all loops were found to be badly pitted after the tests, but much of the surfoce roughness could be attributed to the condition of the inner surfaces of the tubing before the tests, An Inconel forced-circulation loop was operated with NaF-ZrF -UF (50-46-4 mole %, fuel 30) at @ maximum f?md temperature of abowt 1700°F and a maximum wall tempercture of 1840°F. After 1000 hr of operation the loop wos found to have been attacked to a depth of 9 mils, and there were some deposits in cold-leg sections, The fuel mixture No. 70, NaF-ZrF -UF (56-39-5 mole %), wos tested in another |ncone1 forcad-circulation foop operated at o fluid temperature of about 1500°F Loop operotion wos terminated after 716 hr, and ettack to a depth of S mils was found in the hot leg. A thin metallic layer wos aiso noted in the cold leg. An examination of another Inconel forced-circulation loop that operated 500 hr with fuel mixture No. 30 also revecled hot- leg attack to a depth of 5 mils, but no cold-leg deposits were found. An evalustion was made of the effectiveness of cold traps in the removal of oxide impurities from circutating NaK and the resultant effect on mass transfer in Inconel-NeK forced-circulation loops. Cold traps maintoined ot temperatures of 100, 300, 600, and 800°F, respectively, were utilized in cenjunction with loops operoting at o maximum NoK temperature of T1500°F and a fluid temperoture drop through the loop of 300°F. A definite increase in the amount of depasit ma- terial was noted in the loep which contained the cold trap operated ot 800°F os compared with the lcop having the cold trap operated at 600°F The change in the amount of deposited material accompanying a decrease in the cold-trap temper- ature below 600°F was less than the change from 800 to 600°C. The average sizes of the porticles comprising the deposits clso varied with the cold-trop temperature, becoming coarser as the cold-trap temperature increased. The deposits found in these NaK systems were [ess thon one- half the weight of deposit found in sodivm systems operated under similar temperature and time con- ditions. Two lnconel-sodium forced-circulation loops which operated at flow rates of 1.5 and 3.0 gpm were also examined. The maximum sodium temper- oture in these tests was 1500°F, ond the temper- ature gradient was 300°F. Operation of the loops for 1000 hr ot the higher flow rate produced 1'- " deposited material that weighed 14 g compared with 10.4 g for the loop operated with the lower flow rate. The average thickness of the deposit was alse higher in the loop operated with the higher flow rate. A type 304 stainless steel foreed-circulation loop after operation with sodium at 1500°F showed only slight traces of mass-transfer deposits. This loop was operated for 1000 hr with a thermal gradient of 300°F. Long duration tests of Inconel forced-circufation loops were made with both NaK and sedium circu- lated at @ maximum Ffluid temperature of 1500°F. The test with NoK, for which a temperature grodient of §00°F was used, waos terminated ofter 2760 hr. The coocled section of this loop was found to contoin extensive crystclline deposits that ronged te 14 mils in thickress. The loop operated with sodium for 4000 hr with o temper- oture gradient of BQ0°F showed considerably larger deposits that reached a thickness of 50 mils in some areos. Thermol-convection loops fobricoted from various experimental nickel-melybdenum alloys were tested with sedium ond with NeF-KF-LiF-UF , (11.2-41- 45.3-2.5 mole %, fuel 107), for 1000 and 5CG0 hr, respectively, at maximum fluid temperatures of 1500°F. There was attack by the fuel mixture to on average depth of 1.5 mils in all loops except those construcied of alloys containing aluminum additions. For the alloys containing oluminum a maximum depth of attack of 3 mils was found. Correspondingly the pickup of aluminum by the fuel was high in the loops fabricated from alloys Similarly picked up by fuel circuloted in alloys centaining tungsten; no cppreciable increase in ottack accompanied the buildup of tungsten in the fuel, Vaonadism, titanium, and niobium additions to the alloys had no apgarent effect on corrosion; but the fuel picked up slight amounts of titanium and niobium. An average hot-leg attack of 1 mil was found in several nickel-molybdenum alloy leops operated with sodium, ond deposits were visible in the cold legs. These deposits did not adhere tightly to the loop woll, and consequently difficulty hos been encountered in examining them metallogrophically. A series of standard Inconel thermal-convection loops was operated with l‘~~!t:1|‘:-Zt'F4-UF_4 (50-46-4 mole %, fuel 30) at 1500°F to determine whether containing aluminum. tungsten was however, xxvii I l""J the migration into lnconel of voids instituted by the teaching of chromium during the corrosion process would continve if o loop were left at test temperature ofter the fuel was dreined. The results showed that the migration of voids into Inconel did not proceed when the leoching of the chromium was stopped. Three stoinless-steel-clad niebium loops showed onfy slight hotleg cottack in tests with NoF-KF- LiF-UF‘$ (191.2-43-45.3-2.5 mole %, fuel 107) at 1500°F; however, some cold-leg deposits were observed in niobium loops which operoted 1000 hr or longer. A nicbivm loop wos also operoted 1000 hr with sodium ot 1500°F. The attock wos negligible, but cold-leg deposits were observed. Chemical analysis of the deposited material indicated that the sodium probably teoked into the cladding Joop during operation. 3.2. General Corrosion Studies Additional tube-to-header (oints with receystallized welds were corrosion tested in NaK (56-44 wt %) and in Na F-ZrF ,-UF, {50.45.4 mole %) for 100 kr in seesaw-furnace apparctus with a hot- Inconel zone temperature of 1500°F, These samples were fabricated by using a prechamfered header plate which results in decreased material deformation The tests showed no greater attack along the tube-header interface than on the tube and on the header, Haynes No. 8244 brazing clicy (9.4% Cr—4.4% Fe-3.7% S5i~2.2% B8--0.3% Mn-0.06% C-bo! Ni) on Incone! tube-to-header joints showed good cor- rosion resistance o NaK (56-44 wt %) in a Y00-hr seesaw-furnace test at o hot-zone temperciure of 1500°F. Subsurfoce voids fo a depth of 3 mils were observed on the alloy when tested in NaF- ZrF UF, (50-46-4 mole %) under similor con- ditions, ' A seesaw-fumace test of 500 ht at a hot-zone temperature of 16050°F wos run to defermine the compatibility of a 15% Mo—6% Cr—bat Ni alloy and molybdenum when exposed to NoF.KF-LiF-UF, {11.2.41-45.3-2.5 mole %, fuel 107). The presence of nickel on the surface of the molybdeaum specimen ofter the test indicated dissimilar metol and greater weld surface orea, mass tronsfer. Similar results were found with o melybdenum specimen exposed in o 17% Mo-2% V_bal Ni alloy capsule to fuel No. 107 under similar conditions, A Hastelloy B tested with sodium at a hot-leg tempercture of thermal-convection loop was xXxvirl 1600°F ond o cold-leg temperature of 990°F for 1000 hr. The ottock ond mass transfer in this loop were quite similar to the resuits obtoined with sodium in Inconel thermal-convection Joops. A third sodium-beryllivm-Inconel competibility test has shown that chromium plating of lnconei reduces the amount of intermetallic compound formation to approximafely one-third thot found when Inconel and beryllium are placed in direct contact. Thermal cyeling did not result ia spalling of the Be Cr phase. A zirconium specimen exposed to sodium for 400 br of 1600°F in an Inconel standpipe capsule was found to have absorbed oxygen from the sodivm. This removal of oxygen from the sedium appecred, however, to have no effect on the eamount of mass transfer os compared with that found in a stondard Inconel stondpipe copsule containing neo zirconism and tested under similar conditions. Molybdenum and beryilium were tested for com- patibility when exposed to sodium. Exposures of 100 and 500 he at 1500°F resulted in the formation of two extremely hard intermetallic compounds, MoBe., and MoBe, ,, ot the interfoce, Four titanium carbide—nickel cermets, three with 10, 20, and 30% nicke! and one with 25% Ni plus 5% Mo, were attacked to a depth of approximately 0.5 mil during a 100-hr expesure to sodium at 1500°F in o seesaw-furnace. In previous similar tests these cermets were not ottocked by Naf- ZrF4-UFd. Boron carbide specimens with theoreticol densi- ties of 85 ond 90% were found to have fair resistance 1o attack by static sodium in lnconel containers at 1500°F. A dense (2.15 g/em3) boron nitride specimen was severely ottacked in a 100-hr exposure to sodium at 1500°F in o seesaw furnoce. Exposyre of an SiC-St specimen for 100 hr fo sodium ot 1500°F in o seesow furnoce resuited in complete removal of the silicon. Lead-fithium alloys contoining 0.65 wt % Li showed weight and dimensional increoses when tested in water af vorioys temperotures. The weight gains increased with the temperature and time of the test. In the lithium corcosion reseorch being cearried out atNuclear Development Corporation of America, base-line deta for plugging of type 316 stoinless steel-lithium thermal-convection loops hos been obtained. The addition ¢f titanivm and zirconiuvm as getters has led to increosed loop life but has not prevented mass transfer. The use of cold traps for impurities hos also led to improved loop performance. 3,3. Fabrication Research The nickel-molybdenum alloys fobricated ond tested thus far have, in general, significantly better corrosion resistance and strength than Inconel without sacrifice of fabricability and weldability, These alloys now appeor to offer definite possibilifies of use as structural materials of reactors that utilize more efficient fuels at higher temperatures. The corrosion resistance of most of the alloys is equivalent to that of Hastel- loy B, and the stress-rupture data for oll olloys tested show on average life of 40G hr at 1500°F at a stress of BOOO psi. The fabricability depends largely uvpen the kinds ond quantities of elements added to the basic nickel-molybdenum alloy, and with proper control reascnable yields of moterial are obtained from taboratory heats, At present an alloy designated INDR-8, which is baosed on the Ni-Mo-Cr-Fe system, seems to best fulfill all the requirements, In arder to investigate the ronge of mechanicel properties developed in alloys of this system, the tensile and stress-rupture properties are being determined for a series of compositions, with the maximum content of the major components, other than nickel, being 20% Mo, 10% Cr, and 10% Fe. The alloys tested to date with {ow and intermediate contents of Mo, Cr, and Fe are oll stronger than lnconel and approach the strength of type 316 stainless steel. There is evidence that olloys with higher Me, Cr, ond Fe content will respond to aging and show even higher strengths. A series of alloys designated INOR-9 are being investigated, in which the elements Cr, Al, Ti, ond W have been eliminated becouse of their poor corrosion resistance in fuel 107. Alloys with o maximum of 15% Mo and with significant additions of niohium and iron were prepared, and the limits of solubility and oxidation behavior were de- termined. Six tube blanks of ecch of three nickel-molybdenum base olloys prepared at ORNL have been extruded and submitted to Superior Tube Co. for redrawing to tubing, These alloys were designed for studies of the effect of 10% Cr and 7% Fe, singly and to- gether, on the corrosion resistance of a 17% Mo—bal Ni base alloy. Sheet, plote, wire, and bar products fabricated from the six 4800-1b heats designated INOR alloys 1 through & have been received. Alloys INOR-4 and INOR-& became virtually 100% scrap because of fabrication ditficulties, while alloys INOR-2 and INOR-5 were processed with considerable success, The tube shells of the INOR alloys, two each of INOR alloys 1, 2, and 5 and one each of INOR alloys 3 and 6, are presently being tube reduced for conversion to small-diometer seamless tubing at Superior Tube Co., The contract with the Westinghouse Electric Corporation covering the fabrication of large pilot heats of nickel-molybdenum base afloys has been signed, and work will begin immediately. Initially, one 3600-ib heat of alloy INOR-8 will be cast and fabricated inte sheet, plate, wire, bor, and tube products for eveluation, Yarious techniques are being utilized in studying the phose relationships of the Ni-Mo ond Ni-Mo-Cr alloy systems under @ subcontroct at the University of Tennessee, Resulis show that the beto and gammo phoses fransform ot somewhot higher tem- peratures than those previously reported. A totat of 16 tube blanks of four Ni-Mo base alloys which were extruded for Battelle Memorial Institute last quarter failed during tube reduction at Superior Tube Co. These processing failures substantiate earlier evidence that these alloys with 0.12% C are not amenable to tube-drawing operations. Batielle has prepdred new olloys with o lower corbon content and has submitted twelve billets of each of two of the alloys to ORNL for tube-blank fabrication, The tubing processed from these blanks is scheduled for forced-circulation loop tests at Bettelle, Laorge amounts of composite tubing may be re- quired to circumvent moss tronsfer in nickel-base alloy systems., To demonstrate the feasibility of producing the material, several composite tube shells of Inconel over type 316 stainless steel were processed on a production schedule. Ex- cellent yields of souad tubing were obtained from the coextruded material, Two full-sized gomma-ray shielding pfugs com- posed of tungsten carbide and Hastelloy C were prepared for the ART fuel pumps. However, a die failure produced loteral expansion of the plugs, with the result that the parts are considerably over- size ond will be used only for brazing tests, A redesigned die has been obtained, Xxi X Continved difficulty in producing the stainless- steel-clad Cu-B,C shield material at Allegheny- Ludlum has required considerable coordination and evoluotion of moterials, Recent work based on recommendotions made by ORNL has resulted in good yields of sound material, In attempts to eliminate lack of ductility resulting from stringering of fine dispersions of Lindsay Oxide, a technique was developed for producing dense, hard porticles of the desired size, Three cores for extrusion billets were prepared with this material dispersed in electrolytic nickel powder. The recovery and recrystollization of arc-cast and powder-metallurgy niobium are being studied prior to comparing their mechanical properties, Nearly ideaticel microstructures were finally pre- pared from the two materials by an initial anneal at 1450°C followed by severe cold reduction and a leng annecl ot 1250°C, This material will be used in determining the recrystallization kinetics of the two types of niobium, An in-pile test capsule of hydrided zirconium clad with molybdenum was fabricated, Equipment for the production of yttrium metal wos designed ond built., Studies on the cladding of molybdenum with nickel-molybdenum alloys were started, 3.4. Welding and Brazing Investigations An invesfigation wos conducted to determine optimum brazing procedures for fabrication of the ART sodium-to-NaK heat exchangers. The mos? influential variable was found t¢ be the rate-of-rise to brazing temperature, A similar investigation is being conducted to determine the minimum rate-of- rise to lxazing temperature required to effect a satisfactory back braze of the tube-tfo-tube sheet joints of heat exchangers. The techniques developed previousty for the fabrication of valve components were used in the preparation of various valve materials for testing under simulated service conditions, A study of the problems ossociated with the fabrication of the ART fill-and-drain tank is under way. lests are being run to establish welding and brezing procedures and joint designs thot will re- sult in crock-free fusion welds. A promising joint design now being investigated is a trepanned type, Additional results were obtoined in the investi- gation of the mechanicol properties of Hastelioy B and W welds on ]/’z-in. plate, and the results of aoll the tensile test data have been anclyzed. The ‘fz-in.plqte required for welding and brazing studies of some of the nickel-molybdenum experimental alloys wos received ond tests were initiated, No cracking tendencies were found in tests of INOR-7 and -8, Results of Polytechnic Institute on experimental ond commercial nickel- base alloys indicate thet it is usualiy sufficient ta evaluate the hot ductility s measured ot 2300°F during cooling from some higher temperature and to compere these data with the hot ductility measurad at 2300°F during heating. The test results show that none of the INOR alloys behave in as ductile o manner os Inconel and thay they behave more like Inconel X than like Hastelloy B, tests at Rensselaer The effects of brazing variables on braze ad- herence in NaK-to-air radiators were studied further in order to assist the vendor in fabrication prob- Specific recommendations regarding the cleoning methods, and brazing tech- lems. equipment, niques were made, The initial result of a study of the effect of brazing ond hect-treating operations on the grain growth of Inconel tubing indicates that stress relief treatments at 1500°F do not result in grain growth. Significant grain growth resulted, however, from }é-hr brazing cycles at approximately 1922°F. It was also noted that groin growth proceeded more rapidly in the grains locoted along the ocuter wall of the tube than in those located along the inner wall, Straightening and polishing operations had only minor effects on the grain growth, The in- fluence of prior cold work is being studied. In the molybdenum welding studies under sub- contract at Battefle Memorial Institute the effect of atmosphere purity, vorious types of shields, and several cleoning technigues were investigated, Acid etched specimens were somewhat better than samples prepared by other methods, Also, the use of a trailing shield in open air welding was found to yield weldments with significantly greater ductility, 1.5. Mechanical Properties Studies The behavior of Inconel when subjected to re- peated thermal cycles is being investigated by means of relaxotion tests and mechanically induced cyclic strain tests at ORNL; the University of Alabama is contributing to this study by conducting thermally and the induced strain cycle tests; Battelle Memorial Institute is evaluating the effect of dynamic loads superimposed on static loads, Reloxation data were obtained for coarse-grained Inconet at 1300, 1500, and 1650°F, Prier tensile strains at temperature were shown o have little effect on the relaxation behavior. Evidence that coarse-grained Inconegl has poorer resistance than fine-grained material to repeated strain cycles has been obtained. The evoluation studies of creep properties of the varicus new olloys heing developed for reactor use were continued. The results of the alloy de- velopment program thus far indicate that consider- able progress hos been mode toward achieving the objective of developing a material that is as fab- ricable as required for reactor possesses adequate strength, and is corrosion resistant in high-temperatyre fuel mixtures, liquid metals, ond air. [t has been possible to improve the creep characteristics by odditions of carbide- forming elements, such as niobium and tungsten, construction, without seriously cffecting the other good charac- teristics, Several alloys of this type hove ex- hibited a stress-rupture life of 1000 hr when tested in fuel 107 at 8000 psi and 1500°F, Studies were made of the elevated-temperature properties of the beryllium blocks being fabricated for the ART by the Brush Beryllium Co. The tests indicate that the strength properties do not vary appreciably from those predicted on the basis of tests of smaller pressings. 3,6. Mondestructive Testing and Inspection of Materials and Components The recently developed Impedograph, which measures both the a-c resistonce and the reactance of its testing coil over a wide range of freguencies, was applied successfully in eddy-current inspec- tions. This instrument simultaneously presents inspection information from both the inner ond outer surface of tubing, regordless of the materiol or size of the tube, Equipment and techniques were developed for using an eddy-current proche coil to measure the thicknesses of coatings or cladding., Measurements made of the cladding thickness on Mark X MTR fue) plates demonsirated the feasibility of the inspec- tion techniques. With further experience it should be possible to measure cladding thicknesses of most olloys on o cermet core, of any of the oxida- tion-resistant alloys over molybdenum or niobium cores, of on austenitic stainless steel over a nickel-molybdenum core, of o nickel-molybdenum alloy over an austenitic stainless steel core, or of the outer layer of duplex tubing. The ability to measvre Inconel on austenitic stainless steel or austenitic stainless steel on Inconel is currently considered to be marginal. Exposure dota are being compiled for the radi- ography of various thicknesses of Inconel, stainless steel, nickel-melybdenum, and similar alloys, Also, test weldments in L{a*in. Inconel sheet are being radiographed through 8 in. of beryllium to explore techniques for the inspeciion of the closure welds of the ART fuel-onnulus core shells, A b-in.-dia cap, for use as a cotch basin, which had been welded 1o the bottom of the sump tank of the Pratt & Whitmey high-temperature eritical assembly, was removed when leckage was detected and was found to be severely cracked, It wos learned that the cap had been machined from bar stack rather than being a forged fitting, as speci- fied. [nspections construction of reactor and test components resulted in rejection rates for Inconel that voried from 0 to 63%, de- of materials for pending on type and lot of material, All the Hastel- loy B inspected was found to be completely intferior to requirements, One of the six, lorge, beryilium hot pressings fabricated for the ETU and ART reflector-moderators was inspected under laboratory conditions to evalu- afe the fechniques used for the field inspection. The *‘squirter’’ technique being used in the field was demonstrated to be satisfactory, if used with care, Welding inspections indicated a performance record of B3% acceptance of critical welds and over 95% acceptance of other standard welds. PART 4. RADIATION DAMAGE AND FUEL RECOVERY AND REPROCESSING 4,7. Radiation Damcge Metallographic specimens were cut from in-piie loop No. 4 which circulated o fluoride fuel mixture in the MTR., MNone of the specimens examined thus far have shown attack greater than L5 mils in depth, and no signs of mass transfer hove been found, Colored omorphous deposits were found on the pump slinger and on the forward bellows that were similar to deposits found in in-pile loop No. 3. - XXX The MTR-irradiated Inconel capsvle containing beryllium oxide slugs was disassembled and ex- omined, There was no evidence of BeO powder in the caopsule, and ne significant changes wete ob- served in either the lengths or diameters of the slugs. An opparatus for stress-rupture tests of Inconel tubing under irradiation in the MTR was essentially completed, Eight separote specimens will be tested simultaneously. Duplicate specimens will be tested out-of-pile at stresses of 2000, 3000, and 4000 psi ot 1500°F, Rupture times of 1050 and 1650 hr were obtained for two specimens of Inconel tubing tested at 2000 psi ond 1300°F while being exposed te a thermal- and fast-neutron flux of 6 x 10'? neutrons/cm?: sec in hole HB-3 of the LITR. These rupture times for this 0.010-in.-wall tubing were in good ogreement with out-of-pile data, A third in-pile specimen, stressed to 1000 psi at 1500°F, did not rupture ia 1670 hr, ond the total creep deformation will be measured uvpon disassembly of the apparatus. Examination was completed on o tubular Inconel specimen that was stressed in bending at o moxi- mum stress of 1000 psi ond irradiated for 1120 hr ot 1500°F while exposed to NmF-ZrF_‘-UF4 (63-25- 12 mole %, tuel 41) on the inside and sodium on the outside. Corrosion on the fuel side was negli- gible and did not oppear to depend on the sign or magnitude of the stress, On the sodivm side there was attack to a depth of cbout 3 mils, Two MTR-irradiated and twe control copsules fabricated of Inconel ond filled with fuel mixtures of the NaF-ZrF -UF, system conteining 2 mole % UF, were opened ond examined. The capsule exposed to a flux of 1.5 kw/ecm?® for 676 hr ot 1500°F and its control capsule showed corrosion penetration so negligible as to be confused with surface faults, The copsule containing 4 mole % UF ,, which was exposed to a flux of 3.7 kw/em®, wos attacked at the mid-point to a depth of 5 mils in 235 hr at 1500°F, The distribution of the attack was that anticipated on the basis of the tempera- ture profile. The contribution of irradiation to the attack connot be judged until control date ond chemical analyses of the fuel are available. Hastelloy B capsules were tested out-of-pile, and stmilor copsules have been inserted in the MTR, Means for applying oxidatien resistent cootings to the Hastelloy B capsules cre still being investi- gated. Xxxii Qut-of-pile tests of the pump designed for circu- lating fused-salt fuel in the LITR vertical in-pile loop have demonstrated that the newly designed ZrF ~vopor control features are satisfactory. An in-pile loop incorporating a similar pump is being prepored for insertion in the LITR. Facilities are being plonned for the operation of similar foops in the Oak Ridge Research Reactor. During preparotions for filling the LITR wertical in-pile loop, it was discovered that the interior of the dry bux wus contominuted by on unknown gaseous sulfur compound, Sulfur in the Necprene rubber gloves was found 1o be the source of the contamination, Irrodiotion exposures of nine Cu-B,C samples were completed in the MTR. Exominations of six of the sampies ore under way, The applicability of palarographic techniques ta the study of the fission-product chemistry of fused salts is being investigated. Means for accommo- dating the high electrical conductivity of the fused salts, as compared with aoqueous solutions, are being developed. A survey was made of the relative variation of nevtron flux with distence in hole 51N of the ORNL graphile reactor by using sulfur ond cadmivm- covered gold detectors. A plot is presented of the relative activities of the detectors as a fuaction of distance from the caoncrete shield. The minority carrier lifetime of n-type germanium has been found to change under irradiation according tc a power law for both fost-neutron and gomma irradiation. lrradiation with Co®? gamma radiation and subsequent annealing show o complicated the barrier change of diodes and The results of tests indicate that the properties of such devices would be changed by o pulse of gomma irradiation ond that there would not be immediate recovery upon removal of the structure In traonsistors, pulse, A safe was designed for the removal of samples from the ORNL graphife reactor without subjecting personnel to radiation, The device can be used at the reactor loading face, or, by transferring it to another dolly, at holes 50, 51, and 52, An exposure device has been designed for use in hole 30N of the Graphite Recctor with which o sample can be moved from the external shield to the irradiation position in about 10 sec. This device will facilitote measuremenis on semicen- ductor compoenents under irradiation. The loss tangents of polyethylene, polystyrene, Teflon, Nylon, and phenol formaldehyde were measured before and after a series of Co®? irradic- tions, ofter exposures of 10% r; however, the dielectric All samples showed measurable changes constent changes of these materials were less than the accuracy of measurement, that is, £5%, 4.2. Fuel Recovery and Reprocessing Construction of the fused salt—fluoride volatility pilot plant is essenticlly complete, except for the faciliies for handling the ARE fuel, which will not be installed until runs with nonirradiated material are completed, Shokedown tests have been storted, The embrittiement of nickel and nickel alloys with sulfur was studied to determine the allowable sulfur contamination in the volatility process. A nicke! foil fest wos devised which will detect 3 ppm of sulfur in o fused salt. Underordinary con- ditions, however, in equipment with heavy nickel walls, o sulfur contamination of 200 to 500 ppm is necessary 1o produce any effect in ane exposure, but the sulfur effect is cumulative, It appeors that the scavenging of sulfur by nickel means mat if the salt is once exposed in the fused state to nickel equipment it becomes relatively free of sulfur, The sulfur embrittlement of Inconel was found fo be much iess than that of nickel. The gas-phase oxidation resistance of types 316 and 347 stainless steel was found to be quite un- satisfactory in tests of their use as containers for fused fluoride salts., This sub- stanticted pilot plant experience with the charge melt vessel, An over-all porosity of 65% was found for the type of NoF to be used in the absorption-desorption step of the decontamination process. The porticle and bed porosities were 48 and 33%, respectively, There was little difference between different lots of Harshow Chemical Co. material, Experiments were conducted to plating out of ruthenium on metal surfaces could be used to achieve additional decontamination, In the initial tests, low decontaminction was achieved in ¢ nickal trap, but there wos only o small amouat of activity involved and the surface area of the nickel was small, |t is anticipated that the re- moval of ruthenium with a nickel column moy be laboratory tast whether made more effective by using a greater surface area or by operating at o higher temperature, PART 3. CRITICAL EXFERIMENTS AND REACTOR SHIELDING 5.1, Critical Experiments A critical assembly mocking up the circulating fuel reflector-moderoted reactor under study by Pratt & Whitney Aircraft was operated at tempera- tures near 1250°F, The fuel consisted of ¢ molten mixture of sodium, zirconium, and uranium fluorides, and the control rod contained a mixture of 30% rare earth oxides and 70% nickel. With the control rod out, the critical concentration was 10,97 wt % U (5.1 mole % UF,) at 1258°F; with the rod inserted to the midplane, the critical concentration was 12,20 wt % U, The temperature coefficient of reactivity over the range of 1200 to 1350°F was =3,6 x 10~ {Ak/k)/°F, 5.2. Shielding Theory Several Monte Carlo calculations have been per- formed on the Oracle to determine the dose rats, energy flux, energy deposition, and in some cases the energy spectra in laminated shields as a func- tion cf the energy of the gamma-ray source and the angle of incidence of the gamma rays on the shield. Since it is impracticol to publish ali the results from these calculations in o progress report, a summary of the problems is presented along with references to the published data, 5.3. Lid Tank Shielding Facility A new instrument positioner has been installed of the Lid Tonk Shielding Facility (LTS5F) which will indicate the absolute position of any radiatien detector in the tank water to within £0.5 mm, This is o considerable improvement over the old posi- tioner with which absolute pesitions could not be determined to an accuracy greater than 15 mm. The new system also provides for remote control of the positioner, Under Subcontract Neo, 390, Metal Hydrides, Inc., haes investigated the physical properties of lithium borohydride-ammonia, which has been suggested as o neulron shield. Pressure-temperature-composition relationships hove been determined for materiol temperatures ranging from 0 to 80°C, The gmmo- nolysis reaction, which was found to occur to a smoll extent, wos studied briefly hetween 50 and XXX 100°C, The densities of liquid lithium borchydride ammonicates were also determined, A survey of shielding materials, which was per- formed by the Technical Research Group under Subcontract No. 931, confirmed that lithium hy- dride and polyethylene are the most effective neu- tron shields known to dote. Lithium hydride is the only lightweight neutron shield material that can be used in the temperoture ronge of 700 to 1200°F, which is the range thot may be expected in some parts of the direct-cycle reactor shield. The high-density materials required for gamma-ray shields still center around lead, bismuth, tungsten, uranivm, etc, XHXIV 5.4, Tower Shielding Reactor |l From @ nuclear parameter study and a cursory examiration of the heat removal problem, the dimensions and composition of the Tower Shielding Reactor Il (TSR-Il) core have been established. The diameter of the internal water reflector will be 17.5 in,, and the radial thickness of the core will be 5.5 in,, with an aluminum-to-water volume rotio of (.7, This will permit the use of the standard Bulk Shielding Facility reactor fuel plate ond water moderator arrangement, that is, 60-mil-thick fuel plates separated by 120 mils of water, The cooling water flow rate will be 1000 gpm, Part AIRCRAFT REACTOR ENGINEERING S. J, Cromer 1.1. AIRCRAFT REACTOR TEST DESIGN A. P, Fraas APPLIED MECHANICS AND STRESS ANALY SIS K. V. Meghreblian Tests of ART Structural Design Criteria Experience in the design of structures for opera- tion ot high temperatures, that is, temperotures in excess of 1000°F, is limited. Some experience has been gained throughout the technology from the design of jet and rocket engine components and wvery high-performance steam power plants, but little of this experience is directly opplicable to the design of a system such as the Aircraft Reactor Test {ART). Therefore considerable effort has been devoted to establishing suitable design criteria for this reactor. The high-temperature phenomeno that will be encountered in the ART are creep, reloxation, and strain-cycling. The design problems associoted with creep were discussed previcusly in connection with the stress analysis of the north-head structure, and the design criterio used for this onalysis were given in a previous report.! The design criteria for strain-cycling and relaxotion onalyses were discussed in connection with the core shell tests.’ The only test to date which could yield any information on the volidity of the design criteria selected for the ART was the core-shell low-frequency thermal-cycling experiment.? Only one such test has, as yet, been completed, but the resulss indicote thet the strain-cycling criterion used for the core shells is conservative. It was not possible from this single test to deduce the degree of conservotism of the criterion. Further tests ore under way or have been pro- posed with which to evaluate the odequacy of the selected design criteria. In the heat exchaonger test progrom presently under way it should be possible by suitable control of test procedures ond careful obtain selection of operating programs to information on strain-cycling and creep choracteristics of Inconel, as well as ins useful formation on the effects of ‘‘cumulative damage.’ Such ¢ program hos been initigted, ond the 'R, V. Meghreblian, ANP Quar, Prog. Rep. Jure 10, 1956, ORNL-2108, p 19. 2R, V. Meghreblian, ANP Quar. Prog. Rep. Sepi. 10, 1956, ORNL-2157, p 23-26. first of these tests wos completed on Black, Sivalls & Bryson heat exchanger type {HE-8 in IHE-B (see Chap. Development and Testing’’). under 1.4, '"Component This test was made steady-state conditions with @ maximum test stand metal the heat exchonger tubes of the order of 1650°F. Since only a few relatively minor thermatl cycles were imposed on the system, temperature in the principal loads on the structure were those dve to the fluid drag forces on the tubes, The life of the heat exchanger wns estimated on this basis, and the cafculotions indicated that the system should have operared for 600 hr before failure occurred. The test was shut down after 500 hr without o failure. This ottempt to predict the life of a complex structure under creep and corrosion conditions demonstroted the importance of obteining creep measurements of Inconel in fused salts at the corrosion rates expected in the reactor. Additional heat exchanger which will include power-cycling, ore presently being pre- pared, These tests will be conducted on both the intermediate {IHE) and the small {SHE) straight- tube types of test heat exchangers,? tests, In an attempt to simulate the helicol shape of the octual fuel- ta-NaK heat exchanger in the ART, o special small heat exchanger (SHE-9) has been designed and is now being fabricated (see Fig. 1.4,16 in Chap. 1.4, *"Component Development and Testing”'). The tubes in this unit ore in the form of 180-deqg arcs, and the composite design will incorporate many structural features found in the ART heat exchangers., When tested under conditions which the ART design conditions, this heat should demonstrate the odequocy of the reactor compoenent. simulate exchanger Thermal Stress Analyses of Shells B. L. Greenstreet 5. E. Moore D. M. Miller J. R. Tellackson A detailed progrom of analyses is presently under way in order to determine the distribution of stresses in the various shells that result from design-point *Ses, for example, L. H, Devlin and J. G. Turner, ANP Quar. Prag. Rep. Sept. 10, 1956, ORNL-2157, Fig. 1.4.5, p 50.3 £ ? ANP PROJECT PROGRESS REPORT temperature and pressure profiles. Particular em- phosis is being placed on the determination of the thermal stresses produced in the shells. The temperatyre distributions summarized in the previous progress seport! are being used as o basis for these calculotions. thermal In the computations of the assumed This is not a valid assumption in certain local regions corresponding stresses, it is that the entire structure remains elostic, of the shells wherein the temperature profiles are extremely steep. deformation will occur, in these regions, plastic Nevertheless, it is ex pected that except for a few regions of extreme distortion the elastic onalyses will give adequate estimates of the strains induced in the structure. The strains thus obtoined are being used to de- termine the strain-cycling life of the structure. This procedure was applied in a study of shelis V and V1.3 The analysis of shell V was completed® ond is summorized here, The function of sheli ¥ is to separate the boror- tile curtain around the outer surfoce of the heat exchanger from the fuel, and thus it serves pri- marily @s @ container, lts importance as a structural member stems from the foct that a rupture in this shell would expose the tiles to the fused salt, and it is possible that such exposure might cause @ significant change in reactivity because of the high boron content of the tiles. Shell ¥V consists of three ports, as shown pre- viously,® and each part is ottached separately to shell W1 {the pressure shell liner), The boron tiles are contained between these conceniric shells, The inner surface of shell V is bathed with fuel from the core, ond the outer surface of shell V| is bathed with sodium from the island circuit, At full power’ these fluids operate ot markedly different temperatures, and this situation gives rise to differential expansion be- tween the two shells, Because of the apprecioble difference in thickness of these shells (f in. for shell V ond ?{B in. for shell VI), the growrh of thermal 4R, v, Meghreblian, ANP Quar. Prog. Rep. Dec. 3!, 1956, ORNL-2221, p 3-12. SFor shell structure of ART, see R. ¥. Meghreblian, éNP1 uar. g'rog Rep. Dec. 31, 1956, ORNL-2221, g . o] P 8B, L. Greanstreet of al., Thermal Stress Analysis of Shell V intermediate, ORNL CF-57-3-6 {to be published). 7R, V. Meghreblian, ANP uar. Prog. Rep. Dec. 31, 1956, ORNL-2221, Table 1.1.3, p 10. shell ¥ is limited by shell V!, ond thus the stress analysis s shell V, The most critical arec in this ossembly is the intermediate section which extends from jus?t below the equator to about 30 deg south latitude (Fig. 1.1.1). This section is exposed to large tem- perature variations relative to shell VI, which produce free radiol expansions at the equator of 0.02) in. and at the 30-deg south latitude junction of 0,033 in. (note that these growths represent in- terferences between the shells V and VI}. In od- dition, there is a relotive axial growth of 0,028 in. Much of the distortion produced by these relative expansions appears as locol effects in shell V ot reduced principally to @ study of the attachment points te shell V|. Because of the smell thickness-to-radius ratic of shell V, however, the stresses orising from the edge dis- plocements and rotations diminish ropidly with Jatitude ongle. UNCLASSIFIED DREHL-LR-DWG 20652 SHELL M EQUATOR ., = M —_—y Y SHELL ¥ TRANSITION PIECE | e % AREA UNDER CONSICERATION FQR ol TERNATE CONFIGUR&TIONS SEE F1G 11.2 —= === Fig. 1.1.1. Intermediate Section of Shell V., The localized noture of the siresses allows for the reduction of the stress level by decreasing the difference between the mean shell temperafures ond the temperature grodients in shell V neor the Changes in the temperature dif- ferences and gradients from those present in the junction points, configuration of Fig. 1,1.1 can be accomplished by wvarying the shell thickness neor the junction and/or by crecting small regions of stagnant fuel around the junction., The lotter effect can be ochieved by placing o baffle around the edge of the shell. Since the lorgest temperoture effects occur of the lower edge of shell V {Fig. 1.1.2), this will also be the locetion of the largest stresses. De- tailed fwo-dimensional temperature calculations, for which reloxation methods were used, were carried owt for wvarious configurations of this QRML -LR-DwG 208535 BOROM TILES SHELL VI SHELL V THIS AREASHOWS ATTACHMENT COMFIGURATIONS CONSIDERED SHELL VI SCDIUNM PASSAGE A= FLAT PLATE JUNCTION 8 - CONMNE JUNMCTION €~ CYLINDER JUNCTION Fig. 1.1.2, Lower Junction of Shell ¥I and Intec- mediote Section of Shell V. region. [he mean temperatures in shell V for two representative configurations considered in these studies are shown in Fig. 1.1,3. The calculations revealed that the largest reduction in relative expansion between the two shells could be ochieved by the use of the fuel baffie mentioned chove. It was also found that both the gradient ond the near the iunction were affected by a chonge in the thickness of shell ¥V, while a change in the thickness of mean temperatyre di tference the stagnant fuel [ayer affected only the ftem- perature difference. The temperature distributions obtained from these studies were opplied to three geometric shapes for the tronsition section between shells ¥ and Vi, a cone, a cylinder, and a flat plate, as shown in Fig. 1.1.2. Stress analyses were performed PERIOD ENDING MARCH 31, 1957 URCLASSIFIED QRNL-LR-OWG 20854 400 —— E % < |_CONFIGURATION | e : ; | O i 2 300 = | ! | _! L L) f CONFIGURATION [0 , _ é T — T I 1 [T 1§71 3 = 200 141 C1-SHELL V WITHOUT BAFFLE | | | .‘ E O-SHELL V WITH SBAFFLE SHOWRN & N FIG L2 —F—+—F— —/ & | | i | 2 =100 f | Pl | N | | . 1 | . { = Mol & = = 7 ' [ Ll ol b i l - | | | . | 0 2 4 € a 10 i2 DISTANCGE ALONG SHELL W FROM LOWER JUMCTION WITH SHELL VI INUNITS OF Yg INGH Fig. .I-] .3| Temperature of Sedium at Junction of Shells ¥ and VI, Meon Temperature of Shell ¥V Above for each of these geometries in which the tem- perature gradient and the temperature difference across the tronsition section were used aos para- mefers. Secondery parameters in this study were the section thickness ”Ilé and }'4 in.) and the thickness of the stagnont fuel region in the vicinity of the junction {0 to ]f'ré in,). The results of these calculotions were compared on the bosis of the maximum combined stress occwiring in each con- figurotion (usually at the junction between the transition piece and shell ¥), The combined stresses were computed according to the octohedral shear stress theory. In two dimensions the octahe- dral shear stress is given by _ 2 7 T = oy + 95 g, 0, , 0l ) where o, and o, denote the principal stresses in a bioxial system, The results for the three ge- ometries with o }’lfi-in. layer of stagnant fuel are summarized below: T{psi} Flat plate with baffle 20,500 Cylinder with baffle 40,400 Cone with baffle 100,700 Without the botfle, the maximum stresses were significantly larger. section, the octahedral shear sftress was 25,000 psi. In the case of the flat-plate ANP PROJECT PROGRESS REPORT The final design for the junction, selected on the basis of this study, is o lf’lé-in. flot plate with a 74-in. region of stagnant fuel. This general configuration is vsed at other juanction of shells V and VI, but the balfle is omitted because the differences are oppreciably lower. A 20,500-psi value for the octohedral shear stress temperatyre corresponds to a fatigue life of about 300 cycles. The ART will be power cycled, at mest, 25 times. Design Analysis far Creep Bending 0. L. Platus It was mentioned above that the Black, Sivalls & Bryson heat exchanger type IHE-8 used in the design criterion test was operated at steady state and thot under the tubes are subjected to a steady fluid drag force. These forces ploce o bending sfress on o short section of each tube (Fig. 1.1.4), and in a first approxi- these conditions mation the tubes behave os cantilever beams in the wvicinity of the headers. In order to predict the stress.rupture life of these tubes it is neces- sary to toke into account the effect of creep on the stress distribution over the cross section of the tube. Calculations indicote that if this effect is incfuded o reduction of about 20% con be realized in the moximum fiber stress in comparison with that predicted by the elastic theory. This could result in as much as a fivefold increase in stress-rupture life, as indicoted by the tensile stress-rupture data. The calculations® were based on a method® in which tensile creep data are 8p. L. Platus, Siress Analysis of a Heat Exchanper Tgbe in' Creep Bending, ORNL CF-57-2.101 (Fab: 52 9G- H. MacCullough, ""An Experimental and Anclytical Investigation of Creep in Bending,'' J. Appl. Mechanics 1, 35-40 (1923). LWNCLASSIFIED ORNL-_R-DwG 20855 —= FLID FLOW — DRAG FORCE SECTION I BENOING STRESS " hicapen Fig. 1.1.4. Drag Load on Heat Exchanger Tube Stem, utilized to predict the creep rate and stress distri- bution in a beom under ¢ bending stress. In this method it is assumed that o quasi-viscous state of creep exists, by considering the siresses fo be « function of creep rote ond time ond 1o be inde- pendent of strain, and that the cross sections remain in a plane during bending, The lotter assfififlfifi leads to the relation (= e, where é(y) is the strain rate in the beam at distance y from the neutral axis, €_ is the sirain rate in the extreme fiber at y = b/f.r;, ond 5 is the outside |f the tensile creep data ! diameter of the tube. con be ecsily expressed analytically, the equation may be used in on integral statement of the moment at any section to obtain an analytical solfution of the stress distribution and the maximum strain rate as o function of time and the applied moment, If the creep deta connot be represented by a con- venient mathematical expression, the equation must be solved with the moment relation by a For this purpose a set of stress vs creep-rate curves with time as a pora- meter is required, such as those in Fig. 1.1.5. This general oppreach was used to onalyze an aumerical technique. Inconel heat exchanger tube in pure bending stress at 1500°F in an NafF-ZrF ,-UF, (50-46-4 mole %, fuel 30) environment, and @ numerical calculation was mode for which the creep-rate data presented in Fig. 1.1.5 were used, A determination of the stress distributions and the moximum creep rate for a constant moment gave a calculated maximum elastic stress of 6500 psi {these conditions were selected in order to shorten the time required for o creep-rupture bend test)., The results of the calcolations are shown in Figs, 1.1.6 end 1,1,7, Figure 1,1.6 gives the maximum stress and creep rate in the tube, and Fig. 1.1.7 gives the stress distribution at various time intervals. Two important observations may be bosed on this study. First, the calculated maximum stress is quickly reduced to about 80% of the predicted elastic value and remains essentially constant for the life of the member. Second, constant-stress creep data are required for calculations of this type, rather than constant-load data. An experimental attempt to verify the ''reduced- stress effect’” is being made with lead specimens subjected 1o pure bending loads. The immediate PERIOD ENDING MARCH 31,1957 UNCLASSIFIED 1072 ORNL-LA-0WG 20B56 4 L 5 | 5 — E s 2 c e = = 4 ) to = x 2 o o ¥ o 5 o 5 2 ldfi 1000 2000 000 4000 5000 6000 o000 8000 STRESS (psi) Flg, 1.1.5. Tensile Creep Dato for Annealed Inconel Tested at 1500°F in an NoF-ZrF‘-UFJ‘ {50-46 4 Mole %, Fuel 30) Environment. (Secret with caption) ANP PROJECY PROGRESS REPORT C LASSIFEED CRNL =L R-DwG 20857 {51075 $000 [ — - ——| — 500 \ 8000 |+ — T % 800 | . 7000 i - e %m/ - 700 T g | \ l | /bflq [ ;§_ ~ SO0 ".'\ oo — s _451.;:'4_. &0 E @ | || MAXIMUM STRESS ) : w5000 T T T e S 500 = £ “redl | MAXIMUM CREEP RATE /1530 i < 4000 T g e O] a00 A 5 i “-'-r--.i-_s.--;qaj & £ Sigel _ . Cwl || 300 W x Wi/ « ; :;Uf | [ £ ¥ S 3 | ! “'-F.&l&. fi | | g B ol— — 0 o 1C0 200 320 350 TiAE Lir) Fig. l.l.6. Maximum Stress ond Creep Rote in on Annealed !nconel Tube Under Bending 5tress in an NaF-ZrF‘-UF‘i (50-46-4 Mole %, Fuel 3)) Environment, (Secret with captian) UNCLASSIFED CRHL-LR -DWG 20858 o kel o oo o ~ L @ a5 o8 FRACTION OF MAXIMUM FIBER DISTANCE ABOVE MEUTRAL AXIS 3000 4000 5000 6000 7000 STRESS {psi) o o oo 2000 Fige 1.1.7, Stress Distribution in an Annealed Inconel Tube Under Bending Stress inan NnF-Zer -UF_‘1 (50-46-4 Male %, Fuel 30) Environment. (Secret with caption} to predict the lite of these specimens con the objective of the experiment is bending-rupture basis of the tensile creep data. Radiator Stress Analysis Problems D. H. Platus R. V. Meghreblian Detailed stress onalyses of the ART fin-type NaK-to-gir rodictors are presently under Although these anoiyses are not yet complete, way., severa| critical areas in the design have been identified, ond alterations required by stress con- Three problems have been examined, in particular, which oppear to occount for some of the foilures ex- perienced with these units. In these three analyses, siderations have been made in the design, studies were mode of weight and air drag loads, relative thermal expansion between fins ond header, and relative thermal expansion between adjacent tubes as a resvit of flow stoppaoge from oxide plugging, The ART radiator consists of a butterfly arrange- 10 of fins ond headers with the fin banks resting on support plates rigidly attached to the ment headers. Expansion of the hecders relative to the fins will lift the tube-fin banks off the support plotes during power operation and thereby cause the tubes to behove as cantilever beams subjected fo a uniform distribution of drag and weight loads, Since the tubes are conmnected by the fins, the tube bonk will The effect of the fins is to produce a restoring moment at each behove as a unit, tube-fin connection that is proportional 1o the slope of the tube at that point (Fig. 1.1.8). This complex array of connected tubes may be treated as @ homogeneous matrix if the system of discrete restoring moments at each fin-tybe joint is replaced by a continuous distribution. The problem is then analogeus to the classical “beam on elastic foundation.”” A colculation based on this model was performed for the ART radiator, ond the air and weight loads were found to give tube stresses at the heoders of the order of 1500 to 2000 psi. In the second problem, an analysis wos mede of a thermal strain-cycling effect induced by ¢ ”:ll... P, Carpenter, |, T. Dudley, and M. H. Cooper, ANP Quar. Prog. Rep. Dec. 31, 1956, ORMNL-2221, Fig. 1.4.18, p 48, UNCLASSIFIED ORNL-LR-0WG 20859 FINg _._H_,,“) M FIM \ DEFORMATION TUBES}:‘ Fige 1.1.8, Tube-Fin Deformations in Radiotor. temperoture difference between the hecoder drum ond the nearby fins. The unfinned portions of shown in Fig. 1.1.9, will be subjected to bending as a result of cooling of the fins to below the header drum temperoture. Based on strain-cycling ond stress-strain chaoracteristics 1500°F, a plastic onalysis'' in- dicated that temperature differentiols large enocugh to be likely to cause foilure were produced in the 0.5-Mw test units, The radiator units presently being fabricated hove been modified to occcom- modate the temperature differenticls. The length I indicated in Fig. 1,1.9 has been set at 1}4 in., and the entire fin bonk haos been sliced ot 3.]/3-in. intervals (Fig. 1.1,10). (See Fig. 1.4,19 in Chap. 1.4, ““Component Development and Testing'’; this radiator, now being prepared for testing, will be provided with o thermocouple grid to meao- sure the temperature distribution of the air lgaving the radiator.) In the third problem, an onalysis was made of the effect of oxide plugaing of one or more tubes in the matrix. The plugged tube(s) will be colder than adjacent members and will thereby be sub- jected fo thermal strain as a result of relative expansion, Under these circumstances the fins behave as diaphragms and each exerts an axial tubes, of Inconel at force on the tube which fends to pull the tube awoy from the header (Fig. 1,1.11). The mognitude e & Field, Rectangular Cross Section Cantilever Bgam; f;: the Plastic Range, ORNL CF-56:6.85 (June 20, 1956). UNCLASSIFIED ORNL-LAR-0WG 20863 = FIN AND TUBE e = / MATRIX LOWER FIN HE ADER INDIVIDUAL TUBE i i . + HEADER DRUM Fige 1.1,9. Differential Expansion Between Header and Fins, PERIOD ENDING MARCH 131, 1957 URCLASSIFIED ORNL-LR-DWGE 20984 FINS Fig. 1.1.10. Radiater Modifications. UNCLASSIFIED ORNL-LR-DWG 20HE0 HEADER F % FIMNS (TS5 Fra 3 - e PLUGGED TUBE [(COLD) ADJACEMT TUBE [HOTH Flgs 1.1.11. Fin Loods on Plugged Tube. of the force is determined by the flexural stiffness of the fin, by the stiffness of the tube in tension, and by the distance of the fin from the header. By trecting this discrete set of forces os a con- tinuous force distributed along the tube, it is possible to write a differential equation for the axiol stress in the tube ond o corresponding equation for the bending stress in the fins as a function of the position along the tube. This model indicated that the fins were relatively stiff and produced very nearly the maximum strain {0 AT), that is, the omount that would be induced with a system of completely rigid fins. Never- theless, it wos not possible, on this basis, to ANP PROJECT PROCGRESS REPORT demonstrate that the maximym temperature dif- ferential conceivoble in the system could couse failure of the tubes under the cyclic conditions of the test or of plugging. Metallurgical experience indicates that the resistonce of Inconel to plastic strain cycling is seriously impaired by embritile- ment in oreas wetted by the brozing olley. Since two radiotors failed under conditions which in- dicated tube plugging, the embristling effects of the brazing alloy on Inconel are being studied, Core-Shell Thermal Shield D. H. Platus Measurements obtained from the one-halfscale ART-core-model volume-heat-source experiment!? indicated that the core shells might be subjected to surfoce temperature oscillations os large as 80°F at frequencies of from ]{" to 4 cps. Series of tests ond experiments are therefore under way in order to determine the fotigue life of laconel tubing under simuloted ART conditions. If these tests demonstrate that Inconel does not possess fatigue strengths adequate to meet the opersting conditions onticipated for the ART, it moy be necessary to introduce design modifications to olleviate the temperature oscillations in the core. Several possible modifications have been sug- gested. One proposal is to mount a pair of thin Inconel shells in the core to serve as '‘thermal shields'’ for the structurol core shells. '3 These sheils would be similor in appearance to the actual core shells and would define two reiotively thin flow channels, as shown in Fig. 1.1,12, The resulting hydrodynamic structure should be con- siderably more stable than thot in the present core configuration. The instability in the present design results from several effects. One effect is associated with lorge redial temperature dif- ferences in a fluid flowing in o thick passage when a lorge volume heat source is present in the fluid.'* Another effect is the characteristic '2N. D. Greene et al., ANP Quar. Prog. Rep. June 10, 1956, ORNL-2106, p 222. 13D, H. Platus, A Bajjle Design to Shield the ART Core Shells From Temperalure Oscillations in the Fuel, ORNL CF-57-1-134 {Jan. %, 1957). 44, F. Poppendiek and L. D. Palmer, Forced Con- vection fleat Transfer Between FParalle! Plates and in Annuli with Volume Heat Sources Within the Fluids, QRMNL-1701 (May 11, 1954). 10 UNCLASSIFIED GRNL-LR-0wS 2086) N BAFFLES = i\.‘:nl : R N 1 Fig., 1,1,12, Proposed ART Core Boffles. (Secret with caption) flow separation that occurs in o lorge-angle di- verging channel.'® Ancther is the radiol pressure variation associated with swirl obout the island. These adverse effects would be alleviated within the thin channels, ond the haffles would shield the core shells proper from the temperature oscil- letions in the thick central onnulus. Calevlations indicate that the divergence angle of the varicus channels can be maintained below that likely to induce flow separation by careful selection of the thermal shield configuration. A further odvantoge to be gained from the use of baffles is thet the moximum uncooled core-shell temperatures predicted with the baffles are sub stantially * lower than those in the present core, Comparative sketches of the temperature profiles ISJ, Nikyradse, Forsch. Gebicte lagenieurw., B 289, 1-49 {1929}, UNCOQLED wall TEMPERATURE POTENTIAL WALL, PERIQD ENDING MARCH 31,1957 UNCL ASSIFIED QORMNL=-LR-DWG 20862 UNCOOLED Wal L TEMPERATURE HAFFLE TEMPERATURE B S A AT AR A TEMPERATURE VARIATION MIXED - ME AN MIXED = ME AN TEMPERATURE TEMPERATURE \ MAXIMUM CORE-SHELL TEMPERATURE SODIUM S0DIUM TEMPERATURE \y Lel TEMPER.&TURE\B’ YL 7S LA} Fig. 1.1.13. Radial Temperoture Profiles in ART Core {2) Without and (&) With Core Baffles. (Secret with caplion) for the two cases are shown in Fig, 1.1.13. More- over, because of the smaller radial temperature difference within the thin channels, the total power extracted by the sodium circuit would be reduced by opproximately 50%. Even if the sodium system were to fail and no heat was extracted through ‘the core shells, the steody maximum tempercture of the shells would not be more thon 50 to 100°F obove the mean fuel temperoture, depending on the channel thickness. A comparison of axidl temperature profiles with and without the boffles for channels of Y-in. constant thickness is pre- sented in Fig. 1.1.14, Several disadvantoges and problems associated with the use of boffles have been recognized. The neutron poisoning effect of the Inconel baffles would require o critical mass increase of 10 to 15%; the thin baffle structures must be designed to withstand the static and dynamic fluid forces; and design of the entrance region to distribyte UNCLASSIFIED ORNL-LR -0WS 20864 VTO0 1600 § 00 1400 1500 TEMPERATURE ["F) 1200 = 1100 CISTANCE FROM CORE INLET {a} Fig. 1.1.14, Axlal Temperature Profiles in the ART With and Without Baffles In the Core. (Secret with coption) 11 ANP PROJECT FROGRESS REPORT the flow properly between the channels and the central cnnulus may be o difficult problem. These various factoers ore presently being considered, and experiments are being prepared for deter- mining the opfin.-num configuration for the boffle design, CORE HYDRODYMNAMICS W. T. Furgerson J. J. Keyes W. J. Stelzman Flow studies of the full-scole 21-in. plostic model of the ART core were continued in order to investigote wall temperature fluctuations, which may be onalogous to the fluid tempercture fluctu- ations observed in the one-half-scale volume-heat- source experiment, 216 aqad 10 test flow guidonce devices in either the core entrance region or in the fuel annulus that would reduce flow reversals ond other instobilities. An ofttempt was mode to measure a transient surfoce-heat-transfer coef- ficient by utilizing o hot-wire probe located on the ovter wall. The probe waos made by winding o tight flat spiral of enameled Nichrome wire (0.006 in. in diometer) in the end of o 3,{‘ ¢ in.-0D metal tube; epoxy resin woas used to hold the wire in place. The face of the tube was then machined G- W. Greene ¢! af. ANP Quar. Prog. Rep. Sept. 10, 1956 ORNL-2157, p 227, g LOW - TEMPERATURE HELEUM IMLET HELHOM OUTLET GLASS-TG-METAL Eriis e —l— Py, { NICKEL LEAD WIRE e e | AT T T, A ] | e e —r— = 4.5 in N It shoyid be possible from the variation in resistance of the heoted wire with time to calculate the corre- sponding fluctuations in the heat transfer coef- to expese the surface of the spirai wire. ticient arising from boundary layer fluctuations, if the temperature coelficient of resistivity of the wire were known. Attempts were made to measure the temperoture coefficient of resistivity of the wire, but unfortunately the resistance of the wire was not stable at the temperature required to moke a satisfoctory determination. Improved probes are being developed in which the sensitive elements will be thin strips of nickel {vacuum evaporated) or silver {cpplied by painting from sclution) on the ends of a plastic rod. It is believed that these elements will hove good response to high-frequency fluctuations and suf- ficiently high temperature coefficients of resis- tivity to permit operation ot reletively low probe temperatures. clternative boundary-loyer fluctuations in the core, meosure- ore made with o helium-cocled surface thermocouple. The design of the thermocouple is illustrated in Fig. 1.1.15. The thermocouple ““‘gun-barrei’” type,!” and it is In an technique for measuring ments element is of the 7). E. Mott and A. G. Smith, Jr. ANFP Quar. Prog. Rep, Dec. 31, 1956, ORNL- 222],p54 UNCLASSIFIED QANL-LR-DWG-20863 36 =n.- 0D, 0.00-in, - WaALL STEEL TURE "Ya-1n.- 0D INCONEL TUBE - THERMOCOUPLE JUNCTION S5TEEL PLATE . i STEEL "GUN BARREL - TYPE THEARMOCQUPLE Fia. 1.1.15. Schematlc Diagram of Helium-Coofed Surface Thermocouple, mounted in a thin steel plate across which a thermal gradient is maintained by means of a steady blost of helium cooled by liguid nitrogen, The resulting heat flux is sufficient to maintain the probe surface at o temperature obout 60°F below that of the ambient core fluid, whose temper- ature is constant at 95°F, Data ore being obtoined for several core geometries by the use of this technique. The flow-guidance investigations were continued with studies of the core entrance region alone, the core entrance ond equatorial regions simuite- neous ly, and the core island bellows region within the center volute of the axial-flow type of header. The configuration used ot the core entrance con- sisted of a combination of guide vanes, designoted CA-1, and a series of annular tiners, designated shrouds 1 and 2, which split the flow entering the central annulus of the header into separate con- centric ¢ylinders of fluid, The outer cylinder of fluid was allowed to proceed downward at its natural flow angle, whereas the component of downward flow of the inner cylinder of fluid was increased by the guide vanes. The purpose of this configuration was to reduce the flow reversol Complete probe traverses of this system, os well as observations of dye injections, indicated that no significant improve- in flow characteristics were obtainad in ot the core entrance. ments comparison with the charocteristics of the swirl- type core header No. 2 without inlet vanes and with a simuslated conica! island expansion joint.!8 The second configuraticn tested consisfed of o combination of a core inlet arrangement, designated GS5-2 inlet guide vane and GS-2-P10Q conical baffle Flure,w in combinatien with a slotted disk, desig- ]‘BW. T. Furgerson ond W. J. Stelzmon, ANP Quar. Prog. Rep. Sept, 10, 1956, ORNL-2157, p 26. '9%. T. Furgerson, W. J, Stelzman, and D. B, Trauger, ANFP Quar. Prog. Rep. June 10, 1956, ORNL-2106, p 25. PERIOD ENDING MARCH 31, 1957 nated ‘‘flame ring’’ 1, which was located 6 in. above the equator. The purpose of this combination was to stabilize and distribute the flow evenly across the annulus above the equator while pre- serving as much of the rotational component as possible. Results of the test showed an increase in fuel circuit resistonce equivatent to 1.3 ft of working fluid. Claw-probe traverse data showed that the flow distribution was improved both rodially and circumferentially in comparison with that of series 17 tests of a contiguration which had GS-2 inlet guide wvanes and a G$-2-P10 boffle plate but neo “flame ring’" and in comparison with that of series 20 tests of a configuration which had o bare header and core configuration with no inlet guide vanes or botfle plotes. The degree of variation of oxial velocity with time was decreased, aolso, os ob- served by the decreased angle through which injected dye traces fluctuated, These effects on the flow distribution were more morked below the “flame ring'' than above it. The configuration of test series 24 consisted of the bare hecder and the core used in series 20 tests, but with the center body in the north-head region modified by an inverted conical section. The purpose of this modification wos to decrease the adverse axial pressure gradient along the upper islond surfoce and consequenfly to increase the axial flow component in this region. Claw-probe traverses showed that more flow hod been directed downward along the island surface, In the region above the equator this was apparent as a reduction in the amount of reversed flow. An undesirable side effect was shown by dye traces; nomely, a region of large low-frequency fluctuations ol flow with time was apparent which could lead to temperature fluctuations in a volume heat scurce. 13 ANP PROJECT PROGRESS REFORT 1.2. REACTOR PHYSICS A. M. F'erry ART SHIELDING C. M. Copenhaver A. M. Perry A program of calculations hos been undertaken to re-evaluate the shielding of the ART ond such auxiliary equipment os the fuel fill-and-drain tank, fuel-recovery tank, etc. The first step was to compute the gamma-ray dose rate at the outer surfoace of the ART neutron shield, without taking inte account the effects of the several penetrations for MoK lines, fuel lines, etc. The effects of such penetrations must be considered separately. Gamma-ray source strengths in the ART *Z were obtained through the use of two-dimensional neutron-diffusion calculations. [n computing the dose at the surface of the neutron shield (the outer loyer of the water region), on infinite-slab model was used thet waes based on the geometry ond scurce strengths in the equatorial plane of the ART. The plane-to-sphere transformation® was then oapplied to each portien of the source. Secondory gomma rays from the lead shield were neglected. The justification for this is that in the Lid Tank Shielding Facility (LTSF) tests of the gamma-ray dose rates in reflector-moderated reactor mockups with various lead thicknesses,? the dose varied exponentiolly with lead thickness up to about 4.5 in.; the ART lead is 4.3 in. thick. These dota ore interpreted to mean that the intensity of gaomme rays penetrating the 4.3-in.- thick lead shield of the ART wiil be much greater than the intensity of gamma roys produced in the lead. The heat exchanger wos regorded as a distributed source of gamma rays, the reflector as a fomily of five plane surfoce sources, and the core as a set ot six plane surface sources. The shells were treated as plone surface sources. The energy IR. B, Stevensen, ANF Quar. Prog. Rep. Sept. 10, 1956, ORNL-2157, p 32. 24, W. Bertini et al., Basic Gamma-Ray Data for ART Hedt Deposition Calcuiations, ORNL-2113 (Sept i7, 19 56), *E. P. Blizard, Introduction 1o Shield Design, ORNL CF-51-10-70, Part |, revs, p 52 (Jon. 30, 1952), 4G. T. Chopman, J, B. Dee, and H. C. Woodsum, ANF Quar. Prog, Rep. June 10, 1955, ORNL-18%6, p 190, 14 spectro? were divided into energy groups with upper limits at 0.75, 1.5, 3, 5, 7, and 9 Mev. The buildug factors used were those for water, since the outer layer of the shield is 31.5 in. of water. The buildup factor was uvsed in the form Blur) = a + bur , with the constants & aond & evolvated fo fit the buildup-factor curves® for ur between 5 and 15 mean free paths. The calculoted dose rote ot the surface of the water bag {r = 170 cm) is 1840 r/hr. The relative importance of each source is indicated by the percentage coniributions to the total dose rate: core, 22%; outer core shell, 9%; reflector, 12%; reflector shell, 35%; heat exchanger, 22%. In such a calculation the gquestion arises of whether the buildup-factor method can yield volid results for the reflector-moderatedreactor geometry. The gomma rays penetrate @ substantial thickness of lead, and, since the lead absorption cross section has a minimum for gammea-roy energies from 3 to 5 Mev, it might be supposed thot most gomma rays entering the water would have energies in this range, For the higher energy sources, use of water buildup foctors might then lead to appreci- oble errors. In order to check this point, on attempt was mode to determine the energy spectrum of the gamma rays entering ond leaving each component of the shield. Use was made of the energy spectra from monoenergetic point sources in infinite homogeneous media, as computed by Goldstein and Wilkins.?> The sources were divided into a set of point sources, ond the dose rate at the inner surface of the lead shield was computed for each source energy group. Attenvotion and degradation of the rodiation in the lead were then computed® as if the flux incident on the inner surface of the lead were duve to a set of point monoenergetic sources at the center of ¢ hollow covity inside the lead, The same procedure wos applied to the water with a new set of effective SH. Goldstein end J. F. Wilkins, Jr., Calcuwlation of the FPenetrations of Gamma Rays, Final Report, NYO- 3075 (June 30, 1954). peoint monoenergefic sources determined by the energy spectrum emerging from the |ead. This method of calculatien yields a gamma-ray dose rate of 1610 r/hr ot the shield surface. The energy fluxes at the shield surface in each gamma- ray energy group are listed below: Gamma-Rey Eaergy Interval Flux (Mav) {Mavfcrnz-sec) x 10% 0.25-0.75 108 0.75-1.25 86 1.25-3 271 3--5 303 5-7 147 7-8 185 PERIOD ENDING MARCH 31, 1957 The fast-neutron dose rote ot the shield surfoce was computed from LTSF data,? with the use of the transformation from finite-disk surface source to spherical surfoce source and the factors thot accounted for the additional boral aftenuation and source-to-shield surface ratic in the LTSF configuration, as formulated by Dee and Otis.® For an LTSF equivalent surface source strength of 0.428 x 10~? w/em?, the calculated fast-neutron dose rate ot the ART shield surface was 3.86 rem/hr, Thus ot o distance of 50 ft from the center of the ART operating at 60 Mw with a 4.3in.-lead and 31.5-in.-water shield, the calculated gamma-ray dose rate is 22.8 rem/hr and the fast-neutron dose rate is 0.05 rem/ hr. increased 6). B. Dee ond D. R. Otis, ANP Quar. Prog. Rep. Dec, 10, 1955, ORNL-2012, p 204. 15 ANP PROJELUT PROGRESY REPORT 1.3. ART INSTRUMENTS AND CONTROLS E. R. Mann C. 5 Wolker R. G, Atfel FLOW DECAY IN ART PRIMARY MoK SYSTEM FOLLOWING POWER L05% W. F. Werts' A NcK pump power foilure will produce temper- ature and prassure tronsients in the ART heat-dump S5y stem, istics were therefore investigated for use as o The Noll circuit flow-decay choracters guide in evaluating the significance of such o power loss, This investigation was based on the premise that flow is proportionel to pump speed when other fuid cirewit conditions are constant. Experimentsl dota oo the transient chorocter- istics of a NaK circuit were ohigined for o loop in which an ART prototype NaK pump was being tested at high temperotures. The loop contained about & B of circulating Mak, During shutdown tests, high-speed motion pictures were taken o¢f the pump shoft and of a pointer atfached to « synchronous This photographic record provided o refiable and accurote method fiming motor, of determining the number of pump-shaft revelutions gs a function of time, With o comgplete tabulation of pumpeshelt revelutions vs time esfoblished, speed vs time data could be obtained through numericol differentiation, Severol shutdown tests were mode from each of two initial conditions, The NaK flow wos es- sentiolly the some for both conditions, but the ‘nitial pump-shaft speed in one cose was about three-fourths the initial speed in the other cose. & hand valve was adjusted, as required, to provide the desired flow for the pump-shaft speed vsed, The date were compared ond evalucted aceording to the foilowing system-operation-decay snolyticol relotionship: [ power 5upp|ied] { power to e svstem cirentate fluid T pawer to change l kinetic energy When the system driving power was terminated, the relotionship became ( powveer o civeulate fluid () 0 = E power fo chcnge] P kinetic energy | If N is rotor speed and k, ond k, cre squotion constants, the [ power fo b 3 cirgulote fluid | = HE = & N ond the [kinetic energy] = KE = kzN?' : axpressed in power-time units, Then the . | power to change Z{KE) . an (2] L kinetic energy | T T T Zky N A ¥ Eg. 2 is substituted into the original ex- pression, £q. 1, the following expression for speed vs time is obtoined: an ¥ at (3 0 = &, N% & 2k, The selution 1o £q. 3 can be shown to be in any of the following lorms, with the subscript O indi- cating the initicl values at steady-stote conditions bofore the start of operation decay: » | kot } {4} — = —, N2k, W, | N 1 (5} - ¥ e My (¢ o/ KE /2y + 1 ‘ IINQ ‘.‘ Irf Z'KEG\‘ (%) . k, -] - ) Y J \ HP, ln Egs. 4, 5, and 6, N and ¢ are the only variables. Plots of the speed decay vs time were made for various initial kinetic energy-to-power rotics, as 1.3.1. The curves shown are thearefically volid for ony iype of pump, fluid system, or davice, so long as the system power shown on Fig, proporfionel to the cube of the mass-—velocity involved., The initial kinetic energy- to-power rotio must be determined with the kinetic consumption is 1 . .. Do Or ossignment fraom Beodix Products Division, o0 PERIOD ENDING MARCH 31!, 18257 UHCLASSFIED CRNL~-LR—0OwWG 20867 o —— = b SPEED DECAY (%% OF INITIAL SFEED) |/ ANITIAL KINETIC ENERGY-TO-POWER RATIO (AT 100 % SPEED) ' | = * THE TIME UNIT MUST BE THE SAME AS THE TIME UNIT OF THE KINETIC EMERGY EXPRESSION | ' ' g 10 45 20 25 30 33 40 TIME AFTER LOSS OF POWER * {sec] Fig. 1.3.1. Speed Decay Choracteristics of a Centritugel Pump upon Loss of Power, energy expressed in power-time wunits {such as horsepower-seconds, watt-hours, etc.} to give a term having the same units of time as those applied to the abscissa of the curve (seconds, hours, etc.). The data were analyzed in detoil for two shut- downs from the following initial steady-state operating conditions: Condition Rua 1 Run 2 Shatt speed, rpm 3506 24678 Fluid flow, gpm 1220 1216 Dischorge head, ft 394 212 Fower supplied, ha 119.3 68.8 Partial checks of data from several other tests indicated almost identical results for the con- ditions invelved, All the analyzed test dota closely motched the computed decay characteristic shown on Fig. 1.3.1 for on initial kinetic energy- to-power ratio of 2, that is, KE /HP; = 2, and speed decay down to about 30%. Below the 30% speed-decay region, the system mechanicol friction becomes increasingly more significant, since the system kinetic-energy driving force has dropped to less than 10% of the original value. The operating decay characteristics were sub- stantially the same for both sets of conditions, and therefore only the test data for the shutdown frem a shaft speed of 3506 rpm were fully reduced to completed plots, as shown in Figs. 1.3.2 ond 1.3.3. The pressure characteristic curve shown on Fig. 1.3.2 was obtained by using the premise that pressure varies as the square of the speed and the flow rate, With other conditions constant, the flow rote is considered te be proportional to the pump-shaft speed, as previously indicated. The analytical expressions for the two test conditions would be identical if the initiol kinetic energy-to-power ratios were the same. The power ratio for the two conditions is 119.3/68.8 = 1,735, and the experimental data indicated that the decay characteristics for the two sefs of conditions were identical; therefore, the kinetic energy ratic must he neorly the same as the power ratic, An investi- gation of the rotating kinetic energy ratio for the two conditions reveoled that [N \ %, % _ ff?fi) . 1715 . 7678 7 ANP PRUOJECT PROGRESS REPORT 00 UMCLASSIFIED ORNL=-LR— WG 20868 20 : —= . L 50 [——— wde o |— 30 | e e — — | --PRESSURE 20 | — . CECAY CHARACTERISTIC [ % OF INITIAL WALUE ) 19 |— — = a0 | —_— i e -— 4 PPR 20 25 30 35 a0 TIME {sec] Fig, 1.3.2. Flow Rate ond Pressure Decoy in MaK Circuit After Loss of Power to the Centrifugal Pump. Thus it can be seen that the rotating kinetic energy-to-power ratios were about the same for the two test conditions. The fluid kinetic energy cannot be included in the analytical expressions, since the flow was substantiolly constont, In view of this, it would seem that the flow inertia is negligible, as com- pared with the rotating inertia, in its contribution to the system kinetic energy. If the foregoing deductions are considered to be the case, the major contributors to continuing system operation after o power loss are the rotating elements of the pump ond the electric drive motor. This also means that the only appreciable contribution to any extended continving fluid circulotion during the decay period is received from the stored kinetic energy in the mechanically rotating parts, end that the pump is stili the driving force and is inducing ftuid displacement in a manner sub- stantially the same as during the previous steady- state operation, Since the flyid flow is dependent upon the pump driving force, fluid travel around the circulating loop should be substantially proportional to the pump ongular displacement. The information pre- sented on Fig. 1.3.3 was determined by opplying 18 this principle to the test data described above in combination with the computed volumes of seg- ments of the ART primory MaK heat-dump circuit, The volumes used in the preparation of Fig. 1.3.3 were those designated circuit 1 in Table 1.3.1. LIQGUID-METAL-LEYEL TRANSDUCERS G. H. Burger A, M. Leppert R. E. Pidgeon, Jr.2 Tests of the commercial resistance-type liguid- metol-level transducers described previously® were concluded, Operation of the NoK level fest focility was continued until February 21, ot which time only one of the four transducers originally instailed in the test focility remained in operating condition. The performence of the transducer that remained in operation wos excellent for a period of 3732 hr, during which time the NoK leve! of the system was cycled 65,000 times. The four transducers were removed from the test facility for examination, and the unit that remained in 204 loan from Radlo Corp. of Americo. R, E Pidgecn, Jr., ond G. H. Burger, ANP Quar Prog. Rep. Dec. 31, 1956, DRNL-2921, p 20. PERIOD ENDING MARCH 31, 1957 UNCLASSIFIED ORML=LR-DWG 20869 | [-‘ii__'_ T h‘““-—- T 1777 / RADIATORS o /. . NN \ \ Lol L HEAT EXCHANGER | F O{W ER LO-’SS /L OLO PIFE g ) 1 / sz-ml // / / DESIGN POINT _[ OPERATION ] /1 ~ o] | — W RADIATORS —c ] 4 / AN\ |~ HEAT EXCHANGER FLUID MOVEMENT ARQUND CIRCUGT RELATIVE LOOQP SEGMENT POSITIONS POINT OF POWER Loss‘l""—-—-_______ /)Y [/ ////7/ —~ \\ NN A Y & 7/ RADIATORS g / // ! HOT PIPE [/ / HEAT EXCHANGER] DR \\\ N7 / A)LD PIPE \ T [ [ b, { i RADIATORS. _3‘_ L »-,____-':: ] ._\- \ /] " —{Q -3 0 5 [// | 15 Z TIME [sec) 0 25 30 35 40 Fig. 1.3.3. NoK Flow Rote Decay Charocteristic After Power Loss Based on Loop Test Dota and ART System Daesign Yolumes. {(Contidential with coption) ANP PROJECT PROGRESS REPORT Toble 1.3.1. Volumes of NaK in Vorious Segments of the Four NoK Clrcults of the Art Primary Heat Dump System NoK Volume {f1) Segmant Total for ths Circuir 1 Circuir 2 Circuit 3 Circuit 4 Fasi Eoreuiian Radiator 3o pump 1411 1.411 1,411 1,411 Pump (circulating) 0.26 0.25 0.26 0.26 External cold pipe t.787 1.5446 1.305 1,044 Intermal cold pipe 0.762 D.646 0.4656 0.735 Branches (to header pipe) 0.123 0.123 0.123 0123 MNorth hecodsrs and connecting pipe 0.242 0.242 0.242 0.242 Total 4.585 4.228 3.997 3.835 16.645 Haot exchanger 0.722 0.722 0.722 0.722 2,888 South header and cennecting pipa 0.171 g.171 0.1 0.171 Branches (header pipe 1o commen line) 0.123 0.123 0.123 0.123 Interrial hot pipe 0.646 0.838 0.694 0.4687 External hat pipe 1.463 1.188 1.478 1.134 Pips {2 in.}) to elevation 834 1, § in. 0.454 0.561 D.748 0.631 Het pipe to rodictor tubes 1.292 1,392 1.292 1,392 Total 4.449 4.273 4.606 4,138 17.466 Rodiotor 0.476 0.476 0.474 0.476 1.904 Total Circulating Yolumse 10.232 2.699 2.801 2.171 38.903 *Circwits 1, 2, 3, and 4 are referred te on 7503 Facility respectively. operation for 3732 hr s shown in Fig. 1.3.4a. Cne of the three units which failed scon after the start of the test is shown in Fig. 1.3.46. The failure of the unit was caused by MNaK seepage inte the insulotion througn the crack visible neor the bottom of the U-bend, and the other two unsatistactory units failed in a similar manner. The reaction of the NaK with the insulation coused the visible deformation, The NaK-level test facility is being medified to provide facilities for testing CRNL-designed and -fabricated resistonce-type level transducers. These level tronsducers ore to be clamped into 20 heat-dump piping drawings as loops B1, A2, Al, and B2, place in the surge tonks (instead of welded) to facilitote installation and removal. Fabrication of six ORNL-designed resistance- type level transducers is under These instruments will be similar to the commerciol transducers, but they will have better temperature compensation, and way. improved weld design. A further design modification was made to increase the range of level determination; that is, with the ORNL-designed instruments, it will be possible to measure the level closer to the bottom of the tank. Design of a similar resistance-type level transducer for use in the ART sodium expansion tank was completed. PHOTO I5 53 -— Tl T—— UNCL ALEIFIED PERIOD ENDING MARCH 37,1957 UM ASSIFIED PHQTO 28788 (e {4)] Fig. 1.3.4. Resistance-Type Liquid-Metal-Level Transducers After Operation for 3732 hr In o NaK-Level Test Facillty. (a) Uait that remainad in operating condition throughout the test. (b) Unit that operated only 24 hr, but remained in the test facility exposed to NaK for 3732 hr, ON-OFF LEYEL PROBES G. H. Burger A. M. Leppert R. E. Pidgeosn, Jr. Eight of the resistance-type on-off level probes described previously! were constructed and in- stalled in the surge tonks used in the fluid-flow- facility for testing measuring system in the 44, M. Leppert, ANP Quar. Prog. Rep. Dec. 31, 1956, ORNL-222%, p 29. magnetic flowmeters in NaK. These all-welded probes are being ftested os a replacement tor conventional spark-plug probes, which are not suitable for pressurized systems and temperatures above 450°F. The surgetank level control system that incorporates these on-off probes was in operation on the test loop for about 2 doys, but an apporent failure of the gas-pressure control system ollowed helivm to be forced into the NaK system. Some changes are being made in the 21 ANP PROJECT PROGRESS REFORT on-off probe and its control circuit to give better confrol and a better safety margin in operation. The on-off level probe being tested consists of a /fi in. -dlq copper wire contained in ond insulated from a f -in.-0D, 0.025-in.-wall lnconel tube at ali points, except the bottom, where if is welded. A current of B to 10 amp, 60 cps, is supplied to the probe. A relay across the probe is energized when the NaK level is below the probe ond de- energized when NoK touches the probe, A similar on-off probe with an Inconel center wire and a bridge amplifier for the control circuit is being studied. The probe would con5|51 of a .-'"]6-”1 -dia Inconel wire insulated in a ffi-m -00, 0.025-in.- wall Inconel tube. The bridge circuit would be balonced when the NaK touched the probe and unbalanced when the NaK level was below the probe. Since the tempercture coefficient of resis- tivity of Inconel is low, the zero shift resulting from a temperature change would not be so lorge as in the present probe. A specification has been prepared and submitted to manufacturers for o packaged amplifier to be used in this bridge circuit. An especially fabricated spark plug with a bery Hium oxide insuvlator wos tested in NaK as on on-off level probe, The plug failed after 20 he of operation becouse of short circuiting of the insulator. The plug was removed ond reworked, and it is to be retested when the NaK-level test facility (referred to in previous section) is back in ¢peration. Several special plugs with insulators high in alumina and magnesium content were received from the Champion Spark Plug Co. for testing ond evceluating. These plugs will also he tested in the NaK-level test focility or other test rigs as soon as possible. The usefulness of the conventienal type of spark plug as o reliable on-off probe is very doubtful ot this time, The plug life is very short when the probe is operated at temperctures above 450 1o 500°F, and there is always the danger of gas leakoge through the insulator, This leokoge problem could be very sericus if the plug were used with radicoctive fluids, and it would be necessory to completely con or seal the plug. Therefore the use of the spark plug as a reactor type of level element is not recommended, ond the development and testing of the resistance type of on-off probe is continuing. It is expected that 22 this unit will replace the spark plug except in systems which can be operated safely ond reliably within the spark-plug limitations, or in systems in which the process fluid electrical conductivity is too low for use with the resistive type of on-off level probe. FUEL-EXPANSION-TANK LEYEL INDICATOR R. F. Ayland Dynamic-Level Tests Four helium-bubbler-type fuel-level indicators completed 1000.hr tests at 1500°F in the dynamic- level test rig, described previously,” without plugging of the bubbler tubes, Two of the bubblers were fabricated of 31’ -in.-0D, 0, 065-m.-wu|1 Inconel tubing, ond the olher two were / -in,-QOD, 0.035- in.-wall Inconel tubing. The hellum used for these tests was passed through a Drierite filter and through copper turnings maintained ot 1000°F in order to getter the oxygen and remove the moisture. After completion of these tests, the focility was modified in an attempt to cbtain a better series of level calibrations. The medifications included a means for accurately vorying the fuel level continugusly in the two vessels by using gos pressure; a new bubbler design with a shallow V in the bottom of the tube woas used; and the bubblers were positicned within 0.010 in, of the correct level while the vessel was at the operating temperature. An improved type of voriable coli- brating probe was designed, installed, and cali- brated ot the operating temperature. Also, the fuel was thoroughly mixed prier to calibration to preciude density errors due fo thermal gradients. As a result of these modificotions, the firss accurate, repreducible series of static level cali- brations was obtained. The maximum level error was 0.08 in, in 5 in., or 1.6%. reproducible within 1.5%. A dynamic-level test scheduled to operate for 3000 hr at 1500°F has completed 750 hr without bubbler plugging. Prior to startup, however, with the bubblers operating in static fuel ot 1350PF, otl four bubblers plugged in a period of 24 hr, for reasons unknown, Two bubblers were removed and the contents sent for onalysis. The other two were unplugged by roising the fluid temperature The results were SR F. Hyland, ANP Quar. Prog. Rep. Dec. 31, 1936, ORNL-2221, p 29. to 15300°F, The bubbler plugging problem hos become so serious that a separate series of tests, described below, is to be made to determine the cause, Static-Level Tests The average life of a helium-bubbler type of level indicater hos been found to be about 1100 hr in g static-level system in which a NaK scrubber is used to reduce the moisture content of the helium ard in which copper turnings mcintcined at 1000°F are vsed to reduce the oxygen content, Since the average life falls far short of the 3000-hr life specified, ottempts are being made to de- termine the cause of plugging of the bubbler tubes. Although the technigques for onalyzing fuel mixtures for oxygen compounds are not precise, it is thought that the moterial which plugs the bubbler tubes is ZrO,. Therefore o special batch of oxyfluoride- free fuel will be used in the next series of tests., It has been suggested that @ cold trap be used in place of the NaK scrubbers for removing moisture from the helium, since NaK sntrginment might contribute to the plugging. Methods for checking the oxygen content of the helium and for reducing the oxygen content ore being studied, Further, the vessels used for future tests are to be hydrogen fired. These recommendations are to be incorporated into a simple series of bubbler tests in static fuel, without level instrumentation, and the ad- ditional precoutions described below will be taken, 1. An all-silver-soldered spectrometer-leak-tight system, with bellows valves, will be employed. 2. The system will be flushed thoroughly by alternately pressurizing with helium ond evacu- ating. 3. The dewpoint and oxygen content of the supply helivm will be continuously monitored. 4. The purge helium will be preheated to the temperature of the fuel, As a further check on the role of oxygen impurity in the helium as a cause of piugging, one test series will be run with heflium of known oxygen content, as furnished in commercial gas, and onother test series will be run with helium passed over uraniym furmnings held at 600°C to reduce the oxygen confent to as low a value os possible. PERIOD ENDING MARCH 31, 1957 FRESSURE TRANSMITTERS FOR USE AT HIGH TEMPERATURES W. R. Miller Evaluation tests of commercial transmitters for use at high temperatures were continued. Two of the six units mentioned previously® that employ differential tronsformers were tested, The firs? unit tested was not satisfactory in that the over-all occuracy was only 3,3% full scale at 1200°F. The other unit was somewhat better, with an over-all accuracy of 2.1% full scale ot 1200°F. The differential-transformer method of detection has proved to be vausually difficult to use in that the tield of the Calrod heaters used to maintain the aperating temperature has on effect on the output readings. shielding is helpful but does not relieve the situation com- pletely. At present two more units of the type shown in Fig. 1.3.5 are undergoing tests. The unit mentioned previously® that employs a variable-permeance type of pressure transducer was tested, but no datc were obtained. Lack of suitable aligning guides allowed the core of the transducer to rub the coil housing. This wunit (Fig. 1.3.6), which was on consignment, has been The use of magnetic returned to the manufacturer, Redesigned madels of the four-legged strain- gage type of transmitters (Fig. 1.3.7) were also tested. Armor was added to protect the capillary, ond o shock-mounted sub-base was added within the _ase for vibration isolation. The redesigned caose eliminates zero shift when the cover is tightened. Because of a poorly designed shipping clamp the strain goges were domaged during shipment, and therefore the test results for these models were not up to the standord set by the results obtained with the original six prototype medels, The shipping clamp hos now been modified by the manufacturer. The next lot of four-legged strain-gage trans- mitters will feature a sensor housing with improved stress choracteristics for use with more corrosive process fluids. The details of this design change have been satisfactorily resolved with the manu- facturer. Sw. R. Miller, ANP Quar. Prog. Rep. Dec. 31, 1956, ORNL-2221, p 30 23 ANP PROJECT PROGRESS REPORT \ URCLASSIFIED PHOYO 27350 Figl Ilals‘l ducer. Caollery Chemical Co, Pressure Trons- 24 A second set of pneumatic-cutput transmitters completed a suvccessful 2000hr {ife test in a NaK-filled test loop. being examined metallurgically for weld defects and corrosion, These units are presently MAGMNETIC FLOWMETERS G. H. Burger C. L. Pearce’ Six of the 3)-in. magnetic flowmeters purchased for the ETU and the ART were installed in the tlowmeter test loop filled with NaK for calibration agoinst a water-calibrated {(0,25% accurate) venturi. As stated previously® the units will be calibrated over the widest temperature and flow-rate ranges possible with the test loop. These ranges will cover, in general, the design ranges of the ETU and the ART, Operation of the loop began on February 12, 1957, and it had operated a totel of 40 hr when it became necessory to drain the NaK for repairs ond medifications of the loop. During the 40-hr operating period, fluid flow rates of up to 1600 gpm and fluid temperatures of up to 1350°F were achieved. The dota obtoined with the mognetic flowmsters, while not ¢t all conclusive becouse of the short operating time, did give general indications of the operating choracteristics to be expected. [t appears that ot least four of the six flowmeters now installed in the loop will be acceptable for the ETU if the accuracy specifications ore met in subsequent tests. Six of the ART-ETU 2-in. magnetic flowmeters are being installed in another test loop for cali- bratien against o water-calibrated {0.25% occurate) venturi. Operotion of this loop will probably start in May 1957, The :’}é-in. magnetic flowmeters designed for plug indicater and cold-trap flow rate meosurements are being fobricated. Several of the units will be tested for temperature effects on the magnets. These units will not be calibrated because the accuracy requirement is +15%. ?On toen from Radic Corp. of America. BG. H. Burger, and C. L. Peorce, ANP Quar. Prog. Rep. Dec. 31 1930, ORNL-2227, p 23. PERIOD ENDING MARCH 31, 1957 LUNCL ASSIFIED PHOTOQ 17347 MR gl;‘n o ARNE I AN —— AR AR AR KRR R NN R R R Lt Jl'tfefrla||lr|1||1llt1|\|‘li“lt'la1‘1‘- Fig, 1.3.6. Crescent Engineering & Rasearch Co. Pressuyre Transducer, UNCL A5FIED PHQTO 28160 Fig. 1.3.7. Taylor Instrument Companles Pressure Tronsducer. 25 ANP PROJECT PROGRESS REFPORT REMOTELY APJUSTABLE PRESSURE REGULATORS ¥, R, Miller Two prototype models of remotely adjustable pressure regulators were tested. These units were from different manufocturers but were quite similar in operation. is possed through ¢ voicescoil type of trensducer to position the pilot operotor of a pneumatic relay system, The resulting output pressure is directly proportional to the magnitude of the current in the transducer coil. Tests performed thus far showed these units to be stable under line-voltage, supply- pressure, and normal ombient-temperature varis ations. Tests will soon be initiated in which these units will be subjected to extreme ambient conditions in a 3000-hr life test, A remotely adjusted direct current TURBINE FLOWMETERS FOR USE AT HIGH TEMPERATURES G. H. Burger The 1-in. turbine flowmeter, designoted unit No. 2-Rev. 3, described previously,? was installed in a forced-circulation gos-fired Inconel leop con- taining NuF-ZrF4—UF4 (50-46-4 mole %, fuel 30) for calibration egainst an orifice by using Taylor transducers as pressure sensors and for an en- durance test of 3000 hr. Operation of the loop was storted on January 8, 1957, and the turbine operated satisfactorily for approximately 340 hr, |+ was then noted that the turbine output frequency was Considertu different from what it should have been bosed upon the orifice-measured fiow rate, and an investigotion showed that the unit was not operating., An x-rgy examination of the unit showed, as for as could be determined, that the unit was not breken, |t was therefore believed thot, since the unit hod been operoted in NakK systems three times previously, the bearing had been oxidized to some extent and that operation in the salt mixture caused it to bind after a short operating time, the loop is drained ond exomined in order to determine the cause of failure. The unit will be removed when A 3 .ia, turbine flowmeter was installed in a forced-circulation loop filled with NaK in order to test the unit under actual operating conditions. t:"IG. H. Burger, ANP Duar. Prog. Rep. Dec. 31, 1956, ORNL-2221, p 25. 26 Prior to installation in the lcop the unit hod been tested ond calibrated at a high flow rate in a loep containing water, The unit performed satisfoctorily during the calibration tests. The calibration data are shown in Fig. 1.3.8, The only unusual operating characteristic wos noted at a flow rote of 600 gpm, at which point the tyrbine ‘'chattered’’; at flow rates other than this no vunusual chatter of vibrotion was noted. The total test time with water was approximately 6 to 8 hr, and flow rates of up to 1100 gpm were recorded. |t wos felt on the bosis of the results of the water tests that the unit wos satisfactory for calibration under aperating conditions in a NaK system and that any possible failure of the uait could not damage the test loop. UMCLASSIFIED ORNL-LR—DWG 20870 T T T ] n o B o | | & o | | ™ & PRESSURE DROP ACROSS TURBINE [psiol LA Lo T | | | L < ™ L) i | | > | 1 | LT PRESSURE DRGOP o bz L 11| 5 o 200 400 ao0 BOOQ 1000 4200 1908 FLOW RATE f{gpm! OUTPUT FREQUEMNCY OF FLOWMETER |counts/fsec) o Fig, 1.3.8, Turbine Flowmeter. Water-Collbration Dota for o 3‘%-in. Operafion of the loop wos started on February 12, 1957, ond the turbine flowmeter operated os expected for approximately 12 min. The loop flow was started at 420 gpm and was rapidly increased te 1220 gpm, as indicated by the turbine flowmeter, At some point between the flow rates of 970 and 1220 gpm, however, the unit failed in some manner. At the approximate time of failure and possibly during all or part of the operating time, the loop opetators could hear chaitering of the unit., The tempergture of the circulating NaK qt the time of tailure was 155°F, The loop continued to aperate ofter the turbine fallure and eventuclly reached o flow rate of 1680 gpm and o maximum fluid temperature of 1350°F, which wos held for only a short time and then lowered. The loop operated a total time of approximately 40 hr before pump surges necessitated shutdown. The surges may have resulted from ingassing brought about by improper operation of the surge tank level system while measuring venturi pressures. On Februery 14, 1957, before disassembly of the loop, @ radicgraph wos made of the turbine flowmeter which showed that the bearings were broken and thas o number of blades were missing. Cn February 18 the flowmeter was removed from the loop, and the indications of the rodiograph were confirmed, as shown in Fig. 1.3.9. Eight of the ten blades were missing; the two remaining blodes were bent opposite to the direction of rotation; and both bearing shafts were broken. The main throttling valve waos removed from the system, and six of the blades were found therein, A seventh blade was found under the volve housing in the drain line. The eighth blade has not yet PERIOD ENDING MARCH 31,1957 been found, but the seorch is continuing; the piping is to be x-rayed, flushed, and swabbed. The turbine hos been disessembled and will be carefully examined in an effort to determine the cause of failure. ART THERMOCOUPLES J. T. Delorenzo incongl-sheathed closure welds made by the Heliarc welding process are being tested. Nineteen closure welds on sheathed Chromel-alumel thermocouples that had previously passed x-ray and dye-penetrant inspections were exposed for 2100 hr ot 1500°F in sodium, and there were no evidences of leaks. Thirteen similar specimens are now being exposed to NaF.ZrF,- UF, (50-46-4 mole %, fuel 30) at 1500°F. The welds on three platinum~platicum-10% thermocouples with closure rhodiym thermocouples are also being tested in UHCLALLIFIED PHOTO 2294 Fig. 1.3.9. Damaged 3},;3-in. Turbine Flowmeter as Compared with a Similar Undamaged Unit, 27 Tabkle 1.3.2. Results of Drift Tests of Sheothed ond Beaded Chromel-Alumel Thermocouples in Alr Sheathed Assemblies® at 1300, 1600, and 1800°F for Yarious Times Special Beoded Assemblies? Mermol Seaded Assemblies® Sheathed Assembl iesd Test Peried (hr} Deviction® Spreud‘{ Devigtion® Spreod-f Deviotion® Spreudf Deviation® 51:-r:a-ic;u:l-"r (®F) (°F) (°F} (°F) (°F) (°F) (°F} (°F) Test Temperatuce: Y300°F a 5.0 3.3 -7.0 2.1 -5.3 1.1 1000 5.5 3.7 —~ 4.0 3.1 —4.4 2.2 2000 5.3 2.4 -3.8 5 —4,1 6.5 2500 9.3 2.2 ~0.3 3.0 -0.5 4.0 Test Temperature: 1800°F 0 1.8 2.8 6.0 2.0 -7.1 3.5 4.7 4.3 1000 6.4 2.6 3.9 2.5 -2.2 9.1 3.6 3.1 2000 7.0 2.7 6.2 5.5 —0.7 10.7 2500 9.1 3.3 9.4 5.3 -0.8 12.0 Test Temperature: 1800°F 0 1.0 2.6 -7.5 4.3 1.3 2.1 5.5 4.2 1000 7.7 15.1 15.2 19.2 8.7 14.3 10.2 10.5 2600 8.0 16.2 26.2 2.5 11.7 19.2 2500 11.5 20.3 31.4 20.3 19.8 31.0 9%ix ossemblies were tested and each assembly contained two thermocouples aged 24 hr ot 1350°F in heljum prior to testing. bSix assemblies were tested and each gssembly contained two thermocouples fobricated with especially cleaned wire {aceuracy, iafs of 1% ever range 530 1o 2300°F) in carelully cleanad wells. k €Same as special assemblies except thot they received no speciol ¢cleaning. ASume as assemblies described in footnote a sxcept that they ware aged for 200 hr ot 1350°F in helivm. € Deviotion of the averoge of the readings of the twelve thermacouples tested from the stondard test temperature of 1308, 1600, or 1800°F. "’qu'rmum spreod of the twelve readings obtained. IHOd 3y S5IHI0HS L3370 dNY fuel 30. To date, the Heliarc welding process has vielded 30 to 50% acceptable welds. Bend tests have been mode in order to determine the effect of bending the sheath on the output of the thermocouple, Single U-bends on a ¥.in. radius had very little effect, even when the Lent area was exposed to o temperature grodient of 100 to 150°F per inch. The inaccuracies induced were less than 0.5°F. The repeated bending of ¢ single specimen appeared to cause o 2 to 3°F shift, but this change will be rechecked with several more test specimens., The fabrication of the sheath weld similarly was found to have little effect on the occuracy of the thermocouple wire. Aijl deviations measured were less than 0,5°F, The drift of the data obtained with sheathed and beaded Chromel-alumel thermocouples operating in air as o function of time and temperature is being studied. The results of tests at 1300, 1600, and 1800°F in Table 1.3.2, Data are presented FERIOD ENDING MARCH 37,1957 obtoined in the closure tests in static sodium, described above, showed less than 3 or 4°F drift of sheathed Chromel-alumel thermocouples at 1500°F in 2100 hr. A program is being prepared for the Oracle tc focilitate processing drift data. The emf vs temperature curves for Chromel-alumel and plat- inum—platinum-rhadium thermocouples have been tabulated on the Oracle magnetic tape memory, and o workoble program has been outlined in prepo- ration for actual computations with the raw data. The system will be checked with previocusly processed dota before new data are used. Fumaces in which the heating coils can be moved at a uniform rate were designed and fabri- catec for testing the uniformity of thermocouple wire, Two fumaces are now ovailable which give either symmetricol or asymmetrical gradient patterns. The maximuym gradients that can be obtained with the two furnaces are 300 and 700°F per inch, respectively. ANP PROJECT PROGRESS REFPQORT 1.4, COMPONENT DEVELOPMENT AND TESTING H. W. Savage PUMP DEVELOPMEMNT TESTS E. R. Dytko' A. G. Grindell Bearing and Seal Tests W. L. Snopp! W. K. Stair? The dynomic tests of lubriconts under irradiation thot were to be run in the LITR3 are, rather, to be run in o gommo-irradiation facility in the MTR canal. With the MTR facility it will be possible to use o slightly modified fuli-scale pump rotary assembly ond to examine the unit for damage immediately upon removal from the gamma-irradi- otion field. The present schedule colls for fest operations to begin next gquarter, The final selection of a lubricant-cootont for the reactor pumps will be based on the results of the gamma-irradiation tests in the MTR, Since both orgonic liquids ond highly refined paraffin-base mineral oils ore being considered at this time, all parts of the pumps and the external lubricant- pumping system are designed to be compatible with either liquid., For exomple, copper is incom- patible with organic liquids, and therefore copper parts in the seals and journcal beorings ere being reploced. All-stainless-steel bellows-seal test assemblies were ordered ond will be incorporoted into the MTR test units. Journal bearings fabri- coted from Alcoa alloy 750-T5 were selected to replace the original bronze bearings. The small percentage of copper (0.7 to 1.3%) in this alloy is probebly insignificont with respect to the organic liquids of interest, but a somple of the alloy will be tested in UCON LB-140-X, an orgonic liquid, before the MTR test is made. There are no copper parts in the external lubricant-pumping system. Two 1000-hr tests were conducted to determine the suitobility of the aluminum olloy, Alcoo 750-T5, for this particulor bearing application in which the effective journal beoring arec is 2.4 in.% Gulfcrest 34 was used os the lubricant in both tests. Thetest conditions are given in Table 1.4.1, 1on assignment from Prott & Whitney Aircraft. QCDHSU‘TDHT from the University of Tennessee, 3":':'- L. Snapp ond W, ¥. Stair, ANP Quar. Prog. Rep. Dec. 31, 1956, ORNL-222), p 32 30 Neither test gave any evidence of bearing mal- function, and both the bearings were equally as bronze bearings tested under similer conditions, Aluminum alloy becrings hove been placed in rotary elemenis for use in various other tests, and if satisfactory service is obtained the aluminum alley will be used far all recctor pump good os journal bearings. Table 1.4.1. Conditions of Test of Suitabillty of Alcoe Alloy 750-T5 for Pump Bearlng Application Test 7501 Teast 750-2 Shaft speed, rpm 3400 4400 Test temparoture, °F 180200 170-%20) Operating period, hr, ot specified journol bearing loads: 300 1b 621 527 450 |b 287 214 00 b 166 407 Continyous operating 1074 1148 pariod, hr Continued tests of the modified Durametallic seals? being developed for use as seals in NaK pumps have produced further encouraging results, More than 5000 hr of operating time was logged for such seols, including 2500 hr in a rotary element pumping NoK ot 1400°F and 2500 hr in a me- chanical shakedown stand with the seals subjected to a wide range of diHferential pressures from 20 psig, which simulates a vacuum filling operation, to 275 psig, which is more than a maximum catastrophe pressure, and to rubbing speeds from 0 to 60 fps. It wos found thot for the very high differential pressures, obove 200 psig, a slight design modifi- cation will be necessary to prevent relative motion berween the positioning collor for the lower seal aond the shaft, On the bosis of these gocd test results, the Durametallic seals hove been specified for use in the ART MNaK pumps. Tests have shown the buno-N-base O-rings recommended by outside venders for use with UCON LB-140-X lubricant tc be quite satisfactory, Similar tests showed the bunag-N-bose O-rings to be satisfactory for use with Gulfcrest 34 lubricant, and therefore this elastomeric secl can be used for the reactor pumps if either of these lubriconts is acceptable. [f, however, the MTR tests prove these lubricants to be wnsatisfactory, the seal material may ogain become a problem. For the NaK pumps, commercially aovailable elastomer seals will be satistactory, since Gulf- crest 34 will be the lubricant used. similar Fuel Pump Development Woter Tests J. J. W, Simon*? The development tests with water of an accept- able impeller configuration® {designated model 32) for the ART fuel pump were completed with the 4Dn_ assignment from Pratt & Whitney Aircraft, SM. E. Lockey, G. Samuels, ond J. J. W. Simor, ANP Quar. Prog, Rep. Dec. 31, 1956, ORNL-2221, p 33. PERIOD ENDING MARCH 31,1957 tests described below. Performance tests were run for liguid levels of ]/2 to 3 in. in the expansion tank to encompass the level chonges expected during the change from zero power to full power operation of the ART. In general, operction is not affected by a liquid-ievel change when the liquid level is 2 in. or more above the floor of the expansion tank, Below this level the fluid head showad a slight decrease, the expansion-tank fHlow rates decreased, the power required to drive the pump decreased slightly, ond the fHlow rate in the main loop decreased slightly as the liquid level neared ]5 in. The effects of decreasing the liquid level in the system on the flow rate, head, and pumping power ace shown in Figs. 1.4.1, 1.4.2, and 1.4.3, re- spectively, It may be noted thaot the flow rote, heod, and pumping power remained fairly constant down to the %-in. level in the expansion tank. Below that level, definite decreases in flow rate, head, and pumping power occur, ond, also, although not shown on the figures, fluctuations of all three UNCLASSIFIED ORBL~Li=DWs 20871 FLUMD REMOVED FROM LOCGP {lilers) g 1 2 3 4 5 & A A 3 o 18— - - ,:_: INITIAL COMDITIONS ; | 645 gpm [DESIGNI 535 g 735gpm 2 § Z100rpm & 2Z700eom x 2700pm K1 AR === o 2400¢pm =i = = Wil | o 2700 rpm .- = b s 30G0rm S & o 5 25 - a X300 rpm =% . z 2 a | ; ; LOOP WOLUME 487 (~145 iters) (-,_5 30 |- f — — @ man FLOW Fig. 1.4.7. Comparison of (g) Sodium Pump Cenfiguration Presently Beling Tested and (b) Modificotions Being Made 1o Mock Up the Recctor System, {Confidential with ception) 37 ANP PROJECT PROGRESS REPORT UNHCLASSIFIED ORNL-LAR=DWG 20878 210 : ‘ 45300 rpm .-."'-'-'_h 200 | e \L — | aeatlls {4400 cpm .- | ‘. 1o | s 5\‘ ! | | 180 — | W ] ‘ gt 4200 rom ‘ ; 1RO — l a w g | 150 - - | r\- ~ 150‘ J-:fl_‘.'l_““ =4 e | ' \Boomm | | 140 - | | 120 L L 1 — e — 300 400 300 0o TO0 aoo LOW RT lapmt Fig- 1.4.8. Performance Dota for Sodium Pump Ob- tained in Development Tests with Water. sodium pump centrifuge operation; will be stested in future with normal however, this point eoperation, Another seal design, which incorporotes larger radial ¢learances between the inner surface of the small ring ond the outer surface of the pump borrel, will be tested with woter. The purpose of this design modification is to reduce the assembly problems associated with the multipie-ring seal. Sodium Pump Endurance Tests P. G. Smith A sodium pump is being operated in an enduronce test with sodium ond has occumviated o total of 1584 hr of operation, during which the pump pot has been thermally cycled 300 times over the 38 UNCLASSIFIED ORNL-LR- DWG 20879 F W o AR SN PR s — L, DESIG\I NG 2 Fig. 1.4.9. Assembly Showing Proposed Multiple-Ring Seal. Partial Cross Section of Sedium Pump temperature ronge of 1250 to 1050°F. The oper- ating conditions for this test ore given below: 1050 to 1250°F Pump pot temperoture Pump pot pressure 8 psi Fump speed Catch basin helium off-gas purge Helium purge down pump shaft 3500 rpm 50 Vitars/ day 500 liters/day It was found that the pump priming dificulties, were could be which reported previously, ! eliminated by stopping the pump when transferring the sodium into the pump pot. Previously, the transfers of sodium to the pump pot were made with the pump rotating at 500 rpm, and anywhere from 2 to 4 hr were reguired to prime the pump. The off-gos line plugging, also reported previ- ously, ’? was found to be a result of too high o liquid level in the pump pot. The pump probes were found to be incorrectly sized. The lube oil leakage rate varies from 5 to 20 cm3/day from the lower seal, and there is no There is, o slight amount of leakage of lube oil meosurable leckage from the upper seal. however, 10p, G. Smith, ANP Quar. Prog. Rep. Dec. 31, 1956, ORNL-2221, p 39. somewhere in the upper seal region. This leakage is not sufficient to be detrimental, and its source cannot be located until the operation is stoppad. Primary NoK Pump Development Tests H. C. Young!! J. N. Simpson ! testing of an ART primary NaK pump,'? designated PK-P-1, wos continued. Performance and efficiency curves obtoined at a NaK temperature of 1200°F are presented in Fig. 1.4.10. As stated previously the data being obtained are in good ogreement with dote obtained High-temperature with woter. UMCLASSIFED ORML—LR—DOWE 20880 s r | 075 4 ; 30 G.74-. i ~0 TS5 0.73- N | 0.?2 i 7 I-O.?45 g 3850 rpm 7‘77/ o4 — = 340Q rpm ‘C'; A50 —— 300 rpm s——ce—— - % 3200 rom I—_.,c 100 rpm —pe———pt_ a . o B 2 300 —gobt rom = & 2900 rpm 250 2800 rpm _ (2700 rom 2600 - . | rp I A i m v SIGN RANGE 152 400 600 BOG 1000 4200 1400 1500 1800 FLOW RATE {gpm) Fig. 1.4.10. Frimary NoK Pump Operating ot 1200°F, Performance and Efficiency Curves for The results of cavitation runs at several speeds and flow rotes at a NaK temperature of 1200°F are presented in Fig. 1.4.11. The cavitation data hod to be taken ot different speeds for each of several censtont flow rates, 1000, 1220, and 1400 gpm, since it was not possible to maintain a constant speed with the wound-rotor motor which has o step-type resistance speed control. The cavitation porameter, o, was plofted against speed ”Dn assignment from Pratt & Whitney Aircroft, 124, c. Young aond J. N. Simpson, ANP (uar. Prog. Rep. Dec." 31, 1956, ORNL-2221, p 47. FERIOD ENDING MARCH 31,1957 along lines of constant flow ond then ogainst flow alorg lines of constent speed. From the latter plot, the suction pressure suppress cavitation over the normal pump cperating range was plotted, as shown in Fig. 1.4.12, for two NgK temperatures, 1200 ond 1400°F. The vapor pressure of NoK increases by 5.33 psi from 1200 to 1400°F, ond the constant spread between o given constant speed line for eoch of the two temperatures is very necrly 5.33 psi. The gos pressure on the pump surge tank is 0.5 psi less than the static suction pressure and therefore con be determined from Fig. 1.4.12, In order to further show the effect of vapor pressure on cavitation, dota were token at o given head and flow rate for NaK temperotures from 720°F, where the vapor pressure is essentially zere, to 1400°F, where the vepor pressure is approximately 7.5 psia. The results of these tests in terms of the cavitation parameter, o, are indicoted by Fig. 1.4.13. If covitation voried only with wvapor pressure at a given pump operatiag point, it would be expected that ¢ would remain constant over the temperature range. As may be seen in Fig. 1.4.13, there wos essentially o constant ¢ at temperatures from 1180 to 1400°F, and o slightly higher but constont ¢ ot 720 and 914°F. It is believed thot the results would be more significant if speed and flow rote were held constant instead of head ond flow rate in order to hold constant impeller inlet conditions, ond therefore additional cavitation data are to be obtained. static required to This pump and its associated loop have now been operated approximately 2100 hr ot temper- atures from 1100 to 1400°F. The rotory element of the pump was removed and inspected affer 1700 hr operction, ond it was confirmed that, as suspected, some NaK had entered the oil caotch basin when the NaK level rose in the pump tank cs the result of ingassing after approximately 800 hr of operation. The pump hod, however, continued to operate satisfactorily for the next 900 hr. A consideroble amount of carben from the oil was deposited on the pump shoft and on the radictor baffles in the pump tank, and thus it was apparent that the oil seol leokage had run down the pump shaft, even though there was a 50-liter/day helium purge from the oil catch basin and « 500-liter/day helium purge down the pump shaft annulus and out the pump tank reflux condenser. 39 CHANGE IM MAXIMUM HEAD {%) UBCL ASSHIED ORML-LAR-DWGE 20884 02 Q44 D46 0.48 Q.20 Q.22 024 0.26 o8 Q.20 o 32 0.34 0,36 Q.38 VALUE OF CAVITATION PARAMETER r RUM FLOW COMNDITION | —| | 1220 gpm, 3280 rpm, 355-f1 HEAD g Il ! 2 1220 gpm, 3447 rpm, 38{-fl HEAD 3 4220 gpm, 2690 rpm, 225-ft HEAD ‘ | 4 000 gpm, 28¢5 rpm, 281-ft HEAD, NG CAVITATION 5 4000 gpm, 2230 rpm, 338-f HEAD Z & 40C0 gam, 3510 rpm, 405-0 HEAD 74400 gpm, 3150 rpm, 295« HEAD - | . & 1400 gpm, 2580 rpm, 168-1t HEAD I 1 | | L 044 0 46 .48 0.50 Q52 0.54 056 VALUE OF CAVITATION PARAMETER Fig. 1.4.11. Cavltation Data for Primary NaK Pump at Yarious Flow Conditions with NaK ot 1200°F. LHO4IY SSFHO0YL LDOIT0dd ANV UNCL ASSIFIED P f. Lh- NG 2088 1400°F Nak e § - 1200 Nak AL RAINIRALIME STATIC SUCTION PRESSURE TO SURPRESS CAVITATION {psig) 300rpm pas f( £ 7 oo I,_,,C—T ! ! i 1 29000pmy” 4 . 7 | 00 000 100 1200 1300 FMO00 1500 FLOW RATE (gpm) Fig. 1.4.12. Minimum Static Suction Pressure Re. quired to Suppress Cavitation of Primary MoK Pump. I+ is believed that a cylindrical riser around the shaft to obove the seal interface will direct the leakage oil inte the catch basin ond prevent leakage down the shoft into the NaK. On the pump being tested the riser was below the seal interface. Further examination showed that there were no signs of rubbing of the impeller against labyrinth seals, even though the pump wos oper- ated cccosionally at conditions well off the volute- balonce line.'3 The impeller ond volute appeared to be in excellent condition. The rotary assembly was reinstalled in the loop, and a test run of 408 hr wos made without the helivm bleed down the pump-shaft annulus. The 50-liter/doy oil catch basin bleed was maintained, The rotary assembly was again inspected, and a very smoll amount of NaK and oil mixture was BH, ¢, Young and M. E. Lockey, ANP Quer. Prog. Rep, March 10, 1956, ORNL-2061, p 48. PERIQD ENDING MARCH 31,1957 UNCLASSIFIED ORNL=~LR-DWEG 20883 O | | '2 & - I 2 4 2 | L | | = | = E & | = 3 - = = | wog | | Ha¥X TEMPERATURE o L 4 RN AND FLOW COMDITIONS 7 {3 4400°F, 1200 gpm, 3417 rpm, 379-ft HEAD k2 12 914°F, 1200 gem, 3405 rpm, 364-ft HEAD b L 1 T20°F, 1200 gom, 3380 rpm, 347-ft HEAD . 10 1285%F, 1225 gpm, 3370 rom, 368-~1t HEAD | 2 M8O°F, 1205 gpm, 3365 rpm, 37011 HEAD | ian S e _ o4 G1s 08 020 0.22 0.24 0.25 YALUE OF CAVITATION PARAMETER Fig. 1.4.13. Cavitation Data for Primary HaK Pump ot Yarious NaK Temparotures. found in the oil catch bosin, but its presence had not affected the oil seal leakage purge system. The impeller surfaces had an etched appearonce, but approval for further operation was given by the metallurgists. The critical dimensions of the rotary assembly were measured before and after this test run, ond it was found that all dimensions had remained constant, except the volute mouth, which had opened up from 0.003 to 0.010 in., probably because of stress relief and pressure stresses, An additional test is plonned to provide further data on operation without a heliuvm bleed down the pump-shaft annulus. Heat removal from the pump bearrel by the lubri- cation and cocling oil was measured at several NaK temperatures ond liquid levels in the pump tank. At lubricating and coeling oil flow rates of approximately 3.5 gpm, the heat removcl ranged from 1.8 kw at 1200°F, the normal operating level, to 2.3 kw at 1400°F, the maximum operating level. A resistance type of level indicotor was vsed in the pump tank, and the level recdings were com- pared with the indicoted by spark-plug probes. The resistance tfype of level indicator gave very safisfeciory performance ot temper- otures ahove §50°F. level 41 ANP PROJECT PROGRESS REPORT Auxiliary NoK Pump Development Water Tests H. C. Young Initial water tests were conducted on an auxiliary J. N, Simpson NoK pump with an Inconel impeller in o test loop designated PK-A-1. A single-poss shell-and-tybe heat exchonger was installed in the 4-in. Inconel A 60-hp d-c drive motor was used fo permit constant-speed pipe loop to remove pump power heot. measurements, The performence dota obtained in these initicl tests of the auxiliary NaK pump with an Inconel impeller (No. 1) are compared in Fig. 1.4.14 with dato obtained previously with o brass impeller ond volute.'* At moderote flow rates, the dota correlate very weli, but at high flow raotes the head drops more ropidly for the lnconel impeller thon for the brass impeller. It was suspected that cavitation cauvsed the drop, and the tests were repeated with higher pump tank gas pressures than those which appeared to be normally odequate, My, ¢, Young, J. G. Teague, and M. E. Lackey, ANP Quarp Pfflg- Repo J'Mfl‘fi' IO; Igjfip ORNL'Z‘IOé. P 54' UNCLASSIFIED ORML—LR—~DWG 20884 480 — = | | 400 |—— 3550 pm =a | i - | 930 ! 3450 rpm 3250 rpm ' | DESIGN RANGE 300 — -- S — . ~—— 305;0 rpm=1"" 2950 rpm __.--"i' LA E 260 - 2850 l’?l"fi__ a SPECIAL DESIGN POINT-. T | ‘ 2650 rpm——:.‘ $ 200 | 2550 rpmeg = . 5 T | WATER TEST WITH INCONEL 150 IMPELLER NO.1 | ——— WATER TEST WiTH BRASS | IMPELLER 0o 180G rpm 50 |- | 0" Y N i 2 G 1Qa 200 300 400 LS00 600 [isle FLOW RATE [gpm) Fig. 1.4,14., Parformance Data for Auxiliary NakK Pump Operating with Warer. 42 that is, 25 rather than 10 psig. remained the pressures. The pump heac same, however, at the highes The discharge opening of Inconel impeller No, 1 was approximately 10% smaller than that of the bross impeller, ond Inconel impeller (No. 3), with dimensions very close fo those of the brass impeller, was tested. The results were the some as those obtained with Inconel impeller No. 1. All performence dota were token numerous times, and it is possible that the lack of correlation was caused by a difference in dimensions of the Inconel and the brass volutes or by a slight change in impeller inlet geometry. The wvariance is considered to be insignificant over the normal opercting range of this pump. More cavitation data were obieined for this pump operating with water thon for any pump tested thus far. The Inconel impeller cavitetion performance, therefore another Fig. 1.4.15, compared fairly well At 300 gpm the cavitation parameters were practically identical for the brass and Inconel impellers. At higher flow with that of the brass impeller. rates ond speeds, the parameter was somewhat greater for the Inconel impeller and probably reflected fobrication differences between the brass UMCLASSIFIED ORML-LR-DWE 20885 0 . 1 ferre— 2 — — 3 e - — - { F o4 L ]t o I w5 F L I = 5 6 } z | i 27T : = o B : e || ] tr,J F INGONEL IMFELLER | 5 | 8 ——— BRASS IMPELLER r 9 T | ' c| 10 - — - — CURVE FLOW CONOITIONS AND WATER TEMPERATURE " A 2960 rpm, 300 gpm, 280.0-1 HEAD, 190°F 12 8 3353 ipm, 430 gpm, 340.8-1t HEAD, 140°F ' ¢ 3373 /pm, 430 gpm, 347,311 HEAD, 140°F 13 1 - == =; 006 008 QG o2 014 0,16 C18 VALLE QF CAVITATION PARAMETER Fig, 1.4.15. Cavitation Data for Auxiliary MaK Pump with an Inconel lmpeller Operating with Warer Compared with Dato Obtained with o Brass Impeller. and Inconel vones. On the basis of these tests the covitotion perfermance of the Inconel impeller is considered to be entirely satisfactory for oper- otion with NaK over the ART design range. Some additicnal date will be tcken, however, to assure adequcte information for comporison with dato to be taken with NaoK, Bosed on earlier experience with the primary NoK pumps, 1*a % _-in.-dia hole was drilled through the top of the discharge pipe inside the pump tank to permit gas trapped in the discharge line during filling to be vented. This vent permitted satis- foctory pump priming. In order to further determine the effectiveness of this vent, a section of piping was instalied in the discharge Jeg of the test loop to deliberately trop any quontity of gos up to o valve of 0.45 t3. A series of pump priming tests was conducted wherein the loop was filled ot 0 psig with 0.45 #13 of gas tropped in the loop. The pump tank gas pressure was then raised to 15 psig before ottempting to stur‘tlfhe pump, A foter series of tests was alse conducted wherein the gas pressure was raised to 15 psig before the loop was filled so thot twice the previous amount of gas was trapped. In ofl coses, it was possible to start and fully prime the pump by following the starting and stopping technique described below. The pump is brought to an operating speed of 1800 rpm (this speed represents the first control step speed on the wound-rotor drive motor) ond operated ot thot speed until the discharge pressure drops slightly, which indicates that gas has entered the pump, and then the pump is stopped. This procedure is repeated until the dischorge pressure no longer drops. The average number of startup attempts required ranged from a minimum of seven for the first series of tests to 17 for the later series of tests with twice os much trrapped gos. |t appears that with this technique the pump can be started with troepped gas in the system, ond it will not be necessary to vecuoum-fill the loop. 15y, C. Young and J. G. Tague, ANP Quar. Frog. Rep., Sept. 10, 1956, ORNL-2157, p 43. PERIOD ENDING MARCH 31,1957 REACTOR COMPONENT DEVELOPMENT TESTS D. B, Trauger Heat Exchanger and Rodiater Development Tfists J. C. Amos 2 L. H. Devlin'é R. L. Sean D. R. Ward A summary of fuel-to-NaK heat exchanger and NoK-to-oir radiotor test operations during this quarter is presented in Toble 1.4.2. Process Engineering heot exchanger No. 2 (type SHE-7) and Black, Sivalls & Bryson radiator No. 1 com- pleted 1456 hr of nonisothermal operation, including 552 hr at o heat exchanger fuel inlet temperature of 1600°F, and 29 thermal cycles, in SHE test stand B."7 The test was finally interrupted by o NaK leak in the circulating cold-trap economizer ofter o total of 1845 hr of operation. At the time of the interruption, the test was opercting on the tenth step of a 15step progrom '8 for obtaining data on mass transfer in the NoK circuit. The cenditions imposed on the heat exchonger hod been suf- ficiently severe, however, that it wos decided to terminate the test rather than tc complete the mass-transfer study progrom. Dota covering the range of interest hod been obtained and further operation would only have provided more inter- medicte and check points. Anolyses of the data obtained during this test ore being made. The heat exchanger is being examined metallurgically, and the economizer, which had operated in this stand tor o total of 6490 hr, is also being examined to determine the cause of failure. The test stand (SHE-B) is being modified to accommodate a 20-tube, heat ex- chonger, designated *'small heat exchanger type SHE-9'" (Fig. 1.4.16). The dimensions of this semicircular ]'601'1 assignment from Prott & Whitney Aircraft. 7 The design of haat exchanger type SHE-7 is illus- trated in Fig. 1.4.5, p 50, of ANP Quar. Prog. Rep. Sept. 10, 1958, ORNL.2157; the design of radiotor Ne. 1 is the same os thot of rediator Mo, 7 shown in Fig: 1.4.8, p 60, of ANP Quar. Prog. Rep. June 10, 1956, ORNL-2104. 18), ¢. Amos et al,, ANP Quar. Prog. Rep. Dec. 31, 1956, ORNL=2221, p 43 43 144 COMB SPACERS MoK QUT FUEL IN MATERIAL . INCONEL 57 i ORNL-LN-UWG 20886 b -20 TUBES (Q.2315-n OD, 3025-n WALLS) - . '_l i Ju-.__g 3 / 3()5:5"54|n. e e - *, I".___.-___l|r_ * Ziafa—in R ot | ' SECTION A4 // d HEAT EXCHANGER SHELL=" '| / | — Nok HEADER | | ifi-l Rt LW HEAT EXCHANGER 0 | k |;._,,-E ¥ TUBES ! L ), NeK IN & | L= -*"- i J— ' l FUEL HEADER- l FUEL CUT Fig. 1.4.16. Semicirculor Heat Exchanger Designoted “'Small Heat Exchanger Type SHE-2.'" 103 SS3HH0Hd LITFFCUd dNY PERIOD ENDING MARCH 31,1957 Table 1.4.2. Summory of Heat Exchonger and Rodlator Operntlons Hours of Total Mumber Tast Unit Tast Naonisothermal Hours of of Thermal Status of Test shand Operation Operation Cycles Process Engineering Corp. SHE-B 1456 1845 29 Terminated because of foilure heat exchanger Na. 2 of circulating cold-trap {type SHE-7) economizer Black, Sivalls & Bryson IHE-B 547 911 5 Test completed heat exchonger Mo, 1 {type \HE-B) Black, Sivalls & Bryson tHE-B 547 211 5 Test continuing heat exchanger MNe, 2 (type IHE-8) York Corps radiator Mo, 11 iHE-B 547 211 5 Test continuing York Cerp. radiator No. 12 IHE-B 547 o11 5 Test continuing Black, Sivalls & Bryson SHE-RB 1456 1845 29 Terminoted becouse of failure radiator No, | of circulating cold-trap econemizer {operated in con- junction with Process Engi- neering Corp. heat exchanger Na, 2, abeve) heat exchanger, which is being fabricated of sl ORNL-LR-OWG 20887 Inconel, are given below, ond the proposed oper- 325k ating conditions are presented in Fig. 1.4.17, 1500 °F MoK~ TG0 IR 1070 °F SZpva RADIATOR 15 pig Tube material Inconel Number of tubes 20 BFy 5T 32510 | Vapsig Tube cutside diameter, in. 0.2315 pr-\:::p o Tube inside diameter, in. 0.1815 Re o = 109,000 : Tube woll thickness, in 0.025 e NMeK flow length, ft 6.138 D Py = 150310 NaoK free flow area, f12 0.00358 BT ek = 430 °F NaK side heat transfer area, f? 5.74 L1 W o TN 7 . e 1070°F Spacer dimensions, in. 0.018 x 0.040 2 erg FUEL-TO-NoK 3a.2 0810 Spuocer arrangement 45-deg stagger 16O0°F HEfliE_KETEG_EE___ 1250 °F 0-deg incline 36 95”9_-_ t3psin Number of spocers 14 arF”El‘2350fF 8Ppyp * 21 psig Fuel flow length, ft 5.05 Fuel free flow areaq, £2 0.Q036 ¥ fopsia Fus!l side heat transfer oreq, fr? 7.32 Regye = 2790 FUEL | 7840m Fuel equivolent diameter, ft 0.0090 Bl - €l y This heat exchanger was designed to simulate i o the tube geometries of the ART main heat ex- e Rfilgfig{x st ‘ i 3B osig 40 psag changers, The heat exchanger will be subjected i to a thermal-cycling program in order to verify the stress onalysis of the ART meoin heot ex- Flg, 1.4.17. Operoting Conditions for Semicirculor changers. Smecll Heat Exchanger Type SHE-9, 45 ANP PROJECT PROGRESS REPORT York Corp. radiator No. 15 was installed in SHE test stand C for operation in conjunction with Process Engineering Corp. heot exchanger No. 3, type SHE-7. When test operations were storted, proper NaK flow could not be established. The loop was drained, ond examination revecled that the cold-trap economizer inlet and all but four of the radiator tubes were plugged with oxide. The oxide had apparenily been deposited in the main NaK piping at the end of the preceding test,'8 which, as described above, was terminated because of a failure of the cold-trap economizer. When operations were resumed, the oxide was trensferred to the new rodiator and o the economizer inltet York radiator No. 15 has been replaced with York radiater No. 16, and all NoK piping con- taining oxide hes either been replaced or steom line. cleaned. Operation wiil be resumed to obtain information on the heat transfer and corrosion characteristics of o typical system when operating with NaF-ZrF ~UF, (56-39-5 mole %, fuel 70). York radiotor ldc:-. 15 has been thoroughly cleaned and will be installed in SHE test stand B as the heat dump for the test of the semicircular heat exchanger, The first part '8 of the endurance test of Black, Sivalls & Brysen heat exchangers Nos. 1 and 2 {type |HE-8) was completed in IHE test stand B. The test included 503 hr of operation of heat exchonger No. 1 with a NaK inlet temperature of 1700°F and the other conditions of temperoture, pressure, and flow rate shown in Fig. 1.4,18. The NaK pressure drop through heat exchanger No. 1, calculated on the basis of constant flow, increosed to approximately 5.4 times the initial level, and the NaK pressure drop through the radiator increased to approximately 1.3 times the initial level. These pressure drop increases in the NaK circuit ore attributed, as before, ¥ to the byuildup of mass-tronsferred materigl in the small-diometer tubing of the test units. Black, Sivalls & Bryson heat exchanger No, 1 is being replaced by Black, Sivalls & Bryson heat ex- changer No. 3, which is of the some type os No, 1. Endurance testing of heot exchonger No. 2 will continue during the second phase of the test. However, detailed progroming for the second phase ‘IQJ‘ W. Cooke ond H. C. Hapkins, ANP Quar. Prog. Rep. Sept. 10, 1956, ORNL-2157, p 46. 46 ORNL-LR-0WG 20820 toK-TO=AIR RADIATORS YORK NOS. 11 AN 12 1265 °F 5.2 pagliNTiaL] 12,831l FIMAL) e o = ad z@ ¥ FuE 474 psig LIMITIAL) w|E 2 S =|R VEL 46,1 psigIFINAL) g 2 T8 PuMe e < e s a - - in o é_' 1200%F sa T o b T T vo 26.4 perg{(INTIAL) 250 palg [FINALY FUEL FtOW mWaK FLoW 8,500 B e HINITIALY 20800 oo (FINALY FUE:=TO=-Mok HEAT E¥CHANGER BLACK, SIVALLS AND BRVSON NO 2 (TYPE {HE-E} 33,000 Bsnr (INITIALY 14 OO0 Wrne ITINALY Mok - TO-FUEL HEAT EXCHANGER BLACK, SIVALLS AND BRYSON NC Y [TYPE {HE-3) 1600 °F 369 pmg UNITIALY 358 psiglFINAL) 1500 °F N HEATER 1700 F [GAS-FIRED 42 5pug(INITIALY FURNACE ] 38 palg[ATEAL) 44 5 psig{FINAL] AGBSg{FINALY Fig. 1.4.18, Endurance Test of Black, Sivalls & Brysan Heat Ex- chongets Nes. 1 and 2 (Type IHE-B). Operoting Conditions During 503-hr of the test will not be established until the resulits af the metallogrophic examination of heot ex- chonger No. 1 are known. ART-prototype test rodiater No. 1 was received from York Corp. during the quarter. It is currently being modified by slifting the fins as shown in Fig. 1.4.19. These meodifications were recom- mended as the result of recent detailed stress analyses of this radiater design., Tests of this unit will be started soon. Water Flow Tests of Aluminum North-Head Mockup R. Curry 20 J. W. Cooke?? Additional tests were run of the ART twin fuel pump system as port of the water flow tests of the aluminum north-head mockup. For these tests the pumps incorporated the improved model 32 impellers 209, aossignment from Prott & Whithey Aircraft, PERIOD ENDING MARCH 31, 1957 _’; UMCLASIFIED | PHOTO 17484 T— o - - HRE -." I nl.hi.-'-{:----"'"." - o | f bl RN ”'rs-.-‘-“"" oy Fige 1.4.19. ART-~Prototype Test Rodiator Ma. 1 Showing Lines Where Fin Matrix Has Been 5lit to Reduce Stress Concentrations. [Confidential with caption) described previously.?! With the improved im- pellers the liquid spraying and sloshing noted previously in the expansion tank and the resuliont weting of the tank ceiling were greatly reduced because of the reduction in the gross inflow to the tank. Ingassing of the main circuits with one pump stopped and the other still ruaning was not appreciably different with the improved impeller, and flow-rote fluctuation and pump suction pres- sures remoined essentially unchanged. With the bypass loop connecting the pump suction pipes wide open, stopping one pump with the other stil] running cauysed the total flow through the external main loops to be reduced by a factor of . How- ever, the flow continued in the normal direction in 2y, E. lockey, G. Samvels, and J. 1. W. Simon, ANP Quar. Prog. Rep. Dec. 31, 1936, ORNL-2221, p 33. each external main loop with no reversal, and the Hlow rote in the external main loop of the stopped pump was 7'.:"]0 that in the external main loop of the operating pump. One significance of this result with regard to reactor operation is that any tendency for local overheating in an inrermediate heat exchanger tube bundle wouyld be minimized following stoppage of one-half the fuel, sodium, and NakK pumps. The model 32 impeller has greatly reduced the problem of liquid rising in the shoft eanulus. With the criginal impelier, liquid rose inte the shoft annulus of a pump which was stopped if the other pump was still running. In tests of the new impeller over o wide range of pump speeds and gos flow rates down the shoft annulus, the only instance of liquid rising up the shaft annulus upon stoppage of one pump occurred when the 47 AMP PROJIECT PROGRESI REPORT gas inflow was cut off completely; and even then more thon 30 sec elopsed following pump stoppage belore water wos detected 0.4 in. wp the annulus, the lowest sensing point. In operation of the reactor, the reactor dump cycle would be under way within this period if o pump stopped. During the quoster the entire moin loop circuit was sant fo the Hydroulics Laboratory of the University of Tennessee for calibration of the external moin loop orifices. This calibration showed arifice coefficients 2 to 3% less than the accepted values, and also showed no variation of the cosfficients with external main loop valve settings in the range of interest, A special test was colso performed in which water was pumped inte the common purp discharge pipe at o rate of 1300 gpm, and ony Huctuctions of mein loog erilice differentiol pressures were observed. Sewvercl repetitions of this test yielded ditferent reswlts, In abaut hall the runs no fluctuctions were ohserved. In the other runs fluctustions of on orifice diffarentiol pressure, similar to those observed with the complete oluminum test rig, ware observed. In these University of Tennessee tosts, woter was supphied by two dissimilor pumps vperating in parallel, und one of the pumps weos known te be subject to some instebility in the operating region of interest, The purap wvolutes in the twin pumps ware carefully exomined while thaloop wos disassemblad for the colibrotions described ahove. Differences in the design of the volutes in comparison with the voiute design specified for the reacior were noted, ond the cluminum volutes were modified to more closely resemble the reactor pump wvolutes. Both the orifice calibration and the rewarking of the wveolutes were undertcken in the hope of eliminating an apparent loss of 10% of pump sutpu? How rate at design speed and head compured with the output ocbserved for the same impellers in the single pump high-temperature test, Dump Yalve Development Tests l. T. Dudley M. H, Cooper?? Prototype Vaolves: ~ A summary of the tests conducted this quarter on ART prototype dump valves is presented in Table 1.4.3. One prototype MOH aszigoment from Proty & Whithay Alrcrals, Table 3.4,3, Opercting Conditions and Results of Prototype ART Dump Valve Tasts veith N::F-"Z:'FJUF“ {50-48-4 mole %, Fuel 30) Volve temporature: 1 iVt s Fressors difforential across seot: 50 psi Yolve 40C Volve 5B Valve 5C Seat moteriol K18 1A Copper Copper Flug material K-1ETA Malvbdenum Molybdenum Operoting time, hr 1500 4 30 1100 Mumbar of eycles 50 3 36 Stem closing facen, 1b 750 754 1000 Stem apening force [max}, Ib féd 1850 2520 Leckage rore, c:nE,f ke During first 25 eycles {av} 1.4 i .5 During 500-hr closure {av) 1.2 0 Curing logt cycling pariod {ov) 2.4 2,5 Maximum during tasy 506 0.6 &7 valve was received during the latter part ol the quarter from Block, Sivalls & Bryson, designated valve No. 6, which incorporates a swiveled piug. Since the swiveled plug design is now considered to be unsatisfoctory, leakage rote tests will be made on this volve with water only. The two available test stands will be used to test only valves which have rigidly mounted plugs ond which incorporate other refinements now con- sidered to be essential for the suvccessful oper- ation of this volve design. Valve 5B, which had @ rigidly mounted, spherical molybdenum plug and a conical copper seuat, exhibited negligible leakoge during the first 23 operoting cycles. The test of this valve wos terminated after 430 hr because the bellows ruptured while the valve was closed. The bellows is composed of stamped Inconel disks welded together at their inner and outer peripheries, and foilure occurred at an peripneral Preliminary metallographic inspection showed that the failure was located at the point of fusion between the weld bead and the disk. Some scattered impurities were observed in this orea which may have contributed to the failure. The pressure differential approximately 3 psi and therefore not high enough inner weld., across the bellows was to couse direct stress failure, Valve 5C was assembled by using refinished parts from valve 5B. The conical surface of the seat was remachined and the spherical surface of the plug was polished, The high initial leokage rates that occurred when tests of volve 5C were started made it necessary to use ¢ stem closing force of 1000 Ib. The average leakage rate was 0.5 em3/hr during the first 25 operating cycles with this stem force., No measurable leckage occurced during the 500-hr closure test, and teakage rates during eleven oaperating cycles since the E00-hr closure test hove been erratic, with on average of 2.5 e¢m3/hr. The leakage rate has increased raopidly since the thirty-third operating cycle. This valve hos now been operated for 1100 hr, and the test will continue until an oper- ating time of 1500 hr has been reached. Valve 4C, which had a rigidly mounted, spherical Kentanium cermet {K-131A) plug and @ conical Kentanium cermet {K-151A) seat, was tested for 1500 hr ot 1300°F. The average leckage rate during the first 25 operoting cycles wos 1.4 em3/he, 1.2 em=/hr during the 500-hr closure test, and 2.4 cm3/hr during the last 25 operoting cycles. Relatively low stem forces, 500 to 864 Ib, PERIOD ENDING MARCH 37, 1957 were required for opening this valve. This valve is to be tested again with the diametrical ¢clearance of the inner stem guide increcsed from 0.008 to 0.080 in. This valve has given the best over-all performance of any valve tested to date. A valve of o modified design is being fabricated for testing. The new design incorporates o backup bellows to supplement the seal bellows and im- proved stem-alignment control. Also, a valve that will have o spider guide mounted in the end con- directly obove the seor ring is being assembled to determine whether volve alignment nection can be improved by guiding the plug at a point as close to the seot as prociical. Kentonium 162B inserts are being used for the bearing surfaces of the guide. "“InsLine” Valve Operaters — A simple rig has been set up for tests of the Philadelphia Gear Works “‘in-line’’ actuater that is to be used on the ART NaK valves. The test assembly consists of a stmuloted valve on which the actuator is mounted and on opposing actuator that is vsed to determine the “'in-line’" stem thrust. Provisions are made for heating of the simuloted valve body to determine the effect of temperature on the actuator operating characteristics, Seat Materials, ~ Twelve seot and plug materials combinations have been tested?® thus for in NaF-ZrF -UF , (50-46-4 mole %, fuel 30), and three other combinations are being tested. The tests compteted during the quarter and those now under way are summarized in Table 1.4.4. One of two test stands was modified for use with NaK, ond tests with NaK are under woy. The seat and poppet cembinations tested are described in Table 1.4.4, The 1500-hr test of each combination consists of 25 opening and reseoting cycles, a 500-hr closure pericd, ond, firolly, 25 opening ond reseating cycles, Two cermet combinations, K-151A vs K-152B and KM vs 162B, have given the mest satisfactory results. The compositions of these cermets are {in wt %): M 20 WTiC2—10 Co K-151A 70 TiC-10 NbTuTiC3-..2(1 Mi k-152B 64 TiC=5 NbTaTiCa—EU M3 K-162B 64 TVC-6 NbTuTiC3—25 Ni—5 Mo 23p0; results of previous tests see Toble 1.d4.6, p 50, ANP Quar. Prog. Rep. Dec. 31, 1956, ORNL-2221. 49 ANP PROJECT PROGRESY REPORT Takle 1.4.4. Conditlons ond Results of Tests of ¥alve Seat ond Plug Materiols Al motsrials tasted in NoFquFéflUFd [50-A6=4 maole %, fuel 30) sxcept us Indicoted . ol Operating Volve Mo E 3eat Ve Time Tamperature Bmwer @ {omments Moterial Meoterial (hrl {z; Fy Cycles e W 1875 1306--1500 7 Terminoted for exomination; leokage high elter cyching K-54 K94 L5460 1300 hd Tarminoted for pxomination; leokoge high KMallory Maliney tan 1300 21 Terminated for sxamination; teakage high TR0 1006 after cycling Cu Ma 1538 1300 41 Cperatisg K-1628 KM 1001 1300 31 Operating; no leokage at oay time K-15%8 K~162B 172 1300 2 Tarminatad becouse of misclignment fricangl Stellite & 694 0040 11 Oprrating; lzokage high; test Hluid s NoK Ka1528 K-1514 41.5 1300-- 1500 3 Operating K-162E KM Being installed The leokage of the K-1514 vs K-152B combi- Februory. The fest piece is o quarter-scole mode! notion, tested previous!y,” wos less thoan 1 am3/hr during the test; the KM vs K-162B combi- nation, which is still in cperation, has shown neo The wcpening force after the 500-hr closure of 1300°F wos 700 lbh for the K-151A vs K-152B combination ond 900 b for the KM vs K-1628 combinstion. A phetogroph of the KI5YA vs K-1528 combinotion ofter 1549 hr of operation in NoF-ZeF -UF (50-46-4 mole %, fuel 30) of 1300°F is presented in Fig. 1.4.20, Subsequent tests will be performed o determine leakoge. the choracteristics of these materials ot higher temperatures. A Stellite plug ond lnconel seat combination is being tested with Mol ot 1000°F. Mo self-welding of the materials hos been experienced, but the leakage haos for example, 40 cm3/he ot o S50-psi diffsrenticl pressvre ocross the seat. Two KM vs K.15628B combinations ave being instolled for testing in Mal(, been excessive, Ouser Core Shell Thermat Stability Tes? 4. . Amos L. H. Devlin The secend of the two proposed thermal-siability tests of the outer core shell was started in 50 of the bottom half of the ART outer core shell, The test program censisis of three hundred cycles, with each cycle of mognitude comparable to those generated by an ART power cycle between zero and full power. The test thermal cyole comprises 1 hr under o temperature gradient and 1 hr of isothermal oper- ation at 1200°F. The fransient time 15 [0 min, Internct thermocouples iadicate the wall temper- atyre at both ends of the shell. During the temper- oture gradient phase of a cycle the ftemparatures Qre lrner sodivm antronce 15707 F lrwner sodivm axit 1250°F {Ivfer sodivm exit 1075°F Guter sadium antrance 1010°F The ogperoting conditions are thus approximately the same as those for the first test, 24 in which The twe sodium streoms, which flow countercureently the chell suzcessfully endurad 300 cycles. Mg, R, Dvtko et al., ANP Quar. Frog. Rep. Dec 31, 956, GRMNL~2221, p 55 LCL Agsal LD T (5] brat M < 0 I Fig. 1.4.20. Kentanium Cermet X-151A Plug and K-152B S5ear After 1549 hr in NuF-Ier-UF‘l (50-46-4 Mole %, Fuel 30) ot 1300°F. over the shell, serve as the heat transfer mediums. Bursting pressures of 26 and 4 psi exist across the shell at the bottom and top, respectively. Prior to the final assembly of the test housing, the dimensions of the inside surfoce of the shell were carefully measured. The measyring procedure wos the same as that used on the first shell,?® except that a bead of weld material (to serve as a reference point) wes placed on the large end of the shell rather than on the housing, as in the first test, Relecation of the reference point resulted in more gcfurate measurements. Sodium Circuit Water Flow Tests S. Kress 2 R. D. Peak 26 Many regions in the ART sodium circyit which are difficult to onalyze are being individually 25, Curey and A, M. Smith, ANP Quar. Prog. Rep. June 18, 1956, ORMNL-2106, p 65. 280n as signment from Pratt & Whitney Alrcraft. PERIOD ENDING MARCH 31,1957 tested in mockups?? in order to determine the pressure drops. Three of these regions were tested this quarter. Since the heot loads, lengths, ond entrance conditions of the five rows of cooling holes through the beryllium reflector are different, the sodium flow through these cooling holes must be controlled to achieve a uniform temperature pattern throughout the beryllium. A conveniens method of contrel is to erifice individual holes ot the beryllium equator joint with ¥-in.-thick orifice plugs. Such plugs with orifice holes of 0.0595 to 0.1875 in. in inside diometer were tested, The results of the tests are shown on Fig. 1.4.2] as pressure loss coefficients, which include the total loss for the entronce orifice and 4.56 in. of hole length, vs the orifice diameter. A range of orifice sizes was tested, with the smallest orifice in the reflector cooling hele reducing the flow to obout 20% of the flow with the lorgest orifice. As the result of an error in machining the first sovthern hemisphere of the beryllium reflector, holes 29 to 71 in the secend row from the center s, Kress and R. D. Paok, ANP Quar, Prog. Rep. Dec. 31, 1956, ORNL-2221, p 58, UNCLASSIFIED ORNL—LR—DWG 20889 200 T 'y T T T | ' ‘ | I \ PRESIURE TAP e ) 11 WATER IN 4~ OORS | ] o b EQUATOR | 0.38-in-00, ; JOINT Sg-in -THICK - | ] ORIFICE PLUG : QIBT5m 1D i— PRESSURE TAP WATER GUT | SET SCREW FOR =™ PRESSURE CONTROL DiaGRam OF TEST ASSEMELY [ ; . 20 — PRESSURE LOSS COEFFECIENT (dimensionless) ) L r e WITH O 24Bin == — = CMISALIGNMENT =1 Ik s | 1 = Equp,r()n -DIGMETER OF 11— — JOINT COOLING HOLES, _ avigNEp—" AT GBS In —{ | ) | | | | 1 B el 1YL I i b o005 o4 0.2 0.5 f 2 QRIFICE DIGMETER (in) Fig. 1.4.21. Pressure Loss Coefficients vs Orifice Digmeter ot Retlector Equater Joint. 51 ANP PROJECT PROGRESS REPORT were drilled 0.218 in. circumferentially off align- ment. This misalignment will introduce an extra heod loss ot the equotor joint, but it can be compensated by proper selection of the orifice size. A second series of orifice tests was run to determine the effect of this misalignment on the less coetiicient. The results of these tests are also shown on Fig, 1.4.21. Another test involved a full-scole mockup of one-half of the symmetrical sodium circuit in the reflector entrance regicon where the sodium supply to the retlector flows down frem the two pump tees, impinges on the c¢ircular boron cons, and spreads out over the top of the reflector and the core shell. The wooden test model of the top of the beryllium reflector with the circular boron- containing can in place and the spacer bars assembled is shown in Fig. 1.4.22, and Fig. 1.4.23 shows the model with the boron-containing conicol T . gk « ! . = COOLING HOLES J\‘L' CIRCULAR BORON— CONTAINING CAN = \"‘ ® é - ring and the pressure ring in ploce. This model was fitted inte aon aluminum-inconel-Piexiglas piece that simulated the underside of the Inconel north-head shells just obove the reflector, The head loss in this reflector entrance region at the design flow rate of 1.28 fi3/sec was found to be 3.0 ft compared with an estimated 7.5 i1 The relotive tlow distribution through the beryllium cooling holes was obicined by measuvring the height of the water jet from each hole with the complete test assembly turpned upside down, and loss coefficients (Fig. 1.4.24) were calculoted for each hole based on the jet height ond the hole orientation shown in Figs. 1.4,22 ond 1.4.23. The measurements showed that the cooling holes on the shoulder around the pis-shaped depression in the reflector carry much less flow (2 to 3 times) than the rest of the holes. URCLASSIFIED PHOTO 27347 : - NS SPACER BaRS I & —F’_,_-,'fll"""" — Figi ].4.22- and One-Half of the Cooling Heles, 52 Wooden Model of Top of Reflector Showing the Boron-Centaining Ciccular Can, the Spacer Bars, F igl 1 14-231 Assembly. A water test was also conducted on a proposed bypass slot in the north-head sedium circuit. This slot is to be cut between the sodium-to-NaK heat exchanger shell and the external pressure shell of the reactor to allow some sodium flow to byposs the present slots between the pressure shell ond the upper-deck outer shell and ta give o more direct entrance for flow into the heat exchanger inlet. The slot tested, shown in Fig. 1.4.25, was approximately 5 in. wide, 0.8 in. long, and 0.1875 in. high. The Plexiglas top represented the pressure shell. The lcss equation for this slot, os determined experimentally, is V'I.'i)? AH = 1.4 ——, 2g PERIQD ENDING MARCH 31, 71957 UNCLASSIFIED PHOTOQ 275%% Wooden Model of Top of Reflector Showing Boren ¥ *\::\ : II TfiR 0 A, wp PRESSURE TAF Fig. 1.4.25. Diagram of Nosth-Head-5lct Test Piece. The Inconel-nickel ‘‘gun-barrel’’ thermocouple, described previously,?? may be used to measure sinusoidal wall-temperature omplitudes in ¢ ]f2-in.- dio, Y-in.-woll, Inconel tube for several surface heat transfer coefficients, The results of experi- ments with a film heat transfer coefficient of 3140 Btu/hr-ft2.°F cre compared with the Jakob equation®? in Fig. 1.4.26. The deviation of the experimental results from theoretical moy be coused by perturbations of the boundary layer as o result of slight thermocouple protrusion (~0.002 in.) or by entrance region effects. The thermo- couple was located about 30 diometers downstream, which was not far enough awoy from the entrance for uniform turbulent flow 1o be definitely es- tabli shed. Measurements of the oxial fluid temperature amplitude ettenuaticn in turbulent flow through o straight tube as a result of heat exchange with the tube wall were made for comparison with theo- reticel predictions for metal and plastic wolls. In addition, the results enabled an estimate of the wall attenuotion ratic te be made, independent of direct wall measurements, which is in reosonable agreement with the Jokob equation. This work is being continued. 29, E. Mott and A. G. Smith, Jr., ANP Quar. Prog. Rep. Dec. 31, 1956, ORNL-2221, p 54. 304, Jakob, Heat Tramsfer, vol 1, p 298, Wilsy, MNew York, 1949, PERIOD ENDING MARCH 31,1957 UK LASSHIED ORBL-LR—-0wS 20892 0.8 Q.7 05 W a3 - 4 oz ! Q FREQUERLCY [cps} Flgl ]|4-26| the Fluid Temperature Amplitude, ., os a Function of Raotic of Woll Temperature Amplitude so the Frequency, /, of the Thermal Cycle Imposed on the Fluid for a Thick-Walled lnconel Tube with a Film Heat Transfer Coefficient of 3140 Brux’hr-fiz-oF. High-Frequency Thermal-Cycling Test Loop A. G. Smith, Jr.3! The high-frequency thermal-cycling test loop, described previously,?? was completed, and Fig. 1.4.27 shows the pulse generator, pulse pump, ond test piece. The pulse generotor consists of two pistons which produce helivm pressure pulses 180-deg out of phose. These pressure pulses are transmitted to the pulsers which force olternate hot and cold slugs of fluid through the test piece, A helium bubbler type of level device is used to record and contrel the fluid level in the pulse pump. The maximum aond minimum fluid temper- atures will be 1650 ond 1150°F, respectively, 3o, assignment from Prott & Whitney Aircraft, 55 ANP PROJECT PROGRESS REPORT Fig. 1.4.27. High-Frequency Thermol-Cycling Test Loogp, 56 to give o maximum pulse-amplitude fluid temper- oture of 1250°F. The frequency of these pulses can be varied from 0.5 to 10 cps. The maximum flow onticipated is 12 gpm, which will permit o calculated heat transfer coeflicient. of 5500 Btu/ hrf12.°F in the test section, @ :'}é-in. sched-40 pipe. Most of the contrel panel is shown in Fig. 1.4.28, including the gas panels for both the high- ond low-temperature loops and sumps, clarm and motor control panels, and two of the four Yariac cabinets. There are two 14-point Brown temperature recorders, and each contains an integral high- or low-temper- aturg alorm os a safety measure. These recoerders will menitor the 150 thermocouples mounted on the loop. The four Varioc cabinets contein 42 seporate control circuits for preheating and for normal The 250-kva tronsformer for main {cop resistonce heot ond the auxiliory gas secondary hecting. panel are not shown. The loop has operated sotisfoctorily at design specifications with woter, and dota are being taken on temperature .amplitudes at the test section as a function of frequency and flow rate. This infor- mation will form a bosis for high-temperature operation. Some control difficulties have occurred during startup and shutdown, but these are being eliminated, The woter tests will be continued vntil therough fomiliorization with the operation is achieved. Cold Traps ond Plugging Indicators R. D. Peak D. A. Gardiner Plugging indicators are required in each of the eight NaK cold-trap circuits of the ART to monitor the sodium oxide level. The plugging indicater proposed for this serviced? is essentially the same as the type which has been used successfully on all the heat exchanger test stonds during the past two years. Since the plugging indicators used in the heat exchonger tests were never calibrated, calibration tests of an ART prototype plugging indicotor were conducted. A cold-trap test stand®? was used for these calibration tests with the ART plugging indicetor mounted vertically in the stond, 32R. D. Peok, ANFP Quar. Prog. Rep. Sept. 10, 1950, ORNL-21587, p 57, 33R, D. Paak, ANP Quar Prog. Rep. June 10, 1956, ORML-2104, p 63 PERIOD ENDING MARCH 31,1957 The results of o typical test with the ART plugging indicator are shown in Fig. 1.4.29. The test is started by turning the Calrod hearer off ond the cooling air on so that the NaK flowing through the plugging plete gradually cools. At a certain tempercture the NaK flow rate storts decreasing abruptly because precipitated oxide has begun to plug holes in the plugging plate. This temperoture, called the bregk temperature becaouse of the change in tlow rate, is on indication of the oxide content of the NaK. After the breck temperature is de- termined, the air is turned off and the Calrod is turned on in order to disselve the precipitated oxide, All plugging indicator tests were made at o nominal NoK flow rate of 0.5 gom. Experience on the heat exchanger test stands has shown that the breok temperoture is insensitive to this flow rate. Since the flow rates in ART applicotion may vary, dafa on pressure drop vs flow rate were obtained and are shown in Fig. 1.4.30. Air flow rates were also veoried, and it was found that the break temper- atuwre was duplicated to within 5°F at o 400°F breck temperature with air flow rates varying from 30 to B0 scfm, and to within 20°F at a 800°F breok temperature with air flow rates varying from 8 to 40 scfm, The air pressure drop is shown in Fig. 1.4.31. The plugging indicator was colibrated ageinst chemical onolyses for sodium oxide obtained by the Argonne sampler distillation methed.?4 The chemical onolyses showed much greater inherent variations thon did the breck temperatures. In an ottempt to determine the causes for these vari- ations, the Argonne sampler data were subjected to the standord technigques of anclysis of veriance, There appeared te be no significont differences in instrumentation or sampler units from test to test, but somples taken hy one technician were significantly higher in sodium oxide then thase obtained by the other nine technicians. The standard deviction of the analyses was very large and increosed as the number of the analyses increased. Although 86 somples were taken, only 46 were analyzed successfully and used for the calibration. The resulis of these analyses are shown in Fig. 1.4.32 along with the corresponding 3, ¢, White, Procedure for the Derermination of Ox{fen in Sodium and NaK by the Distillation Meibod, ORNL CF-56-4-31 (April 5, 1956). 57 UNMCLASSIFIED ' PHOTD 28130 L S HOT LOOP L 8 2 - -fl-#-fl». a = FROSE CIRCLITE o Eormlc e o L¥0dTY $SIHO0YL LDIFO¥d ANV The feast- squares correlation of breck temperature based on oxide analyses is also shown. The calibration line plugging-indicator breck temperatures. has good validity, os indicoted by o correlation coefficient of (.89, even though the date appear to show wide scatter. The calibration curve includes most of the practical renge of plugging- indicator application, and it should be used as a PERIOD ENDING MARCH 31, 1957 criterion for the oxide content of NaK rather than the solubility line. At low break temperctures, the correlation line is to the right of the oxide solubility line.3% A requirement that o given amount of oxide is g, . Rodgers and J. W. Mausteller, Solubility of Sodium Monoxide in NgK, MSA Tech, Rep. 47, Tig. 2 (March 15, 1958}, UNCLASSIFIED ORNL~LR~—DWG 20893 1_ | 1 — | T TEMPERATURE —— 1 ki Le T8 | = = | a g = ol o | ' ' z = ‘ | | 8 |Fg | I | l g 1 L el e - 1 - = O | = == ' | | = = | | - wl 'LL".E i el — i e g S0 — S 4 — = — |7 | E e | | | | | B e o 1 - — J ! = = o e T = iz H = O | . | ul L | s | | = : — s b e e e | | i’ | | | : . | CI‘: | L e - | 1 e R | R | o | | | | & wd 3= g| o = b — 4 = — — + A S — — — ‘ ‘ | i i c Z - % k- W mEl _ t C | L PLUGGING INDICATOR ‘ £ o w TEMPERATURE |£ o o | - ~ ==l G e 1 — o ‘ S 2 i z [ = - = =1 T o L = e .ol ] = | | & 8 g = = ';'é-' 1= e b — — b D1 B ..~ S - = | o ; '&" a | | v m a = Lot . i L | | e i | 1 TIME ——=— Fig. 1.4.29. Resuvlts of a Typical Test with an ART Plugging Indicoter. {Confidential with caption) ANFP PROJECT PROGRESS REPORT UnCE ASSIFIED QRHL-LR- m_aq Bii_ LHTOR G @ o o w o o Lol L < ~ NeK FLOW THROUGH ART PLLGGING INDICAT o || | - 4 = B T 89w 20 30 40 50 80 MoK PRESSURE QROP (psl) Fig. 1.4,30. HNaK Pressure Drop Through oa ART Plugging Indicoter. {Confidential with caption) UHCLASSIFIED ORKNL-LR-DWSE 20855 alk FLOW THROUGH ART PLUGGING INDICATOR fecfm a7 POPF 14 7 psiol | 2 5 10 £0 a0 4R PRESSURL DROP (ps) Fig. 1.4.31, Air Pressure Drop Through an ART Pluggirg Indicotor. (Confidential with coption) necessary to plug the indicetor holes and thus to show the flow break would move the correlation line to the left of the solubility line, since, as the oxide level fells, the NaK has to be cooled to @ lorger temperature intarvol below the satyration temperature before the required amount of oxide is deposited. The correlotion line is to the right, however, and the above phenomenon maoy not occur or the solubility dota moy be in error at these low temperatures. UNMCLASSIFIED DANL—LA—DWE 20898 500 4 | 1 200 L - el & ARGONME SAM?LER RESULTS C)N E 2 = & T T o = && U i act | | | o £ | = 100 | = S £t b — | 5 f - | — | s | [ [ L = | | 5 ‘ SOLUBILITY OF | /[ | o OXIDE M Nok {REF 35)- I £ 5] = Sl B .‘? - — s S / 4 — . , 4!| L i g | 2t bl | % | 1 i 4 .i { . | | = 2 | o "‘ ¢ 55 | LW o T/ A L0 UE 7~ ) La— LEAST-SQUARES / CORRELATION LINE // | I i | /s | ‘ ‘ 10 ! ' Rt by 100 200 500 0G0 1500 ART PLUGGING INDICATOR BREAK TEMPERRTURE {°F} Flg. 1.4.32. ART Plugglng Indlcator Calibration and Results of Chemicol Anolyses Obtained with on Argonne Sampler. {Confidential with caption) Liquid-Metal-Vapor Condensers M. H. Cooper Tests of the modified liquid-metcl-vapor con- densers3® were completed. The NaK condenser functioned satisfoctorily, but the sodium condenser became partially blocked. The results of these tests are summarized in Table 1.4.5. The re- duction of the gus flow through sodium condenser Il wes coused by the condenscotion and freezing of sodium ot the first boffle, as shown in Fig. 1:4,33; aé M. H. Cooper, ANP Quar. Prog. Rep. Dec. 31, 1956 ORNL-2221, p 54 ¢ e PERIOD ENDING MARCH 31,1957 Table 1.4+5. Summary of Results of LiquldsMetel-¥opor Condenser Tests Condenser infet tamperature: 1200°F Condenser ouilet temperature: FOO°F Condenser Designation Helium Flow Reote Comments Sodium |1} 1.0=0.5 liter/min Condenser became partially blocked after 230 hr ond caused the helium flew ro foll to 0.5 liter/min. Me further decrease in How occurred during 1500-hr test Mak IV 1.7 efm Satisfactery operction through 10 high-flow cycles of 2]-’2 te 3 min each MNal 1V 0.5 liter/min Sotlsfactory performance for 300 hr: hewever, entroined MaK corried into downstreom line by occidentol, con- tinuous high flow Sodium condenser IV, which is to be tested, consists of a 7-ft length of ¥-in. sched-4D nconel pipe that will be maintained at 300°F by electrical heoters ond will be sloped toward the sump. [t is expected thot the sodium will condense and drain back into the sump, since the entire condenser will be above the freezing point of sodium (208°F). The dimensions of the NaK condenser [V have been modified, os shown in Fig. 1.4.34. The cooling section has been reduced from 24 to 12 in, UL ED KO and the separating section has been changed from a 24-in. section of 4-in. sched-40 pipe to & 12-in. section of 6-in, sched-4C pipe. The NaK condenser wos shortened because of space limitations above the NoK sumps in the ART, ond the diameter of the separating section was increased to compensate, PARTIAL SODIUM PLUG AT FIRST BAFELE 1 B Zirconium Fluoride Vapor Traps . 4 M. H. Cooper ' The detailed design of an experimental prototype of the ART zirconium fluoride thermeol-condensation vapor trap, describad previously,®? was completed and a unit is being fabricated. A diagram of the experimental trop, which wos designed to be easily disossembled for examination, is shown Fig. 1.4.33. Inlet Section of Sodium Condenser I S?M H. Cooper ond F. A. Anderson, ANP Quar. Afrer 1500-he Test, Prog. Rep. Dec. 31, 1956, ORNL-2221, p 51. 61 ANP PROJECT PROGRESS REFPORT UNCLASSIFIED ORHL =LA~ 0WG 20597 GAS OUTLET S-u1 SCH- 40 PiPE S T C ——— IMCONEL, DEMISTER PaCKING L Py ar¥eeaietByn s et ~——DEFLECTOR PLATE 2, — INCONEL DEMISTER ] PACKING | | '| 2-1n SCH-40 PPE -~y Yy ~in. TUBING —- l GAS INLET Fig. 1.4.34. Modified NoK Condenser IV, 62 in Fig. 1.4.35. electricolty heoted and therefore does not include the sedium jocket that will surround it in ART use. Three tests of AIEO traps, described previously, *8 were conducted in order to The experimental trap will be reaction also determine the effect of temperoture on the Al 203- Zer reaction. A section through the reaction zone of each test assembly is shown in Fig. 1.4.36. The reaction products fused in the tests made at 1600 ond 1700°F, but they did not fuse in the test at 1500°F. It is believed that the fusion was caused either by the formation of complex reaction products or by impurities in the Al O, pocking material, An Al,O, trop performed satisfoctorily for 2000 br in an in-pile loop test. Also, o fuel pump wos purged ot ART design conditions for 1400 hr through on Al O, trop without difficulty. The A|203 trop used in the Pratt & Whitney high- temperature critical experiment did not completely remove the ZrF from the purge gos during rapid fuel dumps. Some ZrF , was detected in dewnstream gos contro! valves. However, the ZrF removal wos more complete than in the ART hig;h-remper- ature critical experiment for which a thermai- condensation trap wos used. lnsulation Tests . D. Peak Tests to measure the heat losses through three brands of insulation on piping carrying high-temperature NaK in order to determine the type of insulation best suited for the ETU and ART NoK piping. The insviating materiols tested were: {1) Fiber- frax, type XSW, monufoctured by The Carborundum Company, which is o I/z-in.-thick blacket of syn- thetic alumina-silico ceramic fiber; (2} Thermoflex, type RF-600, manufactured by Johns-Manvilie, which is a T.fz-in.-'rhick brown blanket of synthetic elumina-silica ceramic fiber; (3] Hy-Temp, manu- foctured by the Keasbey & Mattison Co., which is dictomaceous earth preformed for 2-in.-thick pipe. The Hy-Temp insulation wos cut to length, placed on the piping, ond tie-wired on. The Fiberfrax and Thermoflex insulations were placed on erdinary Were run galvanized window fly screen and cut te size. I8¢, A, Andersan ond M. H, Cooper, ANP Quar Prog. Rep. Sept. 10, 1956, ORNL-2157, p &1, £G AHCLRSSIPIED ORML~ LR- 0w 20856 = - = = — -—-'Tn———- A5, Wt IRGET ZrFy ~VAPOR CONDENSIT 18 THIS SECTION LT ca: i ZrF; —VAPOR CONDENSES N THIS SECTION k ! fifib&,\ . "I CLRING LOW-FPOWETE (95 RATION It‘» B Ej,‘, DURING HIGH - POWER OPERATION s H::_ B _ ., i o ] h B I e e T Bl A TR Er T T e ‘-‘-—e—t:.. : ‘ e — - . ST 3 " HED1M—ET i I 1 : i M R —— - : e M —in DIA i R g S— L s0ouner #-I: - e 'L'Fl'l =t i A - i ’ } HQE___ T EEEECE PO EEErTFIA OF TR E R ERELT TS fi% i;%lrflr”m”flr";fi = L Ho0 QUTLET REAR WIEW 4—4 OF TUBE CHaMBER Fig- 1.4.35. Experimental Zirconivin Fluoride Yapor Trap. 2561 °1f HOHYW 9ONIONI aoid3d ANP PROJECT PROGRESS REPORT The blanket and screen were then wropped two full turns around the pipe to give o l-in. thickness ond tie-wired on. The thermal conductivities and the heot losses of the three brands of insulation are summarized in Toble 1.4.6. The sime required to apply the Thermoflex insulations indicated that it could be applied ot on average rate of 2 ft/mon-hour, os compared with a rate of 1]{‘ ft/man-hour for Fiber- frax. The rate for applying the Fiberfrax insuletion is lower because it is brittle and requires greater care in handling. URCL ASSIFIED . PHOTO 38001 /700°FY/1600° FY1500° F v —— Fig. 1.4.36. Packed Sections of Three AIEDE Traps for ZrF4I Yopor Showing the Effect of Temperature on the Reoction Products. Toble 1.4.6. Heat Losses Through Insulation Type of Insvlation Tested Mean thermal conductivity ot 700°F, Btu/ heft2.0F Thickness, in. Power input required to hold at 1200°F with 90°F ambient temperoture, w/ft On 3,:’8- and l’z-in. sched-40 pipe On ]!-"2-in. tubing Thermeflex Fiberfrax Hy-Temp 0.050 0.049 0.053 1 1 2 130 107 Bé 154 143 149 64 “ PERIOD ENDING MARCH 31,1957 1.5. REACTOR AND FACILITY CONSTRUCTION W. i. Boudreau ART-ETU REACTOR COMNSTRUCTION AND ASSEMBLY G. D. Whitman H. M. Abele C. K. McGlothlan G. W, Peach The schedule for ossembly of the ETU ond ART reactors was revised on the basis of delayed delivery of components being produced by outside vendors. |t is planned to increase the local shop load by transferring the fabricotion of all pres- sure shells, additional strut-load ring ossemblies and filter plates from outside vendors’ plonts to the shops at the Y-12 plant, The lecal shop is fabricating the ETU north head and will assemble the reactors. The detailed design of the recctor is essentially complete, with some work remaining to be done on the design of the sodium annuli surrounding the fuel overflow, off-gas, and fill-ond-droin lines. Mumerous design changes have been made bosed on further design studies, development tests, component fabrication difficulties, and weld shrink- age tests. The status of the major reactor sub- assemblies and components is described befow. North-Head Assembly Work has been stopped on assembly of the north head pending the arrival of the sodium-fo-NaK heat exchangers. The lower deck assembly has been fabricated; the lower deck skirt has been hot formed and rough mochined; and numerous other small subassemblies have been completed. Ap- proximately 30% of the assembly werk is completed, The work on the sodium-to-NaK heat exchengers is now progressing at a more satisfactory rate than previously. All 30 of the offset-bend-ferming dies hove been completed, The Griscom-Russell Co. has completed assembling the tubes for the first unif, and assembly of the tubes to the headers of the second unit hos been storted. Successful brozes are now being made, and it is felt that no further brazing development work will be needed. Reflector-Moderater Assembly A lower beryllium hemisphere for the reflector- moderator assembty hos been fobricoted, and the spacer ferrules have been installed in the inner M. Bender surfoce. An upper beryllium hemisphere is com- plete, except for contouring the top surface im- mediately below the two sodium coolant inlet pipes. This beryllium component is shown in Fig. 1.5.1 during the machining operations on the top surfoce. A second setof beryllium hemispheres for the ART has been received, ond hole-driltling operations are nearly complete in the lower half, Work is progressing on o strut-load ring as- sembly, ond the struts have been welded 1o the upper ring. The load ring forging has been re- ceived from the outside fabricator, and machining operations have sforted on this piece. The majority of the boron carbide tiles, and spares, required for two reactors have been re- ceived, and no difficulty is onticipated in obtaining the remainder. The fabricatorof the stoinless-steel- clad boren-copper shielding has hod difficulty in rofling the material to desired tolerances, and o relaxation in the toleronce on ratic of cladding to cermet in the matrix has been authorized. Dit- ficulty hos been encountered in rolling e product thot is consistently acceptable metollurgically, and more development work remains to be done on this aperation. The fabrication of Inconel shells, notably the islond ond outer fuel core shells, continues to be a major problem. The effort has been concentrated on the shear spinning process, ond to dote no completely satisfactory component has been pro- duvced. The development problem has turned out to be more difficult then originally estimoted, Raw material quality requirements have had to be improved in that the surface finish must be befter than thot normolly obtained in the stock sizes used. The physical properties of the material, particulerly hardness and grain size, must be carefully controlled throughout the forming process to prevent cracking. The tool forces on the stock during final forming of the inner and outer fuel coce shells produce resuitant forces that tend 1o pull the shells away from the mondrel. This occurs because of the reverse curve in these shells, and several light sizing passes have had to be employed to acquire satisfactory dimensional control. Despite these problems a dimensionally ae- ceptable outer shell has been produced, but over- 65 ANP PROJECT PROGRESS REPORT - N - - s UnCL ASSIFIED PHOTO 8142 Fig, 1.5.1. Upper Baryllium Hemisphere for ETU Reoctor Assembly. pickling after sne of the heot-treating operotions has resulted in excessive intergranular attack. |t is possible thot the surface of the shell moy be cleaned without going below the tolerance on wall thickness. A small parailel progrom has been initiated in an effort to fabricate the thin core shells by hot forming oversized parts and then finish machining them to final thickness. This seems to be o more positive approach to the problem; however, the metallurgical risks are theoretically greater since thicker stock, in which there is greater chance for flows, must be vsed, and there is none of the cold working of the row material which is beneficiol to the metallyrgical structure if properly controlled, Island and Pressure Shell Liner One set of beryllium islond parts is complete, including the insteliation of the spacer ferrules. 66 Ne acceptable Inconel shell parts have been produced, however, as discussed above. The lower section of the pressure shell liner is now to he fabricated by hot pressing and machining inlieu of combination cold forming, shear spinning, and machining. It is felt that the present plon is o safer approach, since there were so meny un- knowns in the celd forming and shear spinning aspects of the original plon. Bids for the fabrice- tion of this component are being evaluated. No fabrication work has been done 10 date on the ]flé-in.-rhick shells to cover the shielding in the reactor. It is planned to fobricate the spherical sections of these poarts by spinning and to fabri- cote the other sections by cold pressing. Fuel-to-NaoK Heat Exchangers The dual effort on fuel-to-NaK heat exchanger fabrication was evoluated, and Black, Sivells & Bryson was selected as the fobricator, All jigs, tools, and fixtures ordered and made by York Corp. are being transferred to Black, Sivalls & Bryson, In the course of machining the first channel at Black, Sivalls & Brysen an error was discovered in the |IBM doto which wos used to construct the cam. Corrections were mode ond the second channel machined showed the mochining method to be satisfactory but demonstrated the need for changes in the method of forming the rough chon- nel. The third chonnel is now being mochined, and the second chennel will be incorporated into rough prototype assembly. The resistonce-heating method of setting the tubes appears to be satis- factory, and enough tubes for the prototype have been formed., Assembly Methods Development Weld shrinkage tests have continued, with a total of 24 tests being completed for the welds required for the '/{3-, ]’fi'f and 1-in.-thick reactor shells. These tests have been performed in order to determine the magnitude of transverse and rodial shell shrinkage as a result of the welding and to develop welding fixtures and procedures that will enoble reasonably accurate prediction of shrinkage, distortion, and quality of the reactor core shell welds. Test results have indicated that transverse shrinkage can be predicted to within £0.010 in. for 'fé-in.-fhick shells. Insufficient tests have been run with the heavier shell sectiens to esti- mate shrinkage voriation. Very litile success hos been obtained in controlling the radial shrinkage. The concentricity of the parts has been held to within 0.010 in. totol indicoted reading, but the amount of radial shrinkage has varied from negligi- ble values to 0.050 in. in the Y%-in.-thick shells. Many of the tests have been performed on very poor quality rejected spun shells which have been very difficult to weld. The tests on shells that were closer to the required metallurgical and dimensional specifications hove given much more uscble welding data. An inner fuel-annulus core shell and welding fixture are shown in Fig. 1.5.2, This fixtute is used in a lathe fo align and support the shell during the welding operations. The first test on the l-in.-thick, 54-in.-dia hoops that simulated the reactor pressure shells showed the necessity of changing the reactor design to accommadate the radial shrinkage. These hoops PERIOD ENDING MARCH 31,1957 pulled in almost ]}:’ in. on the radius. The pressure shelt design was changed from 1- to !'5_-in. thick- ness at the weld by topering the cross section above the equator on the inner surface so that radial shrinkage would not restrict the flow pos- sage or interfere with the shell liner. Additional tests must be performed on the thicker shelils, and preparctions are under way now to perform these tests, Tests hove been completed on spot welding 0.100-in.-thick stainless-steel-cled Cu-B,C cermet shielding material to 0.250-in.~thick lnconel, and satisfactory results were obtoined. Satisfactory results have also been obtoined in spot welding the 0,005-in.-thick stainless steel cons of the copper-coated B, C tiles to the stoinless steel cladding of the Cv-B,C cermets. The reactor assembly procedures are being re- viewed continually, and revisions are being in- corporated as design changes and better assembly techniques are conceived. The reactor assembly area is complete except for one main section of floor reinforcement. The security enclosure around the assembly, inspection, cleaning, and sterage areos is complete, ond isolefien from the remainder of the building will be effected when major reocter assembly operatiens begin. ETU FACILITY G. . Whitman P. A. Gnadt A, M, Smith All installation work on the ETU facility has been tentatively stopped until July 1, 1957, and the present status of the facility is described below: 1. bench fobrication of the moin and auxiliary NoK piping 90% complete; 2. installation of the main furnoce circuits ap- proximately 70% complete; no installation werk started on the isothermal or auxiliary circyits; 3. all cold-trap circuit components available for assembly; 4. all floor supports installed; 5. main air duct installation approximately 50% complete; all parts available for installation; &, control room complete, except for a few miscel- lanecus items; 7. intermediote runs of the auxiliary piping in the basement approximotely 80% complete; no odditional woerk scheduled until components delivered; 67 ANP PROJECT PROGRESS REFORT UNCLASSIFIED PHOTO 27458 | Fig. 1.5.2. 8. instellation of the cable trays for the bosement aree 80% complete; other normel electrical system installation work not sterted; 9. emergency electrical system 95% complete. The following equipment is now on hond and ready for installation: 1. mein and auxiliary NaK pump drive motors, 2. main NaK pump drive motor controller and resistor units, oll tubular and clamshell heaters, 4. oll pipe and components for fabrication and installation of cold-trap systems, 5. NaK dump tanks for the isothermal and auxiliory circuits, 6. induction regulotors ond Powerstots for voltage odjustment of heaters, 7. motor control centers for hydraulic and lube oil pUMP motors., A2 : - L = a’;:—- f':t“%xrj' Inner Fuel Annulus Core Shell ond Welding Fixture. Fabrication of long-term delivery components needed to complete the facility is under way on the following items: ail NaK pump stationary ossemblies, furnace drain tanks, NaK-to-air rediators, NaK system flowmeters, isothermal-system throttling valves, control ponels, NG A N . hydroulic drive and lube oil packages. Mu|-::-r efforts will be expended on these items since they offect the faocility completion date. Some of these items are still in the development aond testing stage, ond therefore delivery dates connot be quoted. Flowmeters are being coli- brated in NoK pump component development tests. The delivery of these flowmeters is contingent upon the calibration test resuits, which are, in turn, contingent upon the success of the NaK pump tests. The NaK-to-air radiators are being fabricated by the York Corp., ond several development problems in brazing techniques must be resolved before a delivery date can be estoblished. Acceptable brazed fin sections hove been produced, but a recent design chunge mokes the fin bank more flexible, and sagging may occur during the brazing cycles., The lube oil systems are nearly completed, but the units have not been tested. Delivery dates for these items are scheduled early encugh to fit in with other piping work; however, leak testing and operational testing resvits may indicate un- foreseen difficulties. Major difficulties hove been encountered in testing hydraulic drive units similar to the drives originally specified for use in the ETU. These difficulties have made it secessory to hold the purchase order for ETU wunits in cbeyance until revised units can be proved. The specifications are being rewritten. Detailed design of the NaK systems piping ond supports is approximately 75% complete, and the detoiled electrical distribution design is approxi- mately 75% complete. The design of the auxiliary service piping external to the test cell is approxi- mately 25% complete. Preliminary estimotes show an expected ETU facility completion dote, ex- clusive of the reoctor and i$s associated equip- ment, of September 1, 1958, TEST CELL COMPONENTS G. D. Whitman A. M. Smith A re-evaluation of the ETU progrom has brought about several chonges in connection with items to be placed within the test cell thot simulates the ART cell. The equatorial ond south-heod lead shielding on the ETU has been eliminated, and this port of the shield contract with Knapp Mills was canceled. Design ond fobrication of the equotorial section of the ART lead shielding was stopped until a review of the shielding require- ments can be completed. This review and neces- sary engineering work is to be completed by June 1, 1957. The design of the south-head shield is being continued by the vendor. Contracts for detoil design and fabrication of the ART fuel {fill-and-droin tank and reacter sup- port structures were canceled. The detailed lay- PERIOD ENDING MARCH 31, 1957 outs necessary for fabrication are now being made by the locol design group. Fabrication of both components is scheduled to be done in the local shops when the necessary design is complete, Preliminary design of the ART fill-and-drain tank lead shield was completed, but the final de- sign myst await establishment of a firm design for the tank. Detail design of the nuclear instrument pod, which was scheduled os port of the design work to be done by outside sources, has beenreassigned to the ORNL Instrument and Controls Deportment. The ETU fuel fill-and-drain tank supports that haove been fobricated will hove to be reworked because design changes hove increcsed the length of these supports. The present statys of procurement and fubrica- tion of other components is given below: 1. The ETU fuel fill-and-drain tank has been received, 2. Prototype fuel dump volves have been re- ceived and are being tested and evaluoted. 3. Design of the sodium expansion tonk was approved, and an order was placed for the neces- sary Inconel. Fabrication of the tanks for the ETU and ART will be done by the local shaps. 4, A contract for fabricotica of the ETU and ART NaK manifolds has been let to the Midwest Fiping Company, and they are now in the process of doing development work on bends and nozzle- to-header welds and of qualifying welders. 5. Design of the hydraulic oil piping inside the cell has been completed, and purchose orders were issued for procurement of the materials required for both the ETU and the ART cells. 6. The sodium system plugging indicator for use en the ETYU and the two ART auxiliary piping junction panels were completed. 7. Fabrication of the ART enricher and enricher line assembly has continued without appreciable difficulty. 8. Welding procedures and designs for the joints between the bellows and nipple on the twelve junction ponel expansion joints have been ap- proved and the vendor is preceeding with fobrico- tion. Design work on other components inside the cell is continuing. Preliminory design loyouts for the fuel-recovery tank, fuel overflow ond off-gas piping, lube oil piping, and the north-head lead shielding are now being made. In addition, design 69 ANF PROJECT PROGRESS REPORT layouts showing equioment locations ot various slevations throughout both cells were started. ART FACILITY F. R, McQuitkin Test Focility G, . Hobinsen R. [, Shotting W. F. Ferguson J. M. Mills, Jr. Contract work on the ART facility hos been contracted in four srages established by the design program. The Ffirst two stoages, packages | and A, which included building oiterations, building additions, cell instollotion, ond installation of auxiliary services piping, hove been completed. The third stoge, package 2, which included the instaliotion of diesel generators and facility, efec- trical control centers, and spectrometer-raom elec- trical ond air conditioning eguipment, wos com- pleted on Februory 20, 1957, The fourth stage, package 34, which includes o distribution system for supplying electrical power to the pipe heaters and equipment heaters, a dry-air plant, and o build- ing t house the air plant and wound-retor-motor controllers, is 28,.2% complete. As reported previously, the contract for package 3A work was awarded to the Rentenbock Engineer- ing Company, effective December 7, 1258, ot o contract price of $114,434, with o contract com- pletion date of Aprid 25, 1937, Work perlormed during the quarter on package 2 included the compietion of installation of anchor bolts and support plates in the penthouse walls, wiring of diesel-generotor control ponels, tests of the air compressor and fuel oil piping for the diesel wunits, and diesel-generator equipment op- erational and performance fests. During the testing of the diesel-generator equip- ment the Ceoterpillar unit generator bearings were damaged because of improper lubrication and had to be replaced. The control equipment required minor design ond wiring changes. The performance testing — ——— PREDICTED BY WANTLAND +— \ e g = ) s — — = = oy 1 : o - [ 5 L e e | | = | | | 'S 0o — — T - . — 1 | | e — e _I na wang - = | | - 002 — - — — ‘— | | | | | | | | | ‘ ‘ | | o n | | | | 0. ] | I I | i | | [ | 100 200 500 1000 2000 SO00 10,000 REYNOLDS MODULUS, A, Flg, 1.7.2. Fluid Friction Characteristics on the Fuel Side of a Straight-Tube Mode! of the ART Fuel-te-NoK Heat Exchanger. (Secret with caption} 78 the range N, = 500 1o N~ = 3000, the doto can be specified by the egquation oL Ng.:'}fi In the laminar region the data lie between the curves { = 56/N,_, for square channels, and f = 6d/NRa' for circular ducts. The early fron- sition, in the vicinity of N, = 400, results from the turbulent wakes behind the heat exchaonger spacers. Preliminory designs were made of a system for studying the heot transfer and velocity structures in o single fuel-side channel of on ART type of heat exchonger for both the square- ond the delro- tube arrangements shown in Fig. 1.7.3. Fer the velocity profile determinotions, the opperatus will be constructed of Plexiglas so that the profiles can be visualized and photographed by using the phospharescent particle technique.2 The heat transfer experiments will be conducted in chonnels with flow cross sections identical to those used in the flow visualization studies. The individual tube sections will be constructed of stainless stee! ond will be electrically insulated from each other, Heat will be generated electricolly in the tube sectiors and will be transferred to the water flowing through the test unis. It will be possible in this system to obfoin the periphera! voriation of the heat transfer coefficient. ART HYDRODYNAMICS L. D. Palmer F. E. Lynch G. L. Muller® Core Hydrodynamics Earlier experimental studies of flow stobilization® in reactor cores demonstrated the value of screens placed in the diverging portion of the flow channel. These experiments were made with on axial-flow entrance sysfem. Megsuremeats are now planned 2, D. Polmer, £. E. Lynch, and G. L. Muller, ANP Quar. Prog. Rep. Dec. 31, 1956, ORNL-2221, p 279; see alsg '"‘Instantonecus Yelocity Prefile Macsurae- ments,'" this chapter. *0n assignment from Pratt & Whitney Aircroft. e N Copenhaver, F. E. Lynch, and G, L, Mullar, ANP Quar. Prog. Rep. Sept. 10, 1956, ORNL-2157, p 225; L. D. Polmer, F. E, Lynch, ond G. L. Mulle, A!;;-’B Quar. Prog. Rep. Dec. 31, 1956, ORNL-222], F + PERIOD ENDING MARCH 31,1957 UNCLASSIFIED ORNL-LR~- WG 18419 i {o) SGUARE ARRAY 1&) DELTA ARRAY Fig, 1.7.3. Typlcal Flow Channels for Velocity Profile Visvolizotion 5Studies of Parolle!-Tube Hea:? Exchongers. with @ swirl entrance system similor to that of the ART core heoder to determine the effect of screens on the hydrodynamic pattern of this system. The experimental system will again involve the 10/44- scole modet of the ART core, olong with provision for the introduction of various mesh screens at a number of planes in the diverging half of the chonnel. Preliminary celculations indicote that the pressure unbalances in the present ART header are of the some order of megnitude as the friction losses through the core. Under these conditions peripheral flow asymmetries in the core could develon. Such flow asymmetries were seen in velocity measurements in the full-scale Plexiglas 79 ANP PROQJECT PROGRESS REFPORT model of the ART core.® Becaouse of the velocity- modifying power of the screens ond the cross- mixing between parallel streams flowing through the core, the extent to which these periphercl flow varigtions are "‘ironed-out’’ cannot be pre- dicted. Thus, experimental the core models are necessary. ohservations with Some calculations were maode of the temperatures to be expected in such flow-stabilizing screens during reactor operation. The cnalysis indicated that the screens would be essentially ot the fluid envircnment temperoture during normal operation. During a fuel dump the screens would be subjected to gammo-ray heating without the cooling normally afforded by the flowing fuel, heat conduction was assumed as the only heat- removal mechanism and the internal heat source was tecken to be B w/cma,. ¢ moximum screen-to- wall temperature difference of 1100°F was obtained, Thus, for a wall temperature of 1100°F, the max- imum screen temperoture would be 2200°F. This calculation provides o coaservative upper limit If one-dimensional in that notural-convection heot tronsfer to the surroundirg helium and radiation heat tronsfer to the cooler walls were not considered. Instentanecus Yeloclty Profile Measurements The program of photogrophic recording of in- stontaneous velocity profiles by using the phos- phorescent dye technique has included studies with circular tubes of severol diameters, a two- dimensional diffuser with o half ongle of 8 deg, ond o l-in. spiral. Examples of lominar flow in a circular tube and turbulent flow in the spiral were presented previously.? Further illustrations under other flow conditions and different geometries w. . Stelzman, G. D. Whitman, ond W, T. Furgerson, private communicetion to G. L. Muller. Re= 8750 aore given in Figs. 1.7.4 ond 1.7.5. Figure 1.7.4 is a photograph of a turbulent-Hlow profile (N = 27,000} in a 3-in. glass pipe. Figure 1.7.5 shows a group of three photogrophs of flow profiles in the diffuser over a Reynolds modulus range of 7000 to 8750. In port {a} of Fig. 1.7.5 the maximum velocity occurs close to the left wall of the channel. tn part () the position of the maximum haos shifted closer to the channel center, and the beginning of a reverse flow region on the right wall can be seen. In part {c} well-developed reverse flow is apparent. This shifting of the velocity pattern is not rapid in the diffuser studied, the photographs being taken during an entire afterncon of intermittent system operation. After each photograph the velocity in the system was increased sufficiently to ensure removal of all UNCLASSIFIED PHOTO 40650 b—- ' Re= 27,000 Fig. 1.7.4, Turbulent-Flow ¥elocity Profile in o 3-in, Gloss Pipe, UNCLASSEFIED PHOTO 406851 Re=8750 Fig. 1.7.5. Velocity Profiles in o 1{; % & in. Diffuser with an 8-deg Half Angle, 80 the phosphorescent dye from the tubing wells. The flow was then reset to the desired test value and the system was allowed to reoch equilibrium conditions before the next photograph was taken. To obtain quantitative information on the fluid velocities, the profile photograph must be super- imposed on a grid photogroph. The grid is ploced within the test section so that it lies in the plane of the collimated light beam used to obtcin the The system is filled with water and o photograph is taken. Thus, the same dis- tortion will exist in both the velocity profiles and the grid phetographs. During this aperation the camera remains rigidly positioned. The velocity profile in the composite photograph of Fig. 1.7.6 wos token at a Reynolds moedulus of 10,000 in a 2!’?-in. plastic tube. The slight dip in the profile neor the tube center probably velocity profile. from the particular entrance coaditions of the test unit. The time interval for this picture {the time that elopsed between the flash of the results light beam which excites the phos- phorescent porticles and the opening of the camera shutter) was 0,2373 sec. collimated The Reynolds modulus Fig. 1.7.6. Composite of Grid and Velocity Profile Photographs for Flow Through «a ?%-In. Tube at o Reynolds Number of 10,000, PERICD ENDING MARCH 31, 1957 based on the mean velocity evcluated from the grid-photograph dato checked with Reynolds the system modulus as determined by calibrated rotameters to within 10%. Further studies over o wide Reynolds modulus ronge are planned. The results of these studies will be compared with datc obtoined by uwsing more conventicnal techniques, such as pitot tubes ond hot wires. HEAT TRANSFER IN REFLECTOR-MODERATED REACTOR CORES N. D. Greene W. R, Gombill ART Core Heat Transfer The hydrodynomic experiments in which screens were used in the 10/44-scole plostic core model indicoted the need for further volume-heot-source studies of a similar geometry. A heat-generation analysis hes shown thot @ number of fine-mesh plastic screens can be placed in the northern hemisphere of the core without drastic disturbance of the flux field. In the pores of the screens (the region in which the flux density is highest) the heat generated will be 2]’2 times that in the free fluid. The effect of these regions of high tem- percture on the over-cll temperature field is made negligible by two factors: (1) the volume of fluid affected is only a very small percentage of the totel fiuid volume, ond (2) the stringers of high- temperature fluid issuing from the screen pores are rapidly dissipoted in the highly turbulent wokes behind the screen wires. Such local in- creases in heat generotion would be limited to resistance-heated systems, and thus similar screens in the ART core would not be subjected to the higher temperatures. Wall-temperature meas- urements will be made in the regions between the screens, as well as in the undisturbed scuthern hemisphere of the core. Fluid temperatures will be obtained with the odjusteble thermocouple probes located ot the core outlet. These probes will be used both to survey the fluid radially in a fixed oxial plane and to investigate temperature- time correlations befween the four thermocouple probes. These latter studies will be made for beth the swirl entrance system with the core screens and for the swirl entrance alone. |t is hoped that the results of these experiments will shed odditional light on the origins of the tem- perature fluctuations which hove been observed in the ART type of core geometry. 81 ANP PROJECT PROGRESS REFORT Vortex Tube Heat Transfer A volume-heot-source experiment was designed that utilizes the vortex flow principle.® For these measurements @ uniform volume heat source will be generated electrically within a sulfuric acid solution flowing through on insulated cylindrical pipe. The desired fluid velocity profile will ke created by vanes in the entrance section of the tube. Both steady-stote and iransient temperature measurements will be obtained by using surfoce, as well os fluid, thermocouples. The fluid ther- mocouples will be located at the tube exit and will provide a radial traverse of the tube. A similar experiment will involve the measurement of heat transfer coefficients in o heated-tube system contoining a fiquid vortex. It is estimated that the heat transfer in this system will be greater than that for cenventional flow of flyid throygh a tube. In such a system it may be possible to maintain satisfactorily Sow tube-woll temperatures without secondary cooling. The effect of centrifugol forces on the temperatyre structure will also be investigated. Hydrodynamic studies of the stobility of the fluid vortex ond other phenomena at the interface between the vortex and the main fluid flow are currently in progress. THERMAL-CYCLING EXPERIMENTS H. W. Hoffman D. P. Gregory® Studies with the system for thermally eycling Incenel tubing were continued in order to determine the effects of fluctuating temperatures and stresses on Inconel exposed to flowing i"'hflF-ZrF“--UFJ1 (50-46-4 mole %, fuel 30). The results obfained to date are summorized in Tobles 1.7.1, 1.7.2, and 1.7.3. Figures 1.7.7 through 1.7.14 show the maximum penetration observed in the test sections used for the experiments described in Tables 1.7.1, 1.7.2, and 1.7.3. In order to investigate the pessible effect on the depth of attack in Inconel of the interaction between the heoter section ond the test section and of the heater length, an experiment was per- formed (ET-S) in which the entire 12-in. test unit served as a heoter. The heater wos subjected to H. . Foppendiek, N. D, Greens, ond L. 0. Palmer, ANP Quar. Prog. Rep. Dec. 31, 1956, ORMNL-2221, » 281, 82 temperature cycling under the some wall-temper- ature-difference conditions as existed in the test sections used in runs ET-H ond ET-0. The test unit for run ET-H was divided into a 4-in. heoter and on B8-in. test section, while the test unit for run ET-0 weos on 8-in. heater and ¢ 4-in. test section. Frem the dota in Tcble 1.7.1, it may be seen that the general subsurfoce-void formation was approximately the same in oll three test sections. However, the ET-H test section showed deeper intergranular stringers than the ET-0 test section. The specimen taken from the test unit for run ET-S showed a tendency toward inter- granular attack in the regions of deepest pen- etrotion, The exposure times for runs ET-H and ET-O were approximotely the same, while run ET-S lested 16 hr less thon ET-H. Although it is difficult to draw specific conclusions on the basis of these three runs alone, it appears thot the heoter-test section interaction and the heater length may not have significant effects on attack in this thermal-cycling system. This result possibly could have been predicted on the basis of the surface area-to-velume ratios in the system. The resulss of run ET-5 probebly connot be caompared directly with those from runs ET-H and ET-0 from the stress stondpoint. The temperature difference across the velume-heated metal wall of the ET-S test section was less thon that of the test sections used for runs ET-H ond ET-0O. Since the thermally induced stress is a function of the temperoture grodient in the wall, it is to be expected thot the stresses in run ET-5 were lower than those in runs ET-H ond ET-0. There- fore, run ET-T was made under temperature ond geometry conditions identical to those of run ET-S with, however, continuous thermal cycling. Since run ET-T lasted for 97 hr, while run ET-S lasted for only 50 hr, the test unit vsed for run ET-T was ot the system maximum temperature opproxi- motely four times as long s was the test unit used for run ET-5. A comparison of Figs. 1.7.12 and 1.7.13 shows thot somewhot deeper attack occurred in run ET-T than in run ET-S. Further, while the aumber of voids in the specimen from run ET-T is less than in the specimen from run ET-S, the ET-T voids are much larger. Additionat dato must be obtained before hypotheses can be based on these results. The series of runs ET-O, ET-P, and ET-Q was designed to obtain a comparison of the effects of low-frequency, high-frequency, and isothermal £8 Toble 1.7.1, Resuits of High-Frequency Thermel-Cycling Tests of Inconel Tubing Exposed to Flowing NaF-ZrF -UF, (50-46-4 Mole %, Fuel 30} Cycling rete: 0.4 cps Tubing size: !‘:1 in. 0D, 0.035-in. wall Heater Section Test Section Ouration Interface Moximum Depth of Artack Interface Moximum Depth of Attock lnlet Mixad Mean Run of Run Length Temperature {mils} ond Type of Temperature {mils) and Type of and Tank {hr) (in.) (°F) Subsurface Voids °F) Subsurface Voids Temperature (°F) Averoge Fluctvation General Intergranuler Average Fluctuation General Intergranular ET-A 14 4 1455 180 & 6 1273 8 o 1 1250 14 1546 225 1273 12 -8 240 4 1415 170 2 None 1330 7 2 None 1250 -C 4 4 1755 189 Nane 2.5 1613 37 2 None -D 14 4 1845 240 None g 1590 83 4 None 1580 -E 5 4 1905 235 None B 1635 43 3 None 1600 -G 23 4 17560 190 None 4 1583 13 4 None 1545 -H &b 4 1730 125 None 13 1600 32 6.5 o 1570 -1 106 4 1850 125 None 9 1600 22 7.5 Mone 1375 -N 13 8 1740 110 3 4,5 1640 16 5 None 1585 -0 59 8 1730 120 Neone 10 1600 20 5.5 6.5* 1565 -R 100 8 1750 100 Mene 2.5 1615 30 3.5 5.5* 1565 -5 50 12 1500 22 5.5 None 1570 -T 97 12 1600 25 None 7.5 1570 -3 100 8 1785 100 1.5 13.5 1625 20 4.5 6* 1560 *The intergrenulor ottack vppeared as stringers of voids thot were more localized than the general void formation. 2861718 HDHVYW ONIONT gO1¥3d ANP PROJECT PROGRESS REPORT Table 1.7.2. Results of Low-Frequency Thermal-Cycling Tests of Inconel Tublng Exposed to Flewing NaF-ZrF -UF, (50-46-4 Mole %, Fuel 30) Cycling rate: 0,01 cps Tubing size: !i in. QD, 0.0353-in. wall Heater Saction Tost Section Maoximum Depth Maximum Depth Inlet Mixad Mean Duration Interface of Attack (mils) lnterfocs of Artock {mils} and Tork Temperature Run of Run Lo Temporature ond Typa of T;mperarure and Type of (°F) and Tamparature thr) enaf {°F) During Subsyrface {"F) During Subsurface During Sscond Hall (el Firgt Halt Volds First Helf Volds of Cyele i Cycel of Cycle o e General lntergranular Ganeral Intrergronulor ET-J 23 4 1800 5 5 1622 2 None 1585 -K 100 4 1850 2 13.5 1640 2 7 1565 A 59 8 1850 None g 1640 None 5.5 1600 Table 1.7.3. Results of Isothermal Tests of Inconel Tubing Exposed to Flowing M-:uF-ZrFJ{-UF‘i (50-46-4 Mole %, Fuel 30) Tubing size: ]/4 in. 00, 0.035%-in. wal! Maximum Depth of Attack {mils) and Type of R Duration of Run Temporoture Subsurfoce-Void Formation un (hr) (°F} General Intergranular ET-F 5 1435 None None - M 100 1580 5 None -P 59 1600 i 4 operotion. The heater sections used for runs served under isothermal conditions in thermal ET-O and ET-Q were 8 in. long. A fresh fluoride salt mixture was chorged to o new system for run ET-0, and the same salt mixture ond tonks were then used successively in runs ET-P and ET-Q. The resuvlts of these runs are shown in Figs. 1.7.8, 1.7.9, ond 1.7.10. The specimen from high- frequency run ET-O shows o higher frequency of attack the the frequency run ET-Q. This comparison is in rec- sonable ogreement with the previously reported comparisons’ of run ET-G with run ET-J ond of run ET.l with run ET-K. The attack in the iso- thermal run ET-P, although higher than thot ob- than does specimen from low- ?H. W. Hoffman and D. P. Grogory, ANP Quar. Preg. Rep. Dec. 31, 1956, ORNL-2221, p 282, 84 convection or forced-circulation loops, is less than that for runs ET-O or ET-Q. The high isothermal attack may be the result of the surfoce oreo-io- volume ratio present in this system. However, since even in the isothermal runs there was some low-temperature-ditference low-frequency cycling, the explanation for the high isothermal ottack is not yet clear. : Runs ET-R ond ET-U {Figs. 1.7.11 and 1.7.14) were made under essentially identical temperoture conditions. However, fresh salt ond a new system were used for run ET-R, while the solt and system for run ET-U hod been used successively through ET-R, ET-S, end ET-T {(approximotely 250 The specimen from run ET-U shows a some- runs fe). what finer void size than does the specimen from run ET-R, but both specimens show intergranuiar [ UNCLASSIFED T-1142 ! . " £aT o ki - T o = R e - (B g = 0 T i PN Fapsem T Loas, . = L "] e . ¥ W = 2| Crpsie) K, . B i I:" ! "1k ] & - - M v J L~ W - 5 213 - > i 1 g L L =, > ¥ T i & i e r Al Fig. 1.7.7, Run ET-M. Inconel Tubing Afrer Exposure to Flowing NaF-Zer-UFA (50-46-4 Mole %, Fuef 30} at 1580°F (fsothermal) for 100 hr. Etchant: modified oque ragia. 250X, Reduced 32%. (Secret with caption) UHCLASSIFIED 2 T-1 o’ i 4 o ‘—-\_ . ks i ) - i."_'- s T 4 :m - L2 i # | - } 1—". -3 ; il e ;G |:—-. Al i ™ : & ! o e = 8 = bl ;-! h B : LY Fig. 1.7.8. Run ET-0, Specimea from Test Section of lnconel Tubing After Thermal Cycling While Exposed to Flowing NnF-ZrF4-UFd (50.46-4 Mole %, Fuel 30). Cycle temperatures: Dutation of test 59 hr. Etchant: 250%. Reduced 32%. (Secret Cycle frequency: D.4 At the other end of the system, molten NaF contains sodium ions and fluoride ions. The addition of NeF to ZrF4 results in the breaking of the bridges to give zirconium ions which cre surrounded partially by bridging fluorides and partially by nonbridging flucrides. According to the proposed model, the addition of ZrF, to a large excess of NaF results in the formation of ZrF,~77 iens, and thus for the com- position range of up to 25 mole % Zrf the liquid is composed of Nu+, F=, and ZrF,” ™" ions. At 25 mole % ZrF | most of the free fluoride ions have been incorporated in ZrF,” 77, since the stoi- chiometry of the meit conforms to Nu3ZrF? (ref &). The fluorides attoched to the ZrF =77 ions are examples of nonkridging fluorides, as distinguished from free fluorides and bridging fluorides. If more ZrF, is odded, it connot form additional ZrF,=~~ lons but can only share some of the olready complexed fluorides. The shared fluorides are referred to as bridging fluorides. With increased Zer concentrations, there is a further decrease in the numbar of nonbridging fluorides and an increase in the number of bridging fluorides to eight per zirconium in pure ZrF (ref 7). 4 If on assumption is made regarding the 5R. D. Burbank in The Crystal Structure of Uranium Tetrafluoride, K-769 {June 8§, 1951), describes the strue- ture of UI:4 crystals, which are isemorphic with Zer, as an fonic lattica in which each uranlum ion is sur rounded by eight fluorine ions, 6T|'|e K+ ions and ZrF;“_ ions are the structural units in solig KEZrF?, which is isomorphic with Naa?_'rF?, according to W. M. Zachariasen, Acta Cryse 7, 792 (1954). correspending to this fomlly of compounds indicates The shorpness of the phose diagrom maxime that they melt with lirtle dissociation, 7s, Langer, in Chap. 2.4 of this report, has observed thot UF4 melts without opprecioble expansion. The model assymes that ZPF‘ behaves analogously und that the coordinotion number remains unchoanged. 126 coordination number of the Zr*' ions, o more definite picture of the liquid structure of fuel compesitions near 50 mole % ZrF4 is available. Because of the rodius reltaionships, no more fhan seven fluorides can touch a Zr#* ion at one time, |f seven, which is near the upper limit, is used as the coordingtion number for the 50 mole % ZrF, region, about 40% of the fluorides are shared, or bridging, and 60% are unshared, or nonbridging, as in ZrF?‘“"'. There are no discrete groups of ions that form a structural entity or complex, such as ZrF_." ions. Rather there is an interlocking network of Zr*' ions joined by an average of four bridges to other ions. The U4" ions substitute for Zr*" ions without altering the picture very much, and Na”* ions, also present, maintain electroneutrality in the vicinity of nonbridging fluorides. The situation is not static, since there is on extremely mobhile equilibrium between the kinds of fluorides, and the bridges are easily broken ond reformed. For simplicity the model has been described as though free fluoride ions did not exist at higher concentrations than 25 mole % Zer. Actuolly they are present throughout the composition range but their effective concentration diminishes rapidly with increasing ZrF, concentrotion, Since the complexing potentialities of a fluaride melt depend on the fluoride ion activity, it is very important to know how this activity vories with compesition, Unfortunately, it connot be measured. The fluoride ion activity can, however, be conveniently correlated in o qualitative manner by an acid-bose scheme in which cations are rated according to their tendency to behave as fluoride donors or occeptors, |If FHuoride denors are defined as bases and tluoride acceptors as acids, the cations foll into the same general pattern as thot used for the classificotion of oxides as acidic or basic, The NaF compound is on example of a strong base and ZrF, of o strong acid., The stronger the acid ond the bose that ore combined, the stronger they complex ecch other on mixing, or stated in thermodynamic terms, the greatsr are the negative deviations from ideal solution behavior shown by the mixtue. The resulting mixture con olso be clossified as acidic or basic. Fuels based on the LiF-NoF-KF sutectic are strongly basic, and they highly complex cor- rosion products, since the latter are usually LT T amphoteric. o contrast, fuels based on the NaF- ZrF ,-UF, system are nearly neutral with respect to corrosion products. In order to map the relative acidity of a fuel sclvent on a numerical scale, it is convenient to use a plot having Z/R ratios for the ordinate and solvent composition {in mole %) for the abcissa, os shown in Fig. 2.3.2, The coulombic UNCLASSIFIEDR DRHL-LR-DWG 19240 COULOMBAC ATTRACTION ENERGY OF A0JOINING IGNS, /7 = 7. o8+ r_i] ACIMC FLUORDES ——— BASIC FLUOQRIDES g oo 1 o 20 G el 80 100 —_ —. BASIC SOLUTIONS ACIDNIG SOLUTIONS Zri, 1M SOLVENT (mole 7a) Flg. 2.3.2. An Acid-Baose Scale for Predicting Neutral Points of Solutes in NuF-Zer Melts (Tentative), PERIOD ENDING MARCH 31, ) 957 attraction energy of odjoining ions (Z/R ratios), obtained by dividing the valence of a cation by the center-to-center distance between the cafion and on odjoining fluoride ion, are, os explained in the preceding section, energy terms which con be used as a measure of the fluoride affinity of A line joining the Z/R ratios for the extremes of the compesition ronge is a very rough a cation. first approximation for evaluating the effective Z/R values at the neutral compositions, described in the preceding section, the flyoride offinity of o salt is the same os that of the solvent. Thus the corrected curve for matching compositions to Z/R values is found intermediate compositions. At by plotting the neutral compositions for various solutes. Currently only cone intermediate neutral point can be approximated. The factors which influenced the choice of NGF-Zer (53-47 mole %) as a fuel solvent served to give ¢ melt in which FeF, behaves idte;e::lfw;.r.3 This point has been plotted in Fig. 2.3.2 to give three points through which to draw a curve. Since the liquid structure probably changes around 25 mole % ZrF,, and since the position of the curve is uncertain, the maximum curvoture was located ot 25 mole % ZrF,. The simplest application of the plot involves the im- plicit assumptions that only negative deviations and thot marked positive deviations are artifacts. This assumption is valid to the extent thot effects due to polarization of the ions are absent and thot real positive deviations can be regarded os evidence of polarization. The purpese of such plots is to aid in predicting the relotive acidity or basicity of a solute toword This permits estimates of the relotive negative deviotions of solutes and, hence, also relotive solubilities in case the pure solute is the saturating phase. An important use is the selection which will reduce cocrosion by complexing the corrosive ageats rather than the corrosion products. Because of uncertainties in theory, ion radii, and neutrcl the plot accur a sclvent. compositions of solvent compositions, is subject to revision. B¢ W Blssd and G. M. Watsen, ANP Quar. Prog. Rep. March 10, 1956, ORNL-2061, p 84. 127 ANP PROJECT PROGRESS REPORT 2.4. PHYSICAL PROPERTIES OF MOLTEN MATERIALS F. F. Blankenship YAPOR PRESSURES OF MOLTEN FLUCRIDES 5. Cantor The importance of detailed knowledge of solt vapor behovior in both engineering considerations and in the solution theory of fuels hos focysed attention on the need for determinations of the vapor pressures of the less volotile components For a theoretical understanding of solutions of molten electrolytes, vapor pressures provide in principle a direct means of obtaining the thermodynamic activities of the constituents. In practice, the presence of associated molecules in the vapor phase greatly complicates this method of arriving at activities. It was formerly thought in fue! mixtures. that temperatures high enough to melt the olkali halides should prevent the existence of all but the simplest, or monomeric, in the vapor; however, this is not the cose. As was recently shown convincingly by Miller and Kusch,' molecules there are appreciable quantities of dimeric and trimeric molecules in the vapor of alkali holides. In order to proceed with a determination of vapor species, the absolute vopor pressures of molten olkali fluorides were meosured by the quasi- static methed? used in this laboratory for obteining vapor A sufficiently wide temperature range was covered to give curvature pressures of fuels. ]R. C. Millar and P. Kusch, J. Chem. Phys. 25, 860 {1958). 2W. H. Rodobush and A. L. Dixon, Phys. Rev. 26, 851 (1925). on a log p vs 1/T plot. Hence the data, sum- marized in Table 2.4.1, cen be more occurately represented by means of the Kirchhoff equotion, A IngmmHg sl BlogT + C The constants were evaoluated by following ¢ procedure resembling that used by Kelley.® Com- parison with previously reported absolute pressure meaf:us.-..nremems't'5 the uncertainties in the extropolations (as much as 350°C) required to reach the ronges shown in Table 2.4.1. Transpiration or corrier gas methods were used at lower temperatures for LiF,% NaF,” and RbF® at Baitelle Memorial Institute, and for MNaF and KF by MNaryshkin.” In these methods, however, the weight of vapor required te saturate o known is scarcely feasible because of 3. K. Keliey, Bulletin 383, Bursou of Mines, 1935, JiH. von Wartenberg ond H. Schulz, Z Elektrochem. 27, 568 (1921}, 50. Ruff, G. Schmidt, end 5. Mugdan, Z. anorg. aligem Chem. 123, 83 {1921). 8E. M. Simons ond R. . Carlson, Progress Relating fo ANP Applications Augusi~October, 1956, BMI-1148, p 19 (Nov. 27, 1956). 7K, A. Sense el al., Vapor Pressures of the Sodium Fluoride-Zirconium Fluoride System and Derived Informa- fion, BMI-1064 {Jon. 9, 1956). 8R. W. Dayton and C. R. Tipten, Progress Relating to Military Applicairons During Ocrober, 1936, 8MI-1145, p 85 {Now. 1, 1954). 9|. I. Naryshkin, J. Pbys. Chem USSR 13, 528 (1939). Toble 2.4.1. Yopor Pressures of Pure Alkoli Fluorides Experimental Ronges Compound Equation Temperature Pressure K} {mm Hg) LiF Log p = —(13,890/T} — 4.021 log T + 23.165 13281575 1.3-30.8 NoF Log p = —(14,60%/T) — 3.518 log T + 21.863 1381-1592 726,06 KF Log p = —(11,910/7) — 3.518log T + 21.002 11991505 1,8-81.4 RbF Log p = —(11,373/T) — 3.518 log T + 20,995 1154~1453 2.2-106 CsF Log p = —{9,845/7) — 3.518 log T + 20.556 1009-1379 1.7-242 volume of carrier gas is measured, and absclute vapor pressures cannot be obtained without an independent determination of the molecular weight of the vapor. The molecular weights that must be used to bring tronspirotion data into agreement with the obsolute pressures givea in Table 2.4.] have hkeen calculoted, in some cases, where svitable data were avoiloble. The molecular weight calculations were based on the ossumption that the vapor consisted only of monomeric and dimeric molecules, and the results, shown in Table 2.4.2, will undoubtedly be subject to considerable revision as better measuremenis are made. The increasing proportion of dimeric molecules with increasing temperature in the case of LiF is not as imprebable as it might seem at first glance. The wapor is in equilibrium with the liquid, and, if the pressure effect is grester than the tem- perature effect (heat of wvaporization is greater Table 2,4.2, Tentative Estimates of the Percentoge of Monomerle Molecules In the Scturated Yapor of Yarious Molten Afkali Fluorides Menomeric Molecules in Yapor (%) Temperature (CK) LiF NaF KF RbF 1400 52.9 48 1200 69.2 45,2 76.5 1200 82.1 {(Solid) 8.7 76.3 1100 {Solid) {Solid) {Solid) 70.5 PERIOD ENDING MARCH 37,1957 than the heat of dissociation}, the proportion of dimeric molecules should increase. SURFACE TENSION AND DENSITY OF MOLTEN UF, S. l.anger A preliminory value for the density of molten UF, was obtained for use with previously reported sessile-drop dota ' to give the surface tension of molten UF,. At 1075°C, a density of 6.80 + 0.09 g/cn® was found by using grophite pycnometers. There were some difficulties in calibration of the pycnometer which prevent this velue from being regorded as final. |t leods to o surface tension of UF, of about 180 dynes compared with the value of chout 140 dynes found from the pre- liminory estimotes given in the previcus repon.w Further experiments are currently being made in order to obtain a firm value for the density. The tentotive experimental velue given obove for the density of liquid UF, is, surprisingly, greater than the density of solid UF, {6.63 q:.],»"'t:m3 based on x-ray dato).!! The greater density of the molten material and the behavior of the salt surfoce leve! upon freezing in the pycnometer appear to indicate that UF, either controcts or expands only very slightly upon melting. 10 Longer, ANP Quar. Prog. Rep, Dec. 31, 1936, ORNL-2221, p 152, PR, D. Burbonk, The Crystal Structure o Uranium Tetrafluoride, K-769, p 14 (June 6, 1951} ANP PROJECT PROGRESS REPORT 2,5. PRODUCTION OF PURIFIED FLUQRIDE MIXTURES G, J. Nessle PREPARATION OF VARIOUS PURE FLUODRIDES B. J, Sturm L. G, Overholser Preparation of YF3 The continving interest in moderators for use at high temperotures encouraged considerable study of the hydride of yttrium. Since the hydride is prepared from metallic yttrium, which is made by reduction of YFS, it has been necessary to prepare considerable quantities of YF, for eveluation in the metal manufacturing step. The method of preparation used ta date has been to dissolve Y,0, in the minimum quantity of aoqueous HC! solution and to precipitate the fluoride by the oddition of aqueows HF sclution. The solid product is washed by decantation, recovered by centrifugation, and given a pre- liminary drying at 150°C in air. The c¢rystalline product is dried for 4 to & hr at 250°C under flowing helium in nicke! equipment end then treated, in this equipment, with anhydrous HF at 700 to 750°C for 12 hr. About 1400 ¢ of YF, has been prepared in this fashion, Preparation of Fluorides of Molybdenum A previous report in this series! described the preparation of what appeared to be a lower fluoride of molybdenum by reduction of MoF, with FeF,. tn odditional experiments this reduction product has been collected in a condenser maintained at 110°C and subsequently redistilled in glass appa- ratus. The yellow product, which is very unsiable toward traces of moisture, melts at 78°C. This is considerably higher than the 60°C previously reported! as the melting point of the material before distillation, The unstability of the material to air and moisture mokes it ditficult to obtain a clear x-ray pattern. The best data available to date indicate the solid to be tetragona) with a = 11.62 A ond ¢ = 9.26 A. The available chemical analyses do not serve to demonstrate conclusively that the moterial is MoF,. Additional studies will be required to '8, J. Sturm and L. G. Overholser, ANP Quar. Prog. Rep. Dac. 31, 1956, QRNL-2221, p 153. 130 identify the compound or compounds in this yellow material. Preparation of Other Materials The method of preparation of FeF, from FeCl,-4H,0 has been improved considerably by partial dehydration of the commercial materici before the hydroflucrination step. The substitution of anhydrous CrCl, for bydrated CrF, as the raow materiol for CrFa preparation results in a pure product; this improvement is entirely due to the higher purity of the commercial chleride, Hydrofluorination of CrCl, ot 700°C yields a product coniaining o smali quantity of Cng. Most of this contominant can be removed by treatment with H, at 700°C. When this reduction is per- formed in silver vessels, less Cr% contaminates the product than when nicke! vessels are used. FILOT-SCALE PURIFICATION OPERATIONS C. R. Croft J. Truitt During the quarter the pilot-scale equipment (5-, 10-, and 50-1b capacity) processed 42 batches totaling 1575 |b ot the wvarious fluoride compo- sitions needed in phase equilibrium studies, physical property measurement, small-scale cor- rosion tfests, and other experiments. A large fraction of this material was MNaF-KF.-LiF-UF, {11.2-41-45.3-2.5 mole %). Usage of this material seems to be fairly constant at about 500 Ib pes month, Nickel storage receivers have been shown to be inadequate for the NoF-KF-LiF-UF, material. The lorge expansion of the moterial upon melting results in failure of 75% of the 50-Ib storage containers upon melting of the charge. Inconel cans have, however, been shown to be satisfactory for the 50-Ib botches. No failures have occurred in the ten tests made to date; it is not certfoin, however, that Inconel cans will be satisfactery for 250-1% or lorger charges. When inadverteny exposure of the molten salt mixture to air or water securs in Inconel cons, extensive contamination of the melt with Crf, ond Fef, results. Since these contaminants cannoi be removed economi- cally by retreatment of the batch, the material must be discarded. PRODUCTION-SCALE OPERATIONS J. E. Eorgan During the quarter 46 batches totaling approxi- mately 11,500 |b were processed in the production- scole focility. The transition to a seven-day continuvous production schedule was begun on November 5, 1956 ond full capocity of 4000 Ib per month was attained in December 1956, No failures of the cepper-lined stainless-steel reactor cans occurred during the quarter. The reactors now in service have each processed neorly 10,000 b of material since their installation. If the supply of storage cons can be maintained and no major breckdowns occur, the present rate of production con apparently he maintained indefinitely. This acceleroted program was adopted ot the request of the AEC to meet the estimated re- quirements for processed fluorides to be used in the ANP program by Pratt & Whitney Aircraft and by ORNL. During the last month of this quarter, however, the Pratt & Whitney requirements were greatly reduced. The projected total requirements for the last half of fiscal year 1957 dropped from 37,000 1o opproximately 12,000 |b. Because of the firm commitments made for the large omounts of row materials, the personnel, and the operating equipment oaeeded for the highly accelerated program initiated in MNMovember 1956 and becouse of the economies achieved by continuous operation, it was deemed advisoble to maintain the high oroduction rate until the end of this fiscal year. However, the main objective has changed from meeting immediate requirements to stockpiling sufficient quantities of processed fluorides for maintaining the ORNL effort in the ANP program in fiscal year 1958. If this objective is attained, the production focility will not be operated during fiscal yeor 1958, except on a limited basis as dictated by speciol large-scale demands of nen- standard fluoride compositions, At present the estimated ORNL-ANP requirements are foreseen as some 14,000 |b of processed fluorides for fiscal year 1958, Sore 18,000 of the 30,000 Ib of NaZrF, ordered has been received. Difficulties encountered by the vendor in eliminating oxide contamination and adjusting the NoF-to-ZrF, rotios have been re- solved by a visit to the vendor's plant. Subsequent shipments have had the proper ratios, and the previous high purity levels have been meintained. PERIOD ENDING MARCH 17,1957 New NaF has been obtoined to replace the high- woter-content NaF previously received ond used as described previously.? The new maferial meets specifications, in genercl, but some of the drums have a prohibitively large quantity of sulfur With the availability of good quality NeZrF, and the resultant low vsage of NaF, it is becoming more feasible to restrict the use of NaF to cp-grade moterial. The design and construction of the Y-12 fluoride processing focility, which would hove permitted much greater throughput, has postponed indefinitety. (2000 ppm or more). been Reprocessing of a low-hafnium barren fluoride mi xture (NaF-Zer, 50-50 mole %) to remove excessive oxides and oxyfluorides wos successful. The matericl wos then certified for use in the Pratt & Whitney high-temperoture critical experi- ment, BATCHING AND DISPENSING OPERATIONS F. A. Doss D. C. Wood A total of 15,700 b of processed fluorides was di spensed during the quarter in botch sizes ranging from 1 t0 250 |b. At the beginning of the quarter, with the onticipoted accelerated production ac- tivity, the stock inventory was completely modified ond redefined. Cleaning moterial previously in- ventoried was removed from the inventory, and compositions were listed so that “‘Special Compositions' sitions besides those specifically numbered. As a result, the present inventory figures differ con- siderably from those of the previous guarter, but the totals differ only some 900 |b, or the amount the heading contained all compo- of cleaning fluoride mixture previously carried in the inventory. Also not listed in the inventory is some 2500 |b of stored salvoge material being stockpifed for use by the Chemicsl Technology Division for testing purposes. A material balance for the past quarter is given in Table 2.5.1. As can be seen from the figures presented, a very sharp increase in production and dispensing occurred during the quarter as a result of the accelerated pregram initiated in November 19546. The lorge shipments to Pratt & Whitney Aircraft and some increose in local consumption y ———— - ———— 2| E. Eorgon, ANP Quar. Prog. Rep. Dec. 31, 1956, ORNL-2221, p 153. 131 ANP PROJECT PROGRESS REFORT Table 2.5.1. Material Balanee for Fluoride Mixture Production and Use Material {Ib) 304 3? 45¢ 1084 107¢ Special Tatal On hand ot beginning of quarter 1452 1439 1787 994 564 1684 7,920¢ Produced during quarter 3703 690 2343 5279 1386 82 13,483 Total 5155 2129 4130 65273 1950 1766 21,403 Dispansed during quarter 3147 1346 3573 5519 1327 771 15,703 On hand ot end of quarter 2008 763 557 754 623 995 5,700 “*Composition 30: NnF-Zer-U Fd {50-46-4 mole %). bComposition 31: NaF-ZrF, (50-50 mole %). “Composition 45! NaF-ZrF4 {53-47 mole %), d(:ornpcsifion 108: NflF-:".'r|"'4-|..l|=_‘1 (56-37.5-6.5 mole %Y. Compasition 107: NaF-K F-LiF-UF, (11.2-41-45.3-2.5 mole %). ”Revised figure obtained by subtracting 907 |b of cleaning fluoride mixture from last quarter’s bolance. resulted in an appreciable drop in stock inventory by the end of the quarter, The main consumers of processed fluoride mix- tures and their alletments during the quorter are given below: Consumer Amount (Ib) ORMNL-AMP groups For chamical and physicel property 284 studies For experimental engtneering tests Z,444 For metallurgical studies and fuel 1,948 reprocessing develiopment Pratt & Whitney Aircraft For experimental use at Hartford 7,500 For high-temperoture criticel 1,366 experiments at OQRNL Other contractors, including BMY, NRL, 187 and WADC Salvoge ond reprocessing 1,974 Taral 15,703 132 SPECIAL SERVYICES F. A, Doss J. Truiit D. C. Wood Filling, Draining, and Sampling Operations Approximately 4000 (b of processed fluorides and 2500 |Ib of liquid metals were charged into test The charge sizes ranged from 1 to 500 Ib, and some 170 operations were performed. units, Fitling of Pratt & Whitney High-Temperature Critical Assembly The Prott & Whitney high-temperature critical ossembly wos charged with low-hafium-content NaF-Z¢F, (50-50¢ mole %) and the enriched con- centrate NuF-UFd 66.7-33.3 mole %). The entire filling operation proceeded very smoathly, but the first charge of barren material hod to be withdrawn from the sump shortly after it wos loaded because of a leak in the bottom of the sump. It was possible to withdraw this material in a cendition suitoble for re-use, and, after the sump was repoired, the barren material was again charged inte the sump and enriching was started. The loading operation begen on Janvaery 9, 1957, and was compteted on February 4, 1957, at which time the responsibility for loading of the assembly wos transferred to the Operations Group of the Criti- cality Section for final additions of enriched uranivm with the ART enricher apparatus. PERIOD ENDING MARCH 31, 1957 2.6, COMPATIBILITY OF MATERIALS AT HIGH TEMPERATURE F. Kertesz PFPENETRATION OF GRAPHITE BY MOLTEN FLUORIDES H. J. Buttrom The study of the behovior of graphite exposed to molten fluorides was continued.! Tests were conducted to evaluate a commercial graphite specimen that was impregnated with NoF-ZrF, (53-47 mole %) before being exposed to a fluoride mixture containing uranium. The impregnation of commercial APC graphite specimens was ac- complished by immersing them for 24 hr in the fluoride mixture melt kept ot BOOPC. After this treatment, the impregnated specimen was heated in vacuum for 24 hr at S00PC in order to remove part of the ZrF, and thus to obtain a residual mixture with o higher melting temperature. [t would be expected thot on impregnating material that was solid when exposed to the uronium- bearing melt would resist penetration more suc- cessfully than one thot was liquid and could thus diffuse from the pores. and a control sample that had not been heated in vacuum wete submitted for analysis. The results of the analyses are presented in Table 2.6.1, along with the calculated Naf-to-ZrF | rotios. The analytical results indicote that the NaF penetrated the graphite to o greater extent than the ZrF, did, by a facter of 12 (4.16/0.34). The sublimation step effected a further separation of the ZrF,, as wos expected, and ofter sublimation the Naf-to-ZrF, ratio was further increased about Both the treated specimen ]H. J. Buttram, ANFP Quar. Prog. Rep. Dec. 31, 1954, ORMNL-2221, p 158. fourfold, with the final rotio of NaF to ZrF being about 16:1, Two other types of graphite, code Nos. R-28 and M-80, obtained from the National Carbon Company were also tested by impregnation, os described above. The samples impregnoted with NaF-ZrF, (53-47 mole %} were subsequently im- mersed into NaF-ZrF,.UF, (53.5-40-6.5 mole %). The olpha counts obtained from these specimens were compared with the counts obtained with specimens immersed directly into the uranium- bearing mixture without preliminary impregnation. The data obtained are presented in Table 2.6.2. The results indicate that the grophite specimens were not penetrated to any consideraoble degree by either of the salt mixtures, and thus these speci- mens compare favorably in this respect with the sample obtoined from the Degussa Company of Germany and, in oddition, appecr to have greater strength. ELECTROLYSIS OF THE MeOH-MNi SYSTEM F. A, Knox In the course of electrolytic studies of the NaOH-Nj system it has been established that, in a nenisothermal system, the hot nickel electrode is usually onedic and the cold electrode is cathodic. It has been found, however, that this situation can be reversed by the use of a hydrogen atmosphere,? Since NaOH is a potential moderator- coolant material, attempts are being made to 2.l'-'lL_ Nichols and D, R, Cuneon, private communication to F. A, Knox. Toable 2.6.1. Analyses of the Fluoride Mixture NuF-ZrF“ Before and After Penetration into Graphite NoF Zrf, NaF-to-ZrF {wt %o} {wt %) Rotie Original fluoride mixture 25.3 74.7 0.34 Flucride mixture n grophite specimen B0.&6 19.4 4,16 Fluoride mixture in graphite specimen ofter sublimation 24.0 6.0 15.80 133 ANP PROIECT PROGRESS REPORT Table 2.6.2. Penetration of Graphite Specimens by l"lnt:lF-ZrF'_,L-UF4 {53.5-40-5.5 Mole %} in 24 hr ot 800°C Alphe Activity {cpm) Initial Weight Weight After Graphite Specimen Aftar Exposure to 1’, in 'I/ - Specimen Weiah Treatmant . . . B 4 gight Impregnation Uronium-Bearing At from i Code Mo, ( . g ° rom 9) (o) Mixture veface Surfoce Surfoce R.28 093117 Placed in Nu::|F-Zrl:d-UF‘1 0.9328 >1 1 Q {53.5-40-6,5 mole %) as recaived R-28 0.9394 Impregnated with NuF-Zer {.9585 0.9544 >3 0 0 (53-47 moie %) before being placed in NcF-ZerfiU Fq {53.5-40-6,5 mole %) M-80 0.9474 Ploced in NoF-Zer-U F‘1 0.9518 1 0 {53.5-40-4,5 mole %)} as received M-80 0.9574 lmpregnated with MaF-Zr Fd (0.94680 0.94664 0 > >1 {53-47 mole %) before being placed in NoF-Z¢F -UF . {53.5-40-£.5 maole %) balance the current in an effort to find a way to eliminate the mass-transfer effects observed in sodium hydroxide circylated under a temperature gradient. The experimental arrangement being used con- sists of three closed concentric nickel crucibles, which serve os electrodes, as shown in Fig. 2.6.1. The outer vessel is 6 in. long and 21{1 in. in diemeter. The middle container is ]]é in, in di- ameter and 8 in. long, and a small hole was drilled in the bottom to atiow the molten sodium hydroxide to rise to the same level as in the outer container, The inner electrode consists of a ]é-in.-dio nickel tube, The bottem of the tube was c¢losed ond o thermocouple was welded inside. For tests, the three electrodes were placed concentrically in the furnace in o controiled atmosphere. About 150 g of sodium hydroxide was used as the charge. in this orrangement the outer electrode had hy- drogen gas on one side and molten sodium hydroxide on the other side. The middle electrode had melten sodium hydroxide on both sides. The ettect of voricus arrangements could be studied by connecting the electrodes to the positive or negative poles of batteries, In one experiment a relatively low test temper- ature (550°C} was used; the middle electrode was 134 connected to the negative peole; and the inner electrode was connected fo the positive pole of the outside bottery. Current and voltage measure- ments were made by slowly raising the applied voltage and meesuring the corresponding current. Two sets of measurements were made with the system under o hydrogen otmosphere ond also with the system under vacuum. The results, plotted in Fig. 2.6.2, show that under a hydrogen atmosphere the current increosed much foster than it did under wvacuum, which indicates that hydrogen participated in the current- carrying mechenism, Measurements were aiso made at 800°C, with o hydrogen atmosphere, for which the curment flowed either from the inner electrode to the outer elec- trode or in the reverse direction. |t may be seen in Fig. 2.6.3 thot, when the current was flowing from the inner electrode toward the middle elec- trode, the current increased continuously with the voltage. In the reverse case o definite ploteau was reached, that is, as the voltoge was increased, the current remained constant up to a value some- what below 2 v. A theoreticol interpretation of these results will require ¢ more systematic study of the effect of current density, The polarization of hydrogen electrodes is probably invelved. UNCLASSIFIED ORNL- LA~ DWGE 20255 THERMOCQUPLE LEADS || INNER ELECTRODE, Yo -in - 0D I GAS AVAILABLE TO INSIDE QF ELECTRODE I CONTACT wiTH | ARaRATuS IN !‘ | MoOH ON QUTSIDE. CONTROLLED LTHOSPHERE (Il MIDDLE ELECTRODE, 1'%, -0n - OD | NoCH D BOTH $I0ES OF Wall BELOW LIGUID LEVEL . QUTER ELECTRDNE, 2% -in-00 [ NaOH ON WSIDE, GAS ON OUTSIDE, [ MOLTEN NaOH I il V27 aND OUTER CHAMBERS . e l=d - _f ~ L2 THERMOCOUPLE WELDED TO || ¥ BOTTOM OF INMER ELECTRODE Fig:s 2.6.1. NaOH-NI Electrolysis Apparatus. PHYSICAL PROPERTIES OF ELASTOMERS EXPOSED TO ATTACK BY LIQUID METALS D. Zucker The first in-service test of valve seot materiols exposed to helium saturated with NaK veopor was completed in the apparotus described previousty.” The system and valves were opened and washed with water, reassembled, and tested with helium at 30 psi. The appearance of the valve seats and their performance after reassembly indicate that General Electric SE-550 and SE-450, Dow-Corning Silastic 80, and Ou Pont 5570 withstoed NaK SD. Zucker, ANFP Quar. Prog. Rep. Dec. 31, 193¢, ORNL -2221, p 151. PERIOD ENDING MARCH 31,1957 UNCLASSIFIED ORML-LR—-DWG 20256 — g a £ f o : - HYOROGEM ATMO$PHERE§ I S . o el z = ——— = = i . — — i, | e - - | e u i 4 S — 605 = _ ] ) 1 | 0.02 ! L ! ] ,O 01 i . —— . = —_— ——— - o .4 08 |2 1.6 2.0 2.4 WOLTAGE (v) Fig. 2.6.2. HNoOH-Mi Voltage-Current Relationships Under Hydragen or Yacuum at 550°C. WHNCLASSIFIED DRNL—LR—DWG 20257 — 1 “CURRENT FLOWING — FROM INNER TO — _MIOOLE ELECTRODE o8 A 1) T CURREMNT FLOWING FROM MIDDLE TO INNER ELECTRODE a ol e S0 s | £ o | = = = = z . —1 = = Lt = = | { & = i 5 = — o 0.5 — — = | - = 4 | 02 e e = i b S e o Q4 o8 b2 16 20 2.4 VOLTAGE (v} Fig. 2.6.2. MNaOH-Ni ¥oltage-Courrent Relationships Under Hydrogen ot 804°C, 135 ANP PROJECT PROGRESS REPORT attack fairly well, with SE-5350 possibly being very slightly better thon the other moterials. These materials connot be used directly in the Skinner electric valves currently being supplied for use in the ART, but they might be acceptable if the edge of the volve orifice were rounded, 136 A cursory test also indicated that curing by heating (200°C) and pressurizing of these materials for 24 hr increased their resistonce to cottock. The reason for this is not obvious, since these elastomers were probably heat treated previously at higher temperatyres although not under pressure. n PERIOD ENDING MARCH 31,1957 2,7. ANALYTICAL CHEMISTRY J. C. White DETECTION OF TRACES OF NoK IN AIR A, 5, Meyer, Jr. J. P. Young The apparatus for the detection of submicrogram quantities of sodium (NaK) in air wos assembled and subjected to preliminary testing. made with this instrument, which was discussed Measurements previously,! are based on the absorbance of sodium resonance radiation by sodium atoms, The instru. ment is illustrated in Fig. 2.7.1, In the compartment on the right, the light from o sodium vepor lomp (not shown) is collimated by a simple lens. The collimated light posses through a mechanical chopper, which consisfs of o disk perforated to pass light through three equally spaced 60-deg sectors. The disk is rotated ot 30 ¢ps by a synchro- nous motor. The interrupted light passes through ‘A. S, Meyer, Ir., et al., ANP Quar. Prog, Rep. March 10, 1956, ORNL-2061, p 207. J. R, Sites limiting circular apertures 3’2 in. in diometer to produce the two beams of light shown in the central porticn of the photograph, The copertures con be rotated about axes through their centers that are perpendicular te the radius of the chopper in order Under conditions of exoct alignment and balance the light to balance the energy in the two beams. ts collimated into two beoms of equal intensity, and eoch beom is interrupted ot a frequency of 90 cps in a manner which maintains the total ensrgy of the two beams constant. In the through a 20-mp bandspass interference filter, and the sodium-sodium doublet at 5890 A is isoloted. Both beams of light are focused by a converging lens on the cothode of a photomultiplier tube. The output of the photomultiplier tube is fed to a $0-cycle tuned amplitier 1o yield o signat that is proportionasl te the difference in intensity of the two beoms of light. second comparimen! the light passes UNCL ASSIFIED FHOTS 19304 AMPLIFIER il FOWER SUPPLY ~ A P Fig. 2.7.1. Apporatus for the Detection of Submicrogram Quantities of Sodium in Air., 137 ANP PROJECT PROGRESS REPORT In the tests which were carried out, a 5-in.-1D fube furnace was placed between the two optical com- ponents of the instrument. Absorption celis, con- structed of 24-in. lengths of :}:‘-in.-diu Inconel tubing and fitted with end windows of optical quartz, were ploced in the furnace so that each light beam traoversed an chsorption cell, After the furnocce was heated, the optical components were aligned and the instrument was balanced by rotating the spertures until a minimum signal wos abserved A sample of sodium-containing air, which wos prepaored by admitting meosured quantities of helium thot had been saturcted with sodium vapor to a stream of air, was introduced into one of the absorption tubes, and the deflection of the cutput meter wos observed. When o sample calculated to contain 25¢ ppb of sodium was introduced into the absorption tube, the observed signal produced o deflection equal to twice that of the original balance of the meter. On the basis ofthe observed stability of the instrument, it was found that 100 ppb of sodium could be easily detected. As was reported,? however, the technique on the ocutput meter of the amplifier, used for the preparation of somples of sodium- containing air did not yield quantitative fransfer of sodium to the air, ond thus these preliminary measurements may not truly reflect the sensitivity of this instrument, It wos found that no evidence of sodium could be observed when the effluent gases containing the sodium from the ocbsorption tube were pessed through an air-propane flame, It oppears that the stipulated limit of detection of 10 ppb of sodium can be achieved by oppropriate sampling techniques and refinements in the alignment of the instrument. Tests were carried out for selecting o suitable material tc use in the fabrication of orifices with which to inject small quantities of NaK into air, Zirconivm was the only satisfactory material found among the materials tested. A 0,003-in, orifice in crystal-bar zirconium was entarged less than 20% by the ejection of NaK for o period of 30 min at o temperature of 450°C., Under these conditions nickel, type 316 stainless steel, and molybdenum are severely corroded by the oxides of the alkali metals. Measurements of the flow rates of NoK through small orifices indicate that orifices approximately 0,002 in. Inconel, in diamerer will be required in order to mcintain a sufficiently QA. 3. Meyer, Jr., ond J. P, Young, ANFP Quar. FProg. Sept, 10, 1956, ORNL-2157, p 129. 138 small How of NaK to provide fest samples for the leok detectors. Since holes of this diameter connot be readily mochined, electralytic methods of drilling® ore being investigoted, DETERMINATION OF OXYGEN IN METALLIC LITHIUM A. S, Meyer, Jr. G. Goldberg R. E. Feathers A method is being tested for the determination of traces of oxygen in metallic lithium that is based on the following reactions 2Li + 2CH,0H ——> 2Li0CH, + H, ti,0 + 2CH,OH ——— 2Li0CH, + H,0 LiOCH, + C,H O, (solicylic acid) ———> LiC,H G, +CH,OH and the subsequent measurement of the water by the Karl Fischer titration. developed by Nuclear Development Corporation of America,® offers a unique advantage in that the The procedure, which was sample can be washed free of surface contamination immediately before the determination is perfarmed. The determination is carried out in the apporatus shown in Fig. 2.7.2. A sample {~] g) is placed in the reaction vessel, and the opparatus is freed of oxygen by evacuation and purging with helium, Surface oxide is removed by transferring three 20-ml portions of dried methanol from the titration flask to the reactien vessel ond allowing eoch portion to react for 1 min ot room temperature. After she final wash solution has been withdrawn, a 60-ml volume of methanol is transferred from the titration flask to the reaction vessel, ond the sample is dissolved by gentle heating. A 20-ml portion of a 50% solution of salicylic acidin pyridine that has been pretitrated to the Karl Fischer end point is admitted to the titration Hosk, and, when the dissolution is com- pleted in the reaction vessel, the sofution of lithium methylate ond water is tronsferred to the titration flask. The solution in the titration flask is then retitrated to the Korl Fischer end peoint. The titration is corrected by subsitracting the volume of Karl Fischer reagent thot is required to titrote a 60-ml portion of methanol. 3A. Uktic, Jr., Rew. Sei Instr. 10, 965 (1955). I{N. l. Sox, private communication to J. C. White. 300-mi SEPARATORY FUMNNE L SOLUTION OF SALICYLIC ACID N PYRIDINE METHANQL IN MACHLETTE BURET HARL FISHER REAGENT ELECTROCES N MACHLETTE BURET - & 250-mi TITAATION FLASK DRAIN e T " MAGNETIC STIRRER PERIOD ENDING MARCH 11,1957 WNCLASSIFIED CRNL-LR-DWG 12874 FRESSURE RELELSE \ {___—’_‘,} HEL UM VaCluwm . ! WATER JACKET REACTION VESSEL L —— LITHIUM SAMPLE 3 HELIUM VaCcuUumM g e e —— Flg. 2.7.2. Apporotus for the Detarmination of Oxygen in Metallle Lithium by the Methanol Method, The salicylic acid is used to drive the second reaction to completion and to eliminate the inter- The contaminants, Li,C, and Li,N, which interfere with the determination of oxygen by the omolgamation procedure, are decomposed according to the following reactions: ference of lithium methylote in the titration. common Li,C, + 2C,H,0, —> 2LIC,H, O, + CH, | LiN + 4C,H Oy ——— 3LIiC,H,0, + NH4C1H503 Since at least 60 ml of methanol is required to dissolve a 1-g sample of lithium metal, the methanol must be thoroughly dried to avoid high blank fti- trations and consequent loss of precision in the determination of traces of oxygen. Metheds for drying methonol were tested that inciude distillation, possage through chrometegraphic columns packed with molecular sieves, vopor phase drying over molecular sieves, anddrying over oxides of alkaline- earth metals. Theconcentration of water inmethanol was reduced to less than 10 ppm by distittation through a 100-plote fractionation column after preliminary drying over barium oxide. Alkoline- earth ond alkali metals cre being tested as drying agents in an effort to find o less time-consuming method of reagent preparation. A pressurized apparatus for the dissolution of somples of lithjum metal in ethereal solutions of butyl iodide and iodine® was constructed, It is anticipated that in the pressurized apparatus the dissolution of samples can be carried out with smaller volumes of liquid reagents than are required for the dissolution of atmospheric pressure, and thus the effect of contaminents in the reagents con be reduced. SA. S. Meyer, Jr., et al., ANP Quar. Prog. Rep. Sept. 10, 1956, DgNL-ZIS?, p 127. 139 ANP PROJECT PROGRESS REPORT APPARATUS FOR SAMPLING AND ANALYZING ALKAL) METALS A, S. Meyer, Jr. R. E. Feathers G, Geldberg A convenient receiver and transfer vessel was designed for the handling of samples of alkali metals, The opparotus, which is shown in Fig. 2.7.3, consists of a Jamesbury volve fitted with a vacuum-tight compaortment at one end and coupled by a Tygon sieeve to o stondard taper joint ot the- opposite end. When the apporatus is fitted 1o the complementary joint of the analyticel apparotus, the tronsfer of the somple of alkali meta! con be UNCLASSIFIED ORNL-LR-DOWG 19875 - f}}il |1 [l =——29/42 STANDARD TAPER ol PYREX JOINT TYGON TUBING I H—u STAINLESS STEEL PIPE =—- TEFLON -PACKED JAMESBURY VALVE —STAINLESS STEEL SAMPLE RECEIVER Fig. 2.7.3. Tronsfer Receiver for Alkali-Metal Somples. 140 corried out without atmospheric contamination, The transfer vessel can be loaded in a suitable inert- atmosphere dry box. It is also ideally suvited for use with the modified Mine Sofety Appliances Co. bucket sampler,® Sample buckets filled with NaK can be tronsferred if the apparatus is kept under refrigeration, A high-vacuum dry box that will have o 10-ft? work chamber is being assembled for processing samples of alkeli metals. It is to be equipped with an evacuable entrance port, a high-capacity diffusion pump, and a purification train for inert gases which includes heated scrubbers containing titanium and Nal(, An dpparotus for the purification of mercury by distillotion was constructed and is now in service. The two-stage still used for the purification hos @ totel capacity of 30 |b of mercury per day. The apparatus is used to remove traces of oxide ond water from mercury in order to eliminate errors in the determination of oxygen in sodium by the amalgomation method and also to reprocess the large quantities of mercury which are reguired in the amalgamation procedure, ANALYSESOF LITHIUM-BASE FLUORIDE 3ALTS FOR METALLIC IMPURITIES The development program on the application of nickel-molybdenum atloys as container materials for fused lithium-base flyoride salts has necessitated o number of modifications in existing methods for the analysis of metallic impurities in the fluoride salts. In additien to the usuval determinations fer iron, chromium, and nickel, the sclts are presently being onalyzed for molybdenum, niobium, titanium, tungsten, vonadiuvm, and aluminum, Methods for determining all these metals were developed previ- ously, but some modifications were necessory in the methods used for the aluminum, vanodium, and titanium analyses in order to eliminate interferences introduced by the presence of other metals. The status af the work on the modifications is given in the following sections. Aluminum W. F. Vaughan The determination of microgram quantities of aluminum in fluoride soits with the use of the Y Goldberg, A. S Meyer, Jr., ond J, C. White, The Sampling of Alkali Metal Systems with the Modijied MSA Sampler, ORNL-2147 {Aug. 21, 1956). ammonium salt of aurin tricerboxylic acid (Aluminon) is subject to interference from zircenium, iron, titanium, ond vanadium, White and Meyer’ removed these interfering metals by precipitating them as the insoluble cupferrate salts. As a result of more recent work by Ross® on the extraction of metal ions with tri-n-octylphosphine oxide from ocidic solutions, these metals are now removed by extracting them from a chloride solution. The separation is complete in obout 10 min. The aqueous phase is then free of iron, titanium, vanadium, zirconium, and uronium, and the aluminum is essentially isoloted. Vanadium J. P. Young J. R. French The method of Wise and Brandt® for the determi- nation of microgram quontities of pentavalent vonadium with benzohydroxamic ocid was applied to fused fluoride salts, The method is based on the reaction of vanadium(V} with benzohydroxamie acid at ¢ pH of 2.0 to produce a complex which exhibits on absorption maximum ot 450 my in a The melar absorbance index of this complex is 3500, A linear relationship exists 1-hexanol medium. between cbsorbance ond the concentration of the vanadium in the complex in the range of 1 to @ ig/ml. The coefficient of variation for this method, based on standards, is 2%. Most of the interfering ions, including nickel, iron, chromium, ond molybdenum, are removed by deposition at the mercury cathode. Although the vanadium is reduced to the quadrivalent oxidetion state by the mercury cothode, it remains in solution and is accompanied by the uronium, alumiaum, and titanium. Argentic oxide, AgQO, is then used to oxidize the vanadium to the pentavalent state. As much as 50 mp of uraniy.n can be tolercted in ihe final determination, When the ratio of either alumi- num or titanium to vanadiom greatly exceeds five, howewver, positive errors Miobium and vanadivm ordinarily do not exist together in these samples, so the possible effect of niobium on the determination ef vanodium waos not studied. result, 7), C. White and A. S, Meyer, Jr., Determination of Traces of Aluminum in NflF—ZrF4—UF4, ORNL CF-56-310 {March 1, 1956). 8w, .. Ross, Extraction of the Elements with Trioctyl- phosp hine Oxide from Acidic Solutions, ORNL CF-56-9- 18 (Sept. 6, 1958). "W, M. Wise and W. W. Brondt, Anal. Chem. 27, 1392 (1955). PERIOD ENDING MARCH 31,7957 Titanium J. P. Young 1. R, French The established method for the determination of trace amounts of titanium'? in fused fluoride salts include titanium in the presence of niobium and molybdenum, was extended to the determination of Since niobiym and molybdenum interfere with the determination of titonium by the Tiron merhod,w it was necessary fo develop some means of removing these interferences. The oddition of sodium hydro- sulfite to reduce the iron{lll) also reduced the molybdenum and thus decreased but did not coms. pletely eliminate the interference of molybdenum. In the determination of titanium in NaF.ZrF .UF , quantitotive separation of the titanium was achieved by an amimonia precipitotion in the presence of corbonate ion. The seporation was adequate to eliminate the interference of molybdenum in the determination of the titonium, Quantitative separation of titanium from the niebium was achieved by an ether extraction of the The nicbhium thio- cyanate complex extracted quantitatively into the ether phase, whereas the titanium thiocyanate com- two metals as thiocyonates. plex did not extract. The titanium in the aqueous phase is determined by the Tiron methed. SPECTROPHOTOMETRIC DETERMINATION OF NICKEL IN ALKAL] METALS A, 5. Meyer, Jr. B. L. McDowell The dioxime derivotive, 4-isopropyl-1,2-cyclo- hexonedionedioxime, which was reported ' to be a very sensitive recgent for nicke!, wos investigoted further, In order to increase the sensitivity of the determination of nicke! by extraction when the ratio of the aqueocus volume to the orgonic veolume is large, organic compounds were investigoted that are less water soluble thon the chloroform used initially, 12 Hydrocarbons, chlorinated hydrocarbons, esters, alcohols, ond aromotic compounds were tested as extroctonts for the nickel chelate, but 19, ¢ White, Determination of Microgram Amounts of Titanium in the Presence of NdF-ZrF‘-UF‘i, ORNL CF- 366111 (June 20, 1958). Mp, 1, Hooker and C. V. Bonks, Preparation, Proper- tzes, and Analytical Applications of 3ome Substituted Alicyelic Vie-Dioximes, |5C-597 {March 1955). 124 5. Meyer, Jr., B. L. McDowell, and R. E. Feathers, .Jr.f ANP Quar. Prog. Rep. Dec, 31, 1956, ORNL-222], p 141 ANP PROJECT PROGRESS REPORT onfy benzene and xylene proved to be better than chloroferm, The melar absorbonce index for the chelate at the absorption maximum of 385 my was unoffected by the solvent, The partition coef- ficients, however, were much higher for the chelate in both benzene {1000} and xylene {5000) than in chlaroform (300). la view of these more favorable partition coefficients, it will be possible to de- termine even lower concentrations of nickel thon the previously postulated'? 0.5 ppm in a 5-g sample of alkali metal, The two eiements that most commonly interfere with the determination of nickel in alkali-metcl Methods for the elimination of each of these elements were therefore developed. Copper{!l) is reduced to copper(i), and the reduced copper is complexed with thiocyencte ion 1o prevent the extraction of copper as the dioxime complex. The interference of iron(lIl} was eliminated by the oddition of fluoride. Since the Huoride ion inhibits the precipitation of zirconium upon neutralization of the selution, this procedure can also be applied to the determination of nickel in solutions of zirconium- or lithium-base fuels, samples are iron and copper. DETERMINATION OF TRACE AMOUNTS OF ZIRCOMNIUM IN SULFATE SOLUTIONS WiITH PYROCATECHOL VIOLET J. P. Young J. R. French Experimental work on the determination of trace amounts of zirconium '3+ in solutions of sulfuric ocid with pyrocotechol violet wos completed, as well as o study of the interference caused by various cations., The data obtained in this in- vestigotion are summarized in Tabie 2.7.1. Microgram omounts of zirconium ia suliate so- lutions can be determined in the presence of high concentrations of thorium, wvranyl, cerium, ond lanthanum ions, |t was possible 1o determine zirconium with a coefficient of variation of 2% even in the presence of more unfovorable rotios of cerium and lanthanum by lowering the fina!l pH of the test solution to 4.5. The determination of zirconium with pyrocatechol vialet is unaffected by the presence of anions such as chloride, perchiorate, nitrate, or borate. Small 13_]. P. Young ond J. R. French, ANP Quar Prog, Rep. Dec. 31, 1956, ORNL-222), p 165. 144, Floschko ond F. Z. Sodek, Z. anal. Chem 150, 339 {1954). 142 Table 2,7.1. Effect of Catlons on the Spectrophotometric Determinotion of Zirconium ia Sulfate Selutions wlth Pyrocatechol ¥Yiclet Concentration of zirconium: 1.2 ug/ml Weight Ratio Error Resulting from Cotion of Cation te Pressure of Cation Zirconium (%) Th? 10 5 Lad? 30 5 Ce” 15 5 vo,?’ 30 0 TR 3 5 NI 15 0 Cr6+ 15 Q ct? 15 0 Fod* 6 5 Fe2’ 6 5 sod? 6 5 Ti4%, v, VAR YL 1 20 amounts of aniens such as citrote, oxalate, tartrate, fluoride, and ethylenediominetetraccetate, however, will destroy the color of the complex. The coef- ficient of variation for this methed, based on the determination of zirconium in stondords, is 2%. CETERMINATION OF SULFUR IN FLUORIDE FUELS T. W. Gilbert, Jr. The methylene-blue method'® for the determi- nation of small omounts of sulfur in fused fluoride tuels was modified by the substitution of a new reducing selution for the mixture of red phosphorus, hydriodic acid, and formic acid that was previously used, The new solution, prepored by dissolving stapnous chloride in dehydrated ohosphoric acid, 155, C. White and G. Goldberg, ANP Quar. Prog. Rep. Dec. 10, 1954, ORNL-1816, p 131. wds reported to reduce sulfates quantitatively to hydrogen sulfide,'® and therefore experiments were carried out to test the efficiency of this solution for reducing microgram quontities of sulfote and to test its applicability to the determination of sulfur in fluoride salts. Difficulty wos experienced with the red phospho- rus reducing mixture when the sample size was increased beyond 200 mg, and therefore the phos- phoric acid mixture, which can conveniently handle l-g samples, has en important advantage in that a fivetold increose in sensitivity is achieved., A second advantage of the phosphoric acid reducing mixture is that the fluoride sclts are decomposed. Uronium tetrafluoride is brought into selution, and zirconivm fluoride is converted to zirconium phosphate, The determination is carried out by adding about 20 ml of a solution of snCl, and phospheric acid to o 1-g sample of fluoride salt. Boric anhydride is then added to complex the fluoride and to mini- mize etching of the gloss apparatus. The phos- phoric acid solution is heated to 300 to 310°C to reduce the sulfates to hydrogen sulfide, which is passed into a solution of zinc acetate by means of a stream of orgon. The quontity of hydrogen sulfide is then determined by the methylene blue procedure. The coefficient of variation of the method was found to be approximately 10% for 5- to 20-pg quantities of sulfur, OXIDATION OF CHROMIUM WITH ARGENTIC OXIDE J. P. Yeung J. R. French A method for the oxidation of chromivm with argentic oxide, Ag(D, reported by Lingene and Davis,'” was investigated for use in the spectro- photometric determination of chromium with di- Lingane ond Davis report that argentic oxide serves advontagecusly as a very powerful oxidimetric reagent in acid media. They recommend AgQ for the oxidotien of manganese, cerigm, or chromium prior to volumetric determi- nations of these metals. Oxidotion with orgentic oxide is ropid and complete for these ions in 2 to 5M acid at room temperature. phenylcarbozide, U1 Kiba er al., Buli. Chem Soc. Japan 28, 641 (1955). ”J. J. Lingane and D. G. Dawvis, Anal. Chim Acta 15, 207 {1958). PERIOD ENDING MARCH 31,1957 A standard solution of potassium dichromate was used in order to establish & calibration curve for the chromium determination by the diphenylcorbazide methed. The chromium in o portion of the standard solutien was reduced with hydrogen peroxide to vield o standord solution of chromium{lll). The calibration curve obtained from the sclution of chromiom(l1]) after oxidation of the chromium with argentic oxide waos identical, within experimentol error, with the ocne cbtained with chromium(VI). |t is recommended that the solution be boiled for several minutes to ensure the reduction of all the excess silver(l}), These investigations indicate that oxidation of the chromivm with argentic oxide con reploce oxidation with perchloric acid in the colorimetric determination of chromium with diphenylcarbazide. The use of argentic oxide results in @ considerable saving of time in the oxidation step. [t is further expected thot oxidation with argentic oxide will produce results which are ot least as precise as those obteined by the present method, An investi. gation of this latter point is presently being carried out, SOLVENT EXTRACTION OF MOLYBDENUM FROM ACIDIC SOLUTIONS WITH TRI+n-QCTYLPHOSPHINE OXIDE W. J. Ross 180 the isclotion, concentration, Previous success and determination of elements encountered in ART fuels, corrosion products, and fission products through sclvent extraction of these elements with tri-n-octylphosphine oxide (TQPQ) has led to o continued study of the anolytical applications of this reagent, It wos found that hexavalent melybde- num is amenable to separation from acidic soluticns by extraction with tri-n-octylphosphine oxide. A systematic study of the variables involved in the extraction showed that hexavalent melybdenum can be concenirated greoter thoan a hundredfold by o single extroction with §,) M TOPO in cyclohexane from HCl and that as much as 20 mg of Mo®* con be quantitatively extracted by 0.5 mmole of this reagent, Less efficient extractions are obtained from stod' HNO,, or HCIO, systems. The extent of the ex- troction is highly dependent on the acid concen- tration of the aqueous phase, and therefore under - aa Yy, 1, Ross, ANP Quar. Prog. Rep. Dec. 31, 1956, ORNL-2221, p 147. 143 certajn conditions practically no extroction is obtained from sulfate, nitrate, or perchlorate media. Extroction with tri-n-octylphesphine oxide is thus o rapid means of isoloting or concentrating hexo- valent molybdenum in either the aqueous or erganic phase. PREPARATION OF RARE-EARTH FLUORIDE TRACERS A. S. Mevyer, Jr, G. Goldberg The precipitation procedure described previausly V¥ wos used for the preparction of additional samples of radicactive tagged tuoride saits. The salts pre- pared were Y7 l.bearing YF,, Ce"“-beoring Cef,, Sm %% bearing SmF,, Bal33.bearing BaF,, and Lo '*C-bearing lLaF, in amounts that voried from 100 to 500 g. The somples contained from 1 10 3 mc of total activity. SERVYICE LABORATORY W, F. Youghan The 1428 samples analyzed during the guorter involved 5746 determinations for an average of 4.0 per sample., A breakdown of the work according to the group requesting the cnalyses is given below: Number of Humber of Somgples Reported Results Ragector Chemistry &66 2255 Exparimental 589 2431 Enginzering Metallurgy 28 33 Miscellaneous 145 1027 Tetal 1428 5746 a5 Meyer, Jr., and G. Goldberg, ANF Quar. Prog. Rep. Dec. 31, 1956, ORNL-2221, p 186, 144 YAPOR-PHASE POLYMERS IN ALKALI-HALIDE SALTS L. Q. Gilpatrick A knowledge of the composition of the vapor phase of the fused-salt fuel mixture is important to the investigation of the vapor-deposition problem in circutating-fuel reactors, It is alsc indispensable for the measurement of activities of components of salt mixtures when vopor-pressure methods of Therefore o study of the vapor phase of alkoli-halide sclts was initiated. It has been reported??=22 that the equilibrium vapor phase of mony simple moterials, such as copper chloride, carbon, and petassium chloride, contain simple polymeric species that are most frequently dimers and trimers. When the olkali- halide salts ore heated in on effusion cell, it is possible to meosure the change in the vopor com- position as o function of cell temperature. The mass spectrometer is well suited for application te this proeblem, since with it the species which are derived from polymers in the vapor con be measured measurement ore used. independently, Onlyrelative values can be measured with the use of this technique; however, energies or heats of vaporization and the heats of palymerization can be determined from the retative values, The mass spectrometer is also o sensitive tool for the qualitative examiration of the vapor phase of halide salts and other moterials, A satisfactory effusion cetl wos developed, and potassium chloride is currentlty being examined at temperatures from 550 to 750°C. Preliminary values for the energy of vaporization of KCi monomer and dimer were found to be 49.3 and 58.3 kecol/mole, respectively, No higher polymers were detected. The next salts to be exomined will be the olkali fluorides, since they are of interest in the investi- gotion of fused-salt fuel systems. 2041, M. Rosenstock et al., J. Chem Phys. 23, 2442 {19255). 2) | Grewer, P, W. Gilles, and F. A. Jonkins, J. Chem. Phys. 16, 797807 {1948). 225, C. Miller ond P. Kusch, J. Chem Phys. 25, 860 876 (1956). Part 3 METALLURGY W. D. Manly 3.1, DYNAMIC CORROSION STUDIES J. H. DeVan FORCED-CIRCULATION LOOP TESTS J. H. DeVon R. 5. Crouse Fuel Mixtures in Inconel and in Hastelloy B Three forced-circulation loops fobricated of Hastelloy B were examined that had circulated NaF-KF-LiF-UF , (11.2-41-45.3-2,5 mole %, fuel 107) at a maximum flyid temperotyre of about 1650°F, The loops were heated by direct elec- trical resistonce and were constructed from !’Q-in.- 0D, 0.060-in,-wail tubing, The operating con- ditions for these three loops are given in Table 311, Two of the loops completed 1000 hr of operation, although interruptions that required temporary shutdowns occurred during both tests. Loop 7641-18 developed o leak while fuel was being admitted to the loop for o test run, The loop was successfully repaired, and it then operated for the scheduled 1000-hr period without further diffi- culties. Loop 7641-2B developed a leak after 65 hr of operation and was likewise repaired and operated for the remainder of the scheduled 1000-hr period, Operation of the third loop, 7641-3, was terminated by a pump tfailure ofter 407 hr of opera- tion, The hot legs of all three loops were found to be badly pitted after the tests, with the pits in the most heovily attacked areas reaching to o depth of 4 mils, Unfortunctetly, the surfaces of the as- received Hastefloy B tybing were rough, as shown by the sample in Fig. 3.1.1, and thus o large part of the pitting was probably present before the test. The cold-leg sectiens of loops 7641-18 and 7641-3 were entirely free of metal deposits, but they had deeper surface imperfections thaan those found in the hot-leg sections, In some areas of the cold legs the pits reached a depth of 7 mils; however, as may be seen in Fig. 3.1,2, which shows a cold-leg section of loop 7641-1B, the surface imperfections appear to be the result of corrosion deepening of the pits present before the test, The examination of loop 7641-2B likewise re- vealed deeper pits in the cold leg than in the hot leg. In contrast to the other two foops, joop 7641.2B, however, was found to have o few small metal crystals in the cold leq. These crystalline depesits occurred in clumps, opproximately 2 mils thick, that were confined to g short section of the loop near the cold-leg outlet, As shown in Fig. 3.1.3 the crystals were completely detached from the loop wall., The quentity of deposited material was insufficient for ¢ chemical analysis, ond it s not known whether the crystals resulted from groins becoming detached from the extremely rough as-received surfaces or from a mass-transfer mechanism, Loop 7641-2B operated with the lowest Reynolds number used in the three tests, and it is doubtiui that mass transfer would take Table 3.1.T Conditions of Operation of Three Hastelloy B Forced-Circulation Loops with NaF-KF-LiF-UF , (11.2-41-45.3-2,3 Mole %, Fuel 107} Temperature grodient: 300°F Ratio of hot-leg surface area to loop volume: 2.2 in2/in.3 Operating Conditiong Moximum fuel mixture temperature, °F Moximum tube wall temperoture, OF Revnolds number of fyel Yelocity of lual, fps Qpercting time, hr Loop Number 7641-1B 7641-28 7641-3 1635 1640 1660 1767 1710 1750 10,000 5,500 10,000 2.613 1.16 2.61 1000 1000 407 147 ANP PROJECT PROGRESS REPORT Fig. 3.1.1. As-Received Hastelloy B Tubing. Etchant: " o T G L alE Fig- 3-]‘.2. Area of Deep Pitting in Cold Leg of Hastelloy B Forced-Cirevlotion Loop 7641-TB Which Circolared I\fcnl':-'l"CF-LiF-UF4 (11.2-41-45.3-2.5 Mole %, Fuel 107} Under the Conditions Given in Takle 3.1.1, Riddle's reogent. 250X, Reduced 32%, {Secret with caption) Etchant: 148 LNCL ASSIFIED T-1181% ; i " - _. i 3 b o3 E = - ;-. i 5 i 014 + ¥ 3 o "‘_’—] # £ i - a5 I ¥ 5 A o » = 3 .--- = ' . ‘,.‘ L] b - . Q18 Riddle's reagent. 250X, Fig. 3.1.3, Hastelley B Lcop 7641-2B Which Cireulated MoF-KF- LiF-UFA {11.2-41-45,3.2.5 Mole %, Fuel 107) Under the Crystols Found Near Cold-Leg Qutlet of Conditions Given in Table 3.1.1. Raduced 32%. (Secret with caption) Unetched., 250X, place in this loop and not in the others, Analyses of the fuel mixtures used in these tests showed no significant changes in any of the metal con- during the tests. The resutts of the analyses ore presented in Toble 3,1.2, An Inconel forced-circulation loop (7425-20) was stituents operated at a maximum fluid temperature of cpproxi- mately 1700°F in order to complete studies of the effect of temperature on the corresion of Inconel by NaF-ZrF -UF, (50-46-4 mole %, fuel 30), The maximum wall temperature of the loop was 1840°F, PERICGD ENDING MARCH 31,1957 and the fluid temperature drop between the hot-leg cold-leg outlets was 300°F, Other loop opercting conditions are given in Table 3.1.3. After 1000 hr of operation, voids were observed in the hot feg to a moximum depth of 9 mils. In addi- tion to the hot-leg otteck there were a few scattered particles of metal deposited on cold-leg surfoces, The deposits contained chromium and, peossibly, on the basis of etching characteristics, some vranium or zirconium compounds. The attock on this loop was 4 to 5 mils greater than the attack and Tabie 3.1.2, Anulyses of NoF-K E:-LiF-LIF4 (11.2-41-45,3-2.5 Mole %) Mixtures Circulated in Hostelloy B Forced-Circulation Loops Uraoium Cantent Metel Constituents (ppm) L.oop MNa, Sample Taken e . {wt %) i Cr Fe Mo 7641-1B During filling 13.7 160 128 150 <2 After operation 12.4 85 330 95 <2 764)-28 During filling 13.0 195 1§D 165 <2 After operation 12.8 185 325 120 2 7641-3 During filling 13.0 20 35 55 15 After operation 12.6 205 270 75 9 Toble 3.2.3. Conditions of Operation of Three Inconel Forced-Circulation Loops with Fuel Mixtures Loop Number Operating Conditions 7425.20 Fuel mixture fuel 30) Maximum fue! mixture tempergture, °F 1715 Maximum tube wall temperature, °F 1840 Raynalds number of fuel 23,700 Velocity of fuel, fps 5.0 Operating time, hr 1000 Ratio of hotleg surfocs arec to 2.21 leop volume, i:1.2,"'in.:3 Temperoture gradient, °F 300 NaF-Zr F4-U Fd (50-46~-d mole %, 7425-25 742526 Ma F-ZrFé-UF‘i (50-46-4 mola %, (56-39-5 mole % fuel 30) fuel 70) 1620 1510 1710 15615 5,800 14,000 2.54 4.79 500 716.5 2.15 2,15 360 200 149 ANP PROJECT PROGRESS REPORT of Inconel loops operated previously with a tuel temperature of 1500°F, a wall temperature of 1600°F, and a temperature differentiol of 200°F,! Examination of ancther Inconel forced-circulation locp (7425.25) that operated 500 hr with fuel mix- ture No, 30 also revealed hot-leg attack to a depth of 5 mils, but no cold-leg deposits were found. A third Inconel forced-circulation loop was operated with fuel mixture 70, NaF-ZrF .UF, (56-39-5 mole %). The results of two other forced- circulation loop tests which compared the corrosion properties of this fuel mixture with those of the more commonly used mixture 30, NaF-ZrF -UF, (50-46-4 mole %), were reported previously,?2 |In this lotest test in the series the {oop operated with a maximum fuel temperature of approximately 1500°F and a maximum wall temperature of about 1600°F, Other operating conditions for this loop, 7425-26, are given in Table 3.1,3. Although scheduled for 1000 hr, operation was terminated after only 716 hr because of a pump pulley failure. VYoid formation during operation progressed to a depth of 5 mils, in the cold leg that wos similor to the layers found in the Inconel loops operated previously with this A thin metallic layer was noted The layer wos too thin to provide material for chemical analysis, and attempts are now being made to determine its com- position spectrographically, The attack to a depth of 5 mils in this loop is similar to the 7 mils of ottack in each of the two loops operated previously with fue!l 70 for 1000 hr, One of these latter loops operoted under tempero- ture conditions identical fo those for loop 7425-26, ~while the other loop operated with a maximum fluid temperature of about 1650°F. The depths and type of attack in these loops are similar to the results cbtained for loops that circuloted fuel 30 under similor fuel mixture. sufficient conditions, except for the presence of thin layers in the cold legs of loops that circulated fuel 7O. V:sible layers or deposits are not normally observed in loops that have circulated fuel 30, NaK in Inconel Studies were made of two Inconel forced-circula- tion loops that circutated NaK (56-44 wt %) and 1. H. DeVan end R. S. Crouse, ANP Quar. Prog. Rep. June 10, 1956, ORNI_-2104, p 133, 2). H. DeVan, ANP Quar. Prog. Rep. Sept. 10, 1956, ORNL-2157, p 135. 150 containad oxide cold traps operated ot 600 and 800°F. The design of the loop and cold trap is shown in Fig. 3.1.4. The data obtained with these loops, together with those cbtained from two loops operated previously with cold-trap temperatures of 100 and 300°F, respectively,®*? provide a bosis for an enalysis of the effeci of cold-trap operation on corrosion and mass transfer in Inconel-Nak systems. loop wes 1500G°F and the temperature drop across the cold-leg section was 300°F, All the loops were operated for 1000 hr. An investigotion of the design of the cold trap The maximum tluid temperature of each used in these loops was made prior to beginning these studies to determine the effectiveness of such a trap in controlling the oxide level. In a spectal test loop containing a bypass cold trap and a device known as a "'plugging meter,’’ NaK was circuloted isothermally ot 1500°F, and meas- vrements were made of the oxide concentration of the NaK under vorious conditions of cold-trap temperatures ond flow rates, The plugging meter was wsed to indicate the soturation temperature of sodium oxide in the NaK under each of the cold- trap opercting conditions, The scturation tempera- ture, together with published information on the solubility limits of sodium oxide in NaK as a function of temperature, was used to establish the oxide concentration, These tests demonstrated that the cold-trap operating temperature in the range from 100 to 1200°F accurately reflected the oxide concentration; that is, the oxide concentra- tion which existed in the NaK corresponded to the limit of solubility for sodium oxide in MaK at the cold-trap temperature, The effect on mass transfer of the various cold- trap operating temperotures Table 3.1.4. Samples token from the cold legs ot similar lacations in each of the loops are compared in Fig. 3.1.5. Difficulties in removing deposits from the walls of the loops, as discussed pre- viously,3 made it impossible to obtain weight determinations of the deposits found in loops 7439-1 and -3, However, in the loops with higher cold-trop temperotures (loops 7426-17 and -18) the deposiis were comprised of larger crystals which t5 summarized in 3.3. H. De¥Yan, E. A. Kovocevich, end R, 5, Crouss, r"-fii’{‘;’? Quar. Prog. Rep. March 10, 1956, ORML.-2061, p . ). H. DeVan and R. S, Crouse, ANP Quar. Prog. Rep. fune 10, 1956, ORNL-2106, p 135. 151 WOTE QIMENSIONS 1M INCHES . UNCLASSIFIED - _-\ SURGE Tank ORNL-LR- W3 15353 = CoLD TRAP ELECTROMAGNETIC ELECTROMAGHETIC [T PUMP _ FLGWME TER A S ..z'r 1 g .‘(,l‘:.’ | “ TO SUME ' \\ | Ry ., ™ . M TRAF PACKRED WITH INCONEL WIRE MESH Fig. 3.1.4. Design of Inconel Loop, lncluding Cold Traps, for Forced Circulotlon of Alkoli Metals, = B LS4 °1E HONYW ONIQN3 QOl¥3d ANP PROJECT PROCGRESS REPORT UNCLASSIFIED 19448 {fgl LOOP 7439-3 { &) LOOP 7439-1 UMCLASSIFIED UNELASSIFIED T-108%3 [-10872 Ll_‘_i_.\_i_u_] ONE INCH [} LOQOP 7426-18 (g} LOOP 7426 {7 Fig, 3.1.5, Mass.Transfer Deposits In Inconel Loops Which Circulated NoK ot o Maximum Temperature of 1500°F and o Temperoture Differential of 300°F with Cold Traps Operated ot Vorious Temperotures. {(a) Cold trap at 100°F, {6) 360°F. {c) 600°F. {d) 800°F. (Confidentiol with caption) 152 W Toble 3.1.4. Effect of Cold-Trap Operating Temperature on Moss Transfer In Inconel Loops that Circuloted NaK Minimum Moximum Weight Loop Cold-Trap Deposit af Metal Mo, Temperoture Thicknass= Daposited (°F) (mils) (g} 7439.3 100 ¥ o 74391 300 12 o 7426-17 800 20 6.29 *Determined by scroping deposits from loop wolls **MNot recorded. were more easily seporated frem the loop walls, The weights of the deposits in these loops show that a noticeoble increose in the quantity of ma- terial deposited was brought about by an increase in the cold-trap temperature from 600 to BOO°F, This increase is also reflected in the deposit thickness. A smaller difference in deposit thick- ness is apparent in comparing the results for the test with o cold-trap temperature of 600°F with those for the two tests with lower cold-trap tems peratures, Metallographic examinations of cold- ieg sections from these loops also indicate that the change in the amount of deposited material accompanying a decrease in cold-trap temperature below 600°F is less than the chonge from 800 to 500 P As mentioned above, the size of the particles comprising the deposits is opparently affected by the cold-trap temperature and the oxide concentra- tion. Deposits taken from similor sections of the toops operated with cold-trap temperatures of 100 and 800°F are comparad in Figs. 3.1.6 and 3.1.7. As con be seen, the average particle size of the crystals found in the loop which included o cold trap operated at BOO°F was considerably larger than that of the crystals from the loop operated with a cold-trap temperature of 100°F, The compe- sitions af the deposits did not vary with cold-trap temperafure; in all the loops, the deposits were found to contain approximately 90% Ni and 10% Cr. The results of these studies of the effect of oxides in Inconel-NaK systems show trends quite similor to those found in the results of tests of Inconel-sodium systems., The tests of Inconel- PERIOD ENDING MARCH 31,1957 UNCL ASSIFIED T8 PEEERR T T 1Nl'-IHE HERINENES % & Fig. 3.1.6. Mass-Tronsfer Deposits in lnconel Loop 7439.3 Which Circuloted NoK und Which lncluded a Cold Trap Thot Was Maintoined ot 100°F, Etchant: modified 150X, Reduced 35%, (Confidantial with URCLASSIFIED | T-11113 _ga1 | aquo regia. coption} 2 o LI (1L LE] o n o o [ e[ 1 1] | 1 I150% 11 T Mass-Transfer Deposits in Inconel Loop Fig. 3.15?- 7426.17 Which Cirevlated MNaK and Which Included @ Cold Trep Thot Was Maintoined ot BOO°F. Etchant: modified aquo regia. 150X. Reduced 9%. {Confidential with caption) 153 ANP PROJECT PROGRESS REPORT sodium systems, which were discussed previously® were carried out by making oxide additions directly to the sodium. The effects on mass transfer were small for oxide additions of 0.05 wt % and less but became significant at higher concentrations, Addi- tiona! data {not presented previcusly) showed that the deposit porticle size alsc increcsed as the oxide level increosed, A difference in the guantity of mass-transferred material in sedium-lnconel systems compared with thet in NaK-lnconel systems has now become apparent, The weighis of the deposits in the two recently tested NeK-Incenel systems are somewhat less thon one-half the weights of deposits found in sodium-inconel systems tested under similar temperature conditions, The thicknesses of the deposits found in both systems are comparable, although as discussed in conjunction with the first NaK ha-s.nr.,:3 thickness measurements do not cccu- rately reflect the weights of the deposits because the crystals comprising the deposits build up quite randomty and in discontinuous patches. The composition ond manner of deposition of the crystals in the two systems oppear to be identical, The average size of the crystals comprising the deposits in both systems is also similer, Thus it appears that the same mechanism for mass transfer exists in both systems but that the process pro- ceeds slower in NaK-lnconel systems than in sodivm-lnconel systems. Sodium in lnconel ond in Stainless Steel Two Inconel forced-circulation loops of a design similar 1o that shown in Fig. 3.1.4 were operated with sodium at ditferent velocities to evaluate the effect of flow rate on mass transfer. The sodium temperatures ranged from a maximum of 1500°F in the hof leg to a minimum of 1200°F in the ¢old leg. The pumps were operated at different power levels to establish sodium flow rotes of Both loops con- tained bypass cold traps fo maintain low oxide levels. Examinations of the toops following 1000 hr of operation revealed a substantial difference in the quantities of deposited material recovered from 1.5 and 3.0 gpm, respectively, the cold tegs. In the loop operated with ¢ sodium 5J. H. DeVan, ANP Quer. Prog. Rep. Dec. 13, 1955, ORNL-2012, p 105, 154 flow rate of 1.5 gpm (loop 7426-22), the deposit weighed 10.4 g, A doubled flow rate of 3.0 gpm (loop 7426-23) resulted in an increase in the weight of the deposit to 14.0 g. Hot-leg attack in both toops was in the form of intergrenular penetration and reached maximum depths of 2 mils in each case. [he average thickness of the deposit alsc varied with the flow rate, The thickness at the lower flow rote was 12 mils, while at the higher flow rate the thickness increased to 22 mils. Several other sodium loops have been operated at flow rates of 2.5 gpm, and the results can be compared with the results of tests described above, While the mojority of the loops operoted with o sodium flow rote of 2.5 gpm, each loop test in- corporated some variable which introduced o slight difference from the condifions described above, An averoge value of deposit weight for the tests which most closely simulated the conditions given above is 13 g. A plot of the data given above and the 13-g volue is presented in Fig. 3.1.8 to show the effect of flow rate, A type 304 stainless steel forced-circulation loop completed 1000 hr of operation with sodium at o maximum temperafure of 1500°F ond a tempero- ture drop of 300°F, The loop contained an oxide cold trap that was maintained ot 300°F., Visval examination of this loop revealed only slight traces of moss-transferred particles in cold portions, A QRNL =LA~ 0DWG Z0330 6.0 r — H———;-— —; — e _—I LOOP OPERATING PERIOD: 1000 hr 150 " HOT-LEG TEMPERATURE: 1500°F ™ g | | TEMPERATURE DIFFERENTIAL: 300°F = OXIDE COLD TRAP TEMPERATURE | 300°F o 1440 f + =+ ' e e a | 4 | 5 [ o t3 0 e l h_ P | ©o Ll g0 b J, - < 1 | i b~ | 1€ 0 | SODIUM FLOW RATE {qum) Fig. 3.1.8. Effect of Flow Rate on Mass Transfer in Inconel-Sodium Systems, ‘n typical cold-leg section is shown in Fig. 3.1.9, The deposits were similar in extent and oppearance to those which were observed in fype 316 stoinless steel loops operated under simifar conditions, 3 and were much less in amount than deposits found in comparable lnconel loops. The hot leg of the loop revealed slight surfoce pitting and void forma- tion to a depth of 2 miis, Long-Duration Tests of NaK and Sodium in Incone! An Inconel forced-circulation loop, 7439-51, was operated with NaK for 2760 hr to determine the long-ronge effects of a high-thermal gradient on mass transfer and corrosion in on Incenel-NaK system, Fig. 3.1.10 and operoted with a thermal gradient of 850°F and o moximum buik fluid temperoture of The loop wos of the design shown in UNCLASSIFIED 7426~25"" HONI ANO Fig. 3.1.9. Cold-Leg Section of a Type 304 Stainless Steel Forced-Circulation Leoop Which Circulated Sedium for 1000 hr at o Maxlmum Temperature of 1500°F and a Grodient of 300°F. Reduced 31.5%. {Confidantiol with caption) Tempercture PERIOD ENDING MARCH 31, 1957 1500°F, Fluid flow was meintained ot 1,28 gpm. After 2480 hr of operation, a [eak developed in the heater coil of the loop, ond the NaK had to be dumped, The heater coil was replaced, ond the loop was again put inte operation. Afrer an addi- tional 280 hr, operation was terminated when a similar leck developed in the new heater coil, Metallographic examination of the hot leg which wos removed from the loop after 2480 hr revealed light-to-heavy intergranular attack to o depth of 1.5 mils, A needlelike deposit, 7 mils in depth, was also observed in the section just beyond the heater coil where the loop first experienced a thermal gradient, The cooled coil, which was in operation an cdditional 280 hr, showed only light- to-moderate pifs, along with intergranular attack to a depth of 1 mil. Metal deposits reached a maxi- mum thickness of 14 mils in the section at the entrance to the cooled coil. A similar {oop was operated with sodium as the circulated fluid. Operation of this loop {7426-51) was terminated after 4000 hr, when a leak developed near the pump. The operating conditions, with the exception of the temperoture gradient, were similar to those for loop 7439-51, Because of the better heat tronsfer properties of sodium, a thermal gradient of BDO®F was achieved., Sodivm attack in the hot-leg section of the loop reached a maximum depth of 5 mils. A heavy deposit of metal crystals that reached o moximum thickness of 50 mils was found in the section at the entronce to the cooling coil. The depesit is shown in Fig, 3.1.11. Carbide precipitates were found at the surfaces of the inner walls of the tubing which hed been exposed to sodium and, to a lesser extent that varied with depth, in the wall of the tubing. The diffusion of carbon therefore appears to have pro- ceeded from the inner wall of the tubing into the tubing, ond thus the source of the carbon must have been the sadium, This loop contaired ¢ mechanical pump, and ¢ slight leak through the pump seal of the oil for lubricating the pump could have been responsible for the carburization found, The loops for these long-duration tests were of a unique design, and therefore the results cannot be compored directly with the results of other tests of shorter duration, observed in the loop which circulated sodium indi- cafe that moss transfer proceeds at a rate which The extensive deposits is not significantty diminished with time, clthough, based on the carburization observed in this loop, 155 ANP PROJECT PROGRESS REPORT UNCLASSIFIED | DRHL—LR-DWG 1535 fre G LN FiNnED-THLBE AR -CO0LED CONL A 'jtf\fi;f# 2 '.NGHI?S Fig. 3.1.11. Deposit Found in Cooled Coil of Incenel Loop 7426-51 Which Circulated Sodium for 4000 br at o Moximum Temperoture of 1500°F und o Thermal Gradient of 800°F. Etchant: modified agua regio, 100X, (Cenfi- dential with coption) 156 impurities may clso have contributed o mojor part to the moss-transfer process, THERMAL-CONYECTION LOOP TESTS J. H. DeVan E. A, Kovacevich D. A. Stoneburner NaF-KF-LiF-UF, and Sedium in Nickel- Melybdenum Alloys Fuel 107, — Corrosion tests of the experimental nickel-molybdenum alloys exposed to scdium and to NoF-KF-LiF-UF, (11.2-41-45,3-2.5 mole %, fuel 107) in thermal-convection loops were completed. The compositions of the alloys tested, the test conditions, and the results of metcllographic ex- aminations of as-tested specimens are given in Table 3.1,5. The daota show that a maximum hot-leg attack of 3 mils occurred in loops 1105 (16% Mo=-2% Al-— 1.5% Ti—bal Ni) and 1108 (17% Mo-2% Al-bal Ni). These results are in good agreement with the data regorted previously for materials with relotively high oluminum content. The attack wos accom- panied by high aluminum pickup in the fuel, as shown in Table 3.1,6. Loop 1093 {17/% Mo—7% Cr~bal Ni} showed hot- leg attack which wos somewhaot higher than that found previously in loops fabricated from material containing comporable amounts of chromium.® Also the attack changed from the moderate general sub- surface-void formation in the loops operated pre- viously to heavy general subsurface-void formation. Loop 1094 (20% Mo-7% Cr-2% Nb—1% Fe~bal Ni) revealed hot-leg attack similar to that for loop 1093, The addition of niobium and iren thus appecrs to have little effect on the corrosion of o nickel- molybdenum atloy centaining 7 wt % chromium., Hot-leg specimens from loops 1093 ond 1094 are pictured in Figs. 3.1.12 and 3.1.13. As may be seen in Toble 3.1.%, the concentration of chromium in the fuel of loop 1094 is also comparable to thot found in the fyel in other nickel- molybdenum alloys containing 7 wt % chromium, circulated Comparisons showed similor maximum depths of attack in loops 1094 and 1099, which were fabri- cated of alloys of similar composition except that the otloy used for loop 1099 contained 1 wt % ®E. A. Kovecavich and D, A, Stoneburner, ANP Quar, Prog. Rep. Dec. 31, 1956, ORNL-2221, p 179, PERIOD ENDING MARCH 31, 1957 aluminum, However, as shown in Table 3.1.6, the chromium buildup in the fuel of loop 1099 was somewhat higher than that reported for loop 1094, Also, the fuel from loop 1099 had a high aluminum content, Exomination of loop 1101 (16% Mo—5% Cr— 1.5% Ti-1% Al-bal Ni} also showed the usual high aluminum buildup found in the fuel after circu- lation in aluminum-containing alloys. The attack -um..mlmb ) T Tiesa et _'E:‘a‘_"_ i-fl_-!_l- : o Lt Lin !_ o r'—:‘ o | Fig. 3.1.12, Moximum Hot-Leg Attock Found In Thermal-Convection Leop 1093 (17% Mo—-7% Cr—bal NI} Which Operated for 500 hr with NaF.KF-LIF-UF, (11.2- 41-45.3-2,5 Mole %, Fuel 107) ot 1500°F. Erchans: aqua regia. 250X, Reduced 32,5%. (Sacret with caption) b & r T IHCHES T 1 EREEEE 3 = o - 7 ko Fig. 3.1.13. Maximum Hot-Leg Attack Found n Thermal-Convection Loop 1094 (20% Mo—7% Cr-2% Mb-1% Fe-baol Ni} Which Operated for 500 hr with NoF-KF-LiF-UF4 {11.2-41-45,3-2.5 Mole %, Fuel 107) at 1500°F. Etchaont: aqua regio. 250X. Reduced 32.5%. (Secret with caption} 157 ANP PROJECT PROGRESS REFORT Table 3.1.5. Conditions and Results of Thermal-Convection Loop Tests of Nickel-Malybdenum Alloys with Na F-KF-LIF-UF4 (11,2-41.45,3-2,5 Mole %, Fuel 107) and Sedium - Maximum fluid temperoture 1500°F Loop Alloy Circulated Operating Metallegropbhic Results - N Composition Fluid Time O 1 1023 11 Mo=2 Al-bal Mi Sadium 1000 Heavy surface pits fo a Modarate surface roughening depth of > 1 mil 1087 20 Mo-1 Nb-1 Ti- Fuel 107 500 Haovy voids to a depth Light surface roughening 0.8 Ma—=bal M of 2.5 mils 1088 20 Mo-1MNb-2 Ti- Sodium 1000 Heavy voids to a depth Meoderate surface roughening 0.8 Mn=bal N; of 1 mil W59 15Mo-3 Nb=0.5 Al- Sodium 1000 Heavy voids to a depth Moderote surface roughening 3 Webal Ni of 1.5 mils 1093 17 Mo =7 Cr—=bal MNi Fuel 107 500 Heavy voids to o depth Light surface roughening of Z mils 1094 20 Mo-7 Cr=2 Nb~ Fuel 107 5S040 Heavy vaids to a depth No attack 1 Fe—bal Ni of 2 mils 1098 17 Mo-2 Ti=bol Ni Fual 107 500 Moderate surfoce pits to Mo atteck o depth of > 1 mil 1099 20 Mo—7 Cr—1 Al- Fuel 107 500 Heovy voids to a depth No attack - ZNb-1 Fe-bo!l Ni of 1.5 mils 1100 17 Mo-2 ¥=bol Ni Fuel 107 500 Fow voids to a depth of Light surface roughening s Q.5 mil - 1101 16 Mo=-5 Cr-1.5 Ti— Fuel 107 500 Heavy voids to a depth Yoids to a depth of 1 mil ) 1 Al —bal Ni of 2 mils 1102 16 Mo=5 Cr=1.5 Ti— Sodium 19000 Heavy voids to o depth Light surfoce roughening™ T Al=bal Ni of > 1 mil 1103 16 Mo=1 Al=1.5 Ti— Fuel 107 500 Heavy voids te o depth Light surface roughening bal Ni of 1 mil 1105 16 Mo=-2 Al-1.5Ti- Fuel 107 500 Heavy voids to o depth Mo ottack bol Ni af 3 mils 1108 V7 Mo =2 Al=bal Ni Fuel 107 500 Heavy voids to o depth Light surfoce roughening of 3 mils 1113 17 Mo -2 W=ba! Ni Fuetl 107 s500 Intargrenular voids to o Mederate surface roughening depth of 1.5 mils 1117 17 Mo=2 W—bal Nj Sodium 10006 Intergranular voids to o Heavy surface roughening depth of 2 mils 1120 17 Mo =4 W=hal Nj Fuai 107 500 Heavy voids to o depth Few voids to a depth of 1 mil of 1 mil - 1128 17 Mo ~3 Mb~ba! Ni Fuel 107 500 Few smal) pits toc o depth Moderate surfoce roughening | of » 0.5 mail 1131 17 Me—=5 Mb—bal Ni Fuel 107 500 Heavy surfoce roughening Light surface rovghening = to o depth of <1 mil *A thin discontinyous metallic loyer was also found. 158 Leop Na. PERIOD ENDING MARCH 31, 1957 Table 3,1.6. Chemical Anolyses of Fuel 107 Bafore ond After Cireulation in Nickel-Molybdenum Alloy Thermal-Convection Loops Alley Composition fwt %} Somple Tolken 1087 1692 1094 1098 1095 1100 1al 1103 1195 1108 13 rag 1124 1131 20 Mo—1 Nb=1 T-0.8 Mn—tal N, 17 Mo ~F Cr=bal b 20 Mo—7 Ce-2 Nb-1 Fa~tal N 17 bho—2 Ti=bo! M, 20 ¥o—7 Cr=1 Al-2 Nb-1 Fa-bhal M 17 Mo ~2 ¥=bal Mi 16 Mo -5 Cr=1.5 Tuw] Atcbal Ni s Mo=1 Al=1.5 Ti-bal N, 16 Mo=2 Al=1.5 Ti—bal Ni 17 Mo -2 Adxbai N V7 Mo=2 W-bal N 17 Mo W =bal Ni W bo=3 Mb=bal M 17 Mo —5 Mh=bal dh * Rawwlis ngd yat avaslabis. During filling Adter aperation Mo |eg Cold leg During Hlling Afler operation Hot leg Cold lag During lilling Alrar operakign Hot leg Cold leg During §illing J‘\fler opardlion Hol =g Cald leg Buring filling Alar gperalion Hot leg Cold leg Dunng fliiing Afrer aperatien Hot teg Cold lag Curing filling Aldter oparolian Hor leg Cold 1ag Curing fillina Alter gperation Hol leg Cald leg Durmg irHing Afrer aperotian Ho! fey Cold leg During filhing Adrar operation Hat leg Cold leg Oyring hilling Aftar apardtion Hat leg Cold &g During lilling Afrar gparation Hor leg Cald leg During fF“lng Ablar eperation Hot leg Cald log Dwring fitling Altar operotron Hot leg Cald l=g Uramium Matallic Constituants [ppm) Content ———— ———— e 5 el {wt %) i Cr Fe Ma Al T ¥ w Mk Ma 12.0 535 i 125 12,2 190 3% 110 80 3T 20 100 12.4 Y80 55 B0 20 3680 g 1 1g 12.6 35 15 125 12.0 145 435 5 140 12.4 200 655 70 25 12.9 170 &0 165 12.3 270 665 80 115 15 12.5 G 455 &0 5 10 12,2 g5 50 210 12,9 140 30 125 135 390 12,9 85 40 5 25 I8z 12.7 3 40 170 12.7 165 755 210 30 2815 ¥ 12.8 14 735 90 15 2945 7 12.5 < 25 105 12.5 85 a0 115 215 < 50 2.8 130 25 S0 40 <50 13.2 &5 55 125 12.8 45 245 130 a0 200 375 12.8 40 255 &3 15 1830 43 12.8 115 &5 125 1.9 &5 as 95 120 2535 3185 V2.4 105 30 115 55 2650 430 12.6 35 is i25 1.9 S0 20 Fiv &0 2210 445 12.2 70 20 80 20 2460 485 i2.9 195 100 135 124 <2 40 &5 43 1238 12.7 110 40 35 335 W0 2.7 0 120 L 1.8 45 50 100 280 1215 1.2 43 45 g5 340 1095 12.46 185 s 175 1.9 0 % g0 15 1465 12.2 215 59 Fiv 80 i 185 12.7 <3 30 125 12.1 70 40 105 170 D 12.5 220 50 g5 i 7 12,1 b5 40 15 . 6 - - 50 sm ¥ 30 * * 25 135 159 ANP PROJECT PROGRESS REPORT of 2 mils in this loop (1101) is comparable to the attacks in the above loops containing 7 wt % chromium, However, the chromium content in the fuel after test was noticeably lower in the case of loop 1101 (5 wt % chromium) than in the loops with 7 wt % chromium, Additions of 2 1o 4 wt % tungsten to the nickel- molybdenum alloy did not affect the depth of attock. The hot-feg attack to a depth of 1.5 mils found in loop 1113 (17% Mo-2% W-bal Ni) is shown in Fig., 3.1.14. As may be seen the attack was pre- dominontly intergranular, which is uncommoen for nickel-molybdenum alloys exposed to fuel 107, Another loop fabricated of material from the scme heat alse showed intergronuler ottack after opera- tion with sodium. The atteck by fuel 107 in loop 1120 (17% Mo~4% W-bal Ni}, fabricated from a different heat containing 4 wt % tungsten, was of the usual general subsurface-void-formation type and there were surface pits to a depth of 1 mil, The differences in the ottack of the alloys con- taining 2 and 4 wt % tungsten moy result from differences in the groin-boundary constituents of the two alloys. The chemical onalyses of the fuel mixtures circulated in the two loops show sizable amounts of tungsten, as high as 1465 ppm, Additicnal loops fabricoted from nickel-molyb- denum olloys conteining vanadium, nicbivm, or titanivm (loop 1100, 17% Mo-2% Y-bal Ni; loop 1126, 17% Mo—=3% Nb~bal Ni; loop 1131, 17% Mo-— UNCLASSIFIED T 14980 P 2 NC-:‘!ES & 3 B & Fig, 3.1.14. Maximum Hot-Leg Attock Found In Thermal-Convection Loop 1113 {17% Mo-2% W-hol Ni) Which Operated for 500 hr with NuF-KF-LiF-UF4 (11.2-41-45.3-2.5 Mole %, Fuel 107) ot 1500°F. Erchont: aque ragic. 250X, Reduced 32.5%. (Secret with caption) 160 5% Nb-bal Ni; and loop 1098, 17% Mo~2% Ti-bal Ni} and operated with fuel 107 showed attack of 0.5 to 1 mil. Chemicol analyses were made of the fuel mixtures circulated in these loops, There was no appreciable vanadium buildup in the fuel from loop 1100, There was, however, as indicated in Table 3.1.6, a buildup of niobium in the fuel from loops 1126 and 1131, with the niobium content of the fuel from the loop containing 5 wt % niobium being greater than that of the fuel from the loop containing 3 wt % nicbium, A slight buildup of titanium was evident in the fuel from the loop con- taining 2 wt % titanium (lcop 1098), although the level of titanium in the fuel after the test was much less than the level of aluminum in fuel from loops Loops containing titanium along with other alloying elements (1087, 1101, 1103, 1105} showed similar titanium con- centrations in the fuel aofter the tests, with emounts up to 485 ppm, containiag aluminum, Sadium, — Date on the nickel-molybdenum alloy loops operated with sodium are presented in Table 3.1.5. Mass-tronster depasits were visible in nickel-molybdenum alloy loops 1023 {11% Mo~2% Al=bal Ni), 1088 {20% Mo=1% Nb=2% Ti=0.8% Mn- bal Ni), 1089 (15% Mo-3% Nb-0.5% Al-3% W-baol Ni), 1102 (16% Mo~5% Cr—1.5% Ti-1% Al-bal Ni), and 1117 {17% Mo-2% W-bal Ni}, whick eperated for 1000 hr with sedium at a maximum temperature of 1500°F; however, deposits were found metallo- graphically only in loop 1102, These deposits differed from deposits in Inconel-sodium systems in that they did not adhere tightly to the locp wall. Consequently, the deposits could be mechanically removed, and thus they were lost during preporation of metallographic samples, The quantity of de- posited material visible in these foops was com- parable to the quantities found in Inconel ioops operated with sodium under similar conditions. Chemical cnalyses of the deposited material found in loop 1102 showed 6350 ppm Mo, 3400 ppm Al, 94% Ni, and 3.57% Cr. The moximum hot-leg attack in atl these loops averaged slightly more than 1 mil. The attack aoppeared es subsurface voids and pits, ond thus was similar to that found in the hot legs of loops thot circulated fuel 107, With the exception of the otloy that contained 2 wt % tungsten, the grain boundaries were not preferentially attacked. This result is in confrast to the results for Inconel loops inwhich attack by sedium is normally intergranulor, Yoid Migration in Inconel Exposed to Na F-ZrF‘-UF4 Three standard Inconel thermai-convection loops were operated with NoF-ZrF -UF , {50-46-4 mole %, fuel 30) at o bulk fluid temperature of 1500°F, One foop {1085) was terminated ofter 277 hr of operation; the fuel in the second loop (1086) was repiaced with helium after 280 hr, and the loop was held at test temperature for the remoining scheduled operating period of 1000 hr; the third leop (1010), included as a control locp, operated the scheduled 1000 hr with fuel. An analysis of the corrosion process in Inconel systems containing fluorides indicates thot the rate of attack (that is, void formation) becomes constant when the test period exceeds 250 hr, This linear relationship of ertack with time is reached following an initial period of rapid attack resulting from the equilibration of the fluorides with |nconel, It was first assumed thai the linear migration of voids into Inconel with time repre- sented a constant rote of chromium removal with time. However, questions were posed as to whether even in the absence of further chromium removal some void formation might continue as a result of the rapid stage of atteck represented by the equili- bration of flucrides. The purpose of these tests was therefore to determine whether the migration of voids into the Incenel, instituted by the leaching of chromium during the corrosion process, would continue if a loop were left at test temperature without fuel, Me tallegraphic examination of loop 1085 revecled heavy surface roughening and heavy general sub- sutface-void formation to o depth of 1 mil in the hot leg, accompanied by heavy intergranuiar subsurioce-void formation to a maximum depth of 8 mils., The cold leg showed only heavy surface roughening, Comparison of the hot legs of loops 1085, 1086, and 1010, shown in Fig, 3.1.15, indi- cated the attack in loops 1085 and 1086 to be identicol in depth, extent, and type of void forma- tion, Further metallographic exaemination through- out both loops revealed similar corrosion of re- spective metaliographic somples. 1n control leop 1010, which operated with a different batch of fuel, the maximum hot-leg attack was 12 mils, which raprasents the normal depth of corresion of Inconel vnder these conditions, The results of these tests provide evidence that the migration of voids into Inconel, instituted by PERIOD ENDING MARCH 31,1957 UNCL ASSIFIED T 11850 s L ooy 4 wr L. - -4 o e G L - | = 1 . * e - - { ‘ o @ - | fos L 5 o a \ | 3 L ! | pemr - = | 1 oan % \ i _._-‘ : _1 | - = g 1‘ | LODY w I i ? ; 1 Long . i Y = e el S . g 3 x - i_m_z_ EEE] T INC:‘IES EFEREEERE e ‘: | Lssz L : ¥ r ? £ L. & S e ™ £.13 - ® ', ¥ “ . o i & & e o i'ril— - & f.--- o Foil e ! y OBy a i/ 4 . -y b : ’ ir ; % .\'h I‘l|l ‘; = - , x P FFEEEED Fig. 3.1.15. Specimens from Hot Legs of Loops 1085, 1084, ond 1010 Which Operated with NuF-ZrF‘-UFd {50-46-4 Mole %, Fuel 30} ot o Maximum Fluld Temper- ature of 1500°F, Loop 1085 (a) operated 277 hr with fuel; leoop 1088 {b) aperated 2BD hr with fual and 720 hr with helium at the test temperature; loop 1010 {c} oper- ated 1000 hr with fuel. Etchant: modified oqua regisa. 250X, Reduced 33%. (Secret with coption) 161 ANP PROJECT PROGRESS REFPORT the leaching of c¢hromium during the corrosion process, does not continue if the loop is left at the fest temperature without fuel. Thus, the coalescence of vacancies in the metal to form visible veoids must proceed at a rate of least commensurate with the rote at which vacancies are formed, |f the removal of chromium from the metal surface is stopped, void formation is alse stopped. NaF-KF-LiF-U F“ and Sodium in Micbium The compatibility of nicbium with NaF-KF-Lif- UF, (11.,2-41.45,3-2,5 mole %, fuel 107} and with sodium was studied in thermal-convection loops operated at @ maximum fluid temperature of 1500°F, The loops, which were fabricated by Battelle Memorial the standard loops employed for corrosion studies of more common materials, The niobium tubing used in the loops was fabricated from welded sheet and had on inside diometer of 0.53 in. ond a wall thickness of 0.020 in. In order to eliminate Institute, were slightly smaller than the niobium oxidation problem which would exist at the test temperature, the niobium was encosed in an outer sheath of type 321 stainless steel. This sheath completely surrounded the nicbium loop but wos not integrally bonded to if, Fabri- cation of a sound loop of this design was difficult in that cracks often developed in the niobium tubing while the sheath was being assembled, Three niobium loops (1072, 1073, ond 1022) were operated 1664, 1000, ond 775 hr, respectively, with fuel 107 ot a hot-leg temperature of 1500°F, Termination of operation of loops 1072 ond 1022 was caused by o power failure and loss of flow, respectively. An onelysis of the fuel circulated in foop 1022 revealed a high buildup of chromium, 715 ppm, and pointed to the probability of a teak that allowed the fuel to contact the cludding. The examination of this foop showed an absence of cold-leg deposits and only slight hot-leg attack in the form of shallow pitting. Loops 1072 and 1073, on the other hond, apparently remained sound during operation, since no elements other thon niobium were found in the fuel after the tests. However, macroscopic examination of the loops revealed metallic crystals in the fuel layer close to the cold-leg wall. These crystols were evident metallograghically, and are shown in Fig. 3,1.16. Hot-leg attock in these loops occurred as shallow pitting to a depth of less thon 1 mil. A typical 162 os-tested specimen from the hot leg of loop 1072 is shown in Fig. 3.1.17, An odditional niobium thermal-convection loop (1091) was operated for 1000 hr with sodium ot @ maximum temperaiuvre of 1500°F, Exomination of UHCLASSIFIED T 11957 Flg. 3.1.16. Metallic Crystals in Fuel from Cold-Leg Section of MNioblum Thermal-Convection Loop 1072 Which' Opercted 1664 hr with NGF-KF-LEF-UF“ {(11.2- 41-45,3-2.5 Mole %, Fuel 107) at o Maximum Temper- ature of 1500°F, Unetched. 50X. Reduced 32,5%. (Sacrat with caption) \'l " _.." iCII 1 ¥ I__'ut . 1y i‘vl— !m: . » . —J ' "\‘ ’ 'i L4 Figs 3.1.17. Maximum Hot-Leg Attock of Nicbium Thermol-Convection Loop 1072 Which Operated 1664 hr with NuF-KF«LiF-UF‘ (11.2-41-45.3-2.5 Mole %, Fyel 107) ot a Maximum Temperoture of 1500°F, Erchont: HF-HNDa-H2504-H2CI. 250X, Raduced 31%, (Secret with caption) the hot leg of this loop showed little evidence of ottack other than, possibly, uniform surface re- moval. Cold-leg deposits were, however, observed macroscopically, Chemical analysis of the de- PERIOD ENDING MARCH 11,1957 posited material indicated that the sodium probably jeoked into the clodding loop during operation, since large emounts of iron, nickel, and chromium, in addition to niobium, were present in the deposit, 163 ANP PROJECT PROGRESS REPORT 3.2. GENERAL CORROSION STUDIES E. E Hoffman TESTS OF INCONEL TUBE-TO-HEADER JOINTS WITH RECRYSTALLIZED WELDS D. H. Jansen The lost of o series of lnconel tube-to-header joints with recrystallized welds were corresion tested in NaK (5644 wt %) and in NaF-ZrF ,-UF {50-46:4 mole %) for 100 hr in seesow-furnoce apparatus with o hot-zone temperature of 1500°F, These somples were fabricaied ot the Glenn L. Martin Co. by using a prechamfered header plote of the type shown in Fig. 3.2.1. In comparisen UMCLASSIFIED ¥-20540 Fig. 3.2.1. Schematic Drowing of Prechamfer Method of Tube-to-Header Jaint Fabrication, with the welds tested previously ' the prechamfered type of weld (Fig. 3.2.2) resulis in decreased material deformation and greater weld surface areo, A prechamfered type of recrystatlized weld that was exposed to I\l-::F-?_’er-UF:J1 (50-46-4 mole %, fuel 30} for 100 hr at 1500°F is shown in Fig. 3.2.2. The attack alorg the tube-header interface was no greater than the ottack on the tube ond on the header. A maximym of 0.5 mil of attock was found on the Incone! components of the specimens tested in NaK, and the attack on the tube-header interface was similar, B, H. lansen, ANF Quar. Prog. Rep. Dec. 3i, 1956, ORNL-2221, p 184. 164 Fig- 3-2-2. oxalic acid, 12X, Reduced 79.5%. URCL ASEIFIED ¥- 2193 Fig. 32.3. Recrystallized Weld Fabricoted by Prechomfer Method After Exposure for 100 hr in MoF- ZrFq'UF.; {(50-46-4 Mole %, Fuel 30) at 1500°F, Etchant: agua regia. 75X, Reduced 43.5%. (Secret with caption} TESTS OF HAYNES NO. 8244 BRAZING ALL QY D. H. Jansen Inconel tube-to-header joints brazed with Hoynes No. 8244 brezing alloy {nominal composition, in wt % 9.4 (Cr, 4.4 Fe, 3.7 5i, 2.2 8, 0.3 Mn, 0.06 C, bal Ni) were corrosion tested in Naf- ZrF,-UF, {50-46-4 mole %, fuel 30} and in NaK As-Received Recrystallized Tubesta- Header Weld Fobriceted by Using o Prechamfer Method. Mote large tube-te-header contoct area. Etchont: 10% {56-44 wt %} in the seesaw-furnace apparotus. The test periods were 100 hr, and the hot zones in which the specimens were retcined were main- tained ot 1500°PF. The brazing alloy showed good corrosion resistance to NoK, but there was light subsurface ottack to o depth of 3 mils on the specimen tested in the fuel mixture, as shown in Fig. 3.2.4. COMPATIBH.ITY OF MOLYBDENUM AND NICKEL-MOLYBDEMUM ALLOYS IN NaF-KF-LiF-UF, 0. H. Jansen In cennection with studies of cladding bydride moderator materials for use in high-temperature cis- culating-fuel reactors, tests were conducted in seesaw-furnace cpporatus to investigate the com- patibility of molybdenum and nickel-molybdenum al- loys in NaF-KF-LiF-UF, (11.2-41-45.3-2.5 mole %, fuef 107). The test assembly consisted of o © UNCLASSIFIEDR Y- 21589 p.o2 | PERIOD ENDING MARCH 31, 1957 %-in.-0D, 0.035-in.-woll alloy capsule in which o cold-rolled strip of molybdenum, 0.018 in. thick and one half the length of the test capsule, wos confined in the hot zone. A capsule fobricated from 15% Mo—6% Cr—bal Ni olloy tubing wds tested for 500 hr ot o hot-leg temperature of 1650°F with a temperature grodient of 300°F, and a 17% Mo—2% V=bal Ni capsule was tested under similor conditions, except that the maximum temperature was 1600°F. Spectrographic onalyses indicated the presence of nicke) on the surfaces of the molybdenum strips from both the copsules as a result of dissimilor metal mass transfer. Mo evidence of chromium or vanadium was detected. Metollographic examination showed that the meolybdenum specimen tested at 1650°PF had become recrystallized, while the one tested ot 1600PF showed the elongoted ond distorted grains typical of rolled materials., No attack to a depth greater than 0.5 mil was found on either olioy copsule, and no thickness chonges or attack of the molybdenum strips could be detected. UNCLASSIFIED Y-21405 ';‘ :1.0 - '. ST st 1-# ' '_.,ég r G034 a . s & '. . ;‘; d "#‘ «‘ ':f'-j j IIJ AT 2 L " ._ |. x K o R i O o IR | e Fig. 3.2.4, Hoynes Braxing Alloy No, 8244 on lnconel Tubo4o-Header Joints After Exposure to {a) NaF- szd'UFd {(50-46-4 Mole %, Fuel 30) and {&) NaK (5644 wt %) in Seesow-Furnace Apparatus For 100 hr at o Hot-Zone Temperoture of 1500°F, Light subsurfoce atteck con be seon in {2}, Specimen nickel ploted lo preserve edge during polishing. Etchont: none, as-polished. 100X. Raducad 6%. (Secret with caplion) 165 ANP PROJIECT PROGRESS REPORT More severe tests of these materials are to be conducted, since the cladding problem would be greatly simplified if it could be established that molybdenum and nickel-molybdenum atloys were compatible in the fuel system. At present it is felt that o duplex clod of molybdenum and nickel- molybdenum clicy may be required to prevent dis- similar metal mass transfer. The molybdenum is required os o hydrogen diffusion barrier for the hydride moderator material. THERMAL-CONVECTION LQOP TEST OF 50DIUM IN HASTELLOY B E. E. Hoffman L. R. Trotter A thermal-convection loop fobricated of Hastelioy B and filled with sodium wos operated to cbtain a comparison of the moss tronster and corrosion resistance eof Hastelloy B and Inconel in sodium systems, The loop operoted for 1008 hr at a hot-zone temperature of 1600PF and a cold-zone temperoture of 990°F. No significent differences were found belween the amount of attack and mass transfer found in this loop and in two lnconel loops operated under similor conditions.? In all three tests an air blast thot impinged on the bottom of the cold leg was used to effect o very sharp femperature drop and thus concentrate any mass transfer deposits. OCnly o few very small mass-transfer crystols were detected in the Hostel- loy B loop following the test, as shown in Fig. 3.2.5. In general the crystals found in this loop did not seem to adhere to the walls as well os those found in Inconel loops. The hot- and cold-leg surfaces of the Hastelloy B loops were ottacked to depths of from 1 te 2 mils, as shown in Fig. 3.2.6. It may also be noted in Fig. 3.2.6 that scattered areas of the as-received tubing had sericus surfoce defects, SODIUM-BERYLLIUM-INCONEL COMPATIBILITY IN A STATIC S5YSTEM (TEST NO. 3} E. E. Hoffman L. R. Trotter The apparotus used for tests of the compatibility of sodium, beryllivm, and lncorel and results of two earlier compatibility tests in this series were %e. E. HoHmon, ANP Quar. Prog. Rep. Sept. 10, 1956, ORNL-2157, » 161, 166 UNCLASSIFIED Y-20702 _ - .'-_-‘ COLD ZONE -990°F ONE INCH Fig. 3.2.5. Sections from Hastelloy B Thermal- Convection Loop Which Circuloted Sodium for 1008 hr, (Confidential with caption) described previously.* The interface conditions tested in this third experiment gre described in Table 3.2.1, along with results of metallographic examipations of the interfaces after the test. During the 1000-hr test the temperature was cycled from 1300 to 500°F ten times to determine the extent to which the brittle intermetallic compounds which form the interfaces might spall. Each cycle required o 5-hr cooling end an 8-hr heating period; therefore, the specimens were actually ot 1300°F for 870 hr of the 100-hr ftest. The results of metallographic examination of the specimen interfaces following the test are illustraoted in Fig. 3.2.7. Several of the phases which formed when the Inconel specimens were plated with 3F_- E. Hoffman, ANFP Quar. Prop, Rep. [une 10G, 1956, ORNL-2108, p 148; E. E. Hoffman ond R. Carlander, ANP Quar. Prog. Rep. Sepe. 10, 1956, ORNL-2157, p 160, PERIOD ENDING MARCH 31, 1957 UNCL ASSIFIED Y-21548 UHCL ASSIFIED Y-21647 UNCLASSIFIED ¥-2 1666 0 INCHES 1 1 INCHE S B - " “\ -_:.1_ i S I a - i '.' v‘l' v - n l 'h"- rl" . E’ ey ool & 5 ' » . [oDOE * f * nh. A ® 4 N o w F q" - - =y - " B . : £ L * et . . " et ) | D04 - - + = o o oo+ & _J[ -cQ', ® e - B i " } e . - .":' ® g e W | AR B L T 38 geat Mol 0 VUL LA ‘:‘ G 2 .“: -::"_4 '::‘* p om e - o N Y -fl..!.,f". J . T f _"; _;.. "*._ o ") Q06 | ~ . - i - 2 _r_._ * Al S ;% i i _r_:“- ey - .‘; T ¥ 1-— . ? gy - = - --" o s S 7 _§ ._M‘ B2 et B ¥y By ','-§.. : _ ; El.]‘ ".; -« AS RE{?ENED U w | s S HOT LEG UEOQQF'}'.,‘_ . |»n COLD LEG (990°F) v R de e A e O e Fome T e f Y ' ’ Fig. 3.2.6. As-Received Hastelloy B and Sections from the Hestelloy B Thermol-Convection Loop Which Circulated Sodlum fer 1008 hr, The hot leg wos ottacked 1o a slightly greatar axtent than the cold leg. Tha as- received material contained a few widely scattered surface irregularities. Etchant: modified agque regia. 500X, Reduced 12%. (Confidential with coption} Table 3.2.1. Results of Metcollographic Exomlination of Interfaces of Specimens from Sodium-Berylium-lnconel Compatibility Test Ne. 3 Test durotion: 1000 hr Test temperoture: 1300°F, cycled te S00°F ten times Contact pressure between specimens: 500 gsi interface Results of Metollographic Examination Across the lnterface Incone! plus T-mil nickel plote plus 4-mil lnconet plus 1.5 mils of o nickel-rich ghase plus 2.5 mils of an chremium plete vs beryllivm unidentified phase plus 3.5 mils of Bech (see Fig. 3.2, 7a) Inconel vs beryllium, direct contect Inconal plus 1 mil of BeMi plus 18 mils of BeflNis {sae {standard) Fig. 3.2.7b) Inconel plus 3-mil chromium plate Inconel plus 2 mils of BeNi ptus 1 mil of chromium plus 6 mils vs beryllium of Be_?Cr (see Fig, 3.2,7¢) Inconel plus 3-mil chromium plate lnconel plus 2 mils of BeMNi plus 1 mil of chromium plus & mils vs beryllium (duplicate of above) of BBECG‘ 167 ANP PROJECT PROGRESS REPORT @ UNCLASSIFIED , e : Y-21647 - * s 1854 ' g 338 a g ‘ 3 )0 INCONEL NICKEL (D (?) | Be,Cr : s wmeA ' 2 g .- E 8 8 8 mcfaes ".: ’ e - UNCL ASSIFIED ® S Y-21548 : ! : 7438 1495 ® 144 - & | & o - 8 P % e N INCONEL ' "* Be Ni . e . () o .~ : 2 g 500X S 8 8 8 3 |NCI{IE5 b _ — - UNCLASSIEIED N Y-21646 : 30 392 Cr .- 7439 > SN e NI INC = 2015 s 4 = s 227@CT _,._ 0 . L \ / Fig. 3.2.7. Metallographic Specimens of Interfaces Described in Table 3.2.)1. The nuymbers are diomond pyramid hardness volues for o 25-9 load. As-polished. 500X, 168 ra both nickel and chromium have not vet been identified. It appears that nickel plating of the Inconel prior to chromium plating is unnecessary and pessibly undesirable for this application. The results found at the chromium-plcted Inconel vs berytlium interfaces confirm the previous findings which indicated that a minimuym of 5 mils of chromium plate is required to ensure that all the chromium is not consuvmed by reaction with the beryllium vnder the conditions of this ex- periment. No serious spalling of the brittle compounds Be, NI, ond Be,Cr was detected in these tests. EFFECT OF ZIRCONIUM ON CORROSION IN AN INCONEL-SODIUM SYSTEM R. Carlander? An lnconel-sodium thermal-convection loop with a zirconium sleeve in its hot leg was operated for 1000 hr with the hot teg at 1500°F and the cold leg ot 1230°F in order to determine whether the zirconium would remove oxygen from the sodium and thus affect the corrosion of the Inconel. Since no mass transfer and little attack occurred, the test indicoted that the presence of zirconium had a beneficial effect.” In an effort to sub- stantiote these results, two Inconel standpipe test copsules, one containing a zirconium speci- men, the other an |nconel specimen, were 50% filled with sedium and tested for 400 hr with the tep and bottom of the sodium bath at 100G and 1600°F, respectively, Mass transfer occurred in both copsules, and, although the weight of the crystsls found in each capsule was opproximately the same, the com- position of the erystals (75.5% Ni—10.4% Cr-14.1% Fe) from the copsule containing the Inconel speci- men differed markedly from that of the crystals (95.6% Ni=3.5% Cie~0.9% Fe) from the capsule which contained the zirconium specimen. The effect of zirconium on the moss-transfer ¢rystal composition is net understood. Visual examingtion of the =zirconium specimen following the test indicated that no oxide scale had formed. Metollographic exomination revealed 4Dn ossignment frem Pratt & Whitney Aircraft. SR. Carlander, ANP Quar. Prog. Rep. Dec. 31, 1956, GRNL-2221, p 192. PERIOD ENDING MARCH 31, 1957 that o transition from alpha to beta zirconium occurred in the center of the specimen, as was expected as a result of heating the zirconium from room temperature fo 1600°F. The outer surfaces of the specimen, however, retained the alpha structure to a depth of 40 mils, as shown in Fig. 3.2.8. The retention of the alpho-structure on the outer surfaces was thought to bhe due to oxygen absorption which raised the alpha to beta transition temperature, which is normally 1548°F, to above the test temperature of 1600°F and thus stabilized the olpha phase. In order to test this hypothesis, two sets of millings from the surface of the tested specimen, cne to o depth of 40 mils (alpha region) and the other from a depth of 40 to 80 mils (beta region), and two sets of similar millings from an as-received specimen were chemically analyzed. The onolyses, reported in Table 3.2.2, revealed that the alpha region did absorb oxygen during the test. ubilities of iron, nickel, ond chromium are higher Since the sol- in beta zirconium than in alpho zirconium, these metais diffused from the alpha region to the beta region during the test, as shown by the onolytical results, The data obtained from these tests thus indicate that the zirconium did remove oxygen from the sodium; however, there wos no observable reduction in the corrosion of Inconel as a result of the oxygen removal by the zirconium. MOLYBDENUM-BERYLLIUM COMPATIBILITY IN SODIUM R. Carlander Two tests of the compatibility of molybdenum ond beryllium in contact in static sodium were conducted in the apparotus illystrated schema- tically in Fig. 3,2.9. The temperoture of the test system was maintained at 1500°F for each of the tests, one of which was for a period of 100 hr and the other for 500 hr. Metallographic examination of the specimens after the test re- vealed thot o two-phase diffusion zone hed formed between the specimens in the 100-hr test, whereas a three-phase diffusion zone formed in the 500-hr fest. The examination of the specimens from the 100-hr test showed that the diffusion layer adjacent to the beryllium specimen was the intermetallic compound MoBe ;. This layer, which was 1 mil 169 ANP PROJECT PROGRESS REPORT UNCL ASSIFIED Y-20675 Fig. 3.2.8. Zirconium Specimen Exposed to Sodium in an Inconel Copsule for 400 hr ot 1600“F. Outer surface is olpha-zirconium to depth of 40 mils. The precipitates at the grein boundories are probably intermetallic compounds el iran, nickel, and chromiom with zircoanium. Etchant: 46% Hzo-dé% HNDS_B% HF. 50X. {Confidential with capticon) Tabkle 3.2.2. Chemical Anolysis of Millings from As-received Zirconium and a Zirconium Specimen Tested in Sodium in an Inconel Capsule Composition {ppm) Specimen e — Iron Nickel Chremium Oxvgen As-recaived zircenium First 40 mils 350 4 28 910 Second 40 mils 350 2 25 720 As-tested zirconium First 40 mils (alpha region) 68 8 20 2500 Second 40 mils (beta region) 850 140 55 870 e ——— e B, ey i = 170 iy UNCLASSIFIED ORNL-L R-0WG 17019 TYPE 316 STAINLESS STEEL CAP | ——MOLYSDENUM POSITION ROD & R %, . N 5 by L e i e o e i lm+—— TYPE 216 STAINLESS STEEL CLAD- , ’ MOLYBDENUM -CAPSULE i - 5Q0IUM -MOLYBDENUM TEST SPECIMEN T BERYLLIUM TEST SPECIMEN e F MOLYBDENUM DISK B \ T "' . i e T T el 0 i 2 ey —— SCALE iN {NCHES Fig. 3.2.% bility Test Capsule. Molybdenum-Beryliium-Sodlum Compati- thick and pink, was crocked and had a hardness of 13598 VHN (50-g load). The layer adjacent to the molybdenum specimen was MoBe,. It was 0.5 mil thick and white, and it had @ hardress of 2107 VHN. The identifications of the inter- metallic compounds MaBe,, and MoBe, were based on previous investigations.® The layer formed adjacent to the beryllium the 500-hr test spalled from the surfoce when the bond between the specimens separated during preparation for metallographic The moterial that spalled has not been positively identified, but it appears to be It may have formed as a result specimen in examination. beryllium oxide, of oxygen contamination of the sodium. The middle layer of the three-phase diffusion zone was MoBe,.. This loyer, which was 2.5 mils deep ond 65. G, Gordon, J. A, McGurty, and G. E. Klein, Inter metaliic Compounds in the System Molybdenum Beryllium, NEP A-1686 (Jan. 10, 1951), PERIOD ENDING MARCH 31, 1957 pink, was cracked and had a hardness of 1598 VHN, The loyer adjacent to the molybdenum specimen was MoBe,. It was 2.5 mils deep and white, and it had a hardness of 2390 VHN. The specimens from the 500-hr test are shown in Fig. 3.2.10. The inherent brittleness of the two intermetallic compounds formed in the tests indicates thot the solid-solid diffusion that occurs between molybdenum and beryllivm ot 1500°PF is of a deleterious nature that would seriously affect the structural properties of the twe metals in o high-temperatyre application. Additiona! tests in which a 500-psi pressure will be applied to the specimens are to be conducted. The results of these tests will be compared with the results obtained in inconel-beryllium-sodium compatibility tests. TITANIUM CARBIDE-NICKEL CERMETS iN MOLTEN SODIUM ¥W. H. Coock Specimens of the four TiC-nickel cermets iisted below were corresion tested in sodium in Inconel capsules for 100 hr in a seesow furnace operating ot | ¢pm with hot- ond cold-zone temperatures of 1500 and 1120°F, respectively. K150A: 80% TiC—10% NbTaTiC, - 10% Ni K1S1A: 70% TiC—10% NbTaTiC,-20% Ni K152B: 64% TiC—6% NbTaTiC,-30% Ni K162B: 64% TiC—6% NbTaTiC,~25% Ni-5% Mo. The specimens were retained in the hot zenes of the capsuvles during the test, The surfoces of oll four cermets were roughened to depth of 0.5 mil, but the K1528 and K162B specimens appeared tc be the most severely attacked. The ottack in each case may have been on on Ni-TiC solid solution along the TiC-binder interface, since it appeared that the metal binder had been removed and that the TiC grains were slightly reduced in size. The typical appearance of the attack is shown in Fig. 3.2.11. Chemical onalyses of the sodium baths after the tests showed erratic scatter of the results from less than 15 te approxi- mately 60 ppm of fitanium or nickel in 20-g samples. 171 ANP PROJECT PROGRESS REPORT UNCL ASSIFIED Y-20794 ik T INC!;‘E‘S o b=t A ¢ os 500X DIAMOND PYRAMID HARDNESS 50-g LOAD " § 008 - = Fig., 3.2.10. Intermetailic Compounds Formed in Compatlbility Tests of Molybdenum and Beryllium in Stotic Sodium After 500 he ot 1500°F. Layer with hardness of 1598 is MoBe|3. Loyer with hardness of 2390 is MDEOT As-polished, 500X, (Confidential with coptien) —-., UNCLASSIFIED ™ e . o UNCLASSIFIED 21261 fl '%‘!" Y-212462 - ‘ o i LB q SN I S S = % : = 1"& » _z' 1 il ¥ ‘“!. ~ 4 3 T ' : - V O kel B A f"}\?-"\" L, $= 7 L {L ! ;‘-: J-T . i ow % “r; : Y.'b " - & -.r ;; ” 1 '\/ \ f-:l- y » 3 : \ -': &' -A_’-— ;‘ e - \-_‘;_ i..' . A .‘n,.' \.- %4 > ; i e r dob g * o2 1o . ’t . :\.' ' ".1_‘ .l'- o - : L d u I 7 SRR ERR N T oy A * w T Ll = L - fllfl # k k l"i' N = ‘)‘ i \ . ‘fi ® \ I - \ ..:l,‘; * . m‘ ‘l-‘fi e 1'?’. ?.. ll- nl * ‘*- A ‘.' - ", F - - ;"“ A YR 4 i { X ‘2“@"’ .y = i, 3 7 ‘{-1 i_‘-_fii_‘ = -’\- . X Y.* % .:‘ = .,\."f r 4 i i 1 Bt oW “" L'J 3 " “ % 3 L 0 i l#‘x = 'fi-:' o3| ™ i% ? "& L :. Ta JC?A- i 3 @'/..- o i}" (5) *®q: b7 2 :. i L .'g. £ o e SN ST AT e E e 2 ‘h Fig. 3.2.11, Cermet XKI151A (4) As-Received and {b} After a 100.-hr Exposure to Molten Sodium in ¢ Seesow Furnoce with Hot- and Cold-Zone Tempecatures of 1500 and 1120°F, Respectively. The white phase is nickel and the large gray, angular particles ore TiC. Both the untested ond the tested specimens were nickesl plated to protect the edges during polishing. Unetched. 1000X. (Confidential with caption) 172 In similar tesis in NaK (50-50 wt %), performed ot Battellie. Memorial Institute, with hot- and cold- zone temperotures of 1600 and 1200°F, respec- tively,” there was surface roughening to o depth of 0.5 mil on cil these cermets, except K162B, in 110-hr exposures. Previous similar tests at ORNL skowed that these four cermets were not attacked by MNaF-ZeF -UF, (53.5-40-6.5 mole %, fuel 44).3 BORON CARBIDE AND BORON NITRIDE IN MOLTEN S50DIUM W. H. Cook The ceramics baron carbide ond boron nifride are of interest as refroctory materiels for use in reactors as thermal-neutron obsorbers, In recent stondard screening fests of ceramics in liquid metals, two boron corbide specimens, with theoreticol densities of 85 and 90%, re- spectively, had better corrosion resistance to molten sodium than that previously observed.® Each of the B,C specimens was exposed to static sodium for 100 % at 1500°F in Inconel containers. 1he results of these tests are com- pared with o result of an earlier test in Table 3,23, Since it is difficult to completely remove sodium and sodivm compounds from a porous ceramic body, 1t is surprising that the calculated ?5. J. Besham, J. H. 5tong, and E. M. Simens, Tilting- Furnace Corrosion Screening of Materials Exposed o Molten Fluoride Salt and NakK, BMI-1132, pp 46, 48 (Sept. 18, 1956). 8E, E. Hoffman, W. H. Cook, end C. F. Leitten, Jr., ANP Quar. Prog. Rep. March 10, 1955, ORNL- 1854, p 84. ?E. E. Hoffman, W. H. Cook, ond C. F. Leitten, ANP Quar. Prog. Rep. Dec. 10, 1954, ORNL-1814, p 84. PERIOD ENDING MARCH 31, 1957 and measured specimen weight losses given in Table 3.2.3 agree so well. The results calculated from the chemical onalyses are considered to be the most important in determining the extent of corrosion. The only visible changes in the tested specimens were that they both had duller surfaces than they had before the tests. The 8,C of 100% theoretical density, which was tested previously,g cracked and fell aport after exposure to sodium. A specimen of boron nitride {nominally, ]{1 % ]a:' % 1/2 in.) with a density of 98% of theoretical (theoretical density of BN = 2.20 g/cm® was severely attacked in o 100-hr exposure to malten sodium in a seesaw furnace operating ot | cpm with hot- ond cold-zone temperatures of 1500 ond 115(PF, respectively. The specimen container was [nconel. The measured weight loss of the specimen was 10.8%, ond the weight loss based on chemical analyses of the sodium after the test wos 8.2% if all the boron found was in the form of BN before the test. Since the BN was extremely soft even in the dense state, some of the weight loss could have been due to atirition between the specimen and its container. However, metallographic exomi- nation with reflected light showed thot the as- tested specimen hod develoeped crocks below and paralle!l to its surfoces. Under polarized light, the specimen appeared to have cltered throughout. There was o dense, shell-like ma- terial approximately 0.003 in. thick surrounding the core of the specimen. This ““shell’’ contained the cracks observed with the reflected light. The core of the specimen oppeared to be less dense than it was before the test and to be covered with black spots. Table 3.2.3, Results of Exposure of Boron Cerbide Specimens to Static Sedium for 100 hr ot 1500°F B,C Specimen Density Dimensional Weight Loss of Specimens {%) i By Weight {% of thearatical™) Change (%) ~ 5 Measurements Calculated ’\"85 "'04..' ].6 1.6 o ~0-04 0.4 0.3 100 6 *Theoretical density = 2,5} gz"crna. **This represents the weight toss calculeted on the basis that oll the boron found in the soedium by chamical onolyses ofter the test was originally Bdc in the specimen, 173 ANP PROJECT PROGRESS REPORT S5iC-51 I MOLTEN 50DIUM W. H. Cook The silicon was completely removed from an SiC-Si specimen during 100 hr of exposure to molten sodivm in an lnconel container in o seesaw furnace operating at 1 cpm with het+ and cold-zone temperatures of 1500 and 1150°F, respectively, The silicon was found on the walls of the Inconel container. [he specimen was submitted as a dense SiC moterial.'® The nominal composition of this type of material is 85 10 0% SiC plus 10 to 15% free silicon plus minor quantities of iron, alumina, and silica, The free silicon probably results from the fobricotion procedure, and the minor constituents aid in the densification of the SiC.'! As-received and tested specimens are compared in Fig. 3,2,12. Designoted Body 4107-22-7 by the Carborundum Campaony, Perth Amboy, N. J. TR, A. Alliegro, L. B. Coffin, and J. L. Tinklepaugh, f. Am. Ceram. Soc., 39, 386-387 (1956). CLASSIFIED 7 Y-21248 The resuvlts of this test were consistent with previous resulis obtoined in o static test of o different type of SiC-Si matericl!? ond in similar tests of pure silicon ond silicon-containing alloys. The nature and rapid rgte of the silicon removal in these tests indicate thot the silicon was ottacked ond that perhaps the ottack was assisted by concentration-gradient moss tronsfer. These data appear to disagree with reporfsw that sodium does not react with silicon. LEAD-LITHIUM ALLCY INWATER D. H. Jansen Lead-tithium alloy specimens were tested in distilled water at room temperature and at the boiling peint, and cracks and dimensienal in- creases, such as those shown in Fig. 3.2.13, were observed after all the tests. The lithium 12\'1'. M. Cook, Met. Semianm Prog. Rep, Oct, 10, 1953, ORNL-1988, ¢ 17. B Sittig, Sodium: Its Manufacture, Properties, and Uses, pp 53, 243, Reinhold, New York, 1956, o UNCLASSIFIED ' Y-21249 INCHES Q.02 Q.03 Fig. 3.2.12. Silicon Corbide~3ilicon (2) As-Received and {(4) After Exposure for 100 fr to Sodium in o Seesow Fumoce with Hot- and Cold-Zone Temperatures of 1500 and 1150°F, Respectively. In {a)} the white areas ore silicen and the groy areas are 5iC; in (&) the silico caption) 174 n has been removed, Unetchad. 100X, {Confidentol with A content of the water ofter the tests and the weight chonges of the individuo! samples are given in Table 3.2.4. The loss of lithium to the water in the 100-hr room-temperature test was 16.6 mg/in.? of alloy surface, and it has been cal- culeted thot this would be equivclent to ohout 53 g of lithium lost to the woter in the Bulk Shieiding Facility {BSF) in 100 hr from a 36-in.- square, 4-in.-thick slab. |f the 4-in.-thick slab were made up of eight 1/2-in. plates with water between them, os proposed, the amount of lithium leoched by the woter would be about 350 g in 100 he. UNMCL ASSIFIED ¥-21522 {a), Fig. 3.2.33, Lead-Lithivm Alloy Specimens (0.65 wt % Li) [a) As-Received, (#) After Exposure to Warer for 100 hr ot Room Temperature, ond (c} After T00 hr in Boiling Weter. (Confidential with coption} FERIOD ENDING MARCH 31, 1957 The lead-lithium spectrometer housing proposed for use in the BSF is to be poured at approximately 400°PC ond ollowed 1o solidify slowly. Therefore a test was conducted to determine whether gross segregation would occur in the alloy if the housing were fabricated in this manner. The test was conducted by filling a !fi-in.-OD, 30-in.-long Armco iron capsule with lead-lithium alloy to o height of 24 in. The copsule was held in o verticol position, heated for 4 hr ot 400°C, and allowed to cool in the furnace. Samples of the alloy were taken from various locations in the copsule and analyzed for lithium content. The analyses showed the lithium contents at the top and bottom of the column to be about the some, 0.73 and 0.70 wt %, but a sample from the center showed an abnormally high lithium content, 0.94%. An- other fest is planned in which the capsule will be ciimped ot varicus places along its length in order fo isolate one section from another while In this monner it can be determined whether segregation takes place while the alloy is in the liquid state. An ottempt was made to cast o 36-in.-square, the alloy is still molten. !’Z-in.-Thick plate of the alloy, and it wes found that dimensioncl tolerances could not be adhered te and thot there was some poresity in the casting. Therefore, it hos been decided to cost s slab 21 in. square, but thicker ('l?{fi in.), and have it relled to the required finished dimensions (36 x 36 x 1;’2 in.). VOLATILITY PILOT PLANT CORROSION STUDIES E. E. Hoffman L. R. Trotter Investigations of the various corrosion problems relative to operation of the volatility pilot plont for fuel reprocessing were continved. These Table 3.2.4. Resuhlts of Cotrosion Tests of Lead-Lithium Alloy Specimens (0,65 wi % Li) in Distilled Woter Water Test Specimen Lithium Last per Unit T emperature Duration Weight Gain of Alloy Surface CF) (he) (%) (mg/in.?) 212 50 +0.5 67 212 1490 +0.9 Sample lost 72 50 +0.3 7 72 100 +0.6 T 175 ANP PROJECT PROGRESS REPORT studies ore being performed in cooperation with members of the Chemical Technelogy Division and are reported in Chap. 4.2, ""Fuel Recovery and Reprocessing,’' of this report. EXPERIMENTAL STUDIES WITH MOLTEN LITHIUM ' E. E. Hoffman T. Hikide? An investigotion of the feasibility of ysing tithium as o reactor coolont was begun at NDA in July 1955 under sponsorship of the Aircraft Reactors Bronch of the AEC, In July 1956 co- ordination of the centract was transferred to the Metallurgy Division of ORNL, The results of the work in fiscal year 1956 were reported by NDA, !¢ The over-all objectives of the fiscal yeor 1957 program were to defermine, principally by the use of thermal-convection loops, the effects of nitrogen and oxygen impurities on mass transfer in type 316 stainless steel-lithivm systems. Other container moterials thot were to be in- vestigated were type 430 stainless steel, niobium, and possibly molybdenum. Fundemental inves- tigations were to include o study of the rate of I‘Repnrr on subcontrect work performed at Nuclear Development Corporation of America (NDA), White Plains, M. Y. This subcontract is coordinated at QORNL by E. E. Hoffmeon and T. Hikide. 'ISOn gssignment from USAF. R. €. Ross, Quarterly Progress Report and Reactor Development fuly 1. 1955 Through September 30, 1953, NDA-15 (Qet. 21, 1955); Quarterly Progress Repori and Reactor Development October I, 1955 flmugb December 31, 1955, NDA-20 {Jan. 23, 1958); Quarterly Progress Report and Reactor Development fanuary I, ]9);6 Through March 31, 1956, NDA-25 {Moy 1, 19568); J. M. McKee and R. C. Ross, Quarterly Progress Report and Reactor Development April I, 1956 Through june 30, 1956, NDA- 32 (Dec. 24, 1956} 176 solution of conteiner meterials in pure lithium, the vultimate solubility of container materials in fithium, and possibly the solubility of tithium nitride in lithiom. Considerable work on the development and improvement of onalytical techniques for deter- mining the nitrogen, oxygen, and corbon contents of lithium wos performed ot NDA in fiscal year 1956 and has been continued into fiscal vyear 1957. The thermoi-convection loop design was standardized so that ORNL and NDA test results covld be correlated. A lithium still has been in operation at NDA for several months, ond oll tests are performed with the high-purity material {less than 20 ppm of N,) produced in this still, Among the most significant results obtained to date are indications that titanium end zi¢conium are benefical in increasing the time required for type 316 stuainless steel Joops (hot leg, 1600°F; cold leg, T1100°F) to plug with moss-transfer crystals. Loops containing titaniuvm and zirconium operated for approximately 500 hr, whereas standard loops with no additions plugged in roughly 100 he. Cold tropping of the lithium by means of g positive-flow cold trap to reduce the impurity content shows promise of incregsing the time required for stainless steel loops to plug. Three recently operated loops of type 316 stainless steel, fabricated from an ORNMNL design {hot and cold legs 30 in. long, horizontal connecting legs 18 in. long), plugged with mass-transfer crystals in 95 £ 25 hr. The results of the tests will be used as base-line data for future tests in which attempts will be made to study the effect on mass transfer aof nitrogen, oxygen, titonium, zirconium, and sositive-flow cold traps. No solution rate data have been obtained to date, but tests have been initioted. PERIOD ENDING MARCH 371, 1957 3.3, FABRICATION RESEARCH J. H. Coobs NICKEL-MOLYBDENUM ALLOY DEYELOPMENT H. Inouye T. K. Roche General $tatus of Development Program The progrom for developing nickel-molybdenum alloy container materials for fluoride fuels that have better heat transfer properties than those of lnconel was continued during this quorter, The mosi favorable characteristics of the new alioys in comparison with [nconel are their superior corrosion resistonce and strength. The corrosion resistance of nearly every one of the new alloys tested in NoF -KF-LiF-UF, (11.2-41-45.3-2.5 mole %, fuel 107) was equivalent to that of Hastelloy B, and the average stress-rupture life at 1500°F and a stress of 8000 psi was about 400 hr, which is better than that of Inconel by a factor of 4. These properties were attained without seriously offecting the fabricability, ond the new alloys do not become brittle during aging or welding. In terms of reactor performance, it appears that the nickel-motybdenum alioys will permit the use of o more efficient fuel than that planned for use in the ART and probably an increase of 150°F over tie ART operating temperature. Consequently, every effort is being made to translate laboratory dato into commercial practice. With this objective, the effort is being concentrated on one or two promising compositions that are to be made in ptlot-plont quantities at the Westinghouse Electric Corporation plant ot Blairsville, The properties of the alloys that have been Pennsylvenia. prepared in the faboratery are summorized below: Fabricability., — The fabricability of the nickel- molybdenum alloy depends on the guantities of other elements that must be added to provide the necessary strength, The indications are that the fabricability will be between that of Inconel and that of Hastelloy B. Corrosion Resistance, — The corrosion resistance of the new atloys in fuel 107 and in sodium at metal temperatures of 1650°F is equivalent to that of Hastelloy B when the criterion is the depth of corrosion. A more sensitive indication of corrosion susceptibility is the chenge in the chemical compo- sition of the fuel as a result of contact with the indicaoted that alloy. The corresion tests hove chromium, aluminum, ond tungsten should be held to a minimum in the new alloys. Stress-Rupture Properties, — The stress-rupture data show that, in most coses, the new alloys fall short of the goal of o rupture life of 1000 hr at 8000 psi and o temperature of 1500°F; however, the considerable scotter of the data prevents accurate strength estimates, The average creep and stress-rupture properties of the various compo- sitions tested to date are plotted in Fig. 3.3.1. Since dota from atl the alloys tested were gveraged, it is expected that the composition selected for further development will have properties somewhat better than those shown in Fig. 3.1.1. Joining Characteristics. — The weldability of these olloys has not been determined as fully as desired. Hot ductility tests on some of the olloys indicate that titanium and oluminum are undesirable, as ore nicbivm and fungsten when used in con- junction with a high carbon content. Similerly, for dry-hydrogen brazing the alloys should contain o minimum of aluminum and titanium, Oxidation Resistance, — The oxidation rote of nearly every composition has been determined to be tolerable in that over 60 thermal-convection loops have been operated in air without failures of- tributable to oxidation. The metal temperature attained in these tests was approximately 1850°F for periods of up to 1000 hr. The alloys that showed the most oxidation contained tungsten ond niobium, Aging Characteristics. — The stability of each alloy wos determined by observing the changes in tensile strength, stress-rupture properties, and hardngss after agingat 1300°F, The agingresponse was significant in compositions that contained 0.25% Be or 2.0% Al + 1.5% Ti. Aslightresponse to aging was observed for olloys containing 1.0% Al + 1.5% Ti. Summaries of the properties of laboratory heots of nickel-molybdenum alloys INOR-T through INOR- 8 are presented in Tables 3.3,1 through 3.3.8. The tuel mixtures referred to in the tobles have the foliowing compositions: Fuel 30 NoF-Z¢F -UE, (50-46-4 mote %) Fuel 107 NaF-KF-LiF-UF, {11.2-41-45,3-2.5 mole %) ANP PROJECT PROGRESS REPORT UNCLASSIFIED - ORNL-LR-0WG 20985 = e o e ey s e o L L LRt E e et W W LT W Ve ) LN _ | T ' [ | | - -_¢_‘_T o - T e =T It ] —— A e | T [— — . —— e 1 — - P s e -~ —'— 'r———l—-— — _— —] —— i e ek . .l - ” | | —|— | | ! | 50000 | e =l = = r__| T‘ il — 14 ] 1 T i a [ o L 1 - s e ll l_._. el el - N i !_‘, 14 ' . | . | [ | | | | | | l | | | | S | == - — T T e T T n | | J- | | | 20,000 e ———— e .—L—.—lr i | — et L B ; | | | | | | | E i | | l | l ! | | ] | = | | /~ RUPTURE | | | ] , 2 10000 L 5% ELONGATION | ¥l e E’ ' e = - JI/:»—'{ 1~ 2% ELONGATION | ——1 11 i ] | - A | 111 R e T % . [ — = =115 - : i = sooo f— L 0 L1 P17 ;&;‘: - = _z — == — —RUPTURE LIFE OF INCONEL | 1 j.__ . — 8 : L 4 e LR - 2 ' ] | t Fo ELONGATION — | | 2000 40 gl L ._! = 20 50 1000 2000 TEST PERIOD (hr) 100 5000 {0,000 Flg. 3.3.1. Average Creep ond Stress-Rupture Propertias of Nickel-Molybdenum Alloys at 1500°F in Argon and in MaF-K F-LiF-UF4 (11.2-41-45,3-2.5 Mole %, Fuel 107), (Secret with caption) Table 3.3.1. Properties of Nickel-Melybdenum Alloy INOR-1 Ni —— Bal Mo Other 15-20 Composition, wt %: 0.06 C; 0.5 Al Mumber of heats: 7 Mumber of compositions: 3 Fabricability: Equivalent to that of Inconel Oxidation resistance: Inadequate; minimum resistance with about 20% molybdanum Joining: Brazoble by conventional techniques; weldability between that of Inconel ond thot of Hastelloy B Stress-ruptura: 1000-hr rupture strength ot 1500°F about 4500 psi [extrapolated)} Corrosion: [n fuel 30 for 1000 hr at 1500°F, 1 mil In fuel 107 for 1000 hr at 1500°F, 2 mils Aging choracteristics: None Remarks: All propertiss favorable except oxidation resistance and strength 178 |f_°£. PERICD ENDING MARCH 131, 1957 Table 3.3.2. Proparties of Mickel-Malybdenum Alloy INOR-2 Mo Cr Othee Ni Composition, wt % 16-20 32-10 0.5 Al, 0.5 #n, 5 Nb, 0.1 C (max), 0.25 Ce (max} Bal Number of heats: 16 Mumbker of compositions: 8 Fabricability: More difficult te fabricate than lacanesl Oxidation resistonce! Sotisfoctory only with 7% er more chromiuvm Jeining: Brezable by conventional techniques; waldobility between that of Incenel and that of Hostel loy 8 Stress-rupture: 1000-hr rupturs streagth at 1500°F {extrapoloted) With 2% Cr 4500 psi With 5% Cr 6000 psi With 7% Cr 6500 psi Corrosion: In fuel 30 for 1000 hr at 1500°F, 0.5 to ¥ mil n fuel 107 for 500 hr at 1500°F, 1 mil n fuel 107 for 1000 hr ot 1500°F, 2 mils n sedium for 1000 hr ot 1500°F, 0 to 1 mil, slight mass transfer —_— Aging characteristics: Nane Romarks: Corrosion in fuel 107 progresses from surface pits to subsurfoce voids as chromium content of alloy is increased; pickup of chromium in fuel olso increases with increasing chromium content of alloy ————— ———— i — Mo Ti Al C Mi Composition, wt % 15-16 1.5 0.5~1.0 0.6 Bal Number of heats: 3 Number of compositions: 2 Fobricability: More difficult to fabcicate thon lnconel; sensitive to changes in forging temperature ond raduc- tion schedule Oxidation resistance: Inodequote; oxide scole spolls on coeling Joining: Net brezoble in dry hydrogen; weldability similar to that of lnconel X Stress-rupture; 1000-hr rupture strength at 1500°F about 5000 psi (extrapolated) Corrosion: [n fuet 107 for 500 hr at 1500°F, 1 mil of penetrotion consisting of heavy pits ond subsurface voids, with metal deposits in the cold leg Aging choracteristics; Solution-annealed samples show oging tendencies during stress-rupture tests ot 1500°F; no response observed when anneaied at 1900°F and oged ot 1300°F Remacks: Stress-cupture ductility improved by vocuum melting 179 ANP PROJECT PROGRESS REPORT Takle 3.3.4. Properties of Nickel-Molybdenom Alloy INOR-4 Mo Ti Al C Ni ——— Compositien, wt %: 16 1.5 2.0 m Bal Number of heats: 4 Fabricability: Vacuum melts similar to INOR-3; air melts more difficult Oxidation resistance: tnodeguate; oxide scale spalls en cooling Jeining: Not brozable in dry hydrogen; weldability equivolent to that of Inconel X Stress-ruptura: 1000-hr rupture strength at 1500°F obout 5500 psi {extropoloted); ductility generally less thon 5% Corrosion: In fue) 107 for 500 hr at 1500°F, 3 mils, accompanied by heavy pits and subsurface voids to o depth of 2 mils Aging choracteristics: Age hardens at 1300°F, but oves-ages at 1500°F; ductility obout 2% when tested ot 1300°F Remarks: Adverse properties in oll categories Toble 3.3.5. Properties of Nickel-Molybdepum Alloy INOR-5 Mo Mb W C Other Mi Composition, wt % 15~14 2-3 2-3 0.06--0.25 0.5 Al, 0.5 Mn Bal Number of heats: 7 Number of compositions: 5 Fabricability: Maore difficult to fobricote thon Inconel; corbon content greoter than 0.10% net recommendad Oxidotion rasistonce: Inodeguate; oxide scele spalis on cooling; oxidation rate higher than that of other alloys because of Wngsten cantent Joining: Brozable by conventicnal techniques; weldability equivalent to thet of Inconel X Stegss-rupture: 10Q0=he rupture strength at 1500°F about 6000 psi (extrapolated) Corrosion: In fuel 107 for 500 hr at 1500°F, no apporent corrosion In sodium for 1000 Ar et 1500°F, 1.5 mils, with subsurfoce voids and slight mass transfer Aging cheracteristics: None Remarks: Stress-rupture strength influenced by heat treatment; variations in carbon content affect fabricability and strength; 1400 ppm of tungsten picked up in fuel during corrosion test 180 PERIOD ENDING MARCH 31, 1957 Table 3.3.6. Properties of Nickel-Melybdenuvm Alloy INOR-6 Mo Cr Ti Al Qthear MNi Compositien, wt %: 14 5 1.5 1.0 0.02-0.06 C, 0.5 Mn Bo! Number of heots: 4 Number of compositions: 1 Fabricabifiry: Cite difficult to fobricate but sesiar than Hostelloy B Oxidation resistance: Marginal; oxide scale slightly unstable during cycling Joining: Not brozable in dry hydrogen; weldability equivalent to that of lnconel X Stress-rupturer 1000-hr rupture strength ot 1500°F about 6000 psi lextrapolotad) Corrogion: o fue! 107 for 500 hr ot ]SUOOF, heavy subsurface voids and pits to a depth of 2 milsg In sodium for 1000 hr ot 1500°F, heovy subsurfoce voids ond pits to o depth of 1 mil, mass-transfer deposits in cold leg Aging characteristics: Slight age hardening at 1300°F; none observed ot 1500°F RBemarks: Air mefts difficult to fabricate Table 3.3.7. Properties of Nickel-Molybdenum Alloy INOR-7 Mo Mb Al Cr Othar Mi ——— Composition, wt %: 17-20 1-2 1.0 6.7 0,06-0.12 C, 0,5-0.8 Mn Bal MNumber of heats: 4 Mumber of compositions: 3 Fabricability: Similer te thot of Hastelloy B Oxidation resistance: Equivatent to that of inconel Jeining: Mot &rezable in dry hydrogen; weldobility poor for compositions conteining the upper limits of the quantities shown chove Stress-ruptore: 1000-hr rupture strength at 1560°F about 8000 psi Corrosion: In fuel 107 for 500 hr at 1500°F, heavy subsurface voids ond pits to o depth of 2 mils Aging characteristies: Insufficient doto Remarks: Proparties sensitive to small changes in malybdenum and gluminum content, high-carbon olloys not emenable to tube reducing; 755 ppm of chromium and 4000 ppm of aluminum picked up in fusl during corros1an fest 181 ANP PROJECT PROGRESS REFORT Toble 3.3.8. Properties of Nickel-Molybdenum Alley IMOR-8B Ma Cr Fe Other Mi Composition, wt %: 10-24 3-10 4-10 Mumber of heats: 25 Mumber of compositions: 18 0.06 C, 0.5 Al, 0.5 Mn Bl Fabricability: Ranges from that of lnconel te that of Hostelloy B, depending on additives Oxidation resistance: Sotisfactery when chromium content is greoter than 6% Joining: Brozable by conventianal methads; weldability between that of Inconel and that of Hastelloy B Stress-ruptu:e: 1000-hr rupture slranglh a¥ ]50001: about 7000 ro 3000 psi Carrosion: In fuel 30 for 1000 he ot 1500°F, | mil of subsurface voids in fuel 107 for 1000 hr at 1500°F, 0.5 to 2 mils of subsurface voids In sodivm for 1000 hr ot 1500°F, 1 mil of carresion and moss-transfer deposits Aging characteristics: Alloys that contain less thon 20% molybdanum show no response to oging Remorks: Wide ronge of strengths possible without detracting from other favorable properties Praperties of Alloy INOR-8 It appears at this time that the alloy INOR-8, which has as its basis the Ni-Me-Cr-Fe system, will offer the best compromise for meeting the requirements of a container material for fused fluorides, In order to investigate the mechanical properties developed in alloys in this system, as well as the mechanical property trends that resuit from changes in the total alley content, the tensile and stress-rupture properties of a series of alloys, included within the composition limits described below, are being determined: 10, 15, and 20 wt % 5 7, and 10 wt % Molybdenum levels Chromivm lavels 4 and 10 wt % lran lewsls QOther 0.5 wt % Al, 0.5 wt % Mn, 0.06 wt % C Mickel Balance Cighteen compositions, approximotely 315 ib eoch, were melted vunder vacvum and cast in graphite, Aluminum, mangonese, ond carbon were odded to eoch chorge, primarily for deoxidation of the melt. Each ingot was rolled to 0.065-in.-thick strip from which twe 1l-in,-long creep specimens were prepared. The remainder of the material was rolled to 0.040-in.-thick strip from which die-cut tensile specimens will be blanked. Stress-rupture data were obtained for six of the alloys in the solution-anneoled condition ot a 182 stress of 10,000 psi and a temperature of 1500°F in argon. The results are presented in Tabte 3.3.9. Although the stress-rupture properties do not follow the anticipated trends, the alloys are stronger than lnconel ot this stress level and approach the strength of type 316 stainless steel, A Torced-circulation loop is to be fabricoted from an INOR-8 alioy centaining 17% Mo-10% Cr-7% Fe-0.06% C-bol Ni in which NeF-KF-LiF-UF, {(11.2-41.45.3-2,.5 mole %, fuel 107) will be circu- lated, Therefore two 3.5-ib ingots with the same nominal compoesition, alloys VT-51 and VT-52, were cast for preparing stress-rupture specimens for testing in fuel 107, One melt, VT-51, was prepared from elemental stock, and the other, VT-52, from Inconel diluted with Ni, Me, and Fe., Actual onalyses of these two aloys showed the molybde- num content to be approximately 19.5%; however, the composition is still brocketed by the limits described for the study of the INOR-8 alloy system, Both these olloys had 1000-hr rupture strengths of 8000 psi ot 1500°F in fuel 107. Metollogrophic studies of alloys VT-51, VT-43 (10% Mo-5% Cr~4% Fe-0.06% C-bal Ni), ond VT-49 (15% Mo-7% Cr—4% Fe-0.06% C-~bal Ni) indicated that ¥T-5] responded to aging ot 1300 end 1500°F and thus nad higher strength than alloys VT-43 and V7-49, which did not show this gross aging response. It therefore appears that higher sirengths can be achieved in the Ni-Mo-Cr-Fe system by raising the quantities of the elements added to the nickel. Further evoluation studies of the alloys prepared » FERIOD ENDING MARCH 31, 1957 Table 3.3.9. Stress-Rupture Dato for INOR-8 Alloys Bosed en the Ni-Mo-Cr-Fe System Stress: Temperature: 10,000 psi 1500°F Environment: Argon Alley No. Nominal Composition (wt %} Rupture Life Elangation {hr} (%) VT-43 10 Mo—5 Cr—4 Fe-0.5 Aj—-0D.5 Mn —0.06 C—bal Ni 234 32 VT-44 10 Mo =5 Cr=10 Fe~0.5 Al-D.5 Mn—0.06 C—ba} Mi 152 21 Y T-47 10 Mo =7 Cr—4 Fe-0,5 Al—0.5 Mn —0.06 C—bal Ni 85 1 Y T-48 10 Mo—7 Cr=10 Fe—0.5 Al=D.5 Mn—0.06 C—ba} Ni 106 16 VT-45 15 Mo—5 Cr—4 Fe—0.5 Al-0.5 Mn —0.06 C—bal Ni 192 16 VT-46 15 Mo—5 Cr—10 Fa—0.5 Al—0.5 Mn—0.06 C—ba! Ni 152 24 in the [NOR-8 system ore to be carried out with particular attention to the siress-rupture properties and aging characteristics of the materials, Properties of Alloy INOR-9 Compositions designated INOR-9 are prepared by adding Nb, V, or Fe plus C to the besic Ni-Mo compos ition. Certain elements, namely, Cr, Al, Ti, and ¥, are excluded because of their corrosion tendencies in fuel 107. Previous studies of the oxidation choracteristics of nickel-molybdenum clloys showed that stable oxide scales were formed when the molybdenum content was lower than 15%. The strengths of the solid-solution alloys of nickel ond molybdeaum show strong dependence on the molybdenum content, and thus support is given to the theory that solid-solution strengthening is dependent upon the extent of alloying.! {n order to maintain the molybdenum level as low as possible for oxidation resistance and yet to have the highly olloyed composition needed for strength, niobium additions are being made to the nickel-molybdenum base alloy, The compositions which exhibit mexi- mum solid solubility ore being determined, and their oxidation characteristics in the tamperature range of interest are being studied. For practical reasons the alleys contain iren, which is derived from the ferroniobium melting stock, The compesitiens and the properties of the alloys being studied ore given in Table 3.3.10. TAs used here, "'extent of olloyin refers to the kinds and quaoatities of elements added te the basic nickel-molybdenum atlloy, Fabrication of ORNL Experimental Alays Three experimental compositions were extruded to tube blanks which are presently being processed into seamless tubing at the Superior Tube Co. for fobrication of ferced-circulation loops which will be operated with fuvel 107. Six tube blonks of each composition were fobricoted, without difficulty, at o temperature of 2150°F and an extrusion rotio of 7:1. The compositions which have been ex- truded are described in Taohle 3.3.11. la view of the time delay anticipated in the fabrication of tubing frem the INOR-8 alloys, two laboratory heats of the composition 15% Mo-6% Cr-5% Fe-0.5% Mn=0.5% Al-0.06% C-=hal Ni were cast, and suf- ficient tubing is to be prepared for fabrication of an odditional forced-circulotion loop, which will also be operated with tuel 107, Production of Commercial-3ize Heats of Nickel-Molybdenum Alloys The various products which were fobricated from the biflet material obtained from the six 4800-Ib heats of nickel-molybdenum base olloys designated 0s INOR-1 through -6 were received frem the International Nickel Company. of these alloys and @ complete moterials inventory 2 The compositions were presented previously.” Only o small quentity of uscble material of the compesition INOR-4 {77.83% Ni=16.9% Mo~1.96% Al=1.68% Ti + re- siduals) remained after ingot breakdown, and it was 2, Inouye and T. K. Roche, ANP Quar. Prog. Rep. Dec. 31, 1956, DRNL-2221, p 205. 183 ANP PROJECT PROGRESS REPORT Toble 3.3.10, Scme Properties of Ni-Mo-Nb-Fe Alloys Nominal Composition (wt %) Forgeability” Oxide Stubili’ryb Phoses® 10 Mo-~5 Nb—4 Fe-ba} Ni Foegeable Stoble Singla 10 Mo=7.5 Nb—6 Fe—-bal Ni Forgeoble Mot yet tested Not yet testad 10 Mo—10 Nb—B Fo—bal Mi 12,5 Mo~5 Nb~4 Fe—bal Nj 12.5 Mo-7.5 Nb~6 Fe—bal Ni 12.5 Me—10 Nb—8 Fe—bal Nij Linforgeable Forgeable Forgeable Unfargeable 15 Mo=5 Nb—4 Fe-bal Ni Forgeable 15 Mo=7.5 Nb=6& Fe~bal Ni Forgeable 15 Mo-10 Nb-8 Fe—-bal Ni Unforgeable 17 Mo -3 Nb-bal Mi Fargeabls 17 Mo -5 Nb—bkal Ni Forgeaoble 17 Mo~5 Nb~4 Fe-bal Nij Forgeable Stable Mot yet tested Stoble Stoble Not yet tested Stable Stable Spalls Spolls Not yet tested Multiphose Not vet tested Multiphose Multiphose Mot yet tosted Multiphase Multiphose Single Single Not yet tested “Cast arc meits rolled ot 2100°F; cold rolied ta 0,065 in, thick. bSpecimens exposed in air for 168 hr at 146 50°F, “Annealed end aged 100 hr at 1300°F. Tabie 3.3.11. ORNL Alloys Extruded to Tube Blonks Allay No. Nominal Compesition {wt %) 30-46 and 3047 17 Mo—10 Cr-7 Fe-0.5 Al- 0.5 Mn-£.06 C~bol Ni 17 Mo—7 Fe-0.5 Al0.5 Mn— 0,06 C-bal Ni 17 Mo—10 Cr-0.5 AlI-0,5 Mn— 0.06 C—bal Ni 30.48 and 30-49 30-50 ond 30-51 requested that }’z-in.-thick plate and 0,065-in.-thick strip be rolled from this stock. The plote and sheet received were of poor quality, with numerous surfoce cracks on the pieces. Thirty-four feet of 3- by 3-in, billet moterial of the alley INOR-5 (74% Ni- 16% Mo—=5.3% Cr-1,15% Al-1,69% Ti + residuals) was to hove been used for fabricating plote, sheet, wire, and bar stock, but this material wos scropped during subsequent billet processing. The report on this difficulty hos not yet been received. The alloys INOR-2 (76.7% Ni-16.1% Mo-5.28% Cr + residuals} and INOR-5 {78.6% Ni-13.1% Mo-2.69% W-2,15% Nb-0,10% C + residuals) were fabricoted successfully, 184 All the products received to dote ore listed in Table 3.3.12. The plate and wire ore being used for weldability studies, ond the 0,085-in.-thick strip is being used to evoluote mechanical properties, Eight 9-in.-die, 12-in.-long billets, two esch of INOR-1, -2, and -5 and one eoch of INOR-3 and -4, were extruded to 315-in.-0D, 0.500-in.-wall tube shells at the International Nickel Company in August 1956. These shells, together with one Hastelloy W ond three Hastelloy B tube shells, which were extruded in Morch 1958, are presently being reduced te 2-in.-0D, 0,187.in,-wall tube blanks. The blanks are scheduled for delivery to the Superior Tube Co. in March 1957, where they witl be processed to small-diameter seamless tubing. A summary of the fabricability of the alloys INOR-1 through -6 is presented in Table 3.3.13. The contract with the Westinghouse Electric Corporation covering the mefting, casting, and fabrication of lorge pilot heats of nickel-molybde- num base alloys ot their Blairsville, Pennsylvania, metals plont hes been signed, ond work is to begin immediately. Although two compositions were originally specified forscaling up to semiproduction quantities, only the alloy INOR-8 will be melted PERIOD ENDING MARCH 31, 1957 Table 3.3.12. Products Fabricered from 4800-1h Heots of INOR Alleys Produced by Internationol Nicke! Company Hect No. Alley Type Quontity Size Remarks ].:{‘.{-in.-Thick Plote — Hot Ralled Y8195 INOR-1 o A §ix T Eligit-coacleson suwfoes Y.8197 INOR-2 7 pieces 3 124w Y8196 INOR-3 8 pieces 6 x 12 in. Y-8198 INOR-4 8 pieces 3 x 12in, Surface ond edge cracks Y8200 INOR-5 8 pieces 3 x 12 in, Weld Wire — Cold Drown Y-8195 INOR-1 6 Ib '{3 i dia Y8197 INOR-2 9 Ib 1;3 in. dia Y-8194 INOR-3 8 Ib % in. dia Seam along length ¥.8200 INOR-5 8 b !fi in. dia Y-8195 INOR-1 6 Ib 3:52 e Y.8197 INOR-2 10 b 3;52 v ifiaa Y-8196 INOR-3 6 Ib 3@2 i di Y.8200 INOR-5 9 1b 362 i i 2?}’3-in.-d|'u Fargings Y-8B195 INOR] ] picce 54 in. leng Crack at one end Y-8197 INOR-2 1 piece 34 in. long Y-8196 INOR-3 1 piece 48 in. long Y-8200 INOR-5 1 picce 44 in, long 0,065-ia.-Thick Strip - Cold Rolled Y8195 INOR-1 25 pieces 6 % 12in, Y-3197 INOR-2 33 pieces 3 x 12 in, Y-8196 INOR-3 17 pieces & %X 12 in. Y3198 INOR-4 21 pieces 3 x 12 i0n. Surface crocks Y -3200 INOR-5 36 pieces 3 x 12in. 185 AMNP PROJECT FPROGRESS REPORT Toble 3.3.13. Fobricability of 4800-1b Heots of Nickel-Molybdenum Alloys Fabricability Characteristics Alloy Designotion Forging Rolling Extrusion Dr\::?ng INOR-1 Fair Fair Good Good INOR-2 Good Good Good Good INOR-3 Fair Fair Good Fair INOR-4* Poor Poor INOR-5 Good Good Good Good INOR-6** Fair Goad *Allay INCR-4d became ?5% scrap during initial forging af the ingot. =*The billet material fabricated from allay |INOR-6 be- came scrop during subsequent processing, af present. The composition of alloy INOR-8 has been altered slightly from that given in the contract, and the nemincl composition (in wt %) is now the fol lowing: Molybdenum 1517 Iron 4-5 Chromivm 68 Carbon 0.04-0.08 Maonganese 0.8 (max) Silicon 0.5 {max) Micke! Balance The average molybdenum content wos raised from 13.5 to 16%, and the average chromium level was increased from 6 to 7%. Before the alloy is pre- pared, details of the melting proctices used by the Internationat Nickel Compony on the 4800-1b heaots of alloys INOR-1 through -6 end by Battelle Memoriol Institute on similar nickel-molybdenum ¢lloys will be made available fo Westinghouse. These melting practices witl be compared with those used ot Westinghouse in order to determine the best melting procedure, Initially, one 35600-lb heat will be prepared for casting two ingots of approximately 1100 Ib and four ingots of approximately 250 Ib. Preliminary forging studies will be catried out on the smaller ingots in order to establish the hot-working temper- oture range of the olloy. Priority will be given to the fabrication of a 3-in,-dia, 6-ft forging which 186 can be further processed, on a loboratery scale, to tube blanks and mechanical property test specimen blonks., Melting of the second composition specified in the contrect, INOR-7, has been postponed because of the detrimental aluminum content would have on its corrosion resistance fivorides. 1t is believed thet on alloy based upon the Ni-Mo-Nb system, the Ni-Mo-Cr-Nb system, or the Ni-Mo-Cr-Fe system with higher total olloy content than that of the INOR-8 composition can be specified in the near future to replace the INOR- effect its in fused 7 composition, Phase Diagram Studies at the University of Tennessee The present status of the phase diagram studies being performed ot the University of Tennessee Subcontract 582 is summorized here. A previous report® described the studies of nickel- base alloys containing 20 to 30% molybdenum, In this work, metallogrophic and x-ray examinations, hardness tests, ond other techniques are being used to establish phase relationships and charac- teristic phase transformations which relate to the mechanical properties of nickel-rich alioys con- under tairing molybdenum ond molybdenum plus chromium, [n the binary system, Ni-Mo, the three secondary phases previously reported in the literature were identified, although only the crystal structure of the beta phase was confirmed. The temperctures ot which the beta and goamma phases decompose on heating were found to be higher than those reported in recent literature and ore at present being con- sidered to be 868 and opproximotely 925°C, re- spectively. A simple ordering mechanism for the formation of the beta phase from the alpho phase wos worked out that yielded o structure from which the observed x-roy dota could be derived., Pre- cipitation of beta ond gamme material from the alpha phase increased the hardness of the alloy to 450 DPH, with little if ony decreose in hardness ofter aging for periods of up to 2000 hr. Nickel-rich nickel-molybdenur alfloys with ad- ditiens of chromium in the range of 4 to 14% were studied, A chromium content of up to 5% does not appear to alter the total selubility of the alse 0. W, Stoffel ond E. E. Stansbury, A Metallograpbic and X-Ray Study of Nickel Alioys of 20--30 Per Cent Molybdenum, AECU-3105 {Dec. 1955). alloying elements in nickel, whereas larger amounts of chromium seem to permit an increase in the total solubility. Additions ot chromium quickly restrict the formation of beta material, and systems that precipitate gomma ond then delto phases develop. There is evidence of an additional phase in the higher-chromium-content alleys which has not vyet been identifiad. Alloy Development at Battelle Memoriel Institute Work on the nickel-molybdenum alloy development program being conducted by Battelle Memorial Institute under Subcontract 979 continued along the lines described previously.*® ORNL has assisted Battelle in their program by determining the stress- rupture properties of selected olloys in the fuel mixture NaF-KF-LiF-UF, {11,2-41.45,3-2.5 mole %, fuel 107) and by extruding numerous tube blonks of their alloys for corrosion evaluation, From the tubing successfully fabricated to dote, ORNL has operated thermal-convection loops with both fuel 107 and sodium. Emphosis is now being ploced on the fabricotion of tube blanks of alloys selected for forced-circulation loop tests with fuel 107 to be performed at Battelle, Four tube blanks of each of the Rattelle olloys B-3404, B-3407, B-3412, and B-3418, described previously,® were extruded and sent to the Superior Tube Co. for redrawing to small-diameter tubing. However, all the blanks failed on the tube reducer and thus substantiated eorlier evidence that atloys with 0.12% carbon are not amenable to tube-reducing operations. At the recommendotion of Superior Tube Co., Battelle hos discorded the high-corbon heats and has melted alloys with a lower carbon level, The compositions of the new olloys are listed in Table 3.3.14. Bottelie has prepared o sufficient number of extrusion billets of these alloys for fabricating the necessory tubing to operate a total of 16 forced-circulotion loops with fuel 107, but only alloys B-3870 and B-3871 are to be used ot 4E. M. Simons, Agendaéor ANP Meeting at Baitelle, April 16=17, 1956, ORNL CF-56-4-156 {April 16, 1956). 5\E. M. Simons, Semi-Annual ANF Meoting, Battelle Memorial Institute — Ocilober 3l-November 1, 1936, ORMNL CF-554-11-15 {Nav. 2, 1956). 'SH. Inouye and T. K. Roche, ANP Quar. Prog. Rep. Dec. 31, 1956, ORNL.-2221, p 203. PERICD ENDING MARCH 31, 1957 this time. ORNL hos received 12 billets of eoch of these two compositions which will be extruded to tube blanks and further precessed to 0,380-in,- 0D, 0.065-in,-wall tubing ot the Superior Tube Co. This should provide sufficient tubing for twe forced-circulotion loops of each of the two alloys. In addition to the alloys which have been pre- pared for loop studies, Bottelle has cast 100-1b heats of the six compositions shown in Teble 3.3.15, which will be evaluated for fabricability, heat treatment, weldability, and stress-rupture properties, An evaluation of these alloys, os well as the alloys scheduled for forced-circulation loop studies, shovld provide additional data for de- termining the effect of aluminum and chromium on the properties of nickel-molybdenym alloys. Table 3.3.14, Bottelle Alloys Scheduled for Forced- Circulation Loop Studies with Fuel 107 Alloy Nori L No. ominal Composition (wt %) B-3870 19 Mo -7 Cr—-2 Al-0.02 C—bol Mi B-3871 19 Mo=7 Cr-1 Al-2 Nb=1.4 Fe 0,02 C- bal Ni B.3a72 19 Mo—-2 Al-7 Mb-0.07 Fe-0.02 C—-bal Ni B-3873 19 Me~2 Nb=1.4 Fe=0.02 C—bal Ni Table 3.3.15, Alloys Prepared by Battelle for Evaluation of Fabricability, Heat Treatment Weldahility, ond Stress-Rupture Properties Alloy Maminal Compeosition {wt %) Mo, B.3874 19 Mo-=1.5 Al=1 Nb-0.7 Fe-0.04 C—bal Ni B.3875 19 Mo =7 Cr=1.5 Al =1 Nb 0.7 Fe-D.06 C~ bgl N B-3876 19 mo—=2 Al=1 Nb-0.7 Fe-0.06 C-bal Mi B-3877 19 Mo~7 Cr=2 Al=1 Nb-{L.7 Fe -0.0& C- bol Ni B-3878 19 Mo—1.5 Al=1 Nb—4 Fe-0.06 C—-hal Ni B-3B79 19 Mo=7 Cr=1.5 Al=1 Nb—4 Fe-0(.06 C- bal Nj 187 ANP PROJECT PROGRESS REFPORT FABRICATION OF COMPOSITE TUBING AT SUPERIOR TUBE co.’ T. K. Roche The corrosion resistance of the nickel-molybde- num alloys to attack by sodium is about equal to that of Inconel. Thus it appears that temperoture- gradient mass transfer is an inherent characteristic H. Inouye of nickel-base alloys and thot it increcses in severity with increasing temperatures. Since the nickel-molybdenum olloys cre being developed for use at higher temperatures than those contemplated for luconel, the use of composite tubing may be desirable or even mandatory. The fabrication of composite tubing by coextrusion has been shown experimentally to be entirely feasible.® On the bosis of this experimentol work a considerable quantity of duplex tubing was pre- pared by commercial practice ot the Internctional Nickel Compony ond the Superior Tube Co. without apparent difficulty, In this production run, 9-in.-dia compos ite billets were coextruded 1o produce 3-in.- 0D tuke sheils having o wall thickness composed of 60% Inconel over 40% type 316 stainless steel, The tube shells were tube-reduced to 2-in.-QD, 0.187-in.-wall tubing by the Intemational Nickel Company and then tube-reduced again ond redrawn to small-diameter tubing by the Superior Tube Co. An evalustion of tuhing thus produced is presented in Tables 3.3.16 ond 3.3.17. The results clearly indicate that layer thicknesses can be held to within 2% of those intended, and that, in general, the defects found by inspection are those normolly associated with conveaticnal tubing., The trans- verse sections of this tubing shown in Figs. 3.3.2 and 3.3.3 illustrate the uniformity of the layers and the metallurgical bond at the interface of the finished tube. Terminal Report No. 1633, Subcontroct 531, which was submitted by the Superior Tube Co., summorizes this work with the following conclusions: (1) The condition of the os-received 2-in.-0D, 0.187-in.- wall composite tube shells was excellent and equol to that which has been furnished to the CX-900 Inconel specifications. (2) The composite tubing was processed without difficulty by using con- ventional tubing precesses. {3) The ratio of wall TSubcontrocl 531, 84 R. D'Amore and H. Inocuye, The Extrusion of Composite Tubes, ORNL CF-54-4-123 {April 18, 1956). 188 thicknesses was maintained essentially as it existed in the as-received tuvbe shells. (4) Over- all yields were excellent. {5} Additional orders for this type of composite tubing mey properly be processed by production schedules. SHIELD PLUGS FOR ART PUMPS J. P. Page Two full-sized gamma-ray shielding plugs for ART f{uel pumps were prepared. The plugs are composed of 75 wt % tungsten carbide and 25 wt % Hastelloy C. The first plug was hot pressed in o large horizontal press, and the die material was CS-312 graphite rather than the AGHT-grade previ- ously used, The die fractured ot about 1800 psi and coused loteral expansion of the pressed plug and the die parts. A verticel hot-pressing facility was adapted for pressing the second plug, and o die identical to the first one wos used. Even though the pressure was limited to 1600 psi, this die olso failed at the end of the pressing cycle, and some lateral ex- pansion occurred. However, the pressed plug had @ vniform density of 12,1 g/cm®, These plugs will be surface ground on one end face and used for brazing and thermal-shock tests. A new graphite die has been designed and ordered for which the dimensions ore such thot the hot- pressed plugwill require lirtle or no grinding on the inner or outer surfaces. This die was made some- whot stronger by increasing the outside diameter and eliminating the sight hole. Meutron shielding disks hove been cut from Ludlum sheet material. These ore ready for insertion into the plug assembly, Allegheny stoinless-steel-clad Cu-8,C NEUTROMKN SHIELD MATERIAL M. R. D'Amore’ The Aliegheny Ludlum Steel Corp. continued to experience difficulty in preparing the stainless- steel-clod Cu-B,C shield material. Of a total of 17 experimental composite packs rolled during Qctober ond November, none yielded more than 40% usable stock, At the suggestion of ORNL, the sintering temperature for the Cu-|34C cores was increased, and the frames for the composite packs were redesigned, Since then on odditional 15 9On cssignment from Prott & Whitnay Aircroft. PERIOD ENDING MARCH 31, 1957 Toble 3.3.186. Metallogrophic Evaluotion of Inconel-clad Type 316 Stainless Steel Tubing Nominal Tube Wall Thickness {mils) Dimensions Specimen Specimen Type 316 . Incone] Outside Wail No. Pasitian Stainless Steel Inconel Composite (Average P&r?ent:l;ge Diometer Thickness A NMox Mo A Wex Min A Men MO comeositel (3a.} {in.) 0,500 0.047 1 Tronsverse 17.5 18 17 29 A 4.5 47 46 62.1 2 Transverse 17.5 18 17 8.5 0 ¥ 44 48 44 51.9 3 Tronsverse 17.6 18 17 221 30 28 46.7 47 46 42.3 4 Transverse 7.9 19.5 17 279 X% 458 48 45 60.9 5 Transverse 7.9 18,5 17 229 30 3.5 438 47 45 60.9 b Transverse 17.3 18 17 26.3 30 X 46.5 48 44 62.9 7 Longitudinal 18 18 18 27.5 29 2% 455 d4 47 41 8 Longitedinal 18.1 1§ 175 274 28 2% 45.3 47 44 60 0.250 0.025 9 Transverse 10 0.5 %5 163 W 155 w2 % 217 62.3 10 Transverse 10.5 11 9 156 16 15 258 26 25 58.2 11 Transverse 10.2 1N 190 155 16 15 258 26 25 601 “Averogn of meosuramant: a1 lour locotiong. **Spacilication, 60% loconal; volves given are averoges of values at four locations. Table 3.3.17. Nondestructive Inspection of Inconel-clod Type 316 Stainless Steel and incenel-clad Type 310 Stainless Steel Tubing Inspection Method Results Resononce-type wltrascund o mojer unbonded oreas disclosed in any of the tubing; nenbonded areas 0.0&0 in. thick and ],fz in, long can be detected by this method Immersed pulse-ache vltrasound Encircling-coil eddy currant Postemulsification flucrescent penatrant Radiagraphy A few cracklike indications Mo detrimental conditions within the tubing A few small pin-hole or pitlike indications Several pin holes ond lengitudine! indications, believed to be shellow packs have been relled with considerable success; the last six composites rolled yielded virtually 100% vsable materiel, TUBULAR CONTROL RODS M., R. D'Amore The feasibility study of extrusion of contrel rods Previous studies indicated that cracking of the cermet core (30 wt % Lindsoy oxide— 70 wt % Ni) in extruded three-ply tubes may have been coused by thermal stresses between the core and Hastelloy X cledding. Therefore the cladding material for the tube-extrusion studies has been changed 1o [nconel, which hos a thermal expansion was continued. necrly equal to that of the cermet core material. The dispersion of fine particles of Lindsoy oxide, which form a nearly continucus network in fobricated cores, may also contribute to the poor ductilities observed in tensile specimens and in extruded three-ply tubes, 1? The major effort has been directed toward the praduction of strong, high-density 44- 1o 105-u porticles of Lindsay oxide. The procedure de- veloped for obtaining the desired particles con- sists of the following: first, the os-received V4 R D’ Amore, ANP Quar, Prog., Rep. Dec. 31, 1956, ORNL-2221, ¢ 210. 189 ANP PROJECT PROGRESS REPORT 100 i _qulnnhmhu i L Fig. 3.3.2. Tronsverse Section of Composite Tubing, Etchant; 50% HC! + 10% solution of Cr03. 7K. Reduced 32%. Inconel=clod Type 3146 Stainless Steel. F;u.gl 3-3.3- Etchanit glycerio regia. 75X. 190 e powders ore compacted in a steel die ot 4 tsi; second, the compacis are fired ot 1900 to 2000°C in a hydrogen atmosphere; and, finally, the fired compacts are crushed and ground in a micropulver- izer to obtain the desired patticle size. A core that was to be clad ond extruded was hot pressed to an apparent density of 91% of theo- reticol by using oxide of the 44. 10 105-p particle size ronge. This core was assembled into a five- ply biliet, with |nconel cladding oend mild steel cons both inside ond out, This billet is now ready to be extruded. Two additional billets have been prepared for extrusion of rods for preparing tensile specimens of the cermet, EVALUATION OF ARC-CAST AND POWDER-METALLURGY NIOBIUM J. P. Page The collection of wsable mechanical property dota for arc-cast ond powder-metallurgy niobium at both low andhigh temperatures requires knowledge and control of the grain structure of oll test speci- mens, and therefore the recrystailization process | LINCL ASSIFIED Y 20786 .0l P v w T U = 0.0 e . Metollurgical Bond ot Interfoce of Composite Tubing, Inconel-clad Type 316 Stalaless Steel, is being studied, A knowledge of recovery and recrystallizotion kinetics con be obtoined from a small amount of materiol by metallographic and x-ray techniques and thus sufficient material from the specimen remains for further comprehensive festing. The chemical powder-metaliurgy richium ore quite similor. The microstructures of the two materials, however, differ greotly, as shown in Figs. 3.3.4 and 3.3.5. The inclusions shown are probably niobium car- bides. The effect of the prior fabrication histery on compositions of arc-cest and the recrystallizotion charocteristics can be seen in Figs. 3.3.6 ond 3.3.7. These photomicrographs indicate thot, as would be expected, the arc-cost material has a tendency to coalesce and form large-grained structures, The first phase of the recrystallization study is essentially complete. The objectives of this phase were to form controlled, fine-grained microstructures in both materials ond thereby minimize the effects size on subsequent recrystallization behavior, to determine the range of recrystallization femperatures for the moterials, and to determine the effects of various annealing atmospheres on niobium. Quontitotive recrystallization studies will be carried cut on the fine-grained material over o wide range of temperatures and test periods. The present informotion indicates that the recrystal- lization ronge for annealing times of wp to 1 hr of grain UNCL ASSIFIED Y-21327 : & Fig. 3.3.4, Arc-Cost Niobium, As-polished. 100X, PERIOD ENDING MARCH 31, 1957 5 . : ] UNCLASSIFIED . . = Y-21320 s - t - . + -y e i e - * - — o = e s i - - % . - 3 —- i s e . a a1 . - ' e Sk 2 7o L e ' - - " i - : . ~y - ¥ # . C . : .- - » .. . “-i 5 o _J.‘ " - * e SR ot - x o = >4 - ok ; ¥ £ * "’f . = i - . L * - 7 | - o, . 1 'y ] b @ ';.: » - g " Filg. 3.3.5. Powder-Metallurgy Miobium. As polished, 100X, , potia UNCL ASSIFIED I 4 - ¥-21328 | | ’ | . - .ff .J:I 4 } v \1 f.;. l\ I c dYy) \ } -’Fn'. llf J’\_I Arc-Cast Niebium Anneoled 10 min ot 50 cme HZO' 14 e H2504a HNOa. 100X, Fig. 3-3;6- 1450°¢. Etchunt; 25 cm® HF, 5 em® 191 ANP PROJECT PROGRESS REPORT UNCL ASSIFIED iy S ¥ 4 F"'I : = e -f-i ‘f-2|323 . J = A T =y e Ly R " B v ..I‘\ " b e e A g i - o “ " ek {.. 5 5 -_.f_ ¥ J'-..- - G i e e = A S ; B 1 0 i o= E" * '“—f i - . e A g ! ; g‘-\" g g i : . % 2 4 H- - Lam B % = T e | e 3 0w ! - il o . .. e e r . -2 * i "I o \S :h B = - - g, ""5 e = Ty o T § i }‘ e e s i = ¥ etk 3 = ! A i T '* ."‘_ \.‘: B Tk, i e P B = P s e O i . i N T . nilm e :J [ ‘;'J'H\' : .); Ene 1 ¢ PR 5 ~ L o e “l i e i = i, e o : e -H.T.\ l‘r. |ll‘l " _JB T u /4 M 5 g ' ¢ / ; e ! . i % o AT \ B % .J- '{};. i - pi o i L L e Lo L § A b b B ] 3""-—,:’?‘ o ‘JI ‘I‘Tff = 2 - o \ L v i o S 'P"- i e, f i Wy s i 4 s /‘ J : Fig. 3.3.7. Powdar-Metallurgy Niohium Anncaled 10 min at 1450°C. Erchont: 50 cm® H,C, 10 cm> H,50,, 25 cm® HF, § cm® HNO,. 100X, lies between 1100 and 1350°C, depending on the omount of cold work te which the materiol is subjected, Severol techniques are being considered for conducting the numerous onnealing freatments required, These include vacuum encapsulation with ond without the addition of getters, treotment in dynamic vacuums of varicus orders of magnitude, and trectment in high-purity argon. Each of these techniques hes on advantage in certain ceonditions: the orgon otmosphere is recommended for short- timeg, high-temperature the dynamic vacuum for intermediate temperature and times, and the vacuum capsule for extended times ot lower temperatures. A quontitative survey of the effects of time and temperoture on the micrchardness and treatment, the lattice parometer of powder specimens is being conducted for each environment, ldentical microstructures for powder-metallurgy and arc-cast materiols have been achieved. The niobium specimens were severely worked (reduced in thickness by 90%) aond annealed for 1 hr at 1250°C in a dynamic vocuum of approximately 10-9 mm Hg. The resuftant material is very fine-groined, but the greins shew elongation in the direction of 192 rolling. Also, the severe reduction limits the thickness of the material available for the recrystal- fization study, Further work will be done with lower reduction ratios and longer annealing times in an attempt ta develop a more randomly oriented microstructure in a thicker material., METAL HYDRIDES FOR USE AS MODERATORS IN HIGH- TEMPERATURE REACTORS R. A. Potter R, E. McDonald'? T. Hikido'? The realization of the great potential improve- ment in performance of circuloting-fuel reactors which is offered by the NaF-KF-LiF-base fuels and the nickel-melybdenum olloys will depend to a large extent on the development of an adequote Of the Be(, beryllium canned in moderator for use at high temperatures, possible moteriois, mojybdenum, and the hydrided metals, the laost appear to offer the mast promise, Research at the General Electric Company aond other organizations has shown that certain metals, notably zirconium and yttrium, are able to abserb and retain large quantities of hydrogen at high temperatures ond yet retain their metallic characteristics, However, at the temperature of interest for advanced reactors, over 2000°F, yttrium is the only material known at this time which offers promise of being satisfactery. Capsule for In-Pile Tests An octive research and development program on hydrided metals was initiated, with one of the first projects being fabrication of the capsule shown in Fig. 3.3.8 for in-pile tests. The speci- men consists of hydrided zirconium (NH = 3.5) conteined ina 0.025-in.-thick arc-cast 0.5% ritonium- molybdenum alloy capsule. The ends of the capsule are ]fain. thick ond the over-all dimensions are, nominally, }2 in, dia x 3 in. long. No protective cladding was put over the molybdenum, becouse the test will be made in o helium ctmoschere, The molybdenum capsule was machined from :",;:1- in~dia rod. A rod of reactor-grade zirconium was machined to 0.460 in. in diameter end 2.75 in, in length ond a .]-’B-in.-diu hale drilled through it lengthwise. This zirconium cylinder was iron- ploted to o thickness of 1.75 mils to aid in ochieving } lUn assigament from Prott & Whitney Aircrofs. IQOn ossignment from USAF. ONE INCH FPERIOD ENDING MARCH 31, 1957 UMCLASSIFIED PHCTO 40448 Fig- 3.3.8. A Molybdenum-—ciad Hydrided-Zirconium Capsule Prepared for oo In-Plle Test, (Secret with caption) a bond to the molybdenum. The ploted zirconium was inserted into the molybdenum copsule and hydrided in situ to an Ny of 3.7, calculoted on the basis of weight gain, The !-é-in. hole was reamed clean, and a zirconium rod wos weighed ond press- fitted into the hole. The colculoted Ny geneization of the rod is 2.5, after homo- A l-mil iron-foil disk was placed over the hydrided zirconium, and the molybdenum ead plug was inserted and copper- brozed in place, After hoving been brazed, the capsule was machined fo size (0.025-in.-wall thick- ness) and tested at 1850°F for 1 hr under a vacuum of 3 x 1072 mm Hg, The weight loss of 4.2 mg under these conditions was not considered to be serious. After the capsule was inspecied by radiography, six Chromel-Alumel thermocouples were oftached by spot-welding. The completed assembly waos heated in an argon atmosphere tc 1650°F, cooled to opproximately 800°F, reheated to 1650°F, and cooled to room temperature, The thermocouples this treatment. A second specimen was processed simultaneously with the in-pile test capsule in order to provide o control somple for examination. However, this specimen wos over-heated during the brozing operation and is therefore not truly representative of the in-pile test capsule, Metallographic exomi- nation of the control semple showed evidence of the owver-heating in the form of melting ond de- composition of the hydride ot the brozed end of the capsule. Although a tight fit was observed remained securely attached aofter between the hydrided zirconium and the molybdenum in the other areas of the capsule, the metailurgical bond was not uniform, The tn-pile test capsule was scheduled to go into the MTR on February 18, 1957, The calculated maximum operating temperoture will be 1550 to 1600°F, and 100 thermal cycles will be imposed by moving the test container in and out of the reactor. Hydriding Equipment The hydriding was accomplished with ¢ system bosed on the design developed by the Generol Electric Company and Sylvania Electric Products, Inc. On the whole, this system worked very well on the in-pile test capsules ond other small speci- mens. However, during these initial operations the need for several improvements became opparent, The modifications include a better temperature control and recording system, provisions for removing the rsetort from the furnace to permit rapid cooling from the hy- driding and equipment to provide hydrogen at o constant pressure or in meosured volumes. In addition, a furnace capable of attaining and these cre now being made. temperature, the high temperatures required for hydriding yttrium hos been built and is now being checked. Y tirium Metal Production Research on hydrided yttrium is being seriously hampered by the unavailability of the material. 193 ANP PROJECT PROGRESY REPORT Althowgh o considerable amount of work is being done ot the Ames Laboratory, lowa State Callege, te cllevictie this shortage, it wos deemed advisable to produce some yttrium at ORNL. The availoble experience influoride technology was a major factor influencing this decision, becayse the conversion of ¥, 05 to YF, is an important step in the process. The purity of the fluoride controls the purity of the final product to a large extent. Accordingly, 15 |b ot Y,0, was obtoined and 1000 g was converted to the fluoride. In the reduction process, which was developed at the Ames Loboratory, the yftrium fluoride will be reduced with a mixture of calcium, magnesium, ond calcium chloride. The yttrium- magnes ium-colcivm alloy thus formed will he refined by vacuum distillation to remove the magnesium and the calcium. The resulting yttrium sponge will then be vacuum melfed. Fabrication of the equipment for producing the metal hos been completed, and it is now being assembled and checked. mixing of the starting material to the vocuum dis- The entire process from tillation of the alloy will be performed under a vacuum or an inert-gas atmosphere, |t is expected that the first metal will be produced in March 1957, 194 Cladding Studies The advanced reactor designs presently being studied picture the hydride moderater as cylindrical rods approximately 3’2 in. in diameter and 30 in, in fength, The hydride will be protected with a duplex cladding of molybdenum and ¢ nickel-molybdenum alloy., The molybdenum is required for o hydrogen diffusion barrier and for compatibility with yitrium, Since the remainder of the fuel circuit will be constructed of a nickelsmolybdenum alloy, a similar alloy must be put over the molybdenum to prevent dissimilar metal corrosion attack, Studies temperatures and amount of work required to achieve a bond between melybdenum ond anickel-molybdenum alloy. The test specimens consist of molybdenum cylinders press-fifted into nickel-molybdenum alloy tubes, which, in turmn, cre press-fitted into lnconel tubes, evacuated, and sealed. la the first test, the sealed capsule was heated te 1600°F ond reduced 10% by swaging. Metallographic exami- nation showed thatonly partial bondingwos achieved under these conditions. In the second test, a pallodium foil will be inserted between the molyb- denum and the nickel-molybdenum alloy. Higher temperatures, different amounts of work, and other intermediote layers will be tested in the future. have been initiated to determine the PERIOD ENDING MARCH 131, 1957 3.4, WELDING AND BRAZING INVESTIGATIONS P. Patriarca HEAT EXCHANGER FABRICATION ART Sodiumsto-NaK Heat Exchangers G, M, Slaughter Brazing procedures are being developed for use in the fobrication of ART sodium-to-NeK heat exchangers by the Griscom-Ryssell Co. Ex- amination of a variety of tube-to-header samples from several brazing experiments performed at the Griscom-Russell Co. has revealed inconsisient fiow and fitleting. A typical example of this condition on o tube-to-heoder joint is shown in Fig., 3.4.1. Attempts have been mode ot ORNL to duplicate the difficulties experienced by the vendor and then to alleviate them by suitable variotions in brazing procedure. For the initial tests, the vendor's heating rate of approximately 100°F/hr was used. Samples taken from a typicol test assembly before and ofter brazing ot this rote of temperature rise are shown in Figs. 3.4.2 ond 3.4.3, The influence of the following variobles was studied in these tests: (1) type of Coast Metals brazing alloy Ne., 52 ring (ORNL cast ring vs York Corp. sintered ring), {2) differences in Inconel base material (ORNL headers vs Griscom-Russell headers), (3) angle of countersink in headers, and (4) direct impingement of hydrogen on samples vs slight baffling. Mo significant differences in braozing were noted os o result of these vorionces. An analysis of all the experimental results indicated thai saotisfactory brozing can be ac- UHCL ALEIMIED T-21547 Fig. 3.4.1, Tube-to-Header Joint Showing Incomplete Fllleting. complished ot 1920°F if oll variables such as hydrogen purificotion, hydrogen flow rate, material cleanliness, etc, are corefully controlled. How- ever, only minor deviations from the optimum conditions may result in inconsistent brazing at o 100°F /hr rate of temperature rise, Additional experiments were then conducted at 200°F/hr and ot J00°F/hr rates of tempercture rise, As con be seen in Figs. 3.4.4 ond 3.4.5, samples brazed at 300°F/hr had satisfactory fillets on all joints. With the faster heating rates, it appeared that brozing could be conducted under slightly reloxed conditions with a reasonable assuronce of success. The 300°F/he heating rate, which should be readily atteinable with most industrial equipment, provides a high degree of assurance of successful brazing, Investigation of Rapid Heating Cycles E. A. Franco-Ferreira Tests were run to investigate the feasibility of vsing very short heating cycles (of the order of 5 min) for the back brozing of heat-exchanger tube-to-tube sheet joints, The experimental procedure consisted essentially in heating the welded side of a small Inconel tube sheet whiie providing a vocuum or an inert atmosphere for protection on the opposite side, which was to be brazed. The heat source used in the experiments was a salt-bath furnace. It is felt that certoin advantages might occrue from this method of brazing, such as minimization of grain growth in the tubes and reduction of fube-wall dilution, while avoiding distortion and the jigging problems associated with conventionol furnoce brazing of entire ossemblies. One of the experimental configurations is shown in Figs. 3.4.6 and 3.4.7. A section through a typical jeint brazed by this method is shown in Fig. 3.4.8. This method of brazing is not limited fo the use of g salt-bath furnace as a heat source. It is felt thot high-energy radiant heat sources based on surface combustion units could also be used to advantoge. Although the experiments described above were prelimincry, the resulis do indicate the feasibility of using rapid heating cycles for some high-temperature heat exchanger brazing operations. 195 ANP PROJECT PROGRESS REPORT AUX. HX.TEST 4 BEFORE BRAZING Flg. 3,4,2, Tube-to-Heoder Tast Assembly Before Brazing, UHCH ASSIFIED AUX. HX.TEST 4 e S AFTER BRAZING Fig. 3-4.3. Tube-to-Heoder Test Assembly After Brazing at 100°F /hr Rote of Temperature Rise. 196 PERIOD ENDING MARCH 131, 1957 .- UMCL ASSIFIED " ¥-21443 PO A &1 P N VA Fig. 3.4.4. Tube4o-Header Test Assembly Brozed at o 306°F /hr Rate of Temperature Rise. R I 5 S -q 1 UNCL ASSIFIED i Y-21453 | J R Flg. 3.4,5. Tubeto-Header Joints Showing the Excellent Fillets Obtalned by Using a Heating Rote of 300°F/hr, 167 ANP PROJECT PROGRESS REPORT 1] - UNMCL ASSIFIED Y-20717 Fig. 3.4.6. Experimental Setup for Rapid-Heat-Cycle Brazing Experlments. UNCL a55IF [ED Youe Flg- 3-‘41?- Braozing Experiments, Completed Setup for Ropid-Heot-Cycle 198 FABRICATION QOF YALVYE COMPONENTS G. M. Sloughter The developmental work on methods for fabri- cating valve components of various types con- tinved. The specialized technigues that were described in the previous rlt=':|:Ju;~r1‘]"2 for joining the different compositions of disk ond seat—ring ma- teriols were used to fobricate the volve com- ponents described in Table 3.4.1. Two brazing steps were utilized in the construction of most parts, Step | consists in the attachment of the IE. A, Fronco-Ferreira, G. M. Sloughter, ond E. 1. Wilsan, ANP Quar. Prog. Rep. Dec. 31, 1956, ORNL- 2221, p 241, 2F‘. Patriarca and G. M. Sloughter, ANP Quar Prog. Rep. Sept. 10, 1956, ORKWL-2157, p 198, esp. Figs, 3.4.12 and 3.4.13. PERIOD ENDING MARCH 31, 1957 ) i L LaTE s e : ' UNCLASSIFIED Q.04 0.02 Hii|o.03 0.04 Fig. 3.4.8. A Typical Joint Brazed by Using the Rapid-Heat-Cycle Method. 75X, Etchant: 10% oxolic acid. Table 3.4.1. Valve Component Fabrication During the Quarter Mumber of Brozes Fype of Yalve Component Step | Step 1l K-94 disk 2 6 {tungsten corbide plus cobolt binder) K-94 ssat ring 1 2 (tungsten carbide plus cobelt binder) K-26 disk 0 2 (tungsten carbide plus cobalt binder) KM disk 3 4 (‘I"'F'Fi(:2 plus cobalt binder) Mallory 1000 seat ring Mo step | broze required 1 {sungsten plus copper and nickel as binder moterials) Thermenal seat ring Mo step | broze required 1 K-138A seat ring 3 2 (TiC-NbTuTica plus cobelr binder) K-162B disk 0 1 {titonium carbide plus nickel and malybdenum os binder maotericls) K-1428 seat ring 1 2 (titonium carbide plus nickel and molybdenum as binder moterials) K-151A disk 0 1 (*itanium corbide pius nickel binder) Copper seot Mo step | braze requirad 3 Melybdenum seat rings 3 3 Malybdenum disk 1 1 Tungsten disk ] 3 199 ANP PRQJECT PROCGRESS REPORT material to a suiteble tronsition loyer, ond Step If consists in the attechment of the subassembly to Inconei. The occosicnal rebroze cycles required to c¢htain components acceptable for use in the test runs are included in the number of brozes listed. ART FILL-AND-DRAIN TANK FABRICATION G. M, Slayghter A study of the problems associoted with the fabrication of the ART fill-and-drain tank is under way. Specifically, tests are being run to establish welding and brazing procedures for the tube-to-tube sheet joints in the tank heads. As a result of the high degree of restraint exerted by the 1 lé-in.-fhick tube sheet, tube-to-tube sheet welds made with the standard fusion procedure used for thin fube sheets consistently exhibited root cracking of the type illustrated in Fig, 2.4.2. The direct oim of the welding investigations has been to arrive at o E. A. France-Ferreira welding procedure which "will produce joints free of such root cracks. A promising joint design currently being investigated is o trepanned type, an example of which is shown in Fig. 3.4.1C. Brozing experiments ore also under way to determine the proper amount of preplaced brazing alloy, the type of preplacement procedures, and a suitable brazing cycle. In the initiel experiments, the Coost Metals brozing alley Ne. 52 was preplaced in the form of rings, two per tube, as shown in Fig. 3.4.11. A photogroph of a typical as-brozed test sample is shown in Fig. 3.4.12. The optimum procedures for welding ond brazing have not yet been determined. Varicus modifi- cations in technique are to be studied in subse- quent experiments. UNGCL ASSIFIED Y-11545 0.0% 0.05 008 Fig. 3.4.9, A Root Crack in o Tube = = o o] L : & | = T | | 80 L - ot N 3 40 ' L% AL L L = = _\ INOR 5 ',/ INOR 6 5 ¢ & 20 ————T—— T - :: L] || | I i | | 0 e L . . . i 1 3400 800 2200 2600 1400 800 2200 2600 1400 1800 2200 2600 TESTIMG TEMPERATURE (°F) TESTED ON COOLING FROW 2400°F oo . 2 < 80 <1 wh o < 50 = Z 20 = [ = a 20 L [ Lo o A0 1800 2200 2600 4400 4300 2200 TESTING TEMPERATURE 2600 1400 1800 2200 2600 (°F) Fig. 3.4.14. Hot Ductility of Rickel-Molybdenum Alleys INOR -4, =5, and -6. TESTED ON HEATING PERIOD ENDING MARCH 31, 1957 UNCLASSIFIED OANL —~ LR —DWG 17452 UI Ll | gl g 1400 B0 2200 2600 1400 1800 2200 TESTING TEMPERATURE (°F) i PR g i [ 1 Eg x e - s e Rl :1 o O & | 4 =] = bob—l e == = o L s £ | & | 5 e = o - o & i | I_"‘il [ b 1 | 1400 1800 2200 2600 400 18Q0 2200 2600 1400 1800 2200 2600 TESTING TEMPERATURE (PF ) TESTED ON COOLING FROM 2400°F | i | i1 M T { I T 1 1 | ! | ; | Y A a | & = s o ! = L e = ] | , | (i 0] | = ) [INCONEL X | | | | HASTELLOYE | = | | o . ! = L — ~ g | b =1 1 | T ! m ! —— -4 2600 1400 1B0D0 2200 2600 Fig. 3,4.15. Hot Ductility of the Nickel-Base Alloys Inconel, Inconel %, ond Hastelloy B. Toble 3.4.9. Results of Tests of the Effect of Heating Rate and Type of Brazing Alloy Ring on Broze Adherence Heating Rote and Type Brazing temperoture: 1905°F Time at temperature: 30 min Percentage of Joint Areas with of Brozing Alloy Ring 75-100% S0-74% 25-49% 0-24% Adherence Adherence Adherance Adlterence Heoting rate: 100°F /hr ORNL cost rings 77 15 1 7 York sintered rings 15 8 3 74 Heating rate: 200° F /hr ORML cost rings 27 3 York sintered rings 51 35 4 Heating rote: 200°F /hr ORMEL cast rings 96 4 York sinterad rings 100 Heating rates 550° F /he York sintered rings 00 207 ANP PROJECT PROGRESS REPORT Table 3.4.10. Results of Tests of the Effect of Brozing Temperature on Braze Adherence Heoting rote: S00°F /he Brazing Temperoture and Percentage of Joint Areas with Type of Brazing Alloy Rings 75-100% 50-74% 25-49% Adherence Adherence Adherance Brozing temperature: 1905°F York sintered rings 105 Brazing temperature: 1870°F York sintered rings g8 Z ORNL cast rings 100 Brazing temperoture: ]BBOOF York sintered rings 70 21 g CRNL cost rings 100 Assistance to Yendors Assistance was given to the York Corp. in the solution of difficulties in the fabrication of the high-conductivity-fin NaK-to-air radiators, It wos recommended thot the retort be boffled to obtain more positive circulation of hydrogen, porticularly through the fin bank, during the brozing operations. The size of the retoct should be held to a minimum 1o lessen channeling of the gos flow and to reduce the total mass. Very siringent cleaning ard storage procedures should be followed throughout the fabrication process. It was suggested thoi the ossembled fin banks be ploced in airtight con- tainers before brozing. The fins should be de- greased immediately prior to assembly. A rate of temperature rise of greater than 300°F/hr (prefer- ably 400 to 800°F/hr) should be used through the temperature range of 1700 to 1900°F. Further experimentation should be corried cut with sintered brazing alloy rings in order to study the influence of processing voriables on the brazing character- istics, ond experiments with rings produced by other methods, including ORNL cast rings, should be continved, The use of mico as a nonwetting support material wos discouraged. It wos sug- gested that alumina be used becaouse of its known inertness., 208 STUDIES QF GRAIN GROWTH IN INCONEL TUBES E. J, Wilsen G. M. Slaughter The interest in maintaining @ fine-groined strycture in the |nconel tubing used for reactor heat exchanger ond radiotor components has led to a preliminory study of the groin growth that results from various brazing and heat-treating operations. The initicl results of this study indicated thot stress-relief treatments at 1500°F did not result in grein growth, while significant grain growth re- suvited from I,i-'nr brazing cycles at approximately 1922°F. It was also noted that growth proceeded more ropidly in the graing locoted olong the outer wall of the tube than in those located along the inner wall, Since high-temperature back-brazing is required in the fabricotion of meny components, a more detailed study was undertaken to defermine the influence of the different variables on the grain growth choracteristics of the tubing. The infor- mation obtoined from an onolysis and evaluation of growth behavior will be useful in determining the optimum procedures for fobricating the warious components, Influence of Brazing Temperature Two different lots of CX-900 Inconel tubing were used for an investigation of the effect of the brazing temperoture on groin growth, These lots of tubing were identified as heat 5759 {0.187 in. OD, 0,025 in. woll) and heot 5789 (0.229 in, OD, 0.025 in. wall). One-inch segments from ecch lot were cleaned with ocetone and subjecied to various brazing temperatures for 30 min in dry hydrogen, After the heat treatment the samples were sectioned and examined in both the transverse and the longitudinal direction. structures of the heat-treoted specimens of 0.187- in.-0D tubing are presented in Fig. 3.4.16 in the order of increasing brozing temperatures., Although wide warigtions in grain size occurred along the Photomicrographs of the outer peripheries of the tubes, the photomicrographs shown are typical of the oreos thot experienced extensive radial grain growth. After the 30-min hect treatment ot temperctures os low as 1814°F oend up to and including 1904°F, the grain growth wos found predominantly in the grains along the outer surface of the tube. The fine-grained structure ¢long the inner surfoce appeared to be relatively stable. After heating at 1922°F and above, general grain growth wos evident, that is, grains along both the inner and outer surfaces had grown to significont proportions and many of those which originated on the outer surface had grown completely across the tube wall. As would be expected, the frequency of large grains in- creased with increasing tempercture, The trends observed in these tests are illustrated in Fig. 3.4.17, in which the grain size is plotied as a function of temperature for both the outer and the imner tube surfaces. The grain dimensions selected for plotting were representative of the grain sizes in areas that exhibited definite grain- coarsening tendencies., At the higher temperatures the curves reflect the coexistence of lorge and small grains in the tube wall, For exomple, the tube heated ot 1922°F for 30 min had grains that penetrated radially from the outside surfoce com- pletaly through the tube wall, but there were adjacent arecs thot contcined smaller grains. Infiuence of Time at Temperature It was felt that the time at temperature might also be an important facter in grain growth, and PERIOD ENDING MARCH 31, 1957 therefore a study was initiated in which both time and temperature were varied. For these experi- ments, 0.187-in.-0D, 0.025-in.-wall CX-900 Inconel tubing from heat 5759 was cleoned with acetone and sectioned into 1-in. segments, which were then heat treated at various temperotures for vorious times. The heat-reated segments were then sectioned in the transverse and longitudinal directions for grain-size determinations. Photo- micrographs of the structures of the heat-treated specimens are shown in Fig. 3.4.18. As may be seen the lowest temperature employed (1848°F) and the 5- and 10-min time intervals produced no appreciable grain growth along the outer periphery, The specimens held at 1868°F for 30 min, however, showed sporadic grain coarsening ot the outer periphery. More extensive grain coorsening oc- in the specimen held at temperature for 1 hr, as was expected. After 5 and 10 min ot 1904°F, no grain growth was observed, but ofter 30 min at this temperoture, some growth was curred evident. After 1 hr, groins occasionally penetrated completely through the tube wall, and the inner surface grains also had grown. In the tests at 1922°F outer periphery groin growth bhecame quite noticeable after 5 min at temperature. Since it hod been estoblished previ- ously thot excessive grain growth would occur in 30 min at 1922°F, no further experiments were conducted. Influence of Tube-Straightening and Tube-Polishing Operations A group of experiments was conducted to study tube-straightening and tube- polishing operations on grain growth in CX-900 lnconel tubing. Since these operations impose a smoll degree of cold deformation on the tubing, it was desirable to determine whether this cold work was o major confributor tfo the ocuter-surface grain growth noted upon hecting ot high temperatures, Samples of 0.187-in.-0D and 0.229-in.-0OD tubing were obtained in the following conditions: {1) an- nealed, (2) anneoled and straightened, and (3} an- nealed, straightened, and polished. The somples were then examined os-received, of subjected fo @ brazing cycle of 30 min at 1868°F and examined, or subjected to a brazing cycle of 2 hr at 1922°F and examined. The specimens were cut transversely and mounted for microscopic examination, the influence of 209 oLe LA L SECTIOMS- 3 RSy T L T DAL ATAD L TTRCLYT W7 1Y0dIY SSIYO0YS LD3T0Hd dNV Fig. 3.4.16. Tronsverse Sections of 0.187-in.-0D, 0.025-in.-Wol1l CX-900 Inconel Tubing Held 30 min ot Temperatures Shown. Original magnification: 100X. Etchant: oxalic acid (electrolytic), Reduced 67%. PERIOD ENDING MARCH 31, 1957 UHCLASSFIED CRNL-LR-DWG 20234 TT T T T T T T T T T T 1 i | ] , . 26 | — MAX MU RADIAL GRAIN S1ZE LIMITED 8Y TUBE WaLL THICKNESS 24 | 22 — 20 b— -QUTER TUBE SURFACE RADIAL GRAIN SIZE tmiist = 3 | J INMER YUBE SURFaCE m AT -HECEIVED ] 1800 1820 1840 1860 188G 200 1920 1940 1980 TEMPERATURE 19F) Figs, 3.4.17. Effect of Temperature on Grain Growth in 0,187.|n.-0D, 0.025-In,.Wall CX-90 Incone! Tublng. As may be seen in Figs., 3.4.19 and 3.4.20 the The samples that were cold rolled were ploced in two sizes of tubing reacted somewhaot differently a retort and subjected to a typicol brezing cycle when subjected to the brazing cycles. Hawever, (heated at 300°F/hr to 1922°F, held for 30 min at it is evident that the straightening end polishing 1922°F, and coocled ar 600°F /hr) before they were operations had only minor effects on the grain prepared for metallegraphic examination of grain growth. The as-onnealed tubing olso showed growth, definite grain growth at the outer surface. Influence of Cold Work A medium-sized grain structure wos observed n ; after heat treatment of the samples which hod been The recrystallized grain size of a metal de- cold reduced 5, 8, 12, and 15%. Some grain creases with increasing amounts of celd werk, ond coarsening wos observed, however, in the sample therefore it was thought thet cold werking could reduced 2.5%. The smallest grain size was ob- be used lo produce o medium-sized grain structure served in the sample heat-treated after 15% cold ofter brazing., Preliminary studies of the influence ,.diction. of cold work were conducted on small segments cut from onnealed lnconel sheet, The segments A length of I,aé—hord {approximately 15% cold were cleaned with ocetone to remove dirt and reduced) Inconel tubing was therefore acguired grease ond then examined in the os-received from the Superior Tube Co. for further experiments. condition and aofter they had been reduced in Samples of this 0.250-in.-0D, 0.035-in.-wall tubing thickness 2.5, 5, 8, 12, ond 15%, respectively, were prepared ond subjected to various simulated by cold rolling, brozing cycles. 211 21 Fig. 3.4.18. Effect of Time and Temperature on Grain Growth of 0.1874in.-0D, 0.025-in.-Wall Reduced &§7.:5%. ALL AT GRS MAMDIELE EPCHANT — OaliC a2 1D FLECTEQLYTICH CX-900 lnconel Tubing, Original magnitication: 100X, 1A0d3Y SS3Y¥00UYd LIIT0Ud NV el L L] R B - § Y-arand s ;M-NE.M.ED. STRAIGHTEMED, ARD HEATED FOR 30 miln AT 1B6E°F = ] i i ) . "B ] ANMEALED, STRAIGHTEMED, POLISHED, T A0 HEATED FOR 2 b AT 1222°F i, P Fig. 3.4.19. Effect of Annealing, $traightening, and Polishing on Graln Growth in 0.229-in.-0D CX-%00 Inconel Tubing. 100X, Etchont: oxalic ocid and copper regia. Reduced 54 5%. . AMPEALED AMD HEATED FOR 30 min AT VE&8*F . e —— F - - LWL TR ¥ raxm ' ANMEALED, STRAIGHTENED, : -mn HEATED FOR 7 he AT 10324F - - ll i ARMEALED, STRAFGHTEMEL, AND FOLIHED ' Tmiy atiErE - I ANNESLED, STRAIGHTERED, Foas AND HEATED FOR 30 min AT 1888%F £561 'IE HOUYW ONIONT QOIY¥3d riZ Fig. 3.4,20, Effect of Annealing, Straightening, ond Polishing on Grain Growth in 0.187-in,-0D CX-200 Inconel and copper regia. Reduced 56.5%. Tublng. 100X. Etchaont: oxalic ocid L¥0dTY §538008d LD3M0dd dNV The structure obtained after rapid heoting to 1922°F and holding for 2 hr is shown in Fig. 3.4.21. The medium-sized grains obtained with the typical brazing cycle (300°F/hr heoting rate) are shown in Fig. 3.4.22, The sample wos held at the brozing temperature of 1922°F for 30 min. A larger quantity of ],zé-hurd tubing is being acquired from the Superior Tube Co. ond o more extensive exemination of its behovior will be mode. SUBCONTRACT WORK The University of Florida subcontroct for on investigation of the diffusion of boren and silicon from high-temperature alloys was completed ond @ fina! report is being prepared. The Glenn L. Martin Co. subcontract for « study of electric- resistance welding of tube-to-heoder joints was also completed and o final report is being prepared. The progress made by Rensseloer Polytechnic Instityte in their hot-ductility studies is reported in the section of this chapter on ""Welding and Brazing of Nickel-Molybdenum Alloys."’ The Battelle Memoricl Institute subcontract for molybdenum welding studies has continyed. UNCL ASSIFIED Y-21404 Fig., 3.4.21, Mlcrostructure Obtoinad upon Heoting Y%-Hard Inconsl Tubing at 1922°F for 2 hr. 100X. Etchant: oxalic acid gnd copper regio. PERIOD ENDING MARCH 37, 1957 The objective of this program is the development of techniques for producing ductile weldments. Carbon-deoxidized arc-cast material was used. Welds were made with a shielded tungsten electrode both in o dry box end in the open otmoesphere ond were tested by o single-point-loaded bend test ot room temperature and at 75°C. In oddition to studying the effect of ctmosphere purity, vorious etching and abrasion techniques were employed in preporing the surfaces, and several types of shields were used in welding the samples in the open otmosphere. The series of samples prepored by wvorious cleaning techniques were welded in o dry box, They showed that acid etching resulted in welds with somewhat better ductility than those prepared by other metheds. They exhibited bend angles at fracture of 40 deg at room temperoture and 76 deg ot 75°C compared with average bend angles of 28 and 62 deg, respectively, for other samples. For weldments prepared in air, the samples welded with a trailing shield showed significantly better ductility than all other samples, UNCL ASSIFIED Y-21395 Fig- 3.4.22. Ifé-HGIrd Inconel Tubing at o Rate of 300°F /hr to 1922°F 100 X. Microstructure Obtained ypon Heating ond Holding ot that Temperoture for 30 min. Etchant: oxolic acid and capper regia. 215 ANP PROJECT PROGRESS REPORT 3.5. MECHANICAL PROPERTIES STUDIES D. A. Douglas DYMAMIC STRAIN PROPERTIES OF INCONEL C. R. Kennedy' The study of the effect of thermally induced strain cycles on the rupture life of Inconel was continued, Two types of tests are being made, including relaxotion tests and mechanically in- duced strain-cycling tests. Stress relaxation data are necessary for determining the octual amounts of plastic strain that occur under operating con- ditions; whereas, strain-cycling data can be utilized in determining the life expectancy of structural members subjected to strain reversals, Although the majority of the strain-cycling problems are cavsed by thermal fluctuations, tests in which the specimen is mechonically strained under isothermal conditions give a definite insight to the effects of thermally induced strain cycles. Yo assignment from Prott & Whitney Aircroft. 24,000 | - ———————r Ei,OOO! — - -_ | et (8,000 |=——18,000 psi AND 0.2% STRAIN- =—16,000 psi AND 0% STRAIN 16,000 }——' ! L e, (2,400 psi AND 0.05% STRAIN & 11,000 psi AND 005 % STRAIN | W ] = 1 2 12,000 r —_— 2d I - —r— Lip} 9000 ¢ = 10,600 psi AND 0.05 % STRAIN .' | | | 6000 3000 | | ! — | | O i i Relaxation tests of Inconel onnealed ot 2050°F for 2 hr were completed at 1300, 1500, and 1650°F, and the results are presented in Figs. 3.5.1, 3.5.2, and 3.5.3. The tests were run at total strains of 0.05, 0.1, and 0.2% at 1300°F and of 0.05 and 0.1% ot 1500 and 1650°F, One specimen was used af each temperoture to determine the relaxation rates for all strains, The procedure was to run four successive 100-hr tests with 0,05% total strain and then run the tests with higher total strains. This was done to determine the effect on the relaxation rates of prior strain at the test temperature. It was tound that the prior strain only slightly offected the relexation properties of annealed Inconel tested ot 1300°F, as shown in Fig. 3.5.1. It may also be seen that, ot ¢ll temperotures, when the total strain is greater than 0.05%, which is the strain of the proportional limit for coarse-grained Inconel at these test temperatures, the relaxation rate is the same as that of the 0.05% total strain test. Since UNCLASSIFIED ORNL=LR—~DWG 192414 A—NO PRIOR STRAIN B— 0.04% PRIOR STRAIN! L | C~0.08% OR GREATER PRIOR STRAIN . O 0.02 0.Ca 0.0 Q.08 o 0.2 0.3 i 2 5 10 20 50 oo TIME (hr) Flg. 3.5.1. Relaxation Characteristics of Inconel Annealed ar 2050°F for 2 hr and Tested ot 1300°F. Stresssd to produce o constant strain. 216 PERIOD ENDING MARCH 31, 1957 UNCLASSIFILD ORNL—LR—-DWG 19942 16,000 14,000 — . ] ' I 12,000 12,000 psi AND 0.4 STRAIN-—— | — Q000 ! i —; [ | : 9000 ps1 4ND ICI.DS‘.’{. STRAIN 2000 - STARESS {psi1] 2000 | Gd— - = . G o0z 004 00 008 o Q2 a5 { 2 5 10 20 50 G0 TIME {hre} Fig. 3.5.2. Relaxation Characteristics of Inconel Annealed ot 2050°F for 2 hr and Tasted at 1500°F. Stressed to produce a constont strain. [Confidential with caption) at these test temperatures strein hardening is small and recovery occurs rapidly, it follows that the plastic strain given the specimen on loading to totel strains greater than the elastic limit has neo effect on the relaxction rate of the material. However, at temperatures less than 1300°F, this may not be the case, ond the motericl may reflect the effects of strain hardening in its relaxation rate. The strain-cycling equipment described pre- viou5|y2 was in operation during the quarter ond preliminary results were obtained ot a test tempera- ture of 1500°F. The greatest number of tests were run with red specimens in two conditions, os- received ond annealed at 2050°F for 2 hr, The test results are shown in Fig. 3.5.4, in which the log of the plastic strein (€.) per cycle is plotted vs the log of the number ofpcycles to failure. The procedure of operation hos been to apply o load which is of a magnitude that will cause the specimen 2], R. Weir, Ir., ANP Quar. Prog. Rep. Dec. 31, 1956, ORNL-2221, p 246. to experience ¢ specified plastic strain in 1 min and then to reverse the load to produce the same plastic strain in the opposite direction. The plastic strain vs time wave has the shope shown on Fig. 3.5.4. It moy be seen thot the coorse- grained specimens (annealed at 2050°F for 2 hr) exhibit fewer cycles to failure for all values of € . Metallographic examination of the specimens showed that the failures were intergranular and that they initiated at the surface of both the coarse- and fhe fine-grained materiol, Tests were also run at 1500°F on 0.75in.-0OD, 0.C6-in.-wall Inconel pipe both in the as-received and the annealed (1950°F for 2 hr) conditions. As may be seen in Fig. 3.5.5 there is some scatter of the deto; however, all but three points fall within the band brocketed by the coarse- and fine-grained rad data, Tests of Inconel pipe in the fused solt NaF- ZrF -UF, (50-46-4 mole %, fuel 30} ot 150C°F are now in progress in order to determine the effects of this corrosive medivm on the stroin-cycling choracteristics of Inconel. Strain-cycle tests will 217 ANP PROJELCT PROGRESS REPORT 20,000 —————————— 18,000 — — 16,000 - 14,000 —_ | 12,000 |-—— S — — —— 11,000 psi AN? 019, STRAIN 10,000 f—— - : - STRESS [psi b 8000 |=— 8000 psi AND 0.05 % STRAIN | | L 6000 4000 | 2000 |- O e | o 002 2.049 .06 0.08 34 02 Flg. 3.5.3. Relaxotion Characteristics of Inconel Annealed at 2050°F for 2 hr and Tasted at 1650°F. ta praduce a constant strain. (Conlidential with caption) al so be run ot 1300 and T650°F on both as-received and annecled specimens in argen ond in fuel 30. Since the stroin-cycle type of test provides an importont measure of an alloy’s ductility, such tests will be included in the program for evaluating potential reactor materials, ln conjunction with this work at ORNL, addi- tional data are being obtained uader subcontrocts at the University of Alabama and Bottelle Memerial Institute, At the University of Alaboma experi- ments are being conducted to sfudy the effect of plastic strain induced by thermaol fluctuations., faitially the tests were progromed to provide o I-hr hold time at gach end of the temperature ex- cursion; however, all the specimens tested in this monner exhibited preferentiol growth and ultimotely tailed by buckling. Recently, tests were conducted so that a complete temperature reversol was ef- fected in 1 min. This rate corresponds to the 218 UNCLASSIFIED QRNL=LR—DWG 19943 — T | L .| || e ‘ "i'i‘| | | | i L . A L)t ERE 05 i 2 5 1o 20 50 100 TIME (hr) Stressod rate used for some of the mecheonicol stroin-cycle experiments conducted at ORNL, and the type of Therefore some corcelation between the two types of tests should be possible, at least for the rapid cycle rates. It might be assumed thot o material would react in the some monner 1o repected plostic strain regardless of the manner in which the strain wos induced. However, foilure was similar. this is true only if no metallurgical changes are initiated by temperature changes and if the stability of the structure at the temperature extremes is independent of time. The main issue to resolve is whether any such changes occur in the operating temperature range of the reactor, The natural desire to obtain information of this iype as quickly as possible led to an attempt 1o obtain data before all the testing techniques were developed. The mony testing difficulties en- countered have, however, necessitoted a slower, 1000 300 200 HH IS FINE - GRAINED ROD % -_ 1 . oo ] S S B = i Y _| i ool bl - | [ M | ] ® tal . = | = P Ml o ' COARSE -GRAINED ROD t'} 20 L | } 1 i ..._il 2 & i ¢ d 2 40l LT s & - S ' e =13 J m il [SE—] S— } + - - —_— i o | ) el - | i % | i I || | ey [ _ | | o | | W | | . - —l 1 L } i it f—— | == i . | 0.5 | | l ozl.' Loa g ] 4 g Pyl | | | 01 | -2 1 340 4 p bbb 0t oz o8 | e 5 10 20 PERIOD ENDING MARCH 31, 1957 UNCLASSIFIED GRNL—LR-DWG 19944 T e ASRECEWED || O ANMEALED AT 2050°F FOR 2 he | | S0 100 200 300 ICO00 2009 LOG OF NUMBER OF CYCLES TO FAILURE (log &) Fig- 3.5.4. Strain Cycle Charactaristics of Incenel Red Tested in Argon ot 1500°F. (Contidential with coaption) more analytical approach. As a result time is now being spent determining the temperature profile over the gage length, the effective gage length, and the effect of commencing the test at various temperature levels. Thus an odditional delay will be incurred before dota of sufficient accuracy become ovailable to attempt o correlation with the ORNL results. A program wos initioted ot Battelle Memorial Institute on July 1, 1956 1o fully explore the slevated-temperature properties of Inconel under dynomic-stress conditions. The progrom entails complete reverse stress fatigue tests and fatigue tests with various constant load stresses applied in the tensile direction. Such information, together with stress-rupture dato, con be used to form “Goodman’’® diagrams. From these plots the stress conditions that will result in failure by ¢creep can be estoblished, ond the stress conditions that will result in failure from fatigue con be determined. Since the primary interest is in low- frequency stress reversals, the tests be conducted at 1 and 10 cps, Preliminary results show that, ot o temperature of 1400°F, opplication of constant load stresses up to 4000 psi will not significantly alter the stress to produce a fatigue failure in 1000 hr. Data arg to be obtained for diagroms for 1200 ond 1600°F. will 35, Timoshenko and G. H. MacCullough, Elements o/ Strength of Materials, 3d ed., p 371, ¥Yon Nostrond, Mew York, 1949, 219 ANP PROJECT PROGRESS REPORT 1200 URCLASSIFIEDR ORML—LR—DWE 19945 1L }H— - -l"r" 500 200 ——— 100 | o [= i O o n - 1 1. L 1l e 4 1111 i 11 | ‘ ® AS RECEIVED LOG OF PLASTIC STRAIN PER CYCLE {log €, | O ANNEALED AT 1950°F FOR 2 hr T T T I | ‘ -.: { — | FE | i :}: ' i | — \‘* | 1 — 1 T — "_.‘_! TN e = =14 | 1 [ [ T ] — as T HH __:fjfr; T T L e 1) Ll (L riiey o 4 L] e A |—__;_ . 3 — | | I — | | e l —|» ' ! ! 4 _i- —_——— l ‘ i } i -1 | | | i { 11 1 1yl Ll 1 Ll 17 TR L a.2 : } | : [ i i ‘ | : | ch- . | T“ H 1 T — o4 : | ' i | | [} || | | ‘ ! | L i1l o1 02 05 t 2 5 10 20 500 100 200 500 1000 2000 5000 10,000 LOG QF NUMBER QF CYCLES TO FAILURE (lag M) Fig. 3.5.5. Stroin Cycle Characteristics of 0.75-in,-0D, 0.08-in.-Wall Inconel Pipe Tested in Argon ot 1500°F, {Confidantial with caption) ALLOY DEVELOPMENT J. W. Woods Evaluation studies were mode of the creep and creep-rupture characteristics under a constant load of two experimental nickel-molybdenum alloys being developed for reactor use. The environment used in these tests was the fused salt NaF-KF- LiF-UF, {11.2-41-45.3-2.5 mole %, fuel 107). The two olloys tested were vacuum melted ot ORNL. Heat ¥T-5) had the nominal composition {(in wt %) 17 Mo—10 Cr-0.5 Al-0.5 Mn-0.06 C-7 Fe~bal Ni, and heat YT-52 contoined (in wt %) 17 Mo-10 Cr-0.08 C-7 Fe—bal Ni. The results of the tests are presented in Table 3.5.1. The corrosion of the unstressed surfaces of the specimens from both 220 heats thot were solution annealed at 2000°F for | hr and aged at 1300°F for 50 hr was 0.5 to 1 mil. The compositions of the two alloys were virtuclly identical, but the methods of preporation were different. Heot VT-51 was prepared from elemental melting stock, and heat YT-52 was prepared from Inconel diluted with Ni, Mo, and Fe. Alloy VT-5I demonstrated an aging response, while alloy VT-52 did net, Becouse the alloys were prepared in small heats, veriations in mechanical properties of of the two alloys were to be expected. Both alloys exhibited good ductility. Photomi crographs of the specimens are shown in Figs. 3.5.6 and 3.5.7. The formation of o con- tinyous network of carbides around each grain is showrn in Fig. 3.5.6, whereos in Fig. 3.5.7 the PERIOD ENDING MARCH 31, 1957 Table 3.5.1. Stress-Rupture Properties of Two Exparimentol Mickel-Molybdenum Alloys Test temperoture: 1500°F Stress: 8000 psi a H N g ; T Rupture Life Elengation 1 ¥ t 1 eat Mo pacimen l[roatmen (hr) () ¥T-51 Solution anneoled ot 2000°F for 1 hr Bal 76 Soluticn annecled at 200G°F for T Ar 1243 45 and aged at 1300°F for 50 hr YT-52 Solution annealed at 2000°F for 1 he g20 72 Selution annealed at 2000°F for 1 hr Test discontinuad ot 780 72 and aged at 1300°F for 50 hr 1 1 3 foowm yogl " e . Ty . .y UNCLASSIFIED " : =21710 b o l.,' ; 'i‘ *, X iy ) ah . “i i 'y WS o A " _' r“ N 5 ‘ ) . ¥ ... ‘ .: . L l-_l_.. 5 - ¥ % ‘-';;"‘_‘-.“ I‘. 3 . ’ i'_:l g O I;f- y VA o 21 ' / ¢ | £, - i f2 1 1 a |‘ . .;u;.. } iy o } | ..IH‘ 'L .t ! \1\\’. t . y ‘.‘ | - 1“-‘. d ' "" 1.‘“..-'I Fig. 3.5.8. Alloy ¥T-51 (17% Mo—-10% Cr-0.5% Al-0.5% Mn-0.06% C—-7% Fe-bal Mi) Creop Tasted in Fuel 107 ot 8000 psi and 1500°F in the Aged Condition. Ruptured in 1243 hr with 45% alongation. 100X. (Secrst with caption) 221 ANP PROJECT PROGRESS REPORT . - 4 . 4 kv o+ .ri‘. wovhay . "‘r- L !.‘- i 4 Faoad BT =G B e i et N S A ah i Pl in T J!-':—- =F . iy TN . 3 ;-'i . "!“. : R = ool g R e S S R iRy t-']'_:" % ] -ty £y ik H gty e ey R Y ' “hh A ‘; 2 - o 1o e et SN Sl ety R e Tmp e R T R o3 Fouag ek F K 3 |"'r'{'€ o o R r]i ; L e M e R & W S A Sigdh g Yeus el il : s I L e i " ER ; AET .:-‘u-i' 5 5 % ' WY e B <0 i d g e oty wk . g . ! ‘ i % o b PN e 1 FA a1y e wEan g thed Tt RN TSN oyt = SR i . & LenE K o=y l oy } 5 LR, e 1 UNSTRESSED Ha 7 v BT A 4 e o rmery ® W0 Yo i Tm W . - e SR o e ol e v & T L Sk . oo S taa T ML UNCLASSIFIED i Y.21708 a o ™ Ay BB o x - i : !:”. e ‘Ca"‘r " ke g i 2% SYRESSED ¥ mit & ey g RO w _' ; T ' N o Vg S A e erk, S ok - L 3 st v ar o T z e ay ! L A T L v “la A AT L = e Ras b Fig. 3.5.7. Alloy ¥T-52 (17% Mo-10% Cr-0.06% C—7% Fe—bal Ni) Creep Tested in Fuel 107 ot 8000 psi ond 1500°F in the Aged Conditlon. Ruptured in 788 hr with 70% elongation. 100X. (Secret with caption) carbide precipitote in the grain boundories has a more random arrangement which could account for the lower strength exhibited by clloy VT-52, In general the precipitates were well dispersed in both specimens. Hostelloy B hos received considerable attention in the olloy development program because it is commerciclly ovailable and it has excellent high- temperature strength and corrosion resistance. However, the absence of chromium in Hastelloy B results in characteristically poor oxidation re sistonce. One aim of the development program, therefore, is to introduce sufficient chromium to provide good oxidation resistonce but not encugh to result in severe corrosion. Hastelloy C, which is also o commercially availeble nickel-molybdenum alloy, centains 15 wt % chromium. |t was recognized that this amount of chromium would lead to con- siderable corrosive attock, but, since the composi- tion of this alioy represents an upper limit of 222 chromium, it was decided that o certain amouynt of data on its strength properties in fused salts would be pertinent to the problem., Therefore, stress- rupture data were obtoined ot 1300, 1500, and 1650°F in fuel 107 for comparison with dota for other alloys being investigated. The results of the tests are shown in Fig. 3.5.8. The dato show quite good stress-rupture properties, and it oappears that for 1G,000 psi ot 1500°F Hostelloy C witl have a rupture life of over 1000 hr. The two specimens tested at 1500°F in Hostelloy B creep test chambers had poorer stress- rupture properties thon those tested in a Hastelley C test chamber. This may be explained by the fact that the creep test chamber made of Hastelloy B contained no chromium and thus provided, through alloying and diffusion, a strong ""sink”’ for chromium and accelerated the removal of chromium from the specimen. - The results of the alloy development program thus far indicote that considerable progress has been mode toward ochieving the objective of de- veloping a material that is as fabricable as required reactor constryuction, possesses adequate strength, oand is corrosion resistant in high- temperature fuel mixtures, liquid metals, and air. Commercial alloys such as Hastelloys B ond W, which have excellent corrosion resistonce and for PERICD ENDING MARCH 31, 1957 strength, will have to be avcided, since, ot the temperotures of interest, they precipitate a brittle phase that causes poor fabricability and low ductility. Experimentol nickel-maolybdenum alloys of the single-phase or solid-solution type have the desired fabricability and corrosion resistance, but they lack adequate creep strength. In spite of the poorer creep strength, however, these alloys are stronger than Inconel. UNCLASSIFIED ORNL—LR—-DWG 19946 100,000 L I 1 l T T _‘ | T l T — =t — | NE | T e e L 3 4 — e — L ] | = || | _ | | 1 50,000 F——— e S I | 27% ELONGATION AT RUPTURE | | _ | ‘ i | i | i — L { —| - HASTELLOY C N HASTELLOY C‘CH,TME!:ER AT 1300°F | ‘ < I} | £ HASTELLOY C IN HASTELLOY C CHAMBER AT {300°F — 20,000 | L '3"'1:? Ll M. -, EE— ; | , 259 _ 32% o | 2 » 10,000 F iy @ L m - '— s : . 1 4 ) L] i ¢ - I | i | | HASTELLOY C IN HASTELLOY € CHAMBER AT {650°F -’r\_l"‘* — || ; I [ | ) | 5000 — - - ——— S I | 1'—.4_- { L = || 4o b Al s = e \ — ——— 4 i i_ 1 _‘__ | | 2000 + - | | e | | . | | | | a | | | | -. iOOO B | | ' ] | ] J ] ] . 10 20 50 100 200 500 1000 TIME TO RUPTURE (hr) 3 Fig. %.5.8. Stress*® indicate that the strength properties do not vary appreciably from those predicted, 4R. G. O’Rourke et al., Mechanical Properties of ReactorGrade Beryllium at Elepated Temperatures, C00-312 {August 1958). R, G, O’Rovrke ond J. N« Hurd, Mechanical Testing of Beryllium at Elevated Temperatures, Progress Report for First Quarter Fiscal, 1357 {undocumented). ®R. G. O'Rourke and J. N, Hurd, Mechanical Testing of Beryllium at Elevated Temperature, Progress Report for Second Quarter Fiscal, 1957 {undocumented). Pt | PERIOD ENDING MARCH 31, 1957 3.6, NONDESTRUCTIYE TESTING AND INSPECTION OF MATERIALS AND COMPONENTS R. B. Oliver EDDY-CURRENT INSPECTION TECHNIQUES R. 8. Oliver Tubing Inspection J. W, Allen The application of the recently developed Im- p-«=.u:h}gr-:1ph,\i an instrument which measures both the a-c resistance and the reactance of its testing coil over a wide range of frequencies, was in- vestigated further. A prototype of this instrument, described by the block diagram in Fig. 3.6.1, was constructed. It is composed primerily of ean oscillator in which the bifilar-wound center-topped testing coil is the frequency-determining element. Both the a-c resistance of the coil and its in- ductance cre influenced by the tubing under in- spection. The amplitude of the clternating voltage generated by the oscillator varies inversely with the resistance of the testing coil, and the frequency of the voltage vories inversely with the square root of the inductance of the testing coil. The amplitude detector (Fig. 3.6.1) and its associated '}, W. Allen, ANP Quar. Prog. Rep. Dec. 31, 1936, ORNL-2221, p 240. TUBE UNDER TEST — A. Taboada amplifier provide o direct coupled signal which varies inversely with the resistive component, R, of the testing coil’s impedance. The frequency discriminator, with its ossociated amplitude limiter ond amplifier, provides a direct-coupled signal which varies inversely with the reactive component, X, of the testing coil's impedance. The change in impedance of the coil is described by the curves of Fig. 3.6.2. On this graph, the short-dashed as o parameter, the frequency ratio ///_, in which [ is the operating frequency of the coil and /. is determined by curve has, / 2 B it wrD, where g o= dr x 10-7 henries/m, permeability of nonferromagnetic tubing, y = conductivity of paort being inspected, in mho/m, D = outside diometer of part, in meters. £ The four sclid curves drawn from the short- dashed curve to the point (0, 1) represent the effect UNCLASSIFIED ORML-LR-DWG 1TITS Ry SELECTIVE e Y y TESTING COIL (OPERATING AT NATURAL . .. DIEFERENTIATION o __J|[_ - _HESONflNT FREQUENCY} CHAMMEL 4 f,';‘_ il L 3 e == ,—;‘;';.IT—_B ! ' | 7 | - OSCILLATOR AMPLITUBE e | R RESOLVING |4 R-A)x | poc. | lcHamneL | & ¥ A DETECTOR 0.C. I COMPONENT BRIDGE AMPLIFIER [ | & & 3 AMPLIFIER N = - : | | E FEEDBACK,”Y -~ SENSITIVITY S GaIN A = g ' K | o o ] "o z CHANNEL 2 o o I.-__-:"_"."-_-‘_"‘;-_n- | | t_"‘ AMPLITUDE .| FREQUENCY o : X RESOLVING | FXL(1-0R 0C. | CHANNEL 2| & LIMITER DISCRIMINATOR k MPONENT | AMPLIFIER o / o g AMPLIFIER | | S | ; ‘ | F ! ‘ r .r P — e ’ £ ; .'l' . ALY T A — I_ ,rf_ —_— : e J ; £ s 7} FREQUENCY ~A GAIN K. ¢ SELECTIVE " ) Ty 7y DIFFERENTIATION Fig. 3.6.1. Block Diagram of Impedograph. 225 ANP PROJECT PROGRESS REFORT UNCLASSIFIED ORHL~LA~0WSE 139954 o I | | l [ fo B — ey ¢o €T v s o = PERMEABILITY DF HORFERRDMAGNETIC TUBING thenrizsfm) ¥ = CONDUCTITY OF PaRT BEING ISPECTED direna/m) 07 \ \ O, = DIAMETER OF PART [m) X % b, DAMETER OF COIL [m) 08 — \ : £ = FREQUENCY - 1 g, \ b= e REGCTIVE COMPONENT o & F [L] | | o3 { ne g aa — Jf“ ‘.( l.é\?z 3% 9% WLl THICKNESS (N 9 OF OD @, o . | 1 — = - 3 4 G Q.4 0.2 Q.3 o4 2.5 06 0.7 Q8 3 10 RESISTIVE COMPONENT Fig. 3.6.2. |Impedonce Plone for Coils Encircling Metal Tubes. of wvarying the tubing wall thickness (as a per- centage of the outside diometes) for (/] ratios of 9, 16, 25, ond 100, The long-dashed curves indicate the effect of varying the outside diameter. It is important to note that if the proper f/fc ratio is selected for o particular tube, angular separation of approximately 90 deg can be obtained between the effects of wvorying diameter and varying wall thickness. An example of this sit- vation occurs at an f/f_ ratio of 25 for a tube hoving o wall thickness which is 10% of its outside diameter. Both the R and X components of any excursion from the operating point are measured by the Impedograph. These 1wo components moy be resclved into any other set of two orthagonal components by the use of resolving bridges, as indicated in Fig. 3.6.). Thus the controls may be odjusted until one channel of the instrument responds primarily to voriations in diometer and the other to voriations in wall thickness. Small defects on the inner wall of the tubing cause impedance excursions thot are nearly in phase with those from wall thickness variations, and small defects on the outer surface cause excursions that are neorly in phase with those from diameter variations. Therefere, small inside defects will appear on the some channel with the woll thickness variations, and small outside defects will appear 226 on the same channel| with the diameter variations. Gross defects cause very large impedance ex- cursions which ore ot some angle between the effects of diameter and woll thickness; thus the large resultant signal is present on both channels. Iflustrotions of the instrument's obility fo dis- tinguish between diameter and wall thickness variations are given in Figs. 3.6.3 and 3.6.4. UMCLASEIFIED GRAKL=LR~DWG {7798 AYERAGE waLlL THICKNESS tin) RELACTIVE COMPONENT COMPONENT REIISTIVE QUTSIDE AMETER Linl LEMNGTH (o]} Fig. 3.6,3. Comparison of Impedegraph Signal Traces with Actvol Dimensionsl VYariations of 0.229-in.-0D, 0.025-in.-Wall Inconel Tubing Specimen 68-1B, UNCLASSIFIED QRML—-LA—0W3 1T 746 s o §: e VIDIGAGE MEASUREMENT L 00250 A §§ 0.0280 : u¥ 00270 &= ; - 4 wa l‘ ! — Z TR CH LT el 2% } e m <. = — mg T F o Fe = s uwh = 2y Bg nE s ~E0 L = Zozun : — ; . : g”‘ozsoo MICROMETER MEASUREMENT au ' r e B T e e - —— T '5% o.ezgoi—‘\cif\.\,/ficjflbfi\:/.}flu \ = o = 0.2260 o 0 5 0 15 20 25 30 35 LEMGTH Lin? Fig. 3.6.4. Comparison of Impedograph Signal Troces with Actual Dimensional VYariotions of 0.229-in.-0D, 0.025-in.-Wall lncone! Tubing Specimen 68-2A. [ 3] The signal traces are recordings of the reactive ond resistive component signols from the Im- pedograph for 35-in. lengths of 0.229-in.-0D, 0.025-in.-wall Incone! tubing which have been stretched to occentuate their dimensional voriation. Above the traces are plots of the overage wall thickness os measured with the Branson Yidigage megsurement). Below the traces are plots of the average outside diameter as measured with micrometers. |t is readily seen that close correlation exists between the instrument signals and the other measurements. These traces were made at an operating frequency of 189 ke, for which the f/fc ratio is opproximately 15 for the 0.229-in.-0OD, 0.025in.-wall lnconel tubing. This frequency and well thickness (11% of OD) have an operating point on the graph of Fig. 3.6.2 such thot the resistive component is {ultrasonic-rescnonce thickness ot a maximum as o function of wall thickness. At this point small changes in wall thickness cause almost no change in the resistive com- ponent, but do cause maximum chonge in the Theotetically, changes in diameter should affect both channels. However, the traces of Figs. 3.6.3 and 3.6.4 ¢leorly indicate that the diameter signals are predominate in the resistive component and have a negligible effect Unfortunately, the variations in both diameter and wall thickness characteristically follow each other at about the same period, ond therefore close analysis is very difficult. Further investigation of this effect is planned with the use of mochined tubes in which changes in diameter and wall thickness moy be introaduced and controlled seporately. reactive companent. on the reactive component. Cladding Thickness Measurements J. W. Allen R. A. Nonce The feasibility of determining the thickness of the cladding on Mark X MTR fuel plates with ¢n eddy-current probe coil was investigoted. Although this study hos no immediate application to ANF work, many of the problems involved are very similor to problems associated with inspections of contrel rods ond other clad or shrouded os- semblies. The Mark X MTR fuel plates ore composed of g 0.022-in. nominal thickness core of 52 wt % Al- 48 wt % U alloy cled with o 0.020-in. nominal thickness of type 8061 aluminum alloy. The defor- mation choracteristics of the core and the cladding PERICD ENDING MARCH 21, 1957 alloy are not the same; hence, during the rolling of the plate to a wniform thickness, the deformation of the core is frequently nonuniform. The result is a thick section at eoch end of the core, the longitudinal cross section of which resembles a Ydog bone.”” Since the plote is of uniform thick- ness, the cladding over the thick sections at the extremities of the core is of course much thinner than the 0.020-in. nomingl thickness. The pos- sibility of a 0.003- to 0.005-in. depth of corrosion attack necessitates the location and rejection of fuel plates which have excessive ‘‘dog boning.” To facilitate the investigation of this problem and to determine the best operating parameters for the eddy-current test, the prototype instrument described in the block diagram of Fig. 3.6.5 was constructed. Since the original purpose of this instrument was to determine the best coil design ond the optimum operating frequency, it is more complex and contains more controls than would be required on a production inspection instrument. The instrument consists of o voriable-frequency oscillator which supplies alternating current to the probe coil through an isolating network and to a bolancing network. The isclating network prevents the presence of the probe coil from affecting the voltage supplied to the balancing circuitry, and supplies the probe coil with current of constant amplitude. Since the probe coil current is constant in amplitude, the voltage at the terminals of the probe is directly related to iis impedoace, which in turn is influenced by the metal specimen in proximity with it. The baloncing network is adjusted monually until the voltage at the netwerk output terminal is equel to the voltage across the coil, ot the initial test con- dition, in both amplitude and phase. Any chonge of the test condition chonges the voltage ot the coil in phuse or amplitude or both. The difference in the voltage of the ccil and of the belancing network is amplified, and hence any change in coil voltage causes o meter deflection. After some experimenting, the probe design shown in Fig. 3.6.5 was established. The coil consists of approximately 540 turns of No. 40 enameled copper wire in a small, cup-shaped Ferrocube core (Ferrocube Corp. Type 3C Ferro- cube). The coil, ofter conncction with the in- strument coble, is potted with en epoxy resin into the end of a short length of micarta tubing. This coil ossembly is contcined in o heavy brass 227 ANP PRCJECT PROGRESS REPORT UNCLASSIFIED ORNL-LR-DWG {8095 AMPLITUDE PHASE SENSITIVITY FREQUENCY fi —/fi 7{ > VARIABLE~ / . £ ~ | FREQUENCY | e Bl SRR R OSCILLATOR | | % & ; | {400~y QUTPUT) ] ; / / | ; ! | BALANCE A _(A-B) ) | I. b B | T4 | | COIL SPRING QL ‘ ' coL™~ T ‘ / LOADING “J~| 1soLATING 1'\ Ea PROBE COIL - ’ | NETWORK ] _ 540 TURNS NO 40 Bt 5 ENAMELED COPPER. | OUTPUT METER | | £=3.25mh | Y - ‘ ., fags =179 ke | i OIAT 179ke1 =256 | i \Z b s ool mmge v e s be ve e e e ] ¥ X PROBE COIL CONTAINED IN PROAE COIL FERROCUBE CUP el 7 e e 7 R - ?,,: 7 ) L S 3 i SPECIMEN 13%in % 7 AV / £ ,/ff 2 i 4 Probe Coil and Hoider L- 21"16‘“' _—l Fig. 3.6.5. terminotions. helder which spring-loads fhe probe against the The use of this mechanism eliminates spurious signols coused by the wvarying coupling associoted with a hand-held probe. metal specimen. Three considerations were of primary importance in selecting an optimum test frequency. First, the frequency was to be sufficiently high to sensitively detect the difference between the type 6061 aluminum alloy cladding {conductivity = 45% IACS?) and the uranivm-aluminum alloy core (conductivity = 22.8% |ACS). Second, it was to be sufficiently low to penetrate the nominal 0.020- 2 - IACS refers to internoticnal annealed-copper stondard, 228 Probe Instrumen? Variable-Frequency Eddy-Current Instrument and Probe-Coil Design for Cladding Thickness De- in.-thick cladding cnd to detect smoll changes in its thickness. Also, it was to be sufficiently high that the 0,022-in.-thick core underneath the 0.020-in.-thick cladding would appear infinitely thick (that is, no eddy-current penetration through the core). This is necessory to prevent the clad thickness on the ‘'back side' of the plate from influencing the thickness determinaticns made on the side under surveillonce. The optimum frequency determined experimentally to satisfy these conditions was 20 ke. Correlation of the meter deflection with the cladding thickness was experimentally determined by first adjusting the instrument to read nearly L i full scale with the probe coil placed on a specimen of bare uwronium-aluminum core, and to reod zero with the probe coil placed on an apparent *infinite"’ thickness of the 6061 oluminum alloy. Shims of the clodding alloy, which varied from 0.003 to 0.020 in. in thickness, were then used to obtain the information for the colibrotion curve shown i Fig. 3.6.6. Three Mark X fuel plates were examined, and only one showed sufficient variation in cladding thickness to warrant a more detailed inspection. This plote was scanned on both sides, with gach pass of the probe coil overlapping the previcus pass 1o ensure complate coverage of the surfoce. The greater portion of the cladding was indicated to be from 0.017 to 0.020 in. thick. AIl deviations from this range were marked for loter destructive examination. Four of the mesi significant areas noted during this to a metallographic examination for correlation ond evaluation of the eddy-current measurements. The investigation were sectioned and subjected locations of these sections are shown in Fig. 3.6.7. Sections 3 and 4 were taken from one end of the plate where the cladding was very thin os -28% in_ PERIOD ENDING MARCH 31, 1957 UNCLASSIFIED ORNL =-_R-DwWG 18096 BD —"i—‘ e -I i 1 | CLADDING MATERIAL: BOGI Al ALLOY CORE MATERIAL® 48, U BY WEIGHT, | ALLOYED WITH &l CONDUCTIVITY OF CLAD: 45%, 1ACS | CONDUCTIVITY OF CORE: 22 8% $ACS [ FREQUENCY=20 ke — | 0 o EDOY -~ CURRENT SIGNAL (% FULL SCALE) B > 20 o o 4 8 2 g 20 24 THICKMNESS CF CLADDING {mits] Fig. 3.6.6, Eddy-Current Signol-Coltbration Curve for Cladding Thickness Measurements of Mark X MTR Fuel Plates, UNCLASSIFIED ORNL—LR~DWG 15097 21-"?16 " PLATE THICKNESS = 0062 in—" Locahon of Seclions Token for Metallographic Exommation {Mark X MTR Fuel Plate) MO it oy~ = MAXIMUM CLADDING THICKMESS BY EDDY — CURREMT IMSPECTION = Q.5211n MAKIMUM CLADDING THICKMESS BY MCTALLO- GRAPHIC EXAMMATION = O 020 in. M2 | - e pAIMIMUM CLADDING THICKNESS BY EDDY - CURREMT INSPECTION = G.0O10 in. MIMIMLR CLADDING THICKNESS BY METALLG- GRAPHIC EXAMINATION = G009 in. Fig. 3.56.7. Meosurements Obtained by Metallegrophic Examinotion. NO 3 fi- Sy, = NO 4 iR e FROBE COiL WiIDTH=04381n _ ~Tu - MINIMUM CLADDING THICKNESS 8Y EDDY — CURRENT INSPECTION = Q.003 1n MINIMURM CLADDING THICKMESS BY METALLD- GRAPHIC EXAMINATION = 0003 in. ¢ —_— b I5.()!32 i, MIMIMUM CLADDING THICKNESS B8Y EDDY — CURRENT INSRECTION = 0003 in MINIMUN CLADDING THICKNESS BY METALLO- GRAPHIC EXAMINATION = 0002 Comparison of Eddy-Currant Thickness Measuwements of Mark X MTR Fuel Plates with Thickness 229 ANP PROJECT PROGRESS REPORT a result of the ‘'dog bone'' effect previously mentioned. Section | was taken through the the thickest portion of cladding, while section 2 was tcken through the thinnest portion of ¢ladding, excluding the very thin clodding over the ends of the core. The results of the metcllographic measurements are summarized in Table 3.6.1 and shown in Fig. 3.6.7. All megsurements shown were mode on one side of the plate only. The meosurements for section | were made on the side of the plate with the thickest cladding, while the remoining sections were meosured on the side with the thinnest cladding. It should be noted that in aoll cases where the metallograghic measurement differs from the eddy-current measuremens, the difference is 0,001 in. below the value obtained by the eddy- current technique. It is therefore concluded that upon choosing the optimum operating porameters, the cladding thickness on Mark X MTR fuel plates can be determined to within £0.001 in.with the use of an eddy-current probe coil. Table Lé.1. Comparlson of Mark X MTR Fuel Plate Cladding Thicknessas Measured by Eddy- Current Inspectlon Technlques and by Metallographie Exomination Clodding Thickness {in.) Spacimen FPortion of No Cladding Eddy-Current Metallogrophic | Measured Result Result 1 Thickest 0.021 ¢.020 2 Thinnest 0.010 0.009 3 Thinnest 0,003 0.003 4 Thinnest 0.003 0.002 There is no comprehensive theory for the ap- plication of eddy-current probe coils on metal surfaces such as the theory which exists for the use of coils encircling rods or tubes. This lack of theoretical background requires that eoch problem be considered separately ond that general statements regarding the capabilities of the probe- coil technique be corefully qualified. The ex- perience gained in the measurement of the cladding 230 thickness of the Mark X fuel plates indicates that if the two metals, forming a system, have a ratioc of conductivities in the order of 2:1 or the thickness of the accessible layer can be accurately measured. As the conductivities of the two materials approach the same value, this system of measurement becomes useless. Continved experience with the eddy-current probe-coil technique should resuit in the satis- factory measurement of cladding thickness of most alloys on o cermet core, of any of the oxi- dation-resistant alloys over malybdenum or nichium cores, of an oustenitic stainless steel over o nickel-molybdenum alloy core, or of a nickel- molykdenum alloy over an austenitic stainless sieel core. The obility of this method to measure greater, Incenel on austenetic stainless steel or austenetic stainless steel on Inconel is currently considered to be marginal, The eddy-current probe-coil method of meosuring independent of the existence or condition of the bond between the two layers, and it is best suvited to the measurement of thin layers. This method cppears to be well adopted to measuring clodding thicknesses on solid-fuel- element ossemblies or on moderater assemblies. It is wiso well adapted to measuring the thickness thickness is of the outer layer of duplex tubing, such as might be used in future heat exchangers and radigtors, provided the conductivities of the two layers are sufficiently different. Both the total wall thick- ness of the duplex tubing and condition of the bond bketween the two loyers can be evaluated by vlirasonic techniques. RADIOGRAPHIC INSPECTION TECHNIQUES R. B. Oliver W. J. Mason The voltage ond current settings required for rodiographic inspection of various thicknesses of Inconel, stainless steel, nickel-molybdenum, and similar alloys are not available, and therefore o program of compilotion of such doto hos been initiated. Test weldments in ]'é-in. Inconel sheet are being radiographed through 8-in. of beryllium to explore technigues for the inspection of the closure welds of the ART fuel-arnuius core shells. Beryllium, an element of low atomic number, causes excessive scatter of the incident x-ray. The scotter reduces image contrast and shorpness so excessively thet the rodiograph is not capoble of revealing any but gross defects. Higher x-ray energies are being explored, but the reduction of image contrast with increasing energy appears to nearly offset any reduction of scattered photons that might be expected. EXAMINATION OF LEAK IK SUMP TANK OF PRATT & WHITHNEY HIGH-TEMPERATURE CRITICAL ASSEMBLY R. Heestand Shortly after the Pratt & Whitney high-temperature critical assembly was looded with barren fuel- carrier salt, o leak wos detected in the sump tank. The insulation was removed and the source of the jeckoge was found to be severe cracks in the &-in.-dia cap which had been welded to the botfom of the tank as o catch basin. Since such cracking is wunusval for lnconel forged fittings, it was surmised that the cap hod been machined from bar stock. A ceall to Prott & Whitney confirmed Figl 3.6-3- Prott & Whitney High-Toemperature Critical Assembly. g PERIOD ENDING MARCH 31, 1957 that forged pipe caps were not immediately avail- able and that o cap machined from bar stock had been used. The cop was removed ond ¢ forged cop was welded to the tank. Examination of Caolrods attoched to the tank revealed thot they were glazed with salt-vaper deposits, and therefore all bottom and side Calrods the tank was cleaned externally, and new Calrods were installed. Visual examination of the faulty cap showed nine separate cracks which penetrated through the cop. Examples of the cracks are shown in Figs. 3.6.8 and 3.6.9, which cre outer and inner wall views, were removed, respectively, of the same crocks. As moy be seen the cracks run to the weld and stop, and thus it is apparent thot they were in the cap before it was installed on the tank. X-ray exomination of the cap-to-tank weld before service did not show cracks in the weld, and the x-ray UNCLASSIFIED ¥-21520 o T o e - A-su -.:l-ll o — -‘h-. ; Cracks on the Outer Sutfoce of the Faoulty Bor-Stock Cap Removed from the Sump Tonk of the 231 ANP PROJECT PROGRESS REPORT FIg- 3-6-9. Prott & Whitney High-Temperature Critical Assembly. examination wos not of sufficient sensitivity to show cracks in the cap. MATERIAL INSPECTION The progrom of inspection of materials of con- struction was continued, with intended use as the criterion for acceptability. A summary of the materials inspected is presented in Table 3.6.2, which gives the vorious types and quantities of material inspected, the methods of inspection, and the rejection rotes. All rejected matericl has been either downgroded for noncritical ap- plications or used in experimental development projects in order to minimize losses. 232 "UNCL ASSIFIED Y-21521 Cracks on the Inner Surfoce of the Faulty Bor-Stock Cap Removed from the Sump Tank of the Tvbing R. W. McClung The results of inspections of smoll-diameter tubing illustrate the high rejection rate that results when long defect-free pieces are requested. For example, it wos necessory to get B8-in. pieces from 120-in. lengths of 0.625-in.-CD, 0.065-in.-wall Inconel tubing, listed in Table 3.6.2, and hence a single rejectable defect located more than 32-in. from either end caused rejection of the entire length. Many of the discontinuities located on outer surfaces by eddy-current or immersed-ultra- sound inspection were grinding marks that resulted Table 3.6.2. Moteriais inspectlon Symmary PERICD ENDING MARCH 31, 1957 Re|ectian ltem Dascription Quantity Method of Inspeclion Rare Remarks - (%) Tubing inconel: randam sizes 419 b Visuol, penetrant 63 Mumerous scrotches, nicks, and gouges were found thot were coused by horrdling or shipping; some cuter surs fece imperfections exceeded 5% of the woll thickness CA-Q00A Inconel; 0,187-in, 2432 B Visuol, penetrant, eddy 12 This matericl was primarily for rodiator 0D, 0.0251n. well, and current, ultrasanic manufaciuvre, ond defects greater rhan miscellaneaus sizes 00005 1n, were cause for rejection CX-9004 Inconel; 0.229-in. 2600 11 Visual, peneironi, eddy Remaining pertion of a lot of abov 0D, 0.025 1n, wall current, uitrasonic 10,000 11, over-oll rajectron rate 15.6% Iheanel; 0,25%in, QD, 1000 i1 Ultrasenic, eddy current Fifty-six short defacts found; rejection 004510, woll rote will depend on minimum vsable length ond defect distribytion; the shart defects were, in general, less than 1 an. in length lacanal; 0.625-in. QD 38390 i Ulirosonic, eddy currem Rejection of 1910 b bosed on minimum 0.085in. wall usable length of 88 in,; if shorter lengths con be used, the rejections will be reduced substantially, since the defects wera, in general, small ond widely seottered; repolishing will olsa prabably reduce the rejectians Hastalloy B; 0.25in. OO, 250 % Ulirosonic, eddy current Seventy-five short defecis found 8.017+in. wall Hastelloy B; 0,.5in. QD, 250 #r Ultresonie, eddy current 40 Thurty-six short defocts found; 100 f 0.035in. wall rejected N Pipa Inconel; random sizes 468 It Visual, penetrant, eddy 1 Where possible, defective conditions current, ond radiagraphic were removed by grinding; 8 It rejected where necessary becouse of trocklike conditions or de- fects in excess of permissible tolerance Incgnel; 3in. sched 40 258 i Ulteasonie 14 Thirty-six teet rajected because of cracks Hastelloy E; %-in. IPS W06 Yisucl, peaeirant 100 Material hod been ceaterless ground, but sched 40 defects ramained; marerial witl be usad, as 1s, for rests Plate and Incanel; random thick- 463 117 Visual, penetrant, ond ultra. & shee nessos sonic where necessary CX-900A Lnconal; random 419 1! Visuvol, penetrant, and ulire- i) Sections with defects were ground, hut thicknesses sonic where necessary if defects exceeded tolerance, 1the en- tire plate was rejected Raod Inconel, random diameiers 30 h Visual, penetiant, and vhra- 0 Filty-eight fect rejected becouse of sonic where necassary seoms and draw marks thot appear te be inherant in the cold-drown malerial CX-900A Incanel (billets); 14 f+ Wisual, penetrant, wltra- 0 Defects indicated by ulirasonic inspec- 4 pieces, 17 in. in sonic tion were removoble by mechining diameier, each 42 in, long CX.900A Inconel; randam i Yisual, penstrant, ultrg- 0 v diometers sonic Firtings inconel ells, roducers, etc 57 pieces Visuol, penatrani 0 ’ Shafts far Inconel § pleces Yisual, penetront, ultre- o » pumps sonie 233 ANP PROJECT PROGRESS REPORT from the explorotion of visual or penetrant in- dications. Either the defects had not been com- pletely removed, the grinding sufficiently disturbed the surfece to produce o further defectlike indication, This botch of tubing was inspected to a stondard such that any discontinuity greoter than 5% of the wall thickness in depth would be rejectable. The tubing will be repolished ond and reinspected, and the rejection rate moy be reduced considerably. However, net oll the dis- continuities were on the outer surfoce, as may be seen in Fig. 3.6.10 which is a photomicrograph of an inner surfoce gouge opproximately 0.017 in, in depth, 0.033 in. in width, and 0.375 in. in length. The special lots of Hastelloy B tubing listed in Table 3.6.2 were fobricated by using ¢ balonced reduction between diameter or and wall thickness ond were drawn with o floofing plug. Despite the lorge number of discrete defects and the high rejection, the tubing was better than many lots of Hastelloy fubing inspected previously. The most severe cracks found are shewn in Fig. 3.6.11, which is a metallographic section tcken from the 0.25:in.-0D, 0.017-in.-wall subing. The crocks appear to be up to cbout 0.008 in. deep. The 0.006-in.-deep single crack shown in Fig. 3.6.12 is representative of the mest common defect found. The very rough inner surfoce, intergranular attack, ond fine fissures throughout the entire batch of the tubing, as shown in Fig. 3.6.13, are of course unsatisfactory, Plote R. W, McClung The requirements for the ultrosonic inspection of Inconel plate in thicknesses up to 1 in. have increased, and therefore special steps have heen taken to increase the inspection rate without sacrificing inspection quality. The -.».n::.‘rping3 which was prevolent with the thinner sections of plate wos partially offset by clomping the plate to o structural frame. With the warpoge reduced, 3R W. McClung, ANP Quar. Prog. Rep. Dec. 31, 1956, ORNL-2221, p 269. URCLASSIFIED Y-21279 n F_’ o A 1 ‘ ¢ o = — Lt — Egd ko f-.-_L = é - » " E ' r ' ' 0.02 Yo, a : 4. = i s - k i i " » 4 & & . & = » - . X » . = 0.03 % - 5 ' . — . E ; L. E ' l..' e et il = L 5 v = i ‘_' * ) : T A ' P F 3 I\ : : & % i - ik A i i & ; ‘ O 5 i " - : 5 . g - . = % = S * v i £ = — O — . 5 ‘ E |2 ! ; K . . Fig. 3.6.10. Gouge Found on the Inner 3urfoce of 0.625-in.-0D, 0.0465-in.-Wall Inconel Tubing. 100X, Re- duced 4%, 234 PERIOD ENDING MARCH 31, 1957 UNCLASSIFIED ¥-21289 I I mopes B | LT B g o 11 o I o Bl T IS?! 1 i [ Bl Flg. 3.6.11. Muitiple Crocks Found in 0.25-in.-0D, 0.017-In.-Wall Hastelloy B Tubing. 150X, Reduced 4%, UMCLASSIFIED Y-21281 B T NCPES ELITTE[TTIRITITRD T I.":?X I 1 [ Bl Fig. 3.6.12. Typicel Crack on Outer Surfoce of o Hestellaoy B Tube. 150X. Reduced 4%, 235 ANP PROJECT PRCGRESS REPORT ¥ ' ® . - " 4 * o Q', " - . . ° ¢ * 1 " fl-" - - - s F " - t‘- o ¥ - & T s ' - * L a - a 8 -~ r - Fig. 3.6.13. Tubing. 530X. Reduced 3%, less time was required to realign the incident beam. Another aid in increesing the inspection rate is the use of the B-scan, which displays the signal received as on instantaneous cross section through the plate being inspected. This permits an increase in linear speed of the transducer from approximately 10 to 25 fpm. In general, it appears that for plate of overage quality, inspected from either face, the inspection rate will be about 10 2 per shift., This of course allows for all the downtime necessary for sefup and may increase or decrease with plate quality; also, an increase in the inspection rote might be expected with larger areas. The rate of rejection increased slightly during the quorter, ond three prime criteric for rejection were established: (1) the detection of a dis- continuity which produces @ signal comparable to or greater than that from a stondard 4{‘_4-{:1. flot-bottem hole; (2) the presence of smaller dis- continuities with their centers nearer than 1 ia. to each other; and (3) excessive ulfrasonic atten- uation, which may be due fo porosiiy or precipitates within the plate. 236 UMCLASSIFIED ¥-21283 tn ui : = I =~ T NG B = T ‘f.:t’- % . #: - et e i '?fl’;fi po 002 '. ™ w B ..fl u ® A : - " . Srcm g W . 0G3 - & s » .- - - " g a . : - : ! «. B 004 ¥ m M T - Py 5 3 - A8 ' e - & - s / L Hos k " . » O _0_ a* ) - - - ! ) - «+ " e 008 - . ' Typical Intergranclar Attack, Fissures, and Rough lnner Surface of As-Received Hastelloy B Beryllium Hot Pressings R. W. McClung R. B. Oliver J. W. Allen One of the six, large, beryllium hot-pressings fobricated by The Brush Beryllium Co., Clevelund, Ohie, was vultrasonically inspected at ORNL, Previcusly, three of these items had been in- spected at the producer’s plant. However, it was felt that ¢ more methodical, complete ultrasonic examination under laboratory coaditions by several different techniques (some of which could not be used at the Brush facility} was needed as o check on techniques which were previously used tn the field. The instrument used for the inspection at ORNL was a Curtiss-Wright 424A Immerscope with o %—in.-diu Li 50, high-resolution trensducer. An attenuation curve was plotted which demonstrates the comparotive signal strength os received from a constant-gsize discontinuity when seen through varying thicknesses of beryllium, Fig. 3.6.14, The instrument was calibrated for all the in- spections by using a ]zé—in. flot-bottom hole and applying its presented signal to the appropriate UNCLASSIFIED ORNL-LR~D™G 18654 130 | | 5Me; Y in. Li; SOy TRANSDUCER: | MODEL 4244 (MMERSCOPE ¥ ?s | I} oy 3 = i = = 50 wd =1 = @ i 25 |- ol i i 0 5 10 5 20 BERYLLIUM {in._} Fig. 3.6.14, Attenuation Curve for Ultrasonic Inspec- tion of Beryllivm. thickness on the attenuation curve. Thus the relative size of any defect could be approximoted by comporing its signal with that of the standard ond by using the atienvotion curve. The general shape of a hot-pressed beryllium piece is shown in Fig. 3.6.15; however, the contours aond di- mensions varied from piece to piece. The section denoted A was inspected completely by three different pulse-echo ultrasonic techniques. The first was a simple immersed method in which the hot pressing wos completely immersed in o tank of water and the surface was scanned in o linear fashion with o E*é-in. index between suc- cessive scans. Three small discontinuities were located which were estimated to be less than the rejectable size. For the second inspection the column-coupled, gimbal-mounted mechanism? illus- trated in Fig. 3.6.16 wos used. Section A wos sconned in o series of overlapping circulor scans; however, the part wos still completely immersed and this technique merely gave comparative in- formation. The inspection results were identical with those obtained by the conventional immersed technique. For the third inspection the gimbel mounting, the circuler sean, and also the column- coupled ‘‘squirter’’ principle were used. More ‘R, & Oliver, J, W. Allen, and P. J. Long, Ultrasonic Inspection of Hot Pressed Beryllium Moderator Blanks, QRNL CF-56-10-34 (Oct. 3, 1958). PERIOD ENDING MARCHM 31,1957 f s & 4 0O 24 5;'9 in. WNCLASSIFIED ORRL-LA—DWG n22G F-in-DIA PILET [18 in. NS \\\\ B L 44 ' in, SECTION M- Fig. 3.6.15. Cross Section of a Typical Hot-Pressed Berylllum Piece. spurious signals were noted in the third in- spection, but the results were equivolent to those obtained by the other two techniques. The sloping section, B, wos inspected with the squirter technique, the transducer being aligned so that the refrocted uliresound beom was per- pendiculor to the boitom surface. in this portion ot the inspection, one discontinuity that was larger than the standord hole was located, but it was in o region that was to be removed by subsequent mochining and thus was not cause for rejection. The hot pressing was olso inspected completely by measuring the voriation in ultrasonic at- tenuation throughout its volume. sistency of back reflections obtained, the pressing seemed to be quite homogenecus. Since no rejectable defects were locoted which would not be removed by subsequent machining, the piece was considered to be acceptable. From the con- 237 ANP PROJECT PROGRESS REPORT UMCLASSIFIED FHOTCO 18490 Fig. 3.6.16. Conical 5ection of a Beryllium Hot Pressing Being Ultrasonically Inspected with the Use of the Column-Couplad, Gimbaoi-Mounted Mechanism. 238 In comparisen with the results obtaoined with the other techniques, it appears that if careful contrel is exercised the obtained with technique are sufficiently vltrasonic inspection inspection results the column- coupled “‘squirter” accurate to warrant such inspection of the re- maining beryllium hot pressings. Welds A. Taboada R. L. Heestand The results of inert-gos shielded-orc weld in- during the months are summarized in Table 3.6.3. spections past six The criteria for the inspection of each weldment are established at the time of design review. Each weldment is classified os C, CN, or 5. A C classification is used for all critical welds that must have optimum soundness, for example, welds sealing between corrosive environments, welds that will be sub- jected to thermal grodients, ond welds that must have high strength. These welds are made according to applicable procedure specifications, PERIOD ENDING MARCH 31, 1957 and they are inspected by visuval, dye-penetrant, A CN weld requires high integrity but cannot be x-rayed. Visual inspection and dye-penetront methods are used in the in- spection of the CN-type weld. Welds which cre out-of-specification because of design limitations, and x-ray techniques. but which are critical, also fall inte this category. The S designation is for structural welds, but it is also used for out-of-specification welds that are not critical. Welds in this category are in- spected by dye-penetront and visual metheds, Dye penetront reveals crocks, but it does not indicote pin holes or porosities, In addition to the welds listed in Table 3.6.3, 115 C-type welds on piping manifolds for the ETL were inspected, with 21% rejected for det- rimental defects. There were also 60 C-type welds of Hastelloy B inspected. Thirteen of these welds were found to be rejectoble for various types of defects. Another 185 welds fabricated on thermocouple leads for critical opplication were 864% rejected. Toble 3.6.3. Weld lnspection Summory C Type Weld CHN- and 5 Type Welds Period Total Number Percentage Tatal Number FPercentage Inspected Rejected Rejected Inspacted Rejected Rejected Sept. 10 to Dec. 10, 1956 1052 141 13 2048 59 2 Deec. 10, 1956, to March 10, 1957 922 202 22 3103 45 1.5 Totol for the two pericds 1974 343 17 5151 104 2 239 Part 4 RADIATION DAMAGE G. W. Keilholtz FUEL RECOVERY AND REPROCESSING R. B. Lindaver 4.1. RADIATION DAMAGE G. W. Keilhaltz EXAMINATIONS OF COMPONENTS AND MATERIALS TESTED IN THE MTR A, E. Richt C. Ellis E. N, Romsey E. J. Manthes E. D, Sims W. B, Parsley R. M. Wallace in-Pile Loops Metellogrophic specimens were cut from in-pile foop Mo. 4 and mounted. All the specimens were examined in the as-polished condition, ond some None of the etched specimens exomined up to this time have shown attack greater than 1.5 mils in depth, and no signs of mass tronsfer were found on the specimens, Wall thickness measurements witl be taken on all the specimens from the nose coil end were examined in the etched condition, on some samples from straight sections of fuel lines. The operating conditions for this loop were described previously.' All the sections of the fuel-circulating pump, except photographed with the remote stereomicroscope. The condition of the rear holf of the pump sump is shown in Fig. 4.1.1. As may be seen, no fuel remained in the sump. A colored amorphous de- posit similor to thet found in in-pile loop Ne, 3 the impeller and impeller housing, were ]A, E. Richt et al., ANP Quar. Prog, Rep. Dec. 31, 7956, ORNL-2221, p 290. UNCLASSIFIED AMG 1591 Fig. 4.1.%. Laap Mo. 4. I{?X. Rear Section of Pump Sump of In-Pile wos found on the slinger ossembly and on the forward bellows, as shown in Figs. 4.1.2 ond 4.1.3. The rotating copper block and its housing were coated with a similar depesit, os shown in Figs. 4.1.4 and 4.1.5, The impeller housing from the pump of loop No. 4, along with the impeller housings from the pumps of loops Nas, 5 and 6, will be cut open on the re- mote lothe at a later date, Disossembly of loop No, 6 will begin os soon os the disassembly equip- ment is made ready, Irradiated Moderator Materials The Inconel capsuie containing beryliium oxide slugs, which was recently irrodiated in the MTR,? was disossembled ond examined. This copsule was the First of o series of copsules centaining moderotor materials to be irradioted to investigate the dimensional stability eand mechonical properties of the material under simulated reoctor operating 2J. A. Coniin, D. M, Haines, ond C, C. Bolta, ANP Quar, Prog, Rep. Dec. 31, 1956, ORNL-2221, p %1. — -y UNCLASSIFIED ! RMG 1594 Fig. 4.1.2. Slinger Assembly from Pump of in-Pile Loop Mo. 4. 2X, 243 ANP PROJECT PROGRESS REPORT L * J - - & UNCL ASSIFIED RMG 15%5 - Fig. 4.1.3. Split Forword Bellows from Pump of In- Pile Loop No. 4. 2X, UMCLASSIFIED RMG 1594 Fig. 4.1.4, Rotating Copper Block frem Pump of In- Pile Loop No. 4. Actual size. 244 UNCULASSIFIED RMG 1597 Fig. 4.1.5. 5plit Copper-Block Hausing from Pump ef In-Pile Loop Mo, 4. Actuval size. conditions. The condition of the irradiated test ossembly after removal of the thermocouples is shown in Fig. 4.1.6. Unfortunately the high-flux end of the capsule {the end closest to the reactor during irradiafion}) was bent slightly while it was being removed from the bracket surrounding it, but the BeO slugs were not domaged. Dicmeter measure- ments were mode on the con before the BeO slugs were removed, and the results of these measure- ments ore listed in Toble 4.1.1, The meosurements were taken ot ];i-in. intervals along the length of the can, ond two series of readings were token 90-deg aport. The slugs were arbitrarily numbered 1, 2, 3, and 4, with slug 1 being closest to the reactor and slug 4 being farthest from the reoctor during irradiatien, An attempt was made to remove the BeD slugs with the use of a remotely controlled lathe, Siugs J and 4 were removed in this manner, but they were damoged slightly by the lathe taol while the con was being machined owoy. Figures 4.1.7, 4,1.8, ond 4.1.9 show the condition of the slugs removed on the lothe as compared with a similar slug of unirrodiated BeQ. |t was therefore de- cided to remove the remaining two slugs by using the remote milling machine. A portion of the cap on the remaining half of the con was cut off with an abrasive cut-off wheel to remove the brace which secured the cop to the can, and the open end of the coan was trimmed on the cut-off machine, Successive cuts were then made with o milling machine, dlong the longitudinei axis of the can, until the BeO slug surface was exposed ond the The slugs were then easily removed from the open con. Slugs | and 2, which can sprang open. UL ATHR FELTO . TT R | BRACKET FOR HOLDING ARND POSITIONING CAPSULE INCONEL CAPSLUILE CONTAINING Be0 5LUGS Fig. 4.1.6. After Removal from the MTER. Inconel Copsule Contoining BeD Slugs PERIOD ENDING MARCH 31, 1957 were removed by this method, were in much better condition than slugs 3 and 4, as shown in Figs. 4.1.10 and 41,11, An unirradicted slug photo- graphed under the same conditions is shown in Fig, 4.1,12 for comparison with slugs | and 2 as shown in Figs., 4.1.10 and 4.1.11, A very small UNCLASSIFIED RMG 1598 Fig. 4.1.7. BeD Slug 4 Removad from Inconel Capsule After Irradiation Showing Domage by Luothe Used to Remove lnconel Con. 2,5X. Table 4.1.1. Diameter Measurements of Irradioted Inconel Copsule Contolning BeD Slugs Taken at Ié-in. Intervals Storting at End Foarthest From Reoctor During Irradiation Diametar before irradiotion: 1.041 to 1.042 in. Dioameter at l;5-i|'1. Intervals Pesiticn en Capsule Digameter 90 deg from Calumn 1 Meosurement lir.) During lrradiation (i) 1.041 End forthest from reactor 1.041 1,042 1.042 1,043 1.042 1.044 1.043 1.044 1.044 1.043 1.044 1.043 1.044 1.042 End closest to reactor 1.044 245 = = - i ANP PROJECT PROGRESS REPORT UNCLASSIFIED RMG 1599 Fig. 4.1.8. BeOQ Slug 3 Removed from Inconel Capsvle After leodietion Showing Damage by Lothe Used to Remove Inconel Con. 2.5X. UNCL ASSIFIED RMG 1600 Fig. 4.1.%. Unirrodioted BeQ Slug for Comporison with Those Shown in Figs. 4,1.7 ond 4,1,8, 2.,5X, 246 UNCLASSITLED RMG 1621 Fig. 4.1.10. BeO Slug 1 After lrradiation. 2,.5X%, UNCL ASSIE1ED RMG 1622 Figs 4.1.11, BeQ 5lug 2 After lrradiotion. 2.5%, crack was found on the low-flux end of slug 2, but since this was the only crack found on the slug, it moy be assumed that the crack was either present before irradiation or was coused by mechonical UNCL ASSIFIED RMG 1623 Fig. 4.1.12, Unirradiated Be0Q Slug for Comparison with 3lugs Shown in Figs. 4.1.10 ond 4.1.11. 2.5X, Table 4.1.2. Dimensioncl Mecsurements of the Four BeO Slugs Before ond After Irradiation in the MTR Slug Dimensions {in.) Number Before Irrodiation After Irradiation Length 1 1.000 1.000 2 1.005 1.001 3 1.005 1.000 4 1,005 1.000 Diameter 1 0.9965 0.997 2 0.997 0.997 0.9965 3 0.997 0.997 4 0.997 0.597 0.998 PERIOD ENDING MARCH 31, 1957 damage ofter iradiation, The ends of slugs 1 and 2 are shown in Figs, 4.1.13 and 4.1.14, The end of slug | that was ciosest to the reactor shows a small crack that was probably coused by mechanicoal damage raother than radiation damage. No evidence of BeO powder wos found in the capsule, The results of the dimensional measurements on all four slugs cre listed in Toble 4.1.2. No signifi- cant changes were observed in either the lengths or diometers of the slugs. Sections of the capsule will be mounted und examined metcllographically. UNCL ASSIFIED RMG 1624 Fig. 4.1.13. Ends of BeO Slugs 1 and 2 That Were Closest to Reoctor During Irradiation. 2,5X, 247 ANP PROJECT PROGRESS REFPQRT ! UNCL ASSIFIED RMG 1625 Fig. 4.1.14. Ends of BeO Slugs 1 and 2 That Were Farthest frem Reoctor During leradiotion. 2.5X. CREEP AND 3TRESS-RUPTURE TESTS OF INCONEL J. C, Wilson C, D, Boumann W, W. Dovis W, E. Brundoge N, E, Hinkle T. C, Price’ Apparotus for Stress-Rupture Tests of Tubing in the MTR Effort has been concentrated recently on com- pleting apparatus for MTR in-pile tests of the stress-rupture properties of Inconei tubing, Diffi- culty was encountered in the ossembly of the 3Dn assignment from Pratt & Whitney Aircraft, 248 apporatus in that the pure helium atmosphere be- came c¢ontaminated by insulating and constructional materials, and the assembly work during the final stages was necessarily slow because the size and complexity of the apporatus limited the number of people who could work at one time, The general design of the apporatus was described previously,? and the nearly assembled specimen chamber, a sample specimen, and a specimen fur- nace are shown in Fig. 4.1.15. An end plate and a water jacket will be welded on in order to complete the specimen chamber. Water and boral will be used as shielding in the plug. Each specimen is a section of 3.8-in, sched-40 Inconel pipe machined down to o wall thickness of 0.030 to 0.030 in, over the gage length, and each specimen is pro- vided with three thermocouples for temperature A Hfi—in.-OD capillary will supply gas pressure (to supply the stress) to each specimen,. Each of the eight specimen furnaces has three windings. A rheostat in series with each of measurement or control. the 24 seperate furnace windings permits separate control, Three recorder-controllers {Speedomax “G" air controilers with pneumatically driven Variacs) control the temperature in three zones corresponding to the front end (the end closest to the reoctor), the middle, and the back end of the specimen, This system is necessary becouse of the gamma-ray heoting gradient ia the MTR. The only alternative would have been the use of 24 controilers or 8 controllers and a system of furnace shunts thot would be contrelled by recctor power. The leod $ime on procurement of the exira con- trollers that would hove been needed was too long, and it appears now that the present system moy be the most suitable, Extensive tests to determine why the Inconel wos heavily cxidized in out-of-pile stress-rupture tests in similar apparatus, despite the use of a high- purity helium atmosphere, showed that some of the materials of comrstruction were contributing oxygen or other contominants to the atmosphere. Lavite, a machinoble ceramic, was eliminated from the ossembly as the worst offender. The fused quartz sleeving was found to require special thermal treatment to rid it of disturbing impurities, Therme- couple wires with glass insulation were also suspect, and accardingly all electrical leads and 45, C. Wilson et al., ANP Quar. Prog. Rep. Dec. 31, 1956, ORNL-222], p 299, TEST SPECIMENS (8) Ta—. T II FERIOD ENDING MARCH 31, 1957 = - UNCL ASSIEIED BHOTO 19779 Sy W5 CABLE TUBING | Fig. 4.1,15. Partiolly Assembled MTR Stress-Rupture Apperotus, thermocouples were provided with ceramic insula- tion. Approximately 50 thermocouples and 35 power leads (copper} were insulated with a total length of 12 # of ceramic insulation, Four racks of power and thermocouple instrumen- tation and the connecting cables were completed, and an ovailoble safety circuit was adapted for use with this apparatus, A rack of helium pressure control circuits, including 8 pressure recorders to monitor specimen pressures (ond thus stresses), was designed, built, and leak tested. Duplicate specimens are to be tested out-of-pile at stresses of 2000, 3000, ond 4000 psi ot 1500°F, The in-pile apparotus will probably be installed in the MTR during March 1957, Tube-Burst Tests in the LITR Two tube-burst stress-rupture tests of Inconel tubing in a helium atmosphere were completed in the L_ITR. The thermal and fast > 1 Mev) neutron Huxes in hole HB-3 where these tests were con- ducted are both on the order of 6 x 10'% q/cm2.5ec, Rupture times for the 0.010-in.-wall lnconel tubing (ART stock) ot 2000 psi and 1500°F were 1050 and 1650 hr ond thus were in good agreement with out- of-pile data obtained in on argon atmosphers,” The specimens in corresponding out-of-pile tests in @ helium atmosphere have passed 1770 hr with- out rupture, A third in-pile specimen, stressed to 1000 psi ot 1500°F, did not rupture ia 1670 hr, and the total creep deformation will be measured upon disassembly of the apparotus, An unstressed Inconel tube was exposed in the LITR (HB-3} with nitrogen inside to determine whether radiction-induced nitriding would occur, This specimen was also in a temperature gradient 33, H. DeVon, ANP Quar, Prog. Rep, Sept, 10, 1955, ORNL-1947, p 122. 249 ANP PROJECT PROGRESS REPORT of 1500 to 750°F to oscertoin the effect of tem- perature, Metalliographic examination of the speci- men is under way, Metallogrophic exomination of an irradioted apparctus, in which a tubular Inconel specimen was exposed to NaF-ZrF4-UF4 (63-2512 mole %, fuel 41) on the inside ond sedium on the outside, was completed. The tube wos stressed in bending at o maximum stress of 1000 psi ot 1500°F for 1120 hr so0 that a range of tension and compressive stresses acted on the metai, Corrosion on the fuel side was negligible and did not appear to depend on the sign or magnitude of the stress; only scottered subsurtace voids to a depth of 1 to 2 mils were observed. On the sodium side, attack to a depth of about 3 mils was found. There were voids at and immediately below the surface, but deeper intfo the wall there were holes in the metal that appeared to be filled with a new constituent, as yet unidentified, A tube-burst rig is being built for LITR tests of lnconel exposed under stress to NuF-Zer-UFd (62.5-12.525 mole %). This type of apparatus has been successfully tested in the LITR without stress. Heaters are used with this apparotus which stress-corrosion will permit control of the temperature even if a 30% error is made in calculating the fission heat generation, EFFECT OF RADIATIOCN ON CORROSION OF STRUCTURAL MATERIALS BY STATIC FUSED SALTS W, E. Browning R. E. Adams H. L. Hemphill J. Lee Inconel Capsules Irradiation tests in the MTR of Inconel capsules filled with NaF-Z¢F -UF, (53.5-40-6.5 mole %, fuel 44) were continued. Further difficulties of the type described previously® were encountered becovse of damage te facilities by the turbulent cooling woter of the MTR. Some improvement of the conditien was obtained through the use of better installation techniques. No design changes of the capsules or the focilities were made, but it ts expected that a change to all-stainless-steel construction of the irradiation facility may be necessary, GW. E. Browning, R, E, Adams, H. L. Hemphill, ANF {Quar. Prog. Rep. Dec, 31, 1956, ORNL-2221, p 300, 250 Two irradioted and two contral capsules were opened and analyzed metcllograghically, and fuel samples were submitted for chemical analysis. The operational histaries and the results of metallo- graphic analyses’ of the capsules are given in Table 4.1.3. In this series of tests only two copsules, Nos, 247 and 248, constituted a matched pair, that is, an irrodiated capsuvle end an identical heat treated but not irradioted capsule. As may be seen in Figs. 4.1.16 ond 4.1.17, the attack was of about the same intensiry in both capsules, The depth of penetration was so minute, however, in both coses, that it may be confused with surface foults and perhops can be considered to be negli- gible. Capsule 276 showed (Fig. 4.1.18) corrosive attack and subsurface voids to a depth of 5 mils. The area of maximum penetration was near the mid-point of the capsule, and the distribution of the atteck tapered slightly toward the ends. This distribution of the attack wos anticipated on the basis of the temperature profile of the capsule. The appearance of the affected areas in this cap- sule indicates that the corrosion attack is real ond considerable; however, the contribution by irradiation control cannet be ascertained until data and chemical analyses of the fuel are avail- able., Copsule 264 (Fig. 4.1.19) will be compared with its irradiated counterpart in a latter report, The excellent temperature conirol achieved with the capsule control system at the MTR is indicated in Table 4.1.3. Capsule 247 experienced only one temperature excursion, which was 32°F above the set point for less than 1 min in an operating pericd of 676 hr through 16 reactor shutdowns, Capsule 276 was operated for 235 hr with ne excursions greater than 10°F above the set point, Hastelloy B Capsules Hastelloy B copsules 320 and 341 were tested out-of-pile, Figs. 4.1.20 and 4.1.21, ond two simifor copsules conteining NaF-KF-LiF-UF , were inserted in the MTR on Januory 28, 1957, The design of these capsules is the some as that of the Inconel copsules. Hastelloy B corrodes in air at high temperatures and must be protected during irradiation, Electro- ptating with chromium over nickel provides the 7A. E. Richt and R. M. Wallace, Metallograpbic Exami- nalion of Static Corrosion Capsules Nos. 248, 264, 320, 341, 247, and 276, ORNL CF.57-2-30 (Fak. 5, 1957), PERIOD ENDING MARCH 31, 1957 Table 4.1.3. Operating Conditions and Results of In-Pile and Control Corrosion Tests of Inconel and Hostelloy B Capsules Containing Static Fuel Mixtures : Time at Number of Metollographic Results Uranium . : Caopsule Cartiiit-ol Capsule Full Flux or Excursions Excursions Depth of L stribution No. Fuel” Material Temperature Abeve I500°F Below Melting Atrack of thr) Paint of Fuel (mil s} Attack leradiated Copsules 247 2 mole % UF., Inconei 474 1 min ot 16 0.5 Uniform (1.5 kw/em®) 1532°F 276 4 mele % UF Inconel 235 None 8 5 Attack concentroted (3.7 kw/em?) at mid-point of capsule Heat-Treated Unirrediated Cantrol Capsules 248 2 mole % UF, Inconel 676 1 min at 16 0,25 Uniferm 1532°F 264 2 mole % UF, Inconsl 218 tNone 28 0.5 Unifarm 320 5.7 male % UF, Hosteiloy 8 621 None 3 0,25 Unifarm 341 Mone** Hasteiloy B 190 Mone To 300°F 0.25 Uni form 13 times * The fuel mixtures used in all capsules, sxcept Mo. 320, were token from the NaF-ZrF ,-UF ; system. Capsule 320 contoined 11.8 mole % NoF, 44.3 mole % LiF, 38.2 mcle % KF, and 5.7 mole % UF . “*No solt; helium otmosphere. Fig. 4.1.16. Inner Surface of Irrediated lnconel Capsule 247 After Exposure te ¢ Z!F4-Base Fuel Mixture Containiag 2 Mole % UF3 for 474 hr at 1500°F in the MTR. {a) Unetched. (b) Etchad with 10% chromic acid (slectrobytic), 250X, (Secret with caption) 251 ANP PROJECT PROGRESS REFORT . z ) & . 5 5 S .' o ¥ : ; o sk, n. - ; ; 5, . B e R e R (a} : - : (-b} : : i o o o ..".r- % i 3 ; _-l.:'. 3 :_ A a b - Fig. 4.1.17. Inner Surfoce of Unirradioted Inconel Capsule 248 After Exposure to « ZrF4-Buse Fuel Mixture Containing 2 Mole % UF3 for 676 hr ot 1500°F, {a) Unatched. (&) Etched with 10% chromic acid {elecirelytic). 250X, (Secret with caption) (g) (5) - : e . Fig. 4.1.18. Inner Surface of Irradicted Inconel Capsule 276 After Exposure to a ZrF,-Base Fuel Mixture Containing 4 Mole % UF, for 235 br ot 1500°F in the MTR. (2) Unetched. (&) Etched with 10% chromic ocid (elactrolytic). 250X, (Secrat with caption) 252 PERIOD ENDING MARCH 131, 1957 RMG 1557 TN r - . - & ’ b e it - ' " - - w— " v - L e - ] . ,‘.1- - i o LN .d"'" o L3 a0 - - = % e s - 3 ! - - = - o O - o - L R - ‘ & e W= L € Fig. 4.1.19. Inner Sucface of Unirradiated Inconsl Capsule 264 After Exposure to a ZrF -Base Fuel Mixture Containing 2 Mele % UFd for 918 hr at 1500°F. (2) Unetched. (5) Etched with 10% chromic acid {elactrolytic). 250X. (Secret with caption) UNCL ASSIFIED RMG 1558 Tl et bl g o e, T BN e SO t Za z "f(‘:- L B e g - - s W T : i < i S 1 '“-"'#".“- ._'-.L;..-. gt " y 1 .I'l-"-I -‘ 2 .- * e . - - ' o .-" - - - F-. M P S el e S e = i 5 5 ¢ L1 ." / " o I - = T e nd LA - 5‘ 'r. i il : ~ AN Ty 2 + .‘ i 9 ' ut - % -',i' z | = 3 - '\. PR . : Sl : S ~ % 5 3 dy ¥ ' . £~ p ke s : 1 = 5 I:-'-. | o s Il ¢ __ ¥ & . & o et ol I T i . N IR ek o T oy 4 B s - " {{?) ; (b] -, e o ~ f s ot LY s " 5 3 . -a 5 i Fig. 4.1.20. Inner Surface of Unirradiated Hastelloy B Capsule After Exposure to NuF'KF-LiF-—UF4 {11.8-38.2- 44.3-5.7 Mole %) for 821 he ot 1500°F. (a) Unetched. (b) Eiched with 10% chromic acid (alactrelytic), 250X, {Secret with caption) 253 ANP FPROJECT PROGRESS REPORT 250X, Reduced 13.5%. (Secret with (g} Fig. 4.1.21. lIoner Surface of Unirredioted Hestelloy B Copsule Tested in o Helium Atmosphare for 190 hr ot 15009F, (a) Unetched., (5) Etched with 10% chromic acid {slectrolytic). caption) basis for formation of on oxide coating which is protective at all femperatures up to 1500°F.8 Details of the plating of Hastelloy B corrosion capsules with nickel and chromium by electro- deposition were reported previously.g Other methods of apelying nickel and chromium coatings are being studied in an attempt to improve the yield of successful coatings. Depositian of nickel coatings by the 'electroless’’ method oppedars to be promising, A nickel salt is reduced by sodium hypophosphite and deposited on the surface of the metcl to be cocted. The metal surfece does not enter into the reaction. Nickel deposited by this method is uniform in thickness on all surfaces, and the plate is reported to be relatively nonporaus.'® This method is superior to electrodeposition in that articles of irregular shape receive uniform deposits, The deposition of chromium by vacuum metafizing i5 also being studied. In this method chromium metal is vaporized from a tungsten filament, under vacuum, and deposited on the metal surface to be plated,'! It is difficult to plate artizles of irregulor 5. Inouye, M. D'Amore, and T. K. Roche, Nickel Base Allovs for High Temperature Service, ORNL CF- 36-4-121 {April 146, 1956). QW. E. Browning, R. E. Adams, and H, L. Hemphilj, ANP Quar. Prog. Rep. Dec, 31, 1956, ORNL-2221, p 305, ]GR. M. Burns and W. W, Bradley, Profective Coatings for Metals, 2d ed., p 205, Reinhold, New Yark, 1955, _] IS. Dushman, Scientific Foundations of Vacuum Tech- riques, p 757764, Wiley, New York, 1949, 254 shape with chromium by electrodeposition, and it is anticipated that vacuum metelizing will over- come this difficulty. Vacuum metclized coatings are also expected to have no entrapped liquids, as might be the cose with an electroplate, and thus a large percentage of the coated specimens should survive high-temperature exposure to air, Tests specimens of Hastelloy B have been nickel olated by electrodeposition and then chromium plated by wacvum metalizing, Other specimens have been nickel plated by the "‘electrofess’ method ond then metalizing. These specimens were then heated to 815°C in a muffle furnace and coocled to room temperature daily to study the characteristics of the oxide film, The preliminory results are promis- ing, and work is continuing. chromium plated by vocuum IN-PILE LOGP EXPERIMENTS W. E. Browning R. E. Adams M. F. Osborne H, L. Hemphill H. E. Robertson R. P. Shields Out-of-Pile Test of Pump for LITR Yertical Loop Operation of the full-size pump designed for cir- culating fused-salt fuel in the vertical in-pile loop, which was started in an out-of-pile test loap during the previous t:]urc:r'fieer_.12 was terminated after 3525.5 hr at 1570°F with NoF-ZrF ,-UF, (50-46-4 mole %, fuel 30}, The pump was stopped for re- pairs to the cooling coils which had been over- heated when o water main broke and interrupted the water supply. The pump could not be restorted, presumably because the overheating had demaged the bearings, The pump wos therefore cut open for examination and is shown in Figs. 4.1.22, 4.1.23, and 4.1.24. The desian of this canned-rotor pump may be seen in the cross-sectional cut shown in Fig, 4,1,22, The ZrF ,-vapor control features of this design are ]2"1'!'. E. Browning, M. F. Osborne, and H, E. Robertson, ANP Quar, Prog. Rep. Dec, 31, 1956, ORNL-2221, p 299, UNELASSIEIED FEaTE ~—{ EVEL OF LOWER i s | T geaRiG 9 i i ] i '.?.* | 8 s Sy | COCLING CQIL - L . v ! o 4 ‘ "’: : . VAPOR-DERGSITION ISOTHERM i. ——VAPDR BAFFLE — __ LIQUID LEVEL OAK RIDGE NATIONAL LABORATORY Fig. 4.1.22, Cross-Sectional Cut Through Pump for Verticel In-Plle Loop Which Circuloted NoF-ZrF‘-UFd (50-44-4 Mole %) for 3525 hr at 1570°F Out-of-Pile. The materiol in the liquid passages is solidified fuel, [Secret with coption) PERIOD ENDING MARCH 31, 1957 of porticular interest. The vapor beffle, indicated in Fig. 4.1.22, provides only a narrow path of considerable length through which ~vapor can diffuse, The baffle is made of Graphitar to avoid stoppage if a piece of solid vapor deposit from L A b FrE Ee 0 T0 1RRAT CAR RIDGE NATIONAL LABORATORY Fig. 4.1.23, Pump Shown in Fig. 4.1.22 with Shaft Removed to Show Yopor Deposits Above Baffle, Fig. 4.1.24. Another Yiew of Pump in Fig. 4.1.22 Showing VYapor Deposits and a Cross-Sectional Cut Through the Shoft. 255 ANP PROJECT PROGRESS REPORT above should foll between the baffle ond the shaft, Every surfoce on the fuel side of this baffle should be above the vapor-deposition temperature. This temperature is about 1370°F for fuel 30 at 1570°F {ref 13}, The vapor-deposition isotherm, shown in Fig, 4.1.22, was deduced from the location of vapor deposits in the pump, and it is approximately at the design point, The small omount of vopor which diffuses through the baffle is spread over the large surface provided for that purpose above the isotherm cnd below the lower bearing. Heavy local depesits which could stop the shaft after short running times are thus avoided, The distribution of vapor deposits is shown in Figs, 4.1.23 and 4.1.24, The spongy masses above the boffle are fine needle crystals, loosely clustered, thot resemble hoarfrost, These de- posits did not touch the shaft or the baffle. The deposit just below the bearing wos obout as hard as cholk and about Ix"]é in. thick. The deposit ot the top of the fuel chamber was quite dense and hard. The growing surface haod reached an equslib- rium position where its temperature was just equal to the vapor deposition temperature. No wvapor V3, H. Cooper, ANP Quar. Prof. Rep., June 10, 1956, ORNL-2106, p 65, esp. Fig, 1.4.12. deposit wos found on the shoft near the baffle, and ne scrotch marks could be seen on the two focing surfaces of the shaft and boffle. Hydrodynamic performance tests, thermal mockup tests, and bearing tests of this pump were described pre- viously.” Examination of the furnaces used in this bench test, which were identical with the furnoces to be vsed in-pile, showed several points where foreign materiols deposited and caused sections of the furnace to burn out, Analyses of these deposits showed them to be from soft solder and flux used in the attempled emergency repair of the cocling coils. Mo traces of other construction moterials were found in these deposits, Assembly of LITR VYertical Loop The in-pile loop (No. A-8) being assembled for operation in the LITR was filled in a dry box and run out-of-pile with temporary heaters and thermo- couples for 3 hr at temperatures up to 1630°F, Permanent hecters aond thermocouples were then The loop is shown in Fig, 4.1.25 ot at two stages of assembly, installed, Ty €, Browning e al,, ANP Quar. Prog. Rep. Sept. 10, 1956, ORNL-2157, p 245. LNCLASSIFIED PHOTO F9587 MiAPToE T T = ‘fl’ b UNCLASSIFIED \\ 19470 \ A | DA [ \-‘ _'q.\ e . P g PHOTO { ',‘1 | ] N e gk b LT e 95 . Fig. 4.1.25. ¥Yertical In-Pile Loop A-8 ot Two Stages of Assembly, 256 The loop control system at the LITR is being inspected and readied for operation, and two modi- fications are being made. Provision is being made for odjusting ond monitering the distribution of cocling air between the two legs of the loop. Also, a reservoir 1S being connected into the cooling water system, and a means is being provided for cutomatically actuating e circulating pump if the main water supply is interrupted, Irradiation Facilities in Oak Ridge Research Reactor In cooperation with the ORNL Operations and the Engineering and Mechanical Divisions, facilis ties are being plonned for the future operation of a minicture corrosion-testing loop in the Qak Ridge Research Reactor (ORR)., The routing of instru- ment and power leads, locations of off-ges lines and carbon traps, locotion of the motor-generator set, location of a fail-safe nitrogen supply, and design of the reactor vessel flange seal for the leads are being worked out, A new control panel, to be located in a third floor laboratery in the ORR building, is being designed by the Instrument Depariment. INVESTIGATION OF SULFUR CONTAMINATION OF A DRY BOX BY NECPRENE RUBBER W. E. Browning F‘Ei E. AdGmS Ho Lt Hemphi” During preparations for filling the vertical in-pile loop, it wos discovered that, while under vocuum, the interior of the dry box was contaminated by an unknown gaseous sulfur compound., The presence of the contaminant was monifested by the appear- ance of a Cu,5 film on the copper-cooling coils of the loop ossembly. The Cu,5 film wos identified by chemtcal analysis ond x-ray diffraction. The wvaricus lubricants and oils vsed in the vacyum system and loop assembly were therefore analyzed for sulfur, and the concentrations of the sulfur found renged from less than 10 to 92 ppm. These quantities are to be expected in pump oils and lubricants, Tests of the foop assembly elimi- nated it as ¢ source of the sulfur contaminant, The helium supply was also investigated for sulfur contamination by bubbling the helium through o silver nitrate solution, Mo evidence of a silver sulfide precipitote was noted, Access to the interior of the dry box is provided by Meaprene rubber gloves. A glove and a copper PERIOD ENDING MARCH 31, 1957 specimen were enclosed in a vacuum system inde- pendent of the dry box, and after several hours under vacuum Cu,5 wos found on the copper surfaces, This indicated thot the sulfur contami- nant was present in the Neoprene rubber and was Sulfur is not used in Neoprene as the wvulconizing ogent, but orgonic sulfides are used as a plasticizing agent. The Inconel surfaces of the loop assembly were investigated by electron diffraction, Samples of the surface film were removed from the loop motor agssembly which had been exposed to the contami- liberated under wvacuum. nated dry-box atmosphere, Simifar semples were removed from another moter assembly which had an identical history except for exposure in the dry box, These surface samples were removed by the lacquer-stripping technique used in preparing rep- licas for electron microscopy. The samples were found to be identical, and crystalline sulfides of nickel, iron, and chromium that were sought were nat found. A small sample of fluoride fuel was exposed over- night to the contaminated dry-box atmosphere and then analyzed for sutfur ciong with o control sample of unexposed fuel, tent was found to be below the limit of medsure- ment {20 ppm S5) of the onalytical method being used., Since the loop surfoces and the fluoride fuel revealed no sulfur contamination, the filling operation was completed and the loop was removed from the dry box, In the case described the quantity of sulfur com- pounds present was not considered to be harmful, but elimination of contominents would be desirable, and various methods cre being studied. The ovail- able sulfur content of the gloves might be removed by chemical treatment without changing the physical characteristics of the gloves, and, although difi- cult, the Neoprene gloves might be replaced with gloves of another suitable material. In both cases the sulfur con- EFFECT OF RADIATION ON THERMAL-NEUTRON SHIELD MATERIALS J. G. Morgan R. M. Carroll M. T. Morgan P. E. Reagon [rradiation exposures of nine Cu-B,C samples wera completed in the MTR, and examingtions of 135, s, Rogers (ad.), The Vanderbilt Rubber Handbook, p 47-48, R, T, Yanderbilt Co., New York, 1948, 257 ANP PROJECT PROGRESS REPORT six of the samples were nearly completed. The results of the examinations'?® showed essentially noe changes in dimensions, weight, ond density ofter irradiation, data, however, as a result of slight oxidotion of the somples. Hardness data are given in Table 4.1.4, The dimensions of the shielding elements tested in these irradiations were 0,1875 x 0.500 x 0,102 in. The core of each specimen was 0.082 in, There woas some scotter of the thick and consisted of a copper matrix with ¢ 6.6 wt % B,C dispersion. The core was doubly clad on two faces with 3 mils of copper and 7 mils of type 430 stainless steel, The core was exposed on the four remaining edges. Samples 4, 5, and 6 were irradiated simultaneously at 200°C for 322 hr in position A-39 of the MTR. The maximum temperature reached waos 220°C, The samples experienced three temperature cycles at 164ardness and metaliographic dato obtoined by A. E. Richt ond reported in Metallographic Examination of Irradiated Cermet Shielding Materials — Report No. 2, ORNL CF+56-12-105 {Dec. 18, 1956) and Meialiographkic Examination oé Irradiaied Cermet Shrelding Maferials — Report No, 3, ORNL CF-57-2-33 {Fab. 7, 1957). a rate of less thon 100°C/min. The avercge burnup of the 819 otoms was estimated to be 7%, No apparent structural changes occurred as the result of irradiation, as shown in Fig. 4.1.26, The cores of both irradioted ond control specimens were examined at both high and fow megnifications, and no evidences of cracking, blistering, or porosity were opparent in either the copper matrix matericl or in the boren corbide particles. Alsg, there was no reaction between the boron carbide particles and the copper matrix. The typical appearance of the stainless-steel-to-copper-te-core bond is shown in Fig., 4.1.27, There were no evidences of blistering, ¢cracking, or separation of the cladding-to-core bonds. Samples 1, 2, and 3 were irradiated at 420°C for 929 hr in position A-28 of the MTR. The maximum temperatyre reached was 380°C. An isetfopic analysis showed an 18% average burnup of the B'C atoms, Hardness measurements made on the stainless steel cladding (Table 4.1.4, sample 2) indicated o large increase in hardness os the result of the Toble 4.1.4. Results of Hardress Measurements of Cu-B‘C Samples 4 ond 2 Knoop Hordness (l-kg locd} Locotion of Imprassion Averoge Before Percentage incracse Averaga After e Irradiation lsradiation Change or Decrease After Irradiation Sample 4 Type 430 stoinless steel clodding 13% 166 + 27 +19 Copper clodding 64 76 +12 +19 Core Canter 76 102 + 26 +34 Edge 76 108 + 32 +42 Somple 2 Type 430 stainless steel cladding 139 186 -+ 47 +34 Copper clodding b4 65 =1 -2 Core Center 76 70 -4 -8 Edge 76 78 +2 +3 258 PERIOD ENDING MARCH 31, 1957 - -1 - p' . UNCLASSIFIED ‘ RMG 1529 ! UNCLASSIFIED Flg. 4.1.26. Typical Core Structures of (a} Unirradlated and (5) Ireadlated CusB,C Shielding Elements. S00X. Reduced 13%. ~afi— COPPER CLADDING —2m= 1 - o .‘ "' , < [ B e - b - ¥ _’" TYPE 430 - — STAINLESS-STEEL 3w -~ - : CLADDING » Sy L) (&) Fig. 4.1.27. Core-to-Clodding Interfoce of a Cu-B,C Shielding Element {a) Befare and (5) After lrradlation. 30X, Reduced 27.5%. 259 ANP PROJECT PROGRESS REFPORT irradiotion thot was significantly greater than the increase noted in the examinotion of sampies 4, 5, end 6, The copper cladding and the core of the specimen showed no significant changes in hord- ness. Although the center of the core decreased in hardness, it is felt that this was the result of the severe cracking, which could cause erroneocus measurements. The ends ond sides of specimens 1, 2, and 3 are shown in Fig, 4.1.28, The core cracking and the core-cladding separotion apparent in all specimens varied in degree from specimen to specimen, Speci- men 2 was selected for metailographic examination, and typical sections of the core are shown in Fig. 4.1,29. The particular area shown in Fig. 4,1.29 gives no evidence of cracking or porosity of either the boron carbide particles or the copper matrix However, as the etched photomicrogreph the etching revealed a heavily attocked material, shows, area immedictely adjacent to the B,C particies. In addition the siructure of the copper motrix appears to be somewhat disturbed when compared with the structures obtained in irrodiated specimens 4, 5 and 6, Both these conditions were noted throughout repeated polishing and etching, Longitudinal cracks were found in the core ot both ends of the specimens, which usually started at the center of the core and progressed approxi- mately one-fourth the length of the specimen. A typical c¢rock is shown in Fig. 4.1.30, and the intergranular ottack in the vicinity of the crack is shown in Fig. 4.1.31, Significant core-cladding seporation was found, as shown in Fig. 4,1,32, [t is interesting to note that no evidence of seporation was found ot the interface., Occasional intergranuler separotion stainless-stee|-to-copper large wveoids ond partial were noted in the grain houndaries of the copper cladding, os shown in Fig. 4.1.33., Examination of the entire length of a specimen indicated that the core-cladding separation was dapproximately 70 to 80% complete. FUSED SALT POLAROGRAFPHY R. J, Carter The applicability of polarographic technigues to the study of the fission-product chemistry of fused salts is being investigated, The polarogroph which is being vused is similar to that used in aquecus 260 poforography; however, the hich electrical con- ductivity of the fused salts as compared with aquecus sclutions mokes it impractical fo wvary the potential applied to the polarogrophic cell linearly with time, For this reason, current-veltage curves are recorded with on X-Y recorder rather then with a conventional strip-chart recorder, Both silver and platinum microelectrodes of various sizes and shapes ore being tested for use as cathodes. The platinum crucible which contains the fused salf is used as the anode. The platinum crucible is mounted in an Inconel contoiner which can be filled with helium in order to maintain a dry, inert atmosphere around the fused salt, The neces- sary electrical connections are made by using Kovar seols which are soldered into the lnconel can, VYertical movement of the microelectrode is accomplished by mounting the electrode support on o fexible bellows, In order to test the equipment, current-voltage curves were obtained at 350°C for severol solu- tions containing from 6.4 to 1,0 parts per thousand of cadmium chloride dissolved in potessivm nitrate. Five or six current-voltage curves were obtained for each scolution, The reproducibility of the curves was good in the initial portions but poor in the diffusion-current region, where large fluctua- tions in current were cbserved., The fluctuction of the diffusion current has since been found to be caused by vibration of the laboratory floor, and a suitable meons for shock mounting of the furnace used to heat the fused salt is presently being sought, NEUTRON FLUX STUDIES D. Binder 1. F. Krause 1’ The rapidity of effects on germanium dicdes and transistors in the donut of hole 51N of the ORNL Graphite Reactor led to an investigation of the variation of neutron flux clong the hole. A pre- fiminary survey wos mode with sulfur ond cadmium- covered gold detectors, ond the results are shown in Fig., 4.1.34, The relative octivities of the de- tectors are plotted against distance from the con- crete shield, ond the last point is 11 in, ocut from the edge of the donut, the position described pre- viously as outside the donut,'® From this position l:"{.'!n ossignmant from Pratt & Whitney Aircreft. 18p, Binder ond 4. F, Kravse, ANP Quar. Prog. Rep. Dee. 31, 1956, ORNL-222%, p 308. PERICD ENDING MARCH 31, 1957 - 1 UNCLASSFIED -y UNCLASSIFIED UNCL ASSIFIED RMG 1578 - BMG 1573 BEMG 1577 — UNCLASSIFIED L RMG 1578A ‘ i UNCL ASSIFIED - RMG 1574 4 ’Iv"' ' v U™ Flg. 4.1.28. MTR-lrrodicted Cu-B,C Specimens. (a, b, ¢} Ends of specimens 1, 2, and 3, 13X. {d, e, [} Sides of specimans 1, 2, ond 3. 7X, 261 ANP PROJECT PROGRESS REPORT .. ; -—‘Ii UNCL ASSIFIED .‘. J \] f} \' 3 UNCLASSIFIED = RMG 1583 | v RMG 1584 Fig. 4.1.29. Core of MTR-lrrodlcted Cu-fldc Specimen Mo, 2 Showing Heavily Atocked Areas Adacent to B,C Porticles. {a) As-polished. (b) Exched. 500X. Reduced 19%. UNGCL ASSIFIED RMG 1586 Fig. 4.1.30. Corea of MTR-lrradioted Cu-B‘{C Specimen Mo, Z Showlng a Typical Fracture. (g) As-polished. (b) Etched. 250X. Reduced 18%. 262 PERIOD ENDING MARCH 31, 1957 7 UNCL ASSIFIED RMG 1588 UNCL. ASSIFIED RNG 1587 : ¥ - na{ (2) SR .. rm‘&"fi > . Fig. 4.1.31. Core of MTR-lrradiated Cu-B,C Specimen No. 2 Showing Intergranular Attack In Yicinity of @ Fracture. {(a) As-polished. (b) Etched. 500X. Raduced 20%. RME 1590 COPPER CLADDING COPPER CLADDING TYPE 430 STAINLESS STEEL CLADDING - TYPE 430 STAINLESS STEEL CLADDING Fig. 4.1.32. MTR-lradigted Cu-B,C Specimen Na. 2 Showing Core-Cladding Separation. [(a) As-polished. (6) Etched. 250X. Raduced 18%. 263 ANP PROJECT PROGRESS REPORT N —— A W P L. Y e, a‘ UNCL ASSIFIED = Yha o RMG 159) NPT S ‘V AT T gc;.\"' CORE - . == 5 gh & TS *{} \,1.4 j “‘Y ‘.;-?; 1.1 ' : 5 _-‘ A _i - ¥ R e — & — ; = - COPPER CLACDING TYPE 430 STAINLESS STEEL CLACDING {g] Flg. 4.1.33. T — UNCLASSIFIED RMG 1592 TYPE 430 STAINLESS STEEL CLADDING (&) MTR-Irradiated Cu-B,C Specimen No. 2 Showing Velds and Pertial Intergranular Separation In Grain Boundaries of Copper Cladding. (a) As-polished, {b) Etched. 500X. Reduced 19%. to the center of the donut, both Np?37 neutron de- tectors and carrier concentrations in n-type ger- manivm indicate an increase in activity by o factor of 3 (ref 18}, The 53:(n,p)P32 reaction has an effective thresh- old of 3 Mev, and Au'%® hos a strong resonance at 5 ev; therefore the two detectors are seasitive to the two extremes of the reactor spectrum. The gold detectors show a smooth increcse with distance from the shield (the curve is drawn through these points}. The sulfur points, in general, fall below the geld peints ocutside the active lattice (24 in, from the shield). The two detectors are normalized ot the innermost pesition, [t would be of interest to compare these wvariations with a variation in radiation effects. The lotter would presumably fall between the detector variations, 264 UNCLASSIFIED ORNL-LR-DWG 16683 5 ? -{ G L{#] | '-l > [ £ 5| 1 L = k2 2 =1 & | 102 ; . | Ay (Cd COVERED) — i * SULPHUR . 2 | ||0_3 | e J 0 20 a0 60 80 100 DISTANCE FROM SHIELD {in) Fig. 4.1.34, Relotive Activities of Detectors in Hole 51 of the ORNL Graphite Reoctor vs Distance from Shield Facs. EFFECTS OF RADIATION ON ELECTRONIC COMPONENTS J. L. Pigg C. C, Robinson 0. E. Schow 0. Curtis Minority Carrier Lifetime Measurements in n-Type Germanium Measurements of the effect of irradiation on the minority carrier lifetime in n-type germanium were inved.'? The hole lifetime § | | centinued, e hole lifetime jor several samples was meosured before and after a series of irradia- tions in the ORNL Graphite Reactor and in a Co®® gamma-ray facility, Sample Sb-28A-3 was irradicted with fast neutrons in the animal tunnel of the ORNL Graphite Reactor, Py e Pigg er al., ANP Quar. Prog. Rep. Dec, 31, 1956, ORNL-2221, o 309, PERIOD ENDING MARCH 31, 1957 This sample, which had on original corrier con- centration of 3 x 104 carriers/cm?, was irradiated until it became intrinsic, Initially, very slight irrodiation produced large changes in the hole lifetime. Since the initial lifetime was 1010 psec, it can be seen from Fig, 4.1,35 thot the hole lifatime changed by about a factor of 5 for a dose of 101! fast neutrons/cm?, which produced a change in carrier concenfration of only 0.1%, The plot of hole lifetime vs fast- neutron dose in Fig., 4.1.35 shows a simple power dependency, but the stroight line produced does not have o slope of unity, but rather 0.7, The departure of the dota from the straight line at the higher doses was to be expected as a result The minority carrier lifetime depends inversely upen the carrier concentrafion when the matericl is near the range, lhe of carriers thus becomes important for this sample after a dose of 1077 neutrons/cm?, Variations in the surface recombination velocity would tend to give scatter in the dota for fong of the change in the carrier concentration, removal infrinsic UNCLABSSIFIED ORNL -LR-0OWG 20382 10} —— —=—— —+H e —— —— — - I EF T ] 1 R - B I i "“J: R o L il I S W | | ‘ I L Pl 59 ¥ 1 S S 1 T _ (1] | 1] | I I . I | ] 2 —— R 5 o 2 5 type of damage produced, The slope of the curve is somewhat less than the slope of the curve for nevtron irradiotion, being in this case about 0.6, The role which the initial carrier concentration plays is being investigoted with samples of widely varying resistivity, Measurements are also being made with a Cs'37 gamma-ray source, Diode Irradiations It was shown pr\evin:-u&‘.l-;.»'2“:l that the reverse voltage-current characteristic curve of a germanium diode is sensitive to Co®® gamma-rays. In the previous experiment, the currents were meosured ot a fixed voltage bios, In forward and reverse 2':'J. C. Pigg and €. C. Robinson, ANP Quar. Prog. Rep. fune 10, 1936, ORNL-2106, p 244, UNCLASSIFIED CRNL-LR-DW6 20383 EAGLE PITCHER COMPANY INGOT NQ. 2 | A SAMPLE EP2-3 ® SAMPLE EP2-4 | | 10'® 2 5 10'7 2 5 108 Co®9 GAMMA-RAY DOSE (photons /em?) Fig. 4.1.36. Effect of o Gumma=-Ray lrradiation on Hole Litetime in n-Type Germanium. 266 order to differentiote between barrier current ond surface-leckage current, o IN 238 dicde was ex- posed ot a dose rate of 500 r/hr in a Co®? focility, Data for a complete characteristic curve were obtained up to a maximum bias of 1.5 v, these data, the soturation current intercept, | From 0 ond the surface-feakage curreny, f;, can be cbtained, The soturation current intsrcept is cbtained by extrapelating the saturation part of the reverse characteristic back to the origin. This value, | go enters into the diode equation for the reverse biased condition as follows: } om !U“ _e—qukT] , 1 = current through barrier at voltage V, g = electronic charge, Boltzmann constant, T = absolute temperature, A it The parameter [, appears in tronsistor considera- tions as the cutoff current {_ , where I__ is the collector current with zero bias on the emitter, The change in 7, as a fuaction of the Es5* gamma-ray dose for a IN 38 dicde is shown in Fig. 4.1.37. The change in i, is rapid during the initial part of the irradiation but tends to saturate as the exposure continues., Previous experiments with 1N 38-A diodes showed a maximum in the reverse current ofter about 1.7 x 107 ¢+, The 1N 38 showed no maximum in Iy after 4 x 107 r, Since UNCLASSIFED ORML-LA-DWG 20384 Pl REVERSE $ATURATION CURRENT, /, amp) 0 ———l = e O 107 2n0’ GAaMMA-R LY DOSE {r) Baiy’ q 107 Fig. 4.1.37. Effect of Co®0 Gomma-Roy Irradiation on the Reverse Saturction Current of a 1N 38 (Mo. 10) Germaniom Disde. PERIOD ENDING MARCH 31, 1957 these diocdes are commercial vnits, there is no indication of the initial carrier concentration or the initial mobility. Thus there is no reason to expect that the moximum observed previously?® would occur of the same integroted exposure for a different type of unit, Upon removal from the gamma-ray source, the change in I, indicated that an annealing process was taking place in the barrier. As con be seen from Fig. 4.1.38, recovery of the unit was not complete, ond the onnealing was not o simple first-order process, The minimum in Iy after 125 hr of annecling may be real, The surface-leckage current, I, is obtained by subtracting /) from the reverse current measured at a bias of 1 v, The value 7, may thus be considered to be the leakage conductance. The chonge in i, as a function of exposure is shown in Fig, 4,1.39, It can be seen that !, saturates after a ropid initial increase of about one order of magnitude. This saturation moy indicate that the depth of surface attack is limited. The annealing of I, upon removal from the gamma- ray source, shown in Fig, 4.1.40, is complicated, as it was in the case of /. A definite minimum can be seen at cbout 40 hr, The fact that annealing occurs indicates that the surfoce teckage is not caused by simple chemical attack alone, Since o commercial unit is being studied, if is not practical UNCLASSIFIED ORNE -LR -0 20345 ROCK TEMPERATURE ANNEALING TIME {hr) 5 0 15 z0 s © 3% = — T T TR TP 1 ® REWERSE SATURATION CURRENT, fplampl 0 - -— o — i e Q o0 100 {50 200 ROCM TCMPERATURE AMNEALING TIME [hrl Fig. 4.1.38. Room-Temperature Annealing of the Rovorse Saturation Current of a IN 38 (Ne. 10) Germa- nium Diode Subsequent to Irradiation to o C:-:'r“JI Gamma- Ray Dose of 3.24 x 107 - 267 ANP PROJECT PROGRESS REFPORT to isclate the different possible sources of surfoce change or to study the surface directly, Transistors A G-E 2N 44 PNP fused-junction germanium transistor wos exposed in the ORNL Grephite UNCLASSIFIED - QREL-LR-GWG 20306 10 L T T a4 |- SURFACE-LEAKAGE CURRENT, Z lamp) 8 ch 0 e 1 ) 167 Zx10’ 3x107 GAMMA-RAY DOSE (A Fig. 4.1.39. Effect of gt Gomma-Rey lrrediation on the Surfoce-Leakcge Cutrent of o IN 38 {Neo. 10) Germanivm Dode. UNGLASSFIED DAL L R=CWG 20T FOCM TEMPERATURE AMNEALIMG TIME [he) 50 00 1540 200 SURFACE -LEAKAGE CURRENT, J, (omp) 15 2_0 ROCM TEMPERATURE ANMCALING TIME (he} Fig, 4.1.40. Room Temperature Annecling of Suifoce- Laukuge Current of ¢ TN 38 {No. 10} Germanium Dicde Subsequent to Irradiction to a Coéo Gamma-Rey Dose of 3.24 x 107 ¢, 268 Reactor, The leo values for different voltoges were recorded os o function of expasure, Both grounded-base and grounded-emitter connections were used, The feg values for the grounded-bose connection are the I, values for the collector It can be seen from Fig. 4.1.41 that the barrier 1, drops until ofter an exposure of about 8 x 10'" neutrons/cm?. The leckage current, Iy mentioned above would be reflected in the spocing between the curves, The change in [, is smell compared with the change in /. The f_, measurements for the grounded-emitter connection are shown in Fig., 4.1.42. The general shape of the curve is the same os that for the grounded-base connection, but the change in leck- age current is much more prenounced in the grounded- emitter connection. The velve of I, in terms of leakage conductance, as defined above, varies from 3.4 x 1078 amp/v initially to o minimum of 1.4 x 107% amp/v ot the minimum of the curve and in- crecses fo approximately 4,2 x 107% amp/v after an exposure to a thermal-neutron dose of 3.45x 1012 barrier, L neutrons/cm?, From the observetions to dete, if appears that the manner in which the choracteristics of a junction device change depends both upon the nature of irradiation to which the device is exposed ond the method by which the junction is made. Qualitative UNCLASSIFIED 6 ORNL—LR—DWG 20398 CUTOFF CURRENT, [,, (omp) | | | o i 401% 2x102 52102 THERMAL-NELUTROM DOSE (adutront feme ) 4 240l E Fig. 4.1.41. Effect of Recctor Irradiation on Grounded- Bose Cutoff Current of o G-E 2N 44 PNP Fusad-Junction Germonium Tronsistor. UNCLASSIFIED P CANL-LR-DWG 20389 310 A5y & £ = | D a , 3 2410 | e = 225w | ¥ e 2w 3 I L S 0t A et AT . 3o | 3 | o o o _—l 0 10'2 20t 32102 4107 THERMAL- NEUTRON DOSE (neutrons/em?] Fig. 4.1.42, Effect of Reactor Irradiation on Grounded- Emitter Cutoff Current of o G-E 2N 44 PNP Fused- Junction Germonlum Transistor. trends in behavior can be established by using commercial units, but the quontitative date neces- sary for reliable interpretation of the effects will require the use of ingots or samples specifically prepared for such on investigation. In porticular, it must be possible to control the history of the sample surface, The somples would be constructed so that the conductivity of the base maoterial could be determined, A Safe for Removal of Samples from the Reactor The removal of samples from the ORNL Graphite Reactor subjects the personnel engaged in the work to beta ond gomma irradiation from the octivated material being removed and to contamination by the radicactive dust associated with the decay of insulation. This problem is particularly acute when samples must be removed from the reoctor loading face, As a first step in solution of this problem, o sample removal sofe was designed, Fig. 4.1.43, The sofe can be handled by two men, and vyet it is thick enough to provide odequote shielding for the levels of activity normally en- countered. All access facilities can be operated by one men., The device can be used either at the reactor loading face, or, by transterring to another dolly, at holes 50, 51, and 52. Provision hos been made Sor vacuum removal of rudicociive dust ond particles through numerous access ports. PERIOD ENDING MARCH 31, 1937 Modifications to Hole 30 of the ORNL Graphite Reactor In order for measurements fo be made con semi- conductor components under irradiation, the ex- posures must be conducted at flux levels one to two orders of magnitude lower than those found in the central region of the ORNL Graphite Reactor, Unless such low flux levels are used, the measure- ments cannot be made in o time interval that is short compored with the fime interval which pro- duces @ significant chonge in the parameters being measured. If exposures are conducted in hole 51, where q fission spectrum, o removal focility, and provisions for instrumentation are available, the reactor must be operated at power levels between 50 and 400 kw, The time available for such operation is limited and the reproducibility of flux levels s difficult. Exposure near the periphery of the reactor couses a positioning problem and provides an undesiroble ratia of thermal to fast flux, In order to eliminate these disadvantages and to supply several advantageous features, an exposure device has been designed for use in hole 30N of the Graphite Reactor, as shown in Fig, 4.1.44, The device consists of a cart which may be moved from a loading shield at the reactor shield foce to a fission chamber locoted inside hole 30N, The sam- ple can be moved from the external shield to the irradiation position in about 10 sec. The fission chamber position may be adjusted to give a range of flux levels. The external shield is designed to facilitate removal of the fission chamber should such action become necessary. The sample moy be instelled ond removed without breaking the electricel connections. This will make possible continuous readings from the pre- exposure to the postexposure periods. DIELECTRIC CONSTANT AND LOSS TANGENT OF IRRADIATED PLASTICS AT MICROWAVE FREQUENCIES R. A, Weeks J. C, Pigg Previous work indicated thet reactor irradiation causes changes in the dielectric properties of polyethylene and Teflon,2! The data showed lorge changes in loss tangent after fast-neutron doses of up to 10'® nevtrons/em?. The samples 2p. A Weeks, Sohid State Semiann. Aug, 30, 1954, ORNL-1762, p 113. Prog. Hep. 269 0LL UNCLASSIFIED - & LEAD-FILLED DQORS - ORML-LR-OWG 20390 Lol EH LEAD-FILLED DOOCRS i, - -LEAD-FILLED BOGDY — m g MOTE - SHIELD WEIGHT — APFROX. 24001 8 [ DOLLY | | | 1 oo A i SwIVEL CASTER ‘RIGID CASTER POISITION LOCK 1012345678910 SCALE IN INCHES ey Fig. 4.1.43. Sample Removal Sofe. 1¥0d3Y S53820¥d 1D370¥d dNY Lig UNGLASSIFIED ORHL-LR-DWG 203591 e A [ i i _ T 1; L] == ‘ . i 5 1 | Fes bl —} :‘ ——r———— | qI—l- _I_ & s o ..r L s T =n ] = ] | | gl e | T 1 B 1———' || | - :‘F SECTION 88 L S fi “ SAMPLE REMOYAL PORT c 4 b _‘:jgfi 1 - = | L} REMOVABLE SECTION - 2 ' || s VIEW G-C !L |,‘f|--*-:$ Q FISSION CH.&MBER\\ /m_ummum LINER Ty )i \ ! i : _? e, o baty? | N “ | SAMPLE GART " e R 1 ___I_L e e — _3 CHAMBER P-osmoi NG // : /7////7/ ///‘ i / e - e /fi, i / L & CONCRETE SHIELD OF s fif“‘ < i /' A 4 o GRAPHITE REACTOR SECTION 4-A REEL SHIELD FOR INSTRUMENE;I'ATION . . | i / f @‘DRIVE MOTOR Fig. 4.1.44, Exposure Facility for Use in Hole 30N of the ORMNL Grophite Reactor. 1561 'IE HOYVYW ONIGNT dold3d ANP PROJECT PROGRESS REPORT were irzadiated in o water~cooled facility in the QRNL Grophite Reactor. Examinction after re- moval from the reactor revealed evidence of wofer in some of the containers. The presence of moisture roised a question as to the amount of water absorbed by the specimen during the irradia- tion. The ovailable evidence indicated, however, that the observed changes were not due to water cbsorption. These studies were resumed during the quarter with exposures of Teflon, polyethylene, polysiyrene, unfilled phenol formaldebyde, and aylon in a Co%° gammo-ray focility, The irradiation temperature The only moisture The same was opproximately 25°C, present wos thot in the otmasphere. sample was vsed for an entire series of irradia- tions. The low temperature, absence of moisture, and use of the same somple throughoui the experi- served to increase the reliobitity of data 21 ment compared with that reported previously. The chonge in loss tongent of polyethylene ot variovs frequencies as o fuaction of the Co®? gamma-ray dose is shown in Fig. 4.1.45, Similar data for Tefon, polystyrene, nylon, and phenol formaldehyde are shown in Figs, 4.1,46 through 4.1,49, It is evident thot the irradiation had a large effect on the loss tangent of polyethylene and Teflon but only o small effect on polystyrene. The nylon and phencl formaldehyde samples have not yet received sufficient irradiation to produce a marked change in less tangent. On the bosis of the results in polyethylene, the nylon ond phenocl UNCLASSIFIED tx ™M | 25 I — 20 = Ladd L] = 3 8 S A0 | all o ey - — e — QL.. e - el bl ! G102 05 0 20 50 00 200 500 (k100 GAMMA-REY DOSE (r) Fig. 4.1.45. Effect of Co®0 Gamma lrradiation on the Loss Tangent in Poiyethylane. 272 LINCLASSIFIED - ORNL-LA-DWE 203593 A T e e T Y | ! | 20 | A BODme & 000 me & | » 3000 me &8 * 8500 me Z | }... L | & 10 : | PREIRRADIATION ; & > VALUE ! S A TI—!—'I'I". =t | 0| |l"lj l O i ] - L= = i =3 Sahiy i el 25 ot 02 05 10 20 50 100 200 500 (xig) GaMMo-RAY DOSE () Fig. 4.1.46. Effect of Co®® Gommo Irradiation on the Loss Tangent in Teflon, UHCLASSIFIED DANL=LA-DWG 200354 HO.—Q] T _“| . "'_"'_‘_| "l" —"_ | § | 1 24 | fact B 4 I | _, e b o { —tfet | | | & 800 me ‘ | | 4000 me || 7 | 3ol g Lt gy s 4 o 8 | [ = 3000 me | | z | * BROO me |I o 16 = | | e | Lokt = = | g o N et e e e & | g | g 4 |e— T i 1 | || O - * il e bl 1 ——— ks — . — ——————— ? o1l 0.2 s 0 20 50 100 200 500 (w109 GAMMA=-RAY DOSE (r) Fig., 4.1.47. Effect of Co%? Gamma leradiction on the Loss Tengent in Polystyrene. UNCLASSIFIEDD ORNL =LR=DW; 20335 tx10™) — - e = | £00 - oc | _.& BO0 mc i ? ' 1000 me 5 « 3000 me | Haon Fe bl e B800O mMe | z . i | w 300 : - e | o - PREIRRACIATION waLUE | 200 A : et . | | s ® gla LLL gl | B 106 = EREr 1 : =it | | | | | C, L Ll R 2N b et N I i of D2 D5 10 20 50 100 200 500 (07 GAMMA-RAY DOSE (r) Fig. 4.1.48. Effect of Co®® Gamma lrradiation on the Loss Tangeat in Mylon, formoldehyde will need approximately twice the present integrated dosage to produce a significont change, The changes in loss tangents of polyethylene and Teflon appear to be frequency sensitive; the WHCLASSIFIED OFML—LR—0ws BOR0E ST mms CTTTIT T 11T | 1T S 1 4 I. |_ SIS S I. 1= .!..I.I | ) | 1000 | i s i = | ' & I ! : % 300 i kL SN = T AR | I. . 1 4 et ek —_— i =& 2 | | soo |4t UL Lodlet] | LY g ‘ ikpéilhmpmflqw VALLE | ‘ ! I | | qoo il il | - - i _: |\ : - | ( & BEIJOan 00— T —- 0 3000 me i | | ¥ B?(}On'bc 5 | L | L LIHE L L] o f i 100 {x107) GamMME-RAY DOSE () Fig- 4.1,49. Ef#fect of Coén Gamma lreadiation on the Loss Tangent In Phencl Formaldehyde. PERIOD ENDING MARCH 31, 1957 greatest change occurred at 800 mc, There was evidence of this frequency dependency in the teactor-irradiated specimens discussed above. On the basis of the change in attenuation observed?? in polyethylene cable measured ar 4 mc and the results shown in Fig. 4.1.45, it seems ciear that the loss tangent of irradiated polyethylene has o maximum in the frequency range between 4 and 800 mc. Such a maximum probably exists also for Teflon. Measurements in this frequency range are needed to substantiate these conclusions. Any chonges in the dielectric constants of the five materials studied are less than the error of measurement, Since the limit of accuracy of the present mecsurements of dielectric constants is 5%, changes smaller than this volue would not be observed, In the cose of Teflon there is a con- sistent trend in the data which suggests that o change in dielectric constant may occur, 22p. A. Weeks and D. Binder, Effect of Radiation on the Dieleciric Constant and Altenuation of Two Coaxial Cables, ORNL-1700, p 11 (Morch 2, 1954). 273 ANF PROJECT PROGRESS REPORT 4.2, FUEL RECOVERY AND REPROCESSING . B. Lindaver D. E. Ferguson PILCT PLANT J. E. Bigelow W. H. Lewis F. N. Browder J. T. Leng W. H. Carr F. W. Miles R. B. Keely 5. H. Stainker C. L. Whitmarsh Construction of the fused salt—fivoride volatility pilot plant is essentially complete, with the exception of facilities for handling ARE fuel, which will not be installed until runs with aon- irradiated materiol ore completed. of the fluorine disposal system it was found that fluorine can be satisfactorily scrubbed from the In studies off-gas stream at normal process flow rates with the use of only three of the seven spray nozzles in the scrubber, The molten-sait handling equipment was tested, and the stainless steel vessel for melting the chorge suffered heovy corrosion. After three test melts were prepared, the salt outlet of the vessel plugged. The stainless steel vessel will be replaced with a nickel vesset. The remainder of the molten-salt system {fluorinator, waste can and carrier, avtoresistance heated lines, and freeze valves) handled the molten salt in a manner which will be acceptable for operations. Heating- ond cocling-cycle studies were started on the MNaF cbsorbers and on the cold traps. Resuits of the first tests indicate that the heating time for the absorbers as designed may be ex- cessive and that neither the 5-in. K-25 cold trap nor the &-in. ORNL.designed cold trap will reach design temperature. Further studies are in progress in order to determine the modificotions and op- erating techniques necessary for satisfactory operation. In one of the test runs, the molten salt NaF- ZrF -UF, (56-37.5-6.5 mole %, fuel 108) was sparged in the fluorinator ot 600°C for 7.5 hr with N, at a rote of 2 scfm. (The pleat flueri- nation ¢ycle is expected to be 2 hr of sparging with F, at a rote of 1.7 sefm.) An anclysis of the deposit in the vopor trap indicated that salt entrainment ond ZrF . vaporization from the salt were of the some order of magnitude. Seme moterial 274 ¥. K. Eister H. E. Goeller passed through the nickel mesh of the vapor trop; this material could not be blown off the walls, but it was easily wiped off. SULFUR EMBRITTLEMENT OF NICKEL M. R. Bennett E. E. Hoffman G. I. Cathers R. L. Jolley L. R. Trotter The embrittlement of nickel and of high-nickel- content alloys by sulfur was investigated chem- ically and metallurgically to determine the importance of the effect in volotility processing. Experiments with fused salts to which known amounts of sulfur were added showed that nickel foil is sensitive to sulfur concentrations as low at 5 ppm. Under ordinary conditions, however, in equipment with heavy nickel walls, a sulfur concentration of 200 1o 500 ppm is necessary to produce severe embrittlement. The sulfur effect is cumulotive, as indicated in o -consultation with an Internationsl Nickel Company repre- sentotive, | ond there is danger of sulfur buildup in fused-salt treatment vessels os a result of processing many batches with small sulfur contents. Evidence has been obtained, however, that the sulfur content of the fused salt can be reduced to a harmless level by one exposure to nickel equipment. The mechanical effect of sulfur em- brittlement wos found to be much less on lnconel than on nickel. Metallurgical examinations were mode of spec- from 0.035-in.-wall nickel test capsules thot had been exposed to sulfur-contemincted fused salt mixtures for 3 hr at 700°C under the conditions given in Table 4.2.1. The sulfur was added in the elemental form and as Ne,SO, to salt mixtures that initiclly contained less than imens 50 ppm. The inner waolis of the capsules used in all the tests showed a characteristic type of cracking when bent, as shown in Fig. 4.2.1. No apprecioble difference was evident in the degree of damage to the walls of the capsules (specimens ]Con.*.ulmtiOn with E. M. Skinner of internotional Nickel Company. PERIOD ENDING MARCH 31, 1957 Table 4.2.1. Conditions of Tests of Nickel for C ond E) exposed to Na,50, or to free sulfur Determining the Effect of Sulfur on the added to NaF-ZrF -UF, (50-46-4 mole %, fuel 30), Mechanical Properties An odditional heat treatment for 50 hr ay 700°C in Tast ismperatore: 7009 vacuum resulted in typical homogeneization (Fig. Test poriod: 3 hr 4.2.2). Further evidence of the degree of sulfur Sulfur added: 500 gpm embrittlement is shown in photomicrographs of as-received moateriai and of specimens from two Test Fused Solt of the tested copsules (Figs. 4.2.3, 4.2.4, ond Copsule Compesition Sulfur Added As d’2'5)' ] ) ) ) SRR CoHaTE) In additicnal tests at G00PC, 50-mil nickel wire specimens were exposed in nickel copsules to A NGF-ZFF4 (55_50) E]Emflflffll SUHUf NGF'Zer (50'50 mOIB %, SUIT 31) WIT|:1 knOWH additions of free sulfur or Na,50,. The nickel B NaF-Z¢F , {50-50) Na, 50, wire was moderately embrittled in o 1-hr fest in a fused solt mixture that contained 250 ppm W NaReAr iy Ha,30y of sulfur os anhydorus Ne,30,, whereas 100 ppm ey of sulfur caused slight embritttement in the some E NeF -ZrF -UF, Elemental sulfur period. Repeated additions of 100 ppm of sulfur (50-46-4) as N02504 ot l-ht intervals to the some salt mixture produced severe embrittlement af o total UNCLASSIFIED Y-20136 Fig. 4.2.1. Results of Band Tests of Specimens Cut from Walls of Nickel Test Copsules Thot Were Exposed to Sulfur-Contalnlng Fused Solt Mixtures, Specimen F is as-received moterial. {(Confidantial with coption) 275 ANP PROJECT FROGRESS REPORT | 0D ' '1!!II:1T||']1I1!!H]I' .I"']L UNCLASSIFIED Y-20200 Fig. 4.2.2, Bend Test Specimens Shown in Fig. 4.2,1 After on Additional Heot Treatment of 50 hr ot 700°C in Yacvum. Mote typicel homogeneization that resulted from the heat treatment. {Confidential with caption) - - A / [ e o f ! o - . - | S - » . = i \..‘ o > > - \' ;: | - - b = -'"_-‘_-_\_ " r — = & - - 1 Fig. 4.2.3. Specimen from Inner Wall of an As-Received Nickel Test Capsvle. Etchant: 500X, 276 003 a9 006 o < S KCN-(NH,)58,0,. PERIOD ENDING MARCH 31, 1957 UNCL ASSIFIED ¥- 20122 UNCL ASSIFIED ¥-20624 UNCLASSIFIED § 5o Y- 20583 | (@) ' -84 () 1 Fig. 4.2.4. Specimen from lnner Wall of Mickel Capsule A {See Table 4.2.1) That Was Exposed for 3 hr at 700°C to NuF-Zer (50-50 Mole %, 5alr 31) Contoining 500 ppm of Elemental Sulfur, (g) As-rested wall — note nickel sulfide compound formation in grain boundaries. 500X. {6) As-tested ond bent, 250X. {(¢) As-testad, heat treated at 700°C for 50 hr in vacuum, and then bent. 250X, Etchant: KCN-{NH,),5,0,. Reduced 11.5%. (Confi- dantial with caption) UMCL ASSIFIED 2 Y-20124 UNCL ASSIFIED Y- 204625 UNCLASSIFIED Y- 20582 s t tNEHE ? 3 g = EEEER o & 2 T 250x 250X 1 (@), (&) i 4 - 4¢) . I - Fig. 4.2.5. Specimen from lnner Wall of Nickel Copsule B (See Table 4,2.1) That Was Exposed for 3 hr ot 700°C 10 Nch-sz‘l (50-50 Mole %, Salt 31) Centoining 500 ppm of Sulfur as Nazsod. fa) As-tested woll. 500X. (6) As-tested and bent. 250X, (c) As-tested, heat treqted ot 700°C for 50 hr in vocuum, and then bont, 250X, Etchant: KCN'(NHAJLFS?OB' Reduced 13%. (Confidentiol with capticn) 277 ANP PROJECT PROGRESS REPORT sulfur concentration of 300 to 500 ppm. These of 50-mil wire, which indicated that the was slight at concentrations of tests embrittlement less thon 100 ppm sulfur, were not considered to be sufficiently seasitive because the em- brittiement was limited to the outer surfoce of the wire and there wos o large loss of sylfur inte the wolls of the nickel container. Therefore a more senstive type of test was performed ia which a strip of 5-mil nickel foil (weight of 1- by 2-in. sheet, ~1.5 g) wos immersed in 150 g of salt contoined in o graphite reactor. A nifrogen at- mosphere wos maintained above the salt. In this test the sulfur concentrates in the nickel foil, since the salt-to-nickel rotio is maintained at about 100:1. A major portion of the Semil foil is available for sulfur penetration in o few hours in this test if a diffusion rate ot 0.4 mil/hr is assumed. ' A 2-hr test of foil ot 600°C in a solt mixture containing 100 ppm of sulfur os Na,50, resulted in essentially complete loss of mechanical strength, and the foil broke under very slight stress. The embrittlement became progressively less as the svlfur concentration was decreased to 1 ppm. When ne sulfur was added to the salt, o foil im- 18 hr retained its mechanical strength, but there was evidence of some embrittlement A comporative test Inconel foil in a salt mixture con- mersed at the salt-vopor interface. with S5-mil 100 ppm of sulfur resulted in almeost ne embrittlement, in confirmation of previous ob- servations that some types of aickel olloys are more resistant than pure nickel to the sulfur eftect. The effect of sulfur on nickel is believed to be dependent on the initial chemicol state of the sulfur and its subsequent reactions, os well as on the rate of diffusion of sulfur or nickel sulfide through Comparafive time studies indicate thot in the case of N02504, 1 to 4 hr is required for moderately complete reaction. This was confirmed by studying the behavior of tracer S°% in an experiment in which o totol of taining the metal. 15 ppm of sulfur was added to the salt mixture. The disapoearance of the 33 activity wos 90% complete in 2 hr. Less thon 5% of the sulfur that disappeared was found in the walls of the nickel capsule, and thus it oppears that only a small part of the sulfur present in the fused salt actuolly causes the embrittiing effect. A sulfur material 278 balonce experiment with an 'nconel capsule also showed that only a fraction of the sulfur actually transferred from the salt to the metal. With 100 ppm of sulfur in NoF-ZrF, at 600°C and o salt-to- metal ratio of 160:1, the sulfur actually feund in the Inconel after a 4-hr exposure accounted for only 3% of the sulfur in the original salt mixture. The sulfur content of the Inconel increased from less than 130 ppm to more than 630 ppm, as determined by activation analyses. OXIDATION RESISTANCE OF ALLOYS IN FLUCRIDE SYSTEMS M. R. Bennett G. I. Cathers R. L. Joliey The gas-phase oxidation resistance of types 316 and 347 stainless steel was found to be quite unsatisfactory in tests of their use as passible container materials for molten NaF-ZrF,-UF, at 1200°F. Inconel was also attacked to an unusval extent in these tests, Nickel showed the least corrosion effect. This study was mode to evaluate the corrosion effects observed in one of the stainless steel vessels for melting salt The low oxidation resistonce of stainless steels in contact with fluoride-bearing vapor is in merked centrast to the wusual resistance of stoinless steels at mixtures in the volatility pilot plaat. high temperatures. The fluoride presumably acts as o destructive agent for the protective film of chromium oxide believed to exist on stainless stee| surfaces. The tests ceonsisted in helding comrosion speci- mens partly immersed in molten NoF-ZrF -UF, {nominal composition, 48-48-4 mole %) at 650°C while bubbling gos through the solt mixture. The first test wos made with air that hoed been passed through Drierite to determine whether the stoinless steels retoined any of their typical corrosion resistance under these coaditions (Fig. 4.2.6). After 2 hr all the iron-centaining alloys (stainless steels and Inconel) had scole above the salt line. The scale, which was strongly magnetic, was thick on the stainless steels, in contrast to the small amount on the Inconel ond none on the A second test with nitrogen dried with Drierite showed similar results after 16 hr (Fig. 4.2.7). out with helium, there was, unfortunctely, some nickel. ln this test, as in several runs carried back-diffusion of air into the reactor as o result of the low flow rete and o leak at the flange. Another test with nitrogen at a higher flow rate I 3 3 NICKEL INCONEL TYPE 316 f 2 PERIOD ENDING MARCH 31,1957 UNCL ASSIFIED 1 FHOTO 19471 490 °C 520° 580° Bl0° —~ SALT LINE ,650°C TYPE 347 STAINLESS STEEL STAINLESS STEEL 3 3 OaK RIDGE NATIONAL LABCRATORY Fig. 4.2.6. Specimens That Were Partly Immersed for 2 hr in NuF-ZrF‘-UF4 Through Which Air Wos Belng Bubbled. to minimize air bock-diffusien resulted in prec- tically no buildup of scale in 26 hr. For this test the nitrogen was dried with Anhydrone and then passed through copper foil ot 750°C to remove any traces of oxygen. In all tests in which there was much scale formation, there was alse an accumulotion of solids around the bottom of the specimen below the salt surfoce (Figs. 4.2.6 ond 4.2.7). This material contained ZrO,, as determined by petrog- raphic examination, possibly as a resuit of iron or chromium oxides dropping into the sclt from the gos phase, POROSITY AND DENSITY OF NoF M. R. Bennett G. |. Cathers R. L. Jolley - Porosity values were colculated from density measurements on three lots of NaF cbtcined from The Harshaw Chemical Co. No significant dif- ferences were found among the three lots, one of which wos 12-20 mesh materiol to be used in the pilot plant and the others were }‘é-in. pellets. Particle, bed, ond over-all porosities of 48, 33, and 65%, respectively, were found for the 12-20 mesh granular material. A crystalline type of NoF obtained from Allied Chemical & Dye Corp. was observed to be much denser, heving an over-all porosity of 35 instead of 65%. The over-ctl porosity is defined os the percentage of totel void space (bed voids plus particle voids} in o bed of the material, The porosities were colculated from deferminations of the bulk densities and the porticle densities as given in Table 4.2.2, along with the use of the crystolline or x-ray density of 2.79 g/Cma. Weight-volume and dis- placement methods of meosuring density were used in determining both the butk and the particle densities of the .'ré-in. pellet material. Mercury displacement wos used in finding the porticle density of the 12-20 mesh NeF from Harshaw. 279 ANP PROJECT PROGRESY REPORT ! 3 : 490°C 530° 580° ‘ : -] 810° ! o * g n'i ‘ I-. ‘fi?‘ 3 J v NICKEL INCONEL TYPE 316 TYPE 347 STAINLESS STEEL STAINLESS STEEL i T ! Z 3 . 0ax RIDGE NATIONAL LABORATORY | UHCL ASSIFIED PHOTS 19470 SALT LINE ,8650°C Fig. 4.2.7. Speclmens That Were Partly Immersed for 16 hr in NoF-ZrF -UF , Through Which Nitrogen Was Being Bubkhled, Toble 4,2.2. Results of Density Detarminotions on Several Lots of NaF Farticle Density (gfl:m3} Bulk Density Materiol Weight-¥olume Displocement (gj,.-cm3) Method Method The Hershaw Chemicol Co. %-in. pellets, batch 2 1.47 .48 0.94 Y-in. pellers, batch 4 1.49 1.47 12-20 mesh pilot plont moteriol 1.45 0.97 Allied Chemical & Dye Cerp. 20-40 moesh material, bateh 2955 2,62 1.81 280 The benzene displacement methed had to be used with the finer Allied material. The weight-volume and displacement methods gave resylts that were in close agreement. It is onticipated that the porosity data will be useful in interpreting the heat «nd material transfer problems associated with the absorption-desorption process. RUTHENIUM DECONTAMINATION M. R. Bennett . |. Cathers R. L. Joiley An experiment was conducted to fest whether the plating out of ruthenium on metal surfaces could be used to achieve odditional decontam- ination in the wolatility process. The column used for the experiment consisted of a 12-in. length of 1-in.-0OD nickel tubing fitled with 192 g of %z-in.«OD 30-gage nickel Fenske packing with o total area of 0.36 m?. This column was placed between the second NaF bed and the UF celd trap and was held at 120°C. It was vused for about 130 min in o desorption run, and it was PERIOD ENDING MARCH 21, 1957 not particularly effective in removing activity from the UF, product coliected. The decontam- inaticn factor, calculated on the basis of the activities found in the nicke! column ond in the final product, was only 1.6. The activity in the nickel packing was removed with an alkaline- tartrate-péroxide solution, and the effectiveness of this method has not been fully evaluated. About 0.025% of the processed uronivm was found in the nickel trap. The low ruthenium decontamination in the nickel trap is perhaps not too surprising in view of the small amount of activity involved and the small surface area used. The product contoined only 28 ruthenium gamma counts per minute per mil- ligram of vrantum. The activity removed by the nickel was calculated to be 200 counts per minute per square centimeter of nickel surface. It is anticipated that the removal of ruthenium with a nickel ¢olumn moy be made more effective by using a greafer surface area or by operating at a higher temperature. 281 Part 5 CRITICAL EXPERIMENTS AND REACTOR SHIELDING E. P. Blizard 5.1. CRITICAL EXPERIMENTS A. D. Caillihan REFLECTOR-MODERATED REACTOR EXPERIMENTS AT HIGH TEMFERATURES The significant results of the experiment are as follows: Critical concentration D. Scott E. Demski' R. E. Malenfant W quer'l At 1258°F with rod out 10.97 wt % U (5.1 mole % J. J. Lynn D. A. Harvey' . UF,) W. C. Tunnell E. V. Sandin At 1259 F with rod in- 12.20 wt % U W G Aiwungl sarted te midplane Rod value with red in- $2.47 The measurements of some of the nuclear charac- teristics of the circuloting-fuel reflector-moderated reactor under study by Pratt & Whitney Aircraft were completed. The ossembly consisted of o cylindrical beryllium central section or ‘‘island"” surrounded by an anaular fuel region, which was enclosed in o reflector of beryllium. Shells of Hastelloy X separated the fuel from the beryllium, Control and safety of the experiment were effected by a rod which could be positioned along the axis of the island. The neuvtron-acbsorbing section of the rod c¢ontoined a mixture of 30% rare-earth oxides (somarium ond gadolinium) and 70% nickel. The reoctor section of the assembly, which was described in detail in an earlier report,? was mounted, with its oxis vertical, above o sank in which the molten mixture of sodium, zirconium, and uranium flyorides was stored. The liquid could be roised into the reactor by pressurized helium. The equipment was operated ot tempera- tures neor 1250°F. ln the experimental procedure followed, the system was first filled with NaoF-ZrF, (50-50 mele %) to which increments of NGF‘UF“ {66.7- 33.3 mole %, contoining uranium enriched to 93.2% U23%) were added until the system became criticol. The concentration was further increased stepwise as the control rod was inserted to the midplane. The value of the rod over the upper hal of its travel (Fig. 5.1.1} was determined from period measurements and the inhour equation. The temperature coefficient of reactivity over the range 1200 te 1350°F was linear, within the precision of the medasurements. ]On assignment from Pratt & Whitney Aircroft. 2D, Seott ei al, ANP Duan Prog. Rep. Sept 10, 1956, ORNL-2157, p 264. serted to midplane Temperature coefficient in ronge 1200 1o 1350°F (based on a delayed neutron fraction B = 0.0073) —0.47 ¢/°F, =3.6 x 10~ (A R/E)/CF A similar experiment was performed in 1955 with the ART core.? The critical concentration ob- served then with the rod removed was 6.30 wt % U (2.87 mole % UF4} and the tempercture ccefficient at about 1250°F was ~2.3 x 10—° (Ak/k}/°F. A, D. Collihan et al., ANP Quar. Prog. Rep. Sepr. 16, 1955, ORNL-1947, p 58; ANP Quar. Prog., Rep. Dec. 10, 1955, ORNL-2012, p 71. e ORNL-LR-OWG 20263 250 : | / 7 f = g 150 | - { . S | L ? = =[ : ‘ g o 2 g = =g I&J'IOOl - —— | i 1 | ;/’ ‘ /| i 0 | o 8 10 t5 20 25 ROD POSITION, MEASURED FROM TOR QF ISLAND BERYLLIUM fin) Fig. 5.1.1. Effectiveness of the Contral Rod in the Pratt & Whitney High-Temperature Reflector-Moderated- Reacter Critical Assembly. 285 ANP PRDJIECT PROGRESY REPORT 5.2. SHIELDING THEORY SUMMARY OF MONTE CARLO CALCULATIONS OF GAMMA-RAY PENETRATION IN MULTIREGION SHIELDS WITH SLAB GEOMETRY S, Auslender! A. T, Futterer' Some of the calculations of gamma-ray shield penetration thot were performed with the use of an Oracle cede based on Monte Corle techniques have been published at intervals? during the past year. A topicel report is now being prepored which will describe the Oracle code used for these calcula- tions.2 In addition, the results of all the colcula- tions are being collected in o separate repert con- sisting of several volumes.? Since the results are especially opplicoble to the ANP program, o summary of the various types of problems is pre- sented here, along with corresponding references to the data. The summary {(Table 5.2.1} designates the ma- terials, thicknesses, gamma-ray energies, and ongles of incidence investigated. For oll the problems the information obrained directly fram the machine calculetions includes dose rate, energy flux, and energy deposition; for some problems it olso includes energy spectra. Dose- oand energy- buildUp “factors, as well as heating in the shield, may be computed directly from the infermation, and in some cases they have been, of dum!“ comparisons of the shield atfenuctions are also made. Two studies, which have been designated the CE137 and COB&0O carried out to determine the penetration of Cs In the compilation respectively, were 137 series, on assignment from Pratt & Whitney Aircroft, 25. Auslender, ANP Quar. Prog. Rep. March 10, 1956, ORNL-2061, p 223; Juwe [0, 1956, ORNL-2106, p 266; Sept. 10, 1956, ORNL-2157, p 271; see olso 5. Auslender, Appl. Nuc. Phys. Ann. Rep. Sept 10, 1956, ORNL-2081, ¢ 180; see olse 5. Ausiender, A Monte Carlo Study of the Gamma-Ray Ernergy Flux, Dose Rate, and Buildup Factors in a Lead-Water Slab Shield of Finite Thickness, ORNL-2194 (lan. 10, 1957). 3. Auslender, Instructions for the Operation of an Oracle Code for a Monte Carle Solution of the Transport Problem for Gamma Rays [ncident Upon a Slab, ORNL CF-57-6-1 (1o be published). S, Auslender, Compilation of Monie Carlo Calcula- tions of Gamma-Ray Penetration in Multiregion Shields with Slab Geometry, ORNL-2310 (tc be published). 286 and Co®® gamma rays through slabs of polyethylene and lead. The primary purpose of these calcyla- tions wos to establish the volidity of the calcula- tional method by comparing calculated results with The porticular experiment chosen was performed by the National The results were in good results obtained in an experiment. Bureay of Standords.® agreement. Ancther calculation, designated the FAB series, was performed to determine the effect of the extent of lamination in a shield consisting of a total of 16 ¢m of water and 4 cm of lead. The materials were subdivided and alternated {2 to 16 regions) to mock up the progression toward a homogenecus shield. In another group of problems, the DO2C5S series, the effect of chonging the relotive amounts of lead ond water in a two-region shield that had o con- stant mean free path thickness was investigated. In this case no transmitted or reflected energy spectra are avoilable, as yet. Two sets of problems identified as the AD and the AB series, respectively, represent an exten- sive study of shields consisting of 7, 14, ond 21 cm of water with and without a 0.1-in.-thick lead hacking. seven gamma-ray energies and seven incident angles. Inifial histories range from 1000 to 2500 for incident angles less than 60 deg. For greater angles the number of histories ranged from 400 to 800 10 avoid excessive machine time. In o]l cases a doubling technique was used which tends to maintain an even populotion throughout the shield. In this way statistics were obtained near the finol boundory for which excessively lorge histories would have been required if this tech- nique had not been used. The trensmitted and reflacted energy spectra from this study have been stored in o systematic order on magnetic tope and are available for calculations. The energy spectra give the fraction of the incident energy which may be expected within each of 120 energy—solid angle intervals (that is 10 epergy by 12 angular inter- vals) for both the reflected and the transmitted energy of each of the 294 cases. Caoleulations were performed for initiel SE. S, Kirn, R. J. Kennedy, and H. 0. Wycksff, Radiology 63, 94-104 (1954), 187 Table 5.2.1, Summary ond Index of Monte Carle Caolculatiens of Gammae-Ray Penetration in Multireglon Shields with Slab Geometry Gammae-Ray Energy 0, Angle of Gammo-Ray Series Shield (Mev) Incidence (deg) References CE137 (for Cs'37)4 0,2,5, 9, or 14 in. polyethylens 0.661 0 ORNL-2310 +0,0.25, or 0.5 in. Pb COB6D (for Co®?) 0, 2, 5. 9, or 14 in. polyethylene 1.25 6 ORNL-2310 +0, 0.25 or 0.5 in. Pb FABb 16 em HZD + 4 ecmPh (8 em H,0 + 2 cm Pb) x 2 (4 cm H,0 + 1 cm Pb) x 4 (2 em Hy0 =0.5 em Pb) x8 1.0, 3.0, 8.0 0 ORNL-2310 4 cm Pb 4 16 em HQU (2 em Pb +8 cm H,0) x 2 (1 em Pb+ 4 cm H20] ® 4 {0.5 cin Pb+ 2¢m H,0) %8 DO2CS5 1 mfp Phb ORNL-2061, p 223; 0.75 mip Pb + 0.25 mip H,O 0, 60, 70.5, 75.5 ORNL-2081, p 180; 0.5 mfp Pb + 0.5 mfp H,0 1.0, 3.0 (sec O=1, 2, 3, 4) ORNL-2310 0.25 mtp Pb +0.75 mip H20 1 mfp HQD 0.75 mfp H,0 +0.25 mfp Pb 0, 60, 70.5, 75.5 ORNL-2061, p 223; 0.5 mfp H,0 + 0.5 mip Pb 1.0, 3.0 (sec 0=1,2,3, 4 ORNL-2330 0.25 mfp H,0 +0.75 mfp Pb 2 mfp Ph 1.5 mfp Pb + 0.5 mfp H,0 0, 60, 70.5, 75.5 1 mfp Pb + 1 mp H,0 1.0 (sec =1, 2, 3, 4) ORNL-2310 0.5 mip Pb + 1.5 mfp H,C 2mfp H,0 ORNL-2061, p 223; 1.5 I'I"I'FP HZD +0.5 I'I'IFP Pk 0 D, 60, ?0-5, ?5-5 0RNL'20813 P 130, 1.0 mip H)0 + 1.0 mép Pb I (sec B=1, 2, 3, 4) ORNL-2310 0.5 mip HEO + 1.5 mfp Pb 8 mip Pb & mfp Pb + 2 mip B,0 0, 60, 70.5 orNL 4 mfp Pb + 4 mfp Hy0 3.0 {sec 6=1, 2, 3) NL-2310 2 mfp Pb + &6 mip H,O L6561 “1f HOYVYW ONIONI AQoid3d ZNg "*s' available on machine. ®Constant total shield thickness with layers censecutivel y subdivided and alternotad to mock up progression from a two-region shield to o homogeneous shield. 882 Table 5.2.1 {continued) ' _ Gaomme-Ray Energy 0, Angle of Gamma-Ray Series Shield (Mewv) [ncidence (dag) References AQ 7,14, or 21 cm HIO 0.5, 1.0, 2.0, 3.9, 0, 20, 40, 60, 70, QORNL-2310 4.0, 6.0, B.0 80, 85 AB 7, 14, or 21 cm H,0 + 0.1 in. Pb 0.5, 1.0, 2.0, 3.0, 0, 20, 40, 0, 70, ORNL-2310 4.0, 6.0, 8.0 80, 85 B¢ 10,0r 20 in, HQO 1.0, 2.23, 2.70, 4.0, 0, 60, 70 ORML-2310 6.814, 9.0 40 in. H,0 1.0, 2.70, 6.814, 9.0 0, 60, 70 ORNL-2310 2 in. Pb +0, 10, or 20 in. H,0 1.0, 2.70, 4.0, 6.814, 0, 60, 70 ORNL-2310 9.0 2.23 0, &0 ORMNL-231%0 2in. Pb + 40 in, H'ZO 1.0, 2.70, 6.814, 2.0 Q, 60, 70 ORNL-2310 4 in. Pb+ 49, 10, or 20 in. HED 1.0 o ORNL-2310 2.23, 4.0, 6.814, 9.0 0, &0 ORML-2310 2.70 0, 80, 70 ORNL-2310 4 in. Pb +40 in. H,0 1.0 O ORNL-2310 2.7 0, 60, 70 ORNL-231%0 6.814, 2.0 a, &0 ORNL-2310 4 in. Pb +0, 10, or 2D in. Hzo 2.70 0, 60, 70 ORNL-2310 4.0 0 ORNL-2310 6.814, 2.0 0, a0 ORNL-2310 6 in. Pb 4+ 40 in. H,0 2.70 0, &0, 70 ORNL-2310 6.814, 9.0 0, 60 ORNL-2310 Undesignot ed 1158 em Pb + 35.81 cm H20 1.0, 3.0, 6.0 0, &0 ORNL-2157, p 277; ORNL-2081, p 184; ORNL-2194; ORNL-2310 Undesignated 3.79 cm fuel? + 0.976 cm Incone 1.0 0, 45, 40, 70.5, ORNL-2106, p 266; +21.19 em Na + 0.488 cm 75.5 ORNL-2310 Inconel (0.7 mip fuel® + 1.0 mtp Inconel + 1.0 mip Ne + 0.5 mfp Inconel} “This series hod a maximum of 800 histories ond a minimum of 400; a doubling technique was used to improve statistics. Even so, the statistics cre poor for the thickest slabs ot slont penetrations os far as energy spectral dotu are concerned, dNoF-Zer-UF‘s {52.5-42.5-5 mole %). | 1 N + » l¥0d3Y SS5FHD0Ad LI3f0Hd dNV Another set of problems, the B series, is a study of thick lead and woter shields. The energy spectra for this series were also stored systema- tically on magnetic tape. It is to be noted thot the low number of initial histories combined with the large thickness of the shields tends toword PERIOD ENDING MARCH 31, 1957 poor statistics for the energy spectra informetion despite the doubling technique. Two additional problems, one for a fuel-Irconel- sodium-Inconel shield and another for a lead-water shield, were also computed. The fuel mixture studied was NaF-ZrF ,-UF, (52.5-42.5-5 mole %). 289 ANP PROJECT PROGRESS REPORT 5.3. LID TANK SHIELDING FACILITY NEW INSTRUMENT CARRIAGE AT THE LTSF W, Zobel The necessity of toking progressively more pre- cise data ot the Lid Tank Shielding Facility (LTSF) made it obvious thot one of the uncertainties which had to be eliminated was that associated with the location of the detectors, While the position of a detector in the tank could be reproduced to within about £2 mm, the absolute position was open to doubt within about +5 mm, It was therefore de- cided to replace the detector holder and positioner. The new equipment was required to be more rigid than the old so that the absolute position and the indicated position would always coincide, and it had to hove an inherent accuracy of about £0.5 mm. The system (Fig. 5.3.1} which wos adopted is very similar te that in use at the Tower Shielding Focility (TSF). This system provides for remote contrel of the carriage from the control room and thereby greotly increases the ease of operation, The new instrument carriage has been installed and is now in use. |t appears to give very satis- factory service, and it is expected that the con- fidence level of future data taken at the LTSF will be increased. The detector carriage is driven in the y-direction by two ball-bearing lead screws which, however, do not support the carriage. Thus greater accuracy and longer life can be obtained. The use of the ball-bearing nut eliminstes backlash. The load is carried on the channet base, which con be made as strong as required, A guide rail ¢n one side assures that the carriage will run true, In the z-direction the load is supported by two large shafts, which also serve as guides. The drive is ogain provided by a ball-bearing lead screw. The drive in the x-direction is of the rack-and- pinion type, with the rack cut info the vertical drive shoft, This is o large tube ond was chosen to provide sutficient rigidity for the holder. Contrel of the drive motors in the three directions is manual at present. The position of the detector suppert, located at the end of the vertical shaft, is indicated at three panels in the control room, Two indicators are provided for each direction. One is a dial for coarse control, driven by a torque transmitter system geared to the drive motor; the other is a fine control, indicated by an Amerac 290 dial, which uses a selsyn system to drive the dial by the usuel null technique., The indication of the fine control is to the necrest millimeter, with interpolation on the dial to 0.5 mm eosily possible. Provision has been made to permit later conversion of the conirols to a closed-loop system by which the desired position on the detector con be selected and the corrioge will then “‘hunt’’ until it reaches that location. Provision is also made for future installation of ¢ readout system for use with an isodose plotter, Preliminory tests showed that the instrument carrioge, as finally constructed does not deviate from a given plane by more than 0.006 in. over the full range of the water tank at the LTSF. This indicates that the aobsolute position of an instru- ment can be determined to at least +5.5 mm and is, at present, limited by the accuracy with which the indicators can be read. It is {elt, however, that +0.5 mm is sufficiently accurate for the purpose, and therefore no changes are contemploted, INVESTIGATION OF THE FHYSICAL PROPERTIES OF LITHIUM BOROHYDR IDE - AMMONIA UHDER SUBCONTRACT NO. 390 E. A, Sullivan S. Johnson Metal Hydrides, Inc. One of the materiats which has been suggested as a neutron shield for a mobile reactor is lithium borohydride, This relatively new compound is particularly attractive because it contains 18.5wt % hydrogen, which is the most efficient lightweight neutron abseorber known, as well as lithivm and boron, both of which suppress secondary gommo radiation arising from neutron capture by the shield material, in oddition to being good neutron ab- sorbers, Lithium borohydride is a white crystalline selid which is stable to its melting point of 275°C and has essenticlly no vapor pressure even of this elevated temperature, In on attempt to achieve a liquid shield which could be cooled externally and would avoid difficult fabrication problems, empha- sis has been cltered to consider shield components utilizing this compound in combination with an ingxpensive diluent that would not change fhe Ammonia, which contains 17.8 wt % hydrogen, is ideclly suited for this purpose. shielding properties appreciably, Since the physical properties of (62 UNCLASSIFIED ol QRHL-LA-DWEG 2379 "XTAXIS DRWE SHAFT —- Ty "r™AXIS DRIVE 80X - - ZANIS GUIDE AND LOAD | CARRYING SHAFTS r-a%IS COORDINATE BO)CT W' COORDINATE and DRIVE BOX P - THIS SIOE FACES REACTOR WaLL "WAXIS DRIVE PINION MATING WITH RACK IN "¥'LAXIS DRIVE SHAFT - "FAXIS LEAD SCREW "Z'-a%iS LEAD SCREW — "F-p0s ORIVE BOX —— e ADDITIONAL "ZAXIS LOAD CARRYING MEMBERS “Z"-AXIS COORDINATE BOX e "YUAxIS LEAD SCREW MUT - 11\\ “Plaxi§ LEAD SCREW -~ — - CHARNEL BASE HORIZONMTALLY ~MOUNTED Y-85 LOAD CARRYING RAIL: PCIIRRER "r'2xi% GUIDE RAIL - ——k Fig. 5.3.1. New LT5F Detector Carrioge. £S61 “1E HOXYYW ONIGNI 00CI¥3d ANP PROJECY PROGRESS REPORT shield materials must also be known, an investi- gation hos been carried out to determine the equi- librium vopor pressure, the thermal stability, and the density of varicus lithium borohydride ammoni- ates. The results of the investigetion have been reported in detail! ond ore summarized below. Pressure-Temperature-Compos ition Relationships The ammonia vapor pressure in eqguilibrium with mixtures of lithium berchydride and ammonia was determined os ¢ function of concentration ond of temperature, The lithium borohydride mole frac- tions used ranged from 1.0 to slightly less than 0.2 in the temperature range O to B0°C. Lithium borohydride forms four stable adducts with gmmenia: lithium borohydride monoammonicte, LiBHd-NHB, which has a melting point of 56.5°C; lithivm boro- hydride diammoniate, LiBH .2NH,, which melts ot 17.0°C; lithium borchydride trismmoniate, LiBH ,-3NH,, which displays an incongruent melting point ot 32.5°C; and lithium borohydride tetroammoniate, LiBHd-dNH}. which melts ot approximately 68°C, The phase diagram in this temperature ronge has been constructed from the experimental dato, The behavior of lithium borohydride —ammonia adducts is such that two eutectic compositions, LiBH . 1.?5NH3 ond LiBH ,-2.35NH,, ore completely liquid abave 13°C, A solid solution of the ftri- ammoniate in the tetraammoniate was found to exist which is stoble vp to the melting point of the tetracmmoniate. The ammonio pressure can readily be calculated for gny temperoture and composition from eguations of the type A log P{mm Hg) = —-—?:1- B . In studying the lithium borohydride —ammonia system, it was found that an interaction occurred to a smaoll extent between the components, which This ammonolysis reoction was studied briefiy in the temperature range of 30 to 100°C, and it was found that the rate of ammonoclysis of fithium boro- hydride: (1} decreases with time, {2) increases gave, as a byproduct, gaseous hydrogen. ]Eu A. Sullivon and 5. Jdohnason, The Lithium Doro- hydride—Ammonia System, Part |, Pressure-Temperature- Composition Relationships. Part I, Density Relation- ships, Metal Hydrides, Inc., report identified as CF-57-2-134 ot ORNL (Feb. 12, 1957). 972 with temperoture, (3) decreases with increosing ammonia concentration {and is essentially consiant beyond an ammonia-to-lithium borohydride mole ratio of 2:1), (4) is approximately on exponential function of composition at a given temperatue, and (5) is approximately on exponential function of reciprocal temperature ot o given composition, Where necessary {0t temperatures >40°C), small corrections were made in the equilibrium data to account for the effect of cmmoneolysis on the com- position of the somples. When precautions were taken, this reaction did not interfere with equilib- rivm measurements, Density Relationships The densities of liquid lithivm borohydride ammoniates were determined as a function of both composition and femperature. Five ceonditions between LiBH ,+1.06NH,; and LiBH .2.74NH , were studied. The temperature range in which each compaosition wos studied depended on the liguidus temperature at the given composition and on the vapor pressure encounterad, Two of the composi- tiens studied, Li|:.‘>H4~'f.7"3NH3 and LiBH4-2.36NH3, correspond to the ewtectics on either side of the diemmonigte of lithium borohydride. These com- positions hove the lowest liquidus temperatures in the entire phase diagram, both ot 15°C, and therefore have the longest temperature ronges for the liquid state. la generol, the study encompassed temperature ranges between 15 and 85°C. The density for o given composition was found to be a linear function of temperature, os expected, and the experimentally determined equeotions are, where ¢ is in °C: (1) LiBH +1.06NH,: (2) LiBH - 1.73NH,: (3) LiBH,+2.04NH: d,=0.651 - (2.537 x 10~ d,=0.663 — (3.683x 10~*): d,=0.675 - (4.664 x 10~*); {4y LiBH,«2.36NH,: 4, =0.676 - (4.201 x 10~4); (5) LiBH+2.74NH: o, = 0.684 — (4.427 x 10~ *) With the exception of L]BH4-2.04NH3, a simple relationship was found to exist between the com- poesition and both the slope and intercept of the density equations. The following empirical equa- tions were found to relate these foctors: (6) Inteccept = 0.629 + 0.020(c, . ) where ¢, o is the composition expressed as the mole ratio of ammonia to lithium borchydride and (7) Slope = —1.97 x 10~* + 8.80 x 10-4(NHH3} where 1"‘«',.”43 is the composition expressed as mole fraction of ammonia. From Eqs. 6 ond 7, the constants for density equations were calculated which cover the entire liquid range. SURVEY OF SHIELDING MATERIALS UNDER SUBCOMNTRACT MO, 931 R. Arcnson K. Held Technical Research Group A recent survey of shielding moterials confirms that lithium hydride and polyethylene are the mast effective neutron shields known to dote. Lithium hydride is by for the best solid shield material in curved geometries. The use of Li®H is expected to lead to a further weight savings of approximately 12%. Lithium hydride is the only lightweight neu- tron shield material which can be used in the range of 700 to 1200°F without developing high pressure or decomposing. This is the range of temperafure which may be expected in some parts of the direct- cycle recctor shield. Neutron shield moterials for use at temperatures above 2000°F may be required for the direct-cycle reacter, Reoctor outlet air at PERIOD ENDING MARCH 31, 1957 o temperature of 1850°F is used to cool the neutron shield at the rear foce., Here the requirement is so severe that the problem is one of obtaining ma- terials that will withstand the high temperature, rather than a minimum weight problem. M a liquid is required because of the need for shield augmen- tation or some other reason, cne of the substituted organic compounds 2 must be used. Polyethylene of high density (>0.95 g/cm?) and of high strength is now available. Some analyses of wvarious crew shield designs indicate the very fow requirement for additionol structural support for a lead-polyethylene shield, Other materials including wverious lithium hydride—polyethylene mixtures are under consideration, The high-density materials required for the re- actor gamma-ray shield still center around lead, bismuth, tungsten, uranium, etc. Possible appli- cation of hydrides, borides, etc., of these elements await clarificotion of the secondory gammo-ray picture, Contact has been maintained with Metal Hydrides, Inc., on their studies on the lithium borohydride— ammonia system, 2Ff.:)r example, boran or lithium substituted into the organic molecule, 293 ANP PROJECT PROGRESS REPORT 5.4. TOWER SHIELDING REACTOR Il C. E. Clifford As was stated previously,! a reoctor which will have a higher and mere uniform fast-neutron and gamma-ray leakage flux than that ovailoble with the present Tower Shielding Reccter is needed for future aircraft shielding experimentation. To fill these requirements a 5-Mw solid-fuel Tower Shielding Reactor |l {TSR-11} has been propesed which will be spherical in shape. The TSR-Il will be controlled by umbrella-shaped beoron-looded plates located in an interna!l water reflector, in which position they will give a minimum perturba- tion to the reactor leckage flux, In order to establish the dimensions of a core configuration that would fit the requirements of the reactor, the following calculational procedures were followed. A nuclear parometer study was carried out first to determine the critical moss and control available for various core sizes, internal woter reflector thicknesses, and aluminum- to-woter volume ratios. From this study o configu- ration was selected which appeared to be the optimum configuration from the viewpoint of critical mass ond small reactor diameter. This configuration was then examined to ensure thot the surface density of the U239 in the fuel plates would be betow 0.0283 g/cm?, a density which was estab- lished during operating experience with the MTR.? Finally the configuration was exomined to deter- mine whether the waoter flow available fo remove the heot from the core was sufficient to prevent local boiling. The results of these tests are presented below, NUCLEAR PARAMETER STUDY Colculations,? for which the three-group, three- region recctor code (the 3G3R code) wos used as a two-group, three-region (2G3R) code, were per- formed on the Oracle to determine the critical mass and control ovailable in reactor configurations lsee, far exomple, C. E, Clifford ond L. B. Helland, ANP Quar, Prog. Rep. Dec. 31, 1956, ORNL-2221, p 352, 2R.‘ 4. Beover, ORNL Metaliurgy Division, private communication, ¥ These colcutations were performed by M. E. La¥erne; pravious calculations by E. G. Silver were helpful in setting up the present problems, see Appl Nuc. Phys. Ann. Rep. Sept. 10, 1956, ORNL-2081, p 47. 294 L. B, Holland having internal water reflector diameters of 32, 40, and 50 cm and core thicknesses of 18, 20, ond 25 cm. The oluminum-to-water volume ratios in the cores ranged from 0,250 1o 2.000. All possible reflector-core combinations were investigated for eoch oluminum-to-water ratio. For the calculations the external water reflector was considered to be 20 cm of woter rather than the lead-water combi- nation that is proposed for the actual reactor. A sketch of the geometry used in the calculation is shown in Fig. 5.4.1, ond socme of the constants are presented in Toble 5.4.1, Calculations were made first to determine the effective multiplication factor for severcl concen- trations of U233 in the fuel plates. Typical results for one geometry ond all aluminum-to-woter volume ratios are shown in Fig. 5.4.2, Earlier calculetions for this reacter showed that 4% excess reactivity would be necessary to compensate for temperature rise, xenon poisoning, and burnup ond to provide 1% for control. The concentration that gave an excess reactivity of 4% in a perticulor configuration was used to compute the mass of U233 that would be required for thot canfiguration. In Figs. 5.4.3 through 5.4.5 the critical mass is shown as o function of internal reflector radius for voricus aluminum-to-woter volume rotios and oll As expected, the smaliest internol reflector and lowest aluminum- fo-water voelume rotio will give the minimum critical mass. core geometries considered. The omount of excess reactivity that it is pos- sible to control for the various gecmetries was determined next. This calculction was performed in o stroightforward manner (os provided in the 3GIR Orocle code) by the insertion of a boron- loaded sheil between the internal reflector and the core region. The results shown in Fig. 5.4.6 are for a very light loading of boron in the shell (0.0022 gz”cmE). Unfortunately, time did not permit o more involved calculation for o heavier boron shell; nowever, volyes for heavier boron concen- trotions will be obtained in later calculations ond experiments, Although it is possible to obtain a larger amount of control by using higher aluminum- to-water velume rotios ond larger internal reflector regions, the greatest ingrease in control is reclized DIME NSIONS A 16,20 OR 25cm 8 16,20 OR 25cm L 20cm WATER FLOW PERIOD ENDING MARCH 11, 1957 UNCLASSIFIED owe 2-04-080-F LOCATION OF CYLINDRICAL TUBE IN 4CTuaL REACTOR IMNTERNAL WATER REFLECTOR MOVABLE BORAL SHELL CORE REGION (WalER PLUS URANIUM - ALUMINUM FUEL PLATES) EXTERNAL WATER REFLECTOR Fig. 5.4.1, Vaerticol Section of Reactor Core Mode! Used in Nuclear Parameter Study for TSR-1L. Taoble 5.4.1. Muclear Poromeaters Used with the 3G3R Orocle Code far Caleulations of the Critical Mo=sz of the T5R-1l with an Aluminum-to-Water ¥Yolume Ratio of 0.707 Crass Section* Region za f Internal reflector 0 Core 0 External reflactor 0 0.01535 + 0.4712702 / 5 Transfar Cross Sic:iflfi** Temperufure (em™ ) (%C) 3 3 x!, Wi 0.0361 0 50 0,0210 0 60 0.0361 0 20 *Volues of Ea obtoined from BNL.325, Neutron Cross Sections, by D, J. Hughes ond J, A, Harvey (July 1, 1955), with correction applied for {1} non-1/v behovior, (2) Maxwellion distribution of neutron speeds, ond {3) temperature effect on density. **Values of D, D‘sJ Ex ., and E.x taken from 100-18133, Reactivity Effect of Reducing the AI/H20 Ratio in the / 5 MTR Core, by J, W, Webster {Oct. 26, 1953). 295 ANP PROJECT PROGRESS REPORT by decreasing the thickness of the core region. This is fortunate since the thinner core region also reduces the heat transfer problem. A calculotion performed to determine the amount of separotion required between the fuel and the control plates fo reduce the effect of the control plates sufficiently to permit operation of the re- acter involved o more subtle use of the 3G3R code. In this cose it wos necessary to artificially maintain the neutron flux and current at the outer water reflector ond core boundary so that the internal reflector could be divided into two regions with a boron shell between them, the core making the third region. |t was then possible 1o vary the thickness of the water regions in the internal reflector ond effectively simylate movement of the The calculation was mode for only ratios, 1.0 ond The resvlts plotted in control plates, two aluminum-te-water volume 0.707, and one geometry, UNCLASSIFIED 2--06a0-~-8 1.o| - _— — | L:EGMETHY rNTERN.flL REFLECTOR RADIUS = 20cm _ CORE THICKNESS = 16 ¢m . ' EXTERNAL REFLECTOR = | "‘HICKNESS 20crn 15 s —— —_ | sz e {VU’T’:‘NOD . ! { d | Moo= ATOMS OF U?* PER cc |~ v=NEUTRONS PER FISSION| oy = MICROSCOPIC FISSION | 7 ceosg gECTIDN ;J.’ o 2 n v%, (PROPORTIONAL TO UZ3S DENSITY) (o] 0.02 |- ' | 0.0 | = A | D6 .7 0.8 09 1.0 1.1 12 13 A, EFFECTIVE MULTIPLICATION FACTOR Fig. 5.4.2, Effective Multiplicotion Foctor in the 2345 T5R-I! o0s o Function of the U Concentration for Yartous Aluminem-to-Water Volyme Ratios. Reoctor geometry: 40-cm-dio internal reflector, 16-cm-thick core, 20-em-thick externol water reflector. 296 Fig. 5.4.7 show that no more than 2.5 in. (~6.5 cm) of travel will be required to reduce the control plase effectiveness to 0.1 of its full value. The results of an earlier experiment of the Bulk Shielding Facility (BSF) recctor, which hos on aluminum- to-water ratio of 0.7, normalized to the colculoted value for the TSR-Il are also shown in Fig. 5.4.7. The change in reactivity of the BSF reactor was observed as o cadmium rod was moved laterally away from the BSF reactor. The fact that the experimental curve is steeper thaa the calculoted curve shows that the use of the calculoted volues in the design is conservotive, Although the information was not required to establish the dimensions of the TSR-II, the effect ot the control plates on the fast- and thermal- UNCLASSIFIED 2=0i=—080=9 7 . . i — ——— CALCULATED VALUES —_— |NTEHP0LMED vm_uasf shomaan £ &y ,f 16 - — CRITICAL MASS (kg} i2 ig 20 24 28 INTERNAL REFLECTOR RADIUS {cm) Fig. 5.4.3. Critical Moss in the T3R-1l as 0 Function of the Internal Water Reflector Rodius for Various Aluminum-to-Water Volume Rotios. Reoctor geometry: 14-cm-thick core, 20-cm-thick external water reflector. UMCLASSIFIED 2—0i—060=10 (5 gk —— CALCULATED ——— INTERPOLATED /s {4 l— -~—t i . i | CRITICAL MASS [kg) 12 28 INTERNAL REFLECTOR RADIUS (em) Fig. 5.4.4. Critical Moss in the TSR-H! o5 0o Functlon of the Alyminum-to-¥arer Volume Ratios. Internal Woter Reflector Rodivs for Yorigus Recctor gaometry: 20-cm-thick core, 20-em-thick external water reflector. neutron flux throughout the reactor was also colcu- lated as shown in Fig. 5.4.8. Cases & and ¢ show the effect on the flux of having the boral shell adjocent fo the core or 5 cm from the core, respec- tively. Cose a represents the same geometry shown in cose & end is included oaly to show the validity of the method used, that is, leaving off the external water reflector region and artificially maintaining the neutren flux ot the outer core boundary. The effect of the boral shell position on the fast- and thermol-neutron leckoge from the TSR-Il for two aluminum-to-woter volume ratios, 0,707 and 1,000, is shown in Table 5.4.2. ln this calculation the internol water retlector was 40 em in diameter, ond the core region and exterpal water retlecior were each 20 ¢m thick, Chonging the PERIOD ENDING MARCH 31, 1957 UNCLASSIFIED 2—0!—060—” 16 . | : — 2 | 15 T — | e T A 4| - %I_Vi —— CALCULATED / ——— INTERPGLATED /7 / B A R g CRITICAL MASS (kg) iz 16 20 24 28 INTERNAL REFLECTOR RADIUS {cm) Fig., 5.4.5. Critical Mass In the TSR.1f as a Functlon of the Internal Water Reflector Radius for Various Aluminum-ta-Water Yolume Ratios. Reoctor geometry: 25-cm-thick core, 20-cm-thick externol water raflector. aluminum-to-water volume rotio produces less than 1.5% chenge in the fast-neutron leckage. Over the porobable operating ronge of the contrel plates (3 to 5 cm), the variation in fast-neutron leckage will be less than 1,5%. ' The spoce required to house the proposed controf mechanism and olso allow it to be withdrawn 2.5 in. from the core will necessitote that the internal water reflector be no smaller than 17.5 in. in diameter. With this parameter fixed it was then necessary fo carry out o study to determine the corresponding core parameters which would give a minimum fuel loading. This was done by plotting the critical mass as a function of core thickness for various cluminum-to-water volume rotios (Fig. 5.4.9). As would be expected, the moss decreased with a decrease in the aluminum-to-water volume ratio; however, it does not seem practicoble to go 297 ANP PROJECT PROGRESS REPORT WNCLASSIFIED 2-0-060—-12 AL/ H,0 | VOLUME RATIO= et 2,000 l 50 CORE .-"""'.-'.—. THICKNESS - 1.000 lemy T psit s roiea i B | e e 18 4= --""_’_ -——-— 0500 1000 ~""""* e 707 _fl--' 2.000 REACTIVITY (% A kfk) 20 25 INTERMNAL REFLECTOR RADIUS fem) Fig. 5.4.6. Chonge in Reoctivity Produced in the T5R-H by the Presenca of o Beral Sheli Between the Internal Woter Reflector and the Core as o Function of the Internol Reflector Radius for Varicus Core Thick- nesses and Aluminum-to-Water Yolume Ratios, Externcl UNC LASSIFIED E—H=060-13 10 — = GECQMETRY: INTERNAL REFLECTOR RADIUS = 20cm CORE THICKNESS = 20cm EXTERMNAL REFLECTOR THICK- MESS =20¢m ey | S T | = f = = = 2 gt = 0707 ).. P- } = : - = | 7 . Q| BSR EXPERIMENT, + = | ul = - GADMIUM EXTERNAL 3 - 05 -TOLATTICE, m,’dzn =072 -7 N i P prn iy T s > \_\_\\_ | TSRil ,-:a.l,fHZG-1.t::rc:+=;k 0.2 = — 0.1 — : —— 0 { 2 3 4 5 6 7 DISTARCE BE TWEEN SHELL AND FUEL (em Ha0l Fig. 5.4.7. Change in Reoctivity Produced in the T5R-H by the Presence of o Boral Shell in the Interncl Water Reflector os o Function of the Distance Betweesn the Shell and the Core for Aluminum-~to-Water Volume Ratios of 0.707 ond 1.0. intarnol water reflector, 20-cm-thick core, 20-cm-thick Reacter geometry: 40-em-dig woter reflector thickness: 20 em. externu| water ref'rec!or (ef’f'ective}l. Table 5.4.2, Predlicted Fast- ond Thermol-Neutron Leckage from the TSR-{l for 0,707 ond 1,000 Aluminum=-to-Water Yolume Ratios ond Yerious Core~Boral Shell Seporation Distonces Shall Separation Core—Boral Qisrance (em) Fast-Meutren L aokoge Thermal-Neutron Leakage Ab:H 2 O Ratio = 0.707 M:HQD Ratia = 1.000 0 5 1.0 13 2.0 25 3.0 3:5 4.0 4.5 5.0 No shell A!--.Hzl) Ratio = 0.707 Al:H,O Ratio = 1.000 0.107¢0 0.1083 0.01294 0.01322 0.1064 0.1080 0.012%1 0.01325 0.1057 0.1074 0.01284 0.01318 0.1051 0.1067 0.01276 0.01306 0.1044 0.1060 0.0126% 0.01300 0.1038 0.1053 0.01258 0.01291 0.1033 0.1048 0.01232 0.51285 0.1028 0.1043 0.01247 0.01276 0.1024 0.1038 0.01243 0.0121 0.1020 0.1035 0.01235 0.01267 0.1018 0.1032 0.01235 0.01264 0.1083 0.1120 0.0142 0.0169 298 Lo — = N oORAL | SMELL FAST (RO | FLLx Fig. 5.4.8. Neutron Flux os a Function of the Radial Position in the TSR-I for Yarious Positions of o Boral Shall in the Internal Water Reflector end o 0.707 Alumi- num-to-Water Yolume Ratio. Reactor geometry: 40-cm-dia interncl water reflector, 20-cm-thick core, 20-cm-thick external woter reflector {effactive). below the ratio of 0.7 used in the BSF reactor.? Also, if this ratic is used the standard arrangement of 60-mil-thick fuel plotes separcted by 120 mils of water can be used. Since the amount of control availoble increases with a decrease in core thick- ness, an approximately 1d4-cm core thickness {5.5 in.) appecrs to be the optimum. This thin core, which requires less thon 6.5 kg of U3 for criticality, will alsc be an advantage with respect to the heat removal preblem (see below). The configuration having a 17.5-in.-dia internal woter reflector and 5.5-in.-thick core region wos then examined to ensure that the U233 fyel plate loading would not exceed the 0.0283 g/cm? surface density previously designoted. It wos found thot the maximum loading pessible for this surface density wos 9.5 kg. This allows for an error in the critical mass obtained from the two-group Oracle calculotions to be as high as 45%. The 4In the BS5F reuctor the fuel piute:s und wolar coalant hove on aluminumr-to-water ratic of 0.5; the side plates required to hold the fuel plates raise the owver-all aluminum-ta-woter volume rotico to approximately 0.7. PERIOD ENDING MARCH 31, 1957 UNELASSIFIED 2« OH--060=—1% T2.0 1o - CRITICAL MASS (kg) 8.0 6.0 40l - - = = 10 15 20 25 >0 CORE THICKMNESS (cm) Fig. 5.4.9. Critical Mass in the TSR-ll us a Function of the Core Thickness for a 44.5-cm-dio {17.5-In.-dia) Internal Water Reflector ond Yarious Aluminum-to-Woter ¥olume Rotios. External water reflsctor thickness: 20 cm. critical mass will be calculated agoin with a multigroup, multiregion code in the near future. HEAT REMOVAL STUDY The heat flux from the fuel plates will be approxi- mately 5 x 104 Btu/ft2.hr, To remove this heot o two-pass cooling system hos been proposed. |t wos previously determined® that a 1000-gom flow rate with a 40°F temperature rise of the water over the inlet water temperature would provide sufficient cooling to prevent beiling or excessive fuel plote temperatures in d reactor core with higher alumi- num-to-water volume ratics. It was clso stated that o larger internal reflector ond thinner core region would make conditions even better. The 17.5-in.-dia reflector and 5.5-in.-thick internal SF“. Staver, USAF, private communication, R Dol - core meet these conditions, but the larger water volume dictated by the lower oluminum-to-water ratio i5 somewhat detrimental. It is felt that if turbulent water How could be maintained in each channel, odequate cooling could still be achieved with the 1000-gpm flow rate. Using o log meon flow aoreo ond ossuming equel flow per channel, the Reynolds number was calculated ond found to vary from 11,000 in the inner chennels to 8500 in the outer channel. It appears, therefore, thot sufficient lotitude will exist over which to adjust flow rates to obtain uniform outlet temperatures and still maintain turbuient flow. FUTURE STUDIES Preparations are being made for several develep- ment experiments to further estoblish the TSR-II design. Several control system mockups consisting of sclid stainless steel plotes, perforated stoinless steel plates, or boron-loaded cluminum plates will be tested in a é-in.-square water-filled hole in the center of the BSF reactor. A prototype of the actual control design is olso being constructed for other dynamic tests. In addition, the fuel element drawings are now complete, and a model will be fobricated to establish a heoder arrange- ment tor the cooling system, o " THE AIRCRAFT NUCLEAR PROPULSION PROJEGT AT THE OAK RIDGE NATIONAL LABORATORY aeRIL 0, 19T ANP PROJECT BHEECTOR W, W KIRDAN a0 CODIRECTOR £ A CHOMER AD ASSRTANT IEECTOR & L MILLER &D O WL v ER, SEC, RE¥ PRATT & WHITHEY AIRCHAFT REPORTS E. R 0¥ TXO, ASST, PRO, ENE, ena . ARE e ET«G::?;.D' ADw, AS5 T i:E rY ??;?II.E::S ARF AMECELFT REAMCTOR ERDINEERIMG DOVISH0H § 1. CROMED, (R ECTOR RE A E LIVIMGSTON, SEC. ~FE SLE PR TG RESEARCH ¥ K, JORDAN Ao L WIELER WP ATEERING OO TTER o JDSDAN, CHAIRMAR E P, BLiZARD BOUDSELLE ELVD MSFIAHT TO GIRECT R R % CARLSM TH ?&GOEEE GEREARCH MASDTIATE . FRAAL W K. ERGIM ARE CRIES EXPRRMENTAL ENGINEEFIHE H_ % SavAGE ARE POwER PLAMT EnGMEEE MG h P OFRALS ARE AT ERTA TP AMD COMT ALY R, MANM i ERCIMEE RIMG DERCH E.J. 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A& RAMEICE ARE 5. 4 DECAMP ARE k. F_BAILEY, LRIVERSITY OF TENWESSEE €. G. HEMLEY ARE R, &, DREISIACH Fua A H, FOY, UMION (OLL EGE LW WINGSLEY MRE R P SHIEL DS” u 1. FRENCH, UNWVERSITT OF TEANESSEE 1 R LOVE &RE L LISTGR, PURAJE UMFYERMTY 6.C wmiLis ARE ENGIHE ERING SERVICES W, LOWEN, UMION COLLEGE 8. H, AHIGOME RY ARE PL . MASWELL UNIVERSITY OF TENNESSEE 0 G FEMH ARE e msv SEC :EE PM mnc'.:.:fm LMIVERETY OF $0UTH :. :Erocm.mn ::;’. F. W LIl SEC. RE CARDL TLaGy & 2. W, FRUNMEL., STATE LHIVERST Y OF 10%A F. . CHnFER ARE j ;' EVANSE -'«;E W K. STAMR UMVERSITY OF TENHESSEE . A, suGarT ARE T. v MAYES ARE J.o B WEST, RLAHCMA AR Y COLLEGE o E :':;:JELL fizi 5 B ASHTOM ARE G l::bn'lm:EEms. P ERHETLYANIA STATE E: TALLiCE :RE € WAETEMS ARE LLEG 8. ¢ wILLIAMS ARE oW, il Som ARE THE AIRGRAFT NUCLEAR PROPULSION PROJEGT THE OAK RIDGE NATIONAL LABORATORY APRIL 1, 1957 SUPPORTING RESEARCH w. H. JORDAN A, J. MILLER RESEARCH ASSOCIATE W. K. ERGEN ARE STAFF ASSISTANT STAFF ASSISTAMT STAFF ASSISTANT STAFF ASSISTANT STAFF ASSISTANT E. P. BLIZARD AP w. R. GRIMES C W. D, MANLY M G, W. KEILHOLTZ 55 R. B. LINDAUER cT APPLIED HUCLEAR PHYSICS . P BLIZARD® AP R. RICKMAN,* SEC. AP CHEMISTRY ANALYTICAL CHEMISTRY HMETALLURGY CERAMICS RESEARCH RADIATION DAMAGE FUEL REPROCESSING L. 8- ABBOTT AP W, R, GRIMES c 4. C. WHITE AC W. D, MANLY*® W L. M. DONEY M G. W. KEILHOLTZ 3 R. B. LINDAUER" cT D. E. CALDWELL, SEC. ¢ E. M. ZARZECK], SEC. AC T. HKIDO USAF C. A. PRDAPS, SEC 55 3. R. CUNEQ c M. R.HILL** M A. L. ATCHLEY, SEC. c J. MORRISON, SEC. " . HARRIS RESEARCH AND DEYELOPMENT ‘fi' A POTTER ’,a MTR LIAJSON CHEMICAL DEYELOPMENT SHIELDING THEORY TOWER SHIELDING FACILITY SPECIAL PROBLEMS A.S. MEYER, JR. AC GENERAL CORROSION J. A GRIFFIN M H. V. KLAUS 55 D. E. FERGUSON cT J. P. YOUNG AC G.l. CATHERS cT A. SIMON* AP C. E. CLIFFORD*~ AP R. F. NEWTON RD R. E. FEATHERS, JR. AC E. E. HOFFMAN M HOT LAB FACILITY M. R. BENNETT cT V. GLIDEWELL,* SEC. 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