MARTTH MARTETTA ENERGY SYEYEMS LigRARIES M; { _H"{} :l 3 yys5g 0350535 5 ORNL-1439 This document censists of 224 pages. Copy (¢ %fi of 246 copies. Series A, Comtract No. WeT7405-eng- 26 AIRCRAFT NUCLEAR PROPULSION PROJECT QUARTERLY PROGRESS REPORT for Period Ending December 10, 1952 R. C. Briant, Director J. H. Buck, Associate Director A. J. Miller, Assistant Director Edited by: W. B, Cottrell DATE ISSUED OAK RIDGE NATIONAL LABORATORY Operated by CARBIDE AND CARBON CHEMICALS COMPANY A Division of Union Carbide and Carbon Corporation Post 0Office Box P 0ak Ridge, Tennessee I 3 4yy5k 03L0OL3S 5 O o~ NI e - o - . 2 s @ - - P A A L ngnmgnm'_:flé:»?:ééné'bm_ér'sc;pmunp?u-fl?fi_mgmmcmno:flm = ' INTERNAL DISTRIBUTION ., Adamson :Eéffel Baldock Baftpn Bettis Billington Blankenship Blizard Bredig Braiant Briggs Bruce Buck Callihan Cardwell . Center Cisar Clewett Clifford Cottrell . Cowen Eister Emlet (Y-12) Ergen Felbeck (C&CCC)- Fraas Gall Graham y Grigorieff {consultant) Grimes ’ ollaender Householder Humes (K-25) Jones / Keilhq'tz . Kellty Kertes$ M. King E. Latson ?:::;:msé oW O TmnOTO h&”Ufl_CdCUEDE:U_:SCU';U:'U:-JR‘_UJPT.UCU ORNL-1439 Progress 41. R. S. Livingston 42. R. N. Eyon 43. W. D..Manly 44. W. B. McDonald 45. J. L. Meem 46. AJ J. Miller 47. K. Z. Morgan 48. E. J. Murphy 49.. H. F. Poppendiek 50. P. M. Reyling 5. H. W. Savage 52. E. D. Shipley <53, 0, Sisman © 54. L. P. Smith (consultant) 55. A. H. Snell 56. F. L. Steahly 57. R. W. Stoughton 58. C. D. Susano 59. J. A. Swartout 60. E. H. Tayler 61. F. C. Uffelman 62. F. C, VonderLage 63. J. M. Warde 64. A. M. Weinberg 65. J. C. White 66. E. P. Wigner (consultant) 67. H. B. Willard 68. G. C, Williams 69. J. C. Wilson 70. C. E. Winters 71-80. ANP Library 81. Biology Library 82-87. Central Files 88. Health Physics Library 89. Metallurgy Library 90. Reactor Experimental Engineering Library 91-95. Technical Information Department (Y-12) Central Research Library 96-97. 198-108. L 109, 110-117. . 118. 119-123., 124, 125, 126-127. 128, 129. 130-134. 135-159, 160-163., 164, 165. 166-173. 174. 175-182. 183-184. 185-187, 188. 189. 190-192. 193-196. 197. 198-199. 200-201. 202. 203. 204-205. 206. 207. 208-209. 210. 211-214. 215-231. EXTERNAL LISTRIBUTTON Argonne National Laboratory (1 copy to Kermit Anderson) Armed Forces Special Weapons Project fiSandla) Atomic Energy Commission, Washington & Battelle Memorial Institute Brookhaven National Laboratory Bureau of Aeronautics (Grant) Bureau of Ships California Research and Development Company Chicago Patent Group Chief of Naval Research duPont Company ! General Electric Company, ANPP(3 coples to AF Engineering Office) General Electric Company, Richland Hanford Operations Office USAF -Headquarters, Office of Assistant for Atomic Energy Idabo Operations Office (1 copy to Phillips Petroleum Co.) Iowa State College Knolls Atomic Power Laboratory -Lockland Area Office Los Alamos Massachusetts Institute of Technology (Benedict) Massachusetts Institute of Technology (Kaufmann) Mound lLaboratory National Advisory Committee for Aeronautics, Cleveland (3 copies to A. Silverstein) National Advisory Committee for Aeronautics, Washington New York Operations Qffice North American Aviation, Inc. Nuclear Development Associates, Patent Branch, Washington Rand Corporation (1 copy to V. G. Henning) Savannah River Operations Office (Augusta) Savannah River Operations Office (Wilmington) Inc. University of California Radiation Laboratory Vitro Corporation of America Westinghouse Electric Corporation Wright Air Development Center 2 copies to B, Beaman 1 copy to Col. P. L. 1 copy te Lt. Col. Hill M. J. Nieléena 1i1 coples to Consolidated Vultee Aircraft Corporation copy to Pratt and Whitney Aircraft Division ' copy to Boeing Airplane Company copy to K. Campbell, Wright Aeronautical Corporation chnical Information Service, Oak Ridge @O = b e DD 232-246. | T iv Reports previously issued ORNL-528 ORNL-629 ORNL-768 ORNL-858 ORNL-919 ANP-60 ANP-65 ORNL-1154 ORNL-1170 ORNL-1227 ORNL-~1294 ORNL-1375 Period Period Period Period Period Period Period Period Period Period Period. Period: in this series are as follows: Ending Ending Ending Ending Ending Ending Ending Ending Ending Ending Ending November 30, 1949 February 28, 1950 May 31, 1950 August 31, 1950 December 10, 1950 March 10, 1951 June 10, 1951 September 10, 1951 December 10, 1951 March 10, 1952 June 10, 1952 Ending September 10, 1952 CONTENTS PAGE FOREWORD . « & & v ¢ 4 v 4 s v 6 6 o v o o o o o o o o s o s « s o o o 1 PART T. RFACTOR THEORY AND DESIGN SUMMARY AND INTRODUCTION . . ¢ & o v ¢ 4 o v o 5 5 5 o o s ¢ 5 o o o & = 5 1. CIRCULATING-FUEL AIRCRAFT REACTOR EXPERIMENT . . + . . + ¢ v « o . 7 Fluid CIiTOUIT v 4 v 6 4 6 o v o v v v o s o v s o o o o o o o o 7 Stress Analysis of Piping « v « + 4 4 o 56 o o o o o s o « o 2 « = 8 RBeactor o o & o ¢ 4 4 v 4 v v u b e e e s e e e e e e e e e e e 11 Instrumentation o « o & « v & o 5 o 5 5 6 0 v s e e s 4 s 2 s s o 11 Off-gas System o 4 ¢ v & & o 4 & 4 s o w4 6 8 s e s s e 8 e w . 11 Description of the system . « v o v ¢ v o & o o o 2 & 6 o o & @ 11 Maximum activity of stack gases « + ¢ 4 v « « « o o« 2 » o o « o 12 Normal discharge from the surge tank . . ¢« ¢ « ¢ o o o +» & « & 15 Gas vented from the fuel dump tank during dumping « « o + . . . 15 Reactor Control System . . & v &« & v v ¢« % o o o » v o o o o o 15 2. EXPERIMENTAL BEACTOR ENGINEERING . & « & & o + 4 o v o o « « o o « 17 Pumps for High-Temperature Fluids . . . . ¢ « ¢ & ¢ o v o o o & 17 Pump with combination packed and frozen seal . . . . ¢« . .« . . 17 Pump with frozen-sodium seal . « ¢ & o ¢ « o o ¢ o o « = o » 19 Allis-Chalmers pump o o v « v 4 o % & o o « « s o« o o s o s s o 19 Laboratory-sized pump with gas seal . . ¢ .+ o 4 « v o s o « o & 19 ABE pump ¢ o v & o v 4 s e s e 4 e v 4 s e s e s e s e e 21 Rotating Shaft and Valve Stem Seal Development . « & « « + o « o 21 Screening tests for packing materials and lubricants , , . , . 21 Packing compression tests o« ¢ « v 4 « » 4 s « s s 5 s o o« o o . 23 Packing penetration tests . v o « o o & « s o + o o s’ ¢ o o o o 23 Face seal tests o & & o & v v & s v o 4 ¢« o o v 4 v e 8 e a e 25 Combination packed and frozen seal . & 4 o & ¢ o & o « o « o & 25 Frozen-lead seal . . . . & ¢ v ¢« & o 4 4 o« ¢« o o s o o v <« o & 26 Frozen-sodium seal . . . . . & ¢« 0 v o s v 6 v 4 e 0 e e e e 26 Bellows-type of valve stem seal « & o & o« « o« o o o « o o o o & 26 Heat Exchangers . . o . « & ¢ v « v v v v o o o o o v o o o o« o & 27 Sodium-to-air radiator .« ¢ s ¢« o 4 o & o 2 & o « o & 3 0 o @ 27 Bifluid heat transfer system . & o o v o o« « o o s o o » o & o 28 InStrumentation + o« o & o s « o 4 o s o 4w o 6 6 8 4 b a0 s « &+ s 29 Rotameter type of flowmeter + . ¢ ¢« & & ¢« v « o o o & o o « o 29 Rotating-vane flowmeter . « v & ¢ & & v &« o & o o o o o « o o« o 30 Diaphragm pressure-measurement device o« o « o s o o o o s o v =« 30 vii Moore Nullmatic pressure transmitter .« . o« + « o = Handling of Fluorides and Liquid Metals . . « « . .« . NaK distillation test ., Gas-line plugging . .« & Q a 9 @ a e 4 9 ? ° a - 9 e * e 9 * e < ° 9 ° ° e * ZrF, vapor condensation test . < + ¢ ¢ ¢ & & ¢ o o Project Facilities . . . Helium distribution . . Fabrication shop . . . Instrument shop facility Gas-fired furnace facilaty 3. GENERAL DESIGN STUDIES . . Air Radiator Program . . Radiator Perfermance . ., Engine Performance . . . Heat Exchanger Design Charts 4. REACTOR PHYSICS . . . . . . - - e . . . . . ® 2 . ® 9 2 a e . - @ e e ° e L . e ? e . - » . e ° * 9 * @ a e * 9 * - e ® . 9 * @ A * . 9 a a o . e 9 . - . . Oscillations in the Circulating Fuel Reactor . . . . LLimits on the oscillations Periodic oscillations . Specific examples . . . Reactor Calculations . . Temperature Dependence of a Resonance . « . . . 5. CRITICAL EXPERIMENTS . . . * ] ° a -« e e o ° e ° . @ L * @ < * * * 9 - - - . " ® - . ° e 9 * L a . Qe » . . - ° * - * e * ° ° e @ . Qe - - Cross Section Exhibiting 9 . * T . . e . - . L] @ 4 @ e e ° e 4 * ° e 9 - . e Reflector-Moderated Circulating-Fuel Reactor Assembly ARE Critical Assembly . . PART I1. SUMMARY AND INTRODUCTION . . . . SHIELDING BESEARCH 6, DUCT TESTS IN LID TANK FACILITY . . « ¢ ¢ &« « ¢ ¢ o o & G-E Outlet Air Duct . . . - * ° - * . ¢ - @ - e a 9 Neutron dose measurements . e . * . . 9 e . . ° . . Calculated neutron dose . G-E Inlet Air Duct . .« . . e - - Al - 2 < 9 - 9 4 ° . . < ° * . - . L - - e e Induced Activity Around a Duct . o . « ¢ « ¢ « o + & Radiation Around an Array of Cylindrical Ducts . . . 7. BULK SHIELDING FACTLITY . . * - » Measurements with the Divided-Shield Mockup . . . . . viiil PAGE 30 32 32 32 32 33 33 33 33 33 35 35 35 35 40 41 41 42 42 44 44 46 48 48 52 61 62 62 62 62 71 74 76 85 85 PAGE Air-Scattering Experiments . . . . . .+ ¢ 4 v 4 e 4 ee e e e 85 Irradiation of Animals . . .+ . + + « & « & o o 4 e s 4 e e 4w 85 Other Experiments . . . . . « . . + .+ + & C e e e e e e e e e e 92 8. TOWER SHIELDING FACILITY . . . . & v 4 v ¢ o o v o o o o s o o = » - 95 Facility Design . . . . & & v v o o v s« o s o o s s 0 s s e s s 95 Structure Scattering . . .+ ¢ « « « « o + « 4 4 4 4 e 4 2 s e e 95 9. NUCLEAR MEASUREMENTS . . . . . e h e e s e 96 Angular Distribution of Neutrons Scattered from Nltrogen P e e 96 Results of nitrogen-scattering experiment . . . . « . + « .+ « . 96 Analysis of nitrogen-scattering data . . . . <« « » s . & o s U4 A Fast-Neutron Dose Measurement . . . . . . . « « « « « « = « « & 97 PART II1. MATERIALS RESEARCH | SUMMARY AND INTRODUCTION . .+ » o o e e e e e e e e e e e e e e w103 10. CHEMISTRY OF HIGH-TEMPERATURE LIQUIDS . . . . . « . . + « + &+ « + & 105 Fuel Mixtures Containing UF, . . . . . . ¢« .« « + . « + v « . 105 LiF-BeF,-UF, . . . . ¢ o o o v v v v 0 o v o e e e e e e 105 NaF-BeF,-UF, . . . . . .« o o v o v o v v v oo oo o v o e 105 LiF-ZreF -UF, 0 0 0 L 0 0 v s v e v e e e e e e e e e e e 107 NaF - L1F ZrF L L e e s e 107 NaZrF -NaUFg . . . . o o o 0 v v v v e v o o e v n e e e 107 RbF - AIF —UF e e e e e e e e e e e e e e e e e e 107 Fuel Mlxtures Conta1n1ng UCI e e e e e e e e e e e e e e e e 108 Fuel Mixtures Containing UF, . . . . . . . . . . . . e s e e . . 109 NaF-UF; .« v v v v v v h h e o e e e e e e e e e e e e e 109 KF-UF, . . . C e e e e e e e e e e e e e e e e .. LI0 Alkali Fluoborate Systems e e e e e e e e e e e e e e e e e e 110 Differential Thermal Analysis . . . C e e e e e e e e . 1T Simulated Fuel for Cold Critical Experlment S O Coolant Development . . . . . « o« v v & « o« = s o o w0 e e - 112 NaF-ZrF, . . . 0 o . v v v v b v e e e e e e e e e e e e 112 LiF-ZrF, . . . . v v v e s e e h e e e e e e e e s e e 113 NaF-KF-ALF; . . . .« o 0 o @ v v v v o s o o o v s 6 o v v o e 113 NaF-BeF,-ZrF, . . . . . « o v o v o 0 v v s v v v v e e 114 NaF-LiF-ZrF, . . . . . < ¢ v o« o o o v o v o o v 00 a e 114 NaF-BaF, . . e e e e e e e e e e e e e e e e e e e e e e I11S NaF-KF - L1F er e e e e e e e e e e e e e e e e e e e e e e 115 NaF-RbF-A1F, . . . . e 115 Studies of Complex Fluor1de Phases e e e s e s e s v e s e e s 115 1% PAGE K,CrFg-Na ,CrF, -Li,CrF, . . . . . . . ¢ o o v o 0 o v o v v o 115 Solid phases in NaF-Bek, -UF, and NaF-ZrF, systems . . . . . . . 115 UF;-ZxF, . . . « o o v o o s e e e e e e e e e e e e e e 115 NaF-ZrF, . . . « o o o o i e e e e e e e e e e e e e e e e 118 Other fluorlde complexes . . P 118 Reaction of Fluoride Mixtures w1th Redu01jg Agents e e e e e 118 Reducing power of various additives . . . + v « « « o « &« o « 118 Identification of reduction products . . . . « « + ¢ 4 o v . o 119 Reaction of fluoride mixtures with NaK ., . . . . . . . . . . . 120 Reaction of NaF-ZrF, -UF, with ZrH, . . . e e e e e e 120 Solubility of potaqs1um in NaF-KF L1F eutectlc e e e e e 4 e e 121 Production and Purification of Fluoride Mixtures . . . . . . . . 122 Laboratory-scale fuel preparation . . . . . . . . « + + + « + & 122 Pilot-scale fuel purification . . . . . . +« « « + + v v « « « . 122 Fuel production facility . . . . e e e e e e e e s 123 Preparation of hydrofluorinated fuel samples et e e e e e e 124 Hydrofluorination of Zr0,-NaF mixtures . . . . . . . .« . . . . 124 Purification of Hydroxides e et e e e e e e e e e e e e e e e 125 11. CORROSTION RESEARCH . . . . . . . . . .. e e e e e e e e e e 127 Fluoride Corrosion in Static and Seesaw Tegts e e e e e e e e 127 Oxide additives . . . . . v e e e e e e e e e e e 127 Comparison of liquid- and vapor - phase COrroS1on . . . « « o+ & 127 Crevice corrosion ., . Ve e e e e e e e e e e e e e 128 Carboloy and Stellite alloys e e e e e e e e e e e e e e 130 Reducing agents . . . . .« « .« 0 v 0 4 v e e e e e e e e 130 Fluoride treatment . . . . o ¢ + ¢ v & 4 & & & o o 4 e 0 e . 131 Temperature dependence . . . + & v 4 v 4 v 4 e e e e e e e e 132 Ceramic materials . . . . e e e e e e e e e e e 132 Fluoride Corrosion in Thermal Convectlon loops . . « .« « o o .. 133 Mixtures containing ZrF, . . e e e e e e e e e e e e e e 133 Hydrofluorinated NaF KF LiF Uf e e e e e e e e e e e e 136 Corrosion inhibitors . . . . . . + . v v v 0« 0 v e e e e 137 Inserted corrosion samples . . . . . + ¢ . ¢ ¢ 0 0 0 e e e e 138 Crevice corrosion . . . . . . e e e e e e e e e e e e e e 138 Variation in loop wall comp051t10n C e e e e e e e e e e e 139 Self-insulating properties of fluorides . . . . . . . . . . . . 139 Other 1oop tests . . v ¢ v v 4 v v o o o o o o o s s e a4 e e 139 Hydroxide Corrosion . . . + « & & v v o« o o o o o o s o o o o & 141 Corrosion inhibitors . . . & + © v v v v v s 4 e e e e 141 Temperature dependence . . . . . . . . . 4 0 4 e e e e e e e 141 Nickel alloys in NaOH . . . . . . . . . « o o ¢ o v o v o o v . 141 PAGE Compatibility of BeO in KOH . . . . e e e a e e e e e e s 141 Nickel 1n NaOH under hydrogen atmosphere C e e e e e e e e e 142 Liquid Metal Corrosion . . . . ¢ & & v « v 4« v o v s « & o o+ « 144 High-velocity corrosion by sodium . . . « « « « + & v v « + & 144 Ceramic materials im sodium . . « & « & &« « & « 4 4 v o 4 4 4 . 146 Lead in metal convection loops . . . . + ¢« v & « v & 4 4 e e 147 Lead in quartz convection loops . . .« & ¢ « « 4 s ¢ s a4 s s e e 148 Compatibility of BeO in NaK . . . . . ¢« « « « v & « v v v s o 150 Sodium in forced-convection loops . . . . . « . . « .. . . . 150 Fundamental Corrosion Research . . . . . « . . « « ¢« 4 « « « « . 151 Interaction of fluorides with structural metals . . . . . . . . 152 Air oxidation of fuel mixtures . . . . . + « « & - ¢ ¢ . . . 152 EMF measurements in fused fluorides . . . . . . . . . v .+ +« . . 153 Preparation of trivalent nickel compounds in the hydroxides . . 154 12. METALLURGY AND CERAMICS . . . . v e s e e a s 4 s aa e s e s 155 Fabrication of Solid Fuel in bpheres &« e b e e e e ee e e s 155 Suspension in refractory powder . . . . . « & . 4 s 4 e 4 e 4 s 156 Momentary melting in a high-temperature arc . . . . . . « . . . 156 Spraying from a metallizing gun . . . . . . . « « + ¢ o« . . . 156 Solid Phase Bonding of Metals . . . . . . . « . + + & « &+ & « « & 156 Columbium Research . . ., . . . . . . . . . . . o . . e e e e 157 Gaseous Treactions . + + o 4 o o s o & o o o o o = 4 e e 0. 157 Oxidation in air . . . . . c e s e e 5 e e e s ae e e e 158 Creep Rupture Tests of Structural Metals . . . . . .+« « ¢« . + . . 159 Inconel 1n air . . & 4 & ¢ o i e 4 e e v e e e e e e e e e e e 159 Inconel in hydrogen . . . e e e e e e e e e e e e e e e 159 Inconel in molten fluorldes e 159 Type 316 stainless steel in argon . . . . + « v « &« o v & o & 159 Type 316 stainless steel in molten fluorldes e e e s e e e s 159 Brazing and Welding Research . . . . . . . . + + « . « v o o 4 & 161 ARE welding . . . . &« v v 0 v h e e e e e e e e e e e 161 Cone-arc welding . . . « . . « « & 4 « i e e w e e e e e e e 161 Reésistance welding . . . T 162 Automatic heliarc machine weldlng T 164 Fabrication of heat exchanger units . . . . . . . « . « .+ + .+ . 164 Brazing of copper to inconel . . . . . . . . . o . 0 0 o . . 165 Evaluation Tests of Brazing Alloys . . . . . + « « « « « « &+ « . 165 Oxidation of brazing alloys . . . . « . . « « ¢ ¢ o s « o+ + . 165 Corrosion of brazing alloys by sodium hydroxide . . ... . ., . . 168 Corrosion of brazing alloys by sodium and lithium . . . . . . . 168 Tensile strength of brazed joints . . . « . . . . . + « « . .+ & 169 X1 PAGE Melting point of 60% Pd-40% Ni alloy . . . . . . . « « « « . . 171 Ceramics Research . . . . . « « ¢ v v v v o v v 0 e e e e e . e 171 Development of cermets for reactor compomnents . . . . . + + .+ & 171 Ceramic coatings for an aircraft-type radiater . . . . . . . . 171 Ceramic coatings for shielding metals . . . . . . . . « . « « . 171 Uniformity of beryllium oxide blocks . . . . . . . « . « .« « . 171 13. HEAT TBANSFER AND PHYSICAL PROPERTIES BESEARCH . . . . « « ¢« & « & 174 Thermal Conductivity of Liquids o « ¢ ¢ o & o o o o s o o o s s = 174 Heat CapaCitY Of Liquids T @ 8 % e & & 4 @ @ 8 94 % @ @ 4@ @ @& e 9 ].76 Viscosities of Fluoride Mixtures . . ¢« « &« o« ¢ s o v « o o o o & 176 Measurements with the Brookfield viscometer . « o« ¢ ¢ « o + « & 176 Capillary viscometer . & o« o & o o« o s s o o ¢ o o s & o o o 176 Density of Fluoride Mixtures . « & ¢« ¢ ¢ ¢ ¢ o ¢ v v o o o« o o = 178 Vapor Pressure of Molten Fluorides . .« « + ¢« ¢ v ¢ o ¢ o o o o o 178 Convective Heat Transfer in Fluoride Mixture Nalb-KF-LiF . . . . . 179 Analysis of Specific Reactor Heat Transfer Problems . . . . . . & 180 Heat Generation in the reactor reflector .« ¢ ¢ & o o ¢ o« & o o 180 Analysis of fluid-to-air radiators . « « o « o « o« o o o « s 181 Natural Convection in Confined Spaces and Thermal Loop Systems . 182 Turbulent Convection in Annuli . . ¢« ¢« ¢ &« ¢ &« o o o o s o s o 182 Circulating-Fuel Heat Transfer . « ¢ ¢« ¢« o« ¢ o o ¢ o & o o o & = 185 14, RADIATION DAMAGE . . ¢ ¢ ¢ ¢ o o o ¢ o o o s s o s 5 s s s o o o 186 Irradiation of Fused Materials . . &« ¢ &« ¢ ¢ ¢ ¢ o o o o« s o s o 186 In-Reactor Circulating Loops « ¢ « ¢ ¢ « ¢ « o o o o « o o o o s 187 Creep Under Irradiation « o« o« o o o o o o o o« o o o o o s « o« o @ 188 15, ANALYTICAL STUDIES OF BREACTOR MATERIALS . . + & ¢ ¢ o ¢ o « o« o o & 190 Chemical Analysis of Reactor Fuels . . ¢« ¢« & ¢ ¢ ¢« o v ¢ o o o o 190 Zirconium « « « o s s o o s s © s+ s s s e s+ s a o 2 s e e s o s 191 Chromium .« + ¢« ¢ ¢ ¢ o ¢ o o « o s ¢ o s s & « o s o o a o « s 192 Aluminum o v & & & ¢ 4+ ¢ o s s s 4 6 s s s 8 v s s s e e e = s 192 OXYEEN & « & & s o o o o 5 s v s s 5 o o s o v o o o o s 3 o 192 Water + ¢ ¢« o ¢ o o o 4 s o 3 © 5 s e 6 ° v s s s e & e 3 a4« 192 Determination of Beryllium in NaK . . . ¢« & « ¢« ¢ o« o ¢ ¢ o o & 192 Spectrographic Analysis . « ¢ ¢« « o o ¢ ¢ o ¢ & 4 o s s s 8 s s e 193 Uranium oxides « & o « o o o o o o & s o s s » s o s s o o o o 193 Nickel fluoride « « « &« « o o o o o o s « o o s o o o « 5 o s o 193 Petrographic Examination of Fluorides . « « « ¢ ¢ ¢« ¢ ¢« « & « & & 193 ZI‘Oz—HF . . . e . . . @ v o % % - ° @ L) e L e s « 9 . ] ) ° . - 193 NaF“ZrOFz . s e . e . ° @ ° ° ° e . e 4 - ° . ® e ° e s 9 ° ® . 193 x11 - Optical Properties of Some Fluoride Compounds . . . . . . . NaQUFG < L] @ .’ . » a - # 2 9 ® 2 a 2 @ - ] - " ° - ® * . - KaUF7 - * - a o » a4 ? a - ¥ a . a 9 w -« - a . * . - & * o NaaZrFT » - o @ L] L] < > - . < e - o o a . 2 * e L] < .I - * 2: ZI'F4'UF3 . e - ° - ) ) ° & . Chemical Analyses for UO, in UF, , . . . . . . . .. Service Chemical Analyses « ¢ v ¢ o 4 « o 4 « o 5 o & o o s | PART IV, APPENDIXES SUMMARY AND INTBODUCTION + & » v v v v v v e e v e e e e e e a o 16, LIST OF REPORTS ISSUED . . v v v v 4 ¢ v s v v o o o o o o 4 17. DIRECTORY OF ACTIVE ANP RESEARCH PROJECTS AT ORNL . . . . . I. Reactor and Component Design . . . + ¢« v +v 4 o« o + & IT. Shielding Research .« . . ¢« ¢ ¢ & ¢ ¢ & v o a « o o & ITI. Materials BResearch . . . . ¢« o o' v ¢ v v v 4 o + & IV. Technical Administration of Aircraft Nuclear Propulsion Project at Oak Ridge National Laboratory . PAGE 194 194 194 194 194 194 194 199 199 202 202 203 204 209 X111 ANP PROJECT QUARTERLY PROGRESS REPORT FOREWORD This quarterly progress report of: the Aircraft Nuclear Propulsion Project at OBNL records the technical progress of the research on the circulating-fuel reactor and all other ANP research at the laboratory under its Contract W-7405- eng-26. The report is divided into four parts: I. Reactor Theory and Design; 1T, Shielding Research; III. Materials Research; and IV, Appendixes. Each part has a separate Summary and Introduction. The Aircraft Nuclear Propulslon Project is comprised of some 300 technlcal and scientific personnel engaged in many phases of research directed toward the nuclear propulsion of aircraft. A considerable portion of this research 1is performed in support of other organizations participating in the national ANP effort. However, the bulk of the ANP research at ORNL is directed toward the development of a circulating-fuel type of reactor. The nucleus of the effort on circulating-fuel reactors is now centered upon the Aircraft Reactor Experiment - a 3-megawatt high-temperature prototype of a circulating-fuel reactor for the propulsion of aircraft. The current status of the ARE is summarized in section 1; however, much supporting research and developmental information on materials and problems peculiar to the ARE will be found in other sections of Part I and Part III of this report, in addition to the general design andmaterials research contained therein. Shielding Research, Part 11, is devoted almost entirely to the problems of aircraft shielding. SUMMARY AND The Aircraft Reactor Experiment (sec. 1) is now well into the transi- tion period between design andreality. The design is essentially complete, almost all the components are onorder, and a substantial number of these have been received and installed in the ARE Building. The significant modifications during the past quarter include completion of the off-gas system design (incorporating holdup tanks rather than charcoal adsorbers) and the inclusion of a reactor by-pass (so that the fluid circuits may be checked out independently of the reactor). Coincident with the com- pletion of the reactor design, the Aircraft Reactor Experiment Hazards Summary Report, ORNL-1407, was sub- mitted to the AEC for approval. It is anticipated that even though the experiment may be completely assembled by the summer of 1953, a significant and indeterminant period will be re- quired for shake-down operation before the reactor becomes critical. | Valves, pumps, instrumentation, and other components of both the fluoride fuel (NaF-ZrF,-UF,, 50-46-4 mole %) and reflector coolant (NaK) circuits are being developed for the Aircraft Reactor Experiment (sec. 2). In most instances, these components have been tested on smaller than full- scale prototypes of the actual ARE components. Tests are now under way; however, on the full-scale pumps, valves, and some instrumentation designed for the reactor experiment. At this time, centrifugal pumps with both gas seals and frozen seals have operated satisfactorily for extended periods at temperatures between 1200 and 1500°F. A combination packed and frozen seal has been specified for the ARE pump. Although a bellows type of seal has been specified for the ARE, a considerable program has been undertaken on high-temperature, self- lubricating seals. INTRODUCTION The rotameter type of flowmeter and the modified Moore Nullmatic pressure transmitter have both operated satisfactorily at high temperatures (~1400°F). Neither of these instru- ments is affected by the ZrF, vapor above the fuel. Vapor traps of the type that will be required in the gas system above the fuel surge tanks have been satisfactorily developed. The heat transfer coefficient of an aircraft type of sodium-to-air radiator, in which the radiator fins were sectioned every 2 in. 1in the direction of air flow, was increased 20% over that of the same radiator with plain flat fins. : The general design studies (sec. 3) were confined to performance analysis of a Sapphire turbojet engine in which the engine radiator performance was extrapolated from a sodium-to-air radiator section tested at ORNL. Performance data for both the radiator and engine are presented. Arrange- ments have been completed with the Wright Air Development Center for their participation in the development of high-temperature liquid-to-air airvecraft radiators. The several reactor physics studles (sec. 4) include those of oscillations in a circulating fuel reactor, a technique for reactor calculations, and the temperature-dependence of a cross section exhibiting a resonance. The damping influence of fuel circula- tion has been demonstrated even when the earlier assumptions are replaced by more realistic conditions. With regard to reactor calculations, 1t 1s shown that the slowing down of neutrons in parallel slabs of materials with different properties can be described in some instances by a set of 1mages of the original neutron source, Critical assemblies of both the Aircraft Reactor Experiment and a reflector-moderated reactor have been tested (sec. 5). Critical mass, ANP PROJECT QUARTERLY PROGRESS REPORT control rod effectiveness, flux and fission distribution, and self- shielding factors have been determined for this 1nitial reflector-moderated assembly. As was expected, this as- sembly gave rather peaked flux dis- tribution curves, and the lumped fuel resulted in rather large self-shielding effects. Measurements on the ARE critical assembly continued. Cali- bration curves for the ARE control rods were obtained, and the effects of various core components on reac- tivity were compared. PERIOD ENDING DECEMBER 10, 1952 1. CIRCULATING FUEL AIRCRAFT REACTOR EXPERIMENT | J. H. Buck Research Director’s Division E. S. Bettis ANP Division A few relatively minor changes in the design of some phases of the Aircraft Reactor KExperiment have been made 1n the past gquarter., These changes involved the off-gas system and the fuel disposal system, pri- marily, and are discussed below. There have been no changes in the general design, and detailing of con- struction and installation designs has been largely completed. Installa- tion of equipment in the building has proceeded at an accelerated rate throughout the quarter but has not yet reached the expected peak rate. Components from outside vendors, as well as those fabricated 1n ORNL shops, are being received in increas- ing quantity; but some of the major items, notably, the heat exchangers, have not yet been received. It 1s expected that all components will be on hand by the end of the year. Component testing is proceeding in the experimental engineering labora- tories (sec. 2}, but the final component testing 1s to be done in the ARE Building. It is new planned to by- pass the reactor so that a thorough system test can be made before the nondrainable reactor is tied into the ~ circuit. This procedure will make possible a complete shake-down run without the possibility of incorporat- ing a nondrainable component 1in the system. The design change necessitated by this alteration in operational procedure is minor and will be effected in the field. Considerable effort during the quarter went 1nto the preparation of the “Haz ards Report, (1) which, in addition to serving the (1)J. H. Buck and W. B. Cottrell, Aircraft Reactoer Experiment Hazards Sumeary Report, OBRNL-1407 (Nov. 24, 1952). purpose implied in the name, provided the first draft of an operations manual for the experiment. It is practically impossible to predict a date for satisfactory opera- tion of the ARE. There are no means available for predetermination of the time required to correct difficulties. It is not so difficult to attempt to predict a date for the completion of the installation of equipment, and therefore a date for beginning the system test in the building. At present it is expected that the system will be ready for initial testing near the first of June 1953. No uranium will be added to the system until all reasonable checks have been made to ensure the integrity of the entire assembly. FLUID CIRCUIT G. A. Cfisty, Engineering Department The previous report(z) discussed design changes necessitated by the higher fuel viscosities. In brief, the higher viscosities reduced the Reynold’ s number of the heat exchanger tube side and changed the heat transfer coefficient to such an extent that the calculated minimum film temperatures were 1n the vicinity of the freezing point. Two corrective measures were discussed; redesigning the heat ex- changers and increasing the flow rate through the entire circuit. The first change has been accomplished. The need for the increased flow rate has been obviated by an accurate measure- ment of the fuel thermal conductivity; the new value of £kis 1.5 Btu/hr*ft"°F, whereas 0.5 had been used in earlier {ZJG. A. Cristy, ANP Quar. Prog. Rep. Sept. 10, 1952, ORNL- 1375, p. 6. ANP PROJECT QUARTERLY PROGRESS REPORT analyses. With this higher conduc- tivity value and the redesigned heat exchangers, the calculated minimum film temperatures are comfortably above the freezing point, with the original flow rate, Restoring the flow rate to its original value will reduce the reactor inlet temperature to 1150°F and reduce the maximum system pressures and pressure shell stresses. It has been decided to employ NakK as the reflector and pressure-shell coolant. This has necessitated com- plete redesign of the reflector- coolant heat exchangers, primarily because NaK will extract more heat from the fuel tube elbows and other components washed by the coolant than would the lower conductivity salt around which the earlier calculations were based. The heat exchangers have been re-engineered and currently are being constructed. The changes re- ferred to above are reflected 1n the revised flow sheet, Fig. 1.1. Detailed engineering designs for most of the outstanding i1tems have been released during this quarter. The items included were such components as the fuel system surge tanks, the reflector-cooling system surge tanks, the reflector-cooling system heat disposal loop and ducting, the thermal barriers, the water system piping, the glycol surge tank, the off-gas dis- posal system, and some of the fuel system piping. The redesigned ARE pump is described in section 2, “Ex- perimental Reactor Engineering,” and, as stated therein, initial tests are now in progress. Delivery of the bellows type of valves that will be used in the fuel and reflector systems is expected within a month. The parts for these valves are being supplied by Fulton Sylphon Co., but the valves are to be welded at ORNL. STRESS ANALYSIS OF PIPING R. L. Maxwell J. W. Walker Consultants, ANP Division The maximum stresses that will be encountered in the piping for the ARE have been calculated to be approxi- mately 24,000 1b/in.%. Since these stresses will be somewhat relieved by creep at the operating temperature, this stress value 1s only significant in defining the stress range of the pipe in going from the cold to the hot condition. If the stresses were completely relieved by creep, this would correspond to a strain of about 1%. In order to reduce the loads and stresses in the pipe in the hot con- dition, the piping will be pre- stressed, or presprung, by an amount equal to 75% of the total thermal de formation. This will have the effect of putting the maximum loads on the pipe in the cold condition and reducing to a large extent the load in the hot condition. Because of the uncertainty of realizing the designed cold spring in the actual instal- lation, only partial credit should be taken for prespring. However, the loads and stresses in the cold con- dition were determined by considering the full amount of the prestressing, and the loads and stresses in the hot condition were determined by con- sidering only 50% prespring. This 1is in agreement with accepted practice. The maximum stresses in the cold condition will be higher for the same deformation than in the hot condition because of the difference 1in the modulus of elasticity. The maximum values of the stresses are: Cold § .. = 25,000 lb/in.? 12,000 1b/in.? HOt Smax = The maximum stress in the cold con- dition is about one half the yield- point stress, and the maximum stress L 2-in. GATE VALVE TO DRAIN TO STACK GLYCOL ] o EXISTING EQUIPMENT SHOWN DOTTED - SURGE TANK g i L ————— -~ (‘j —e— r ~ _ \ B i N f \ 4-in. PIPE = - i { r+li:ESERVOIR e e A ——= . : = ‘ - ! o | 55-gal DRUM & \\ 3 ) ] Y | - 12 "_‘_] . i T % I i P e e - ) Lot ' r= w o w O ! V2 T y L | w i F E|Z 15:2 i i - i ] k- : V= : ) = Y, -in. PIPE SL,r ; | g% i 18l i L : &t —L~—- Sive g4, P30 . : : / G i 2 - ; * wik® iz 519 @ . z ? // ! PRESSURE I vaLves | a ¥ g [ g - 2 > | SWITCH | VALVES TO POND 5 Sl g : a ' : el B i - : ! 1 gl L 2 5 £ ;lj r e Yo £l X i Y ! * % { o i 1 f | | ! ; ! | P ) l 5 55-gol DRUM ouTsIDE OF ' —{He} — s | BUILDING . FROM He CONTROLLED SUPPLY - ' $ P : i FROM Hz CCNTROLLED SUPPLY i : i | I E i i [ ! | i | i } B @ @ ! S : oz ECONOMIZER _— S5 o . 2 a x wi i el g MAINTENANCE] w w i wl oy DRAIN 7@ i 51 3 ! 3000 | 7,300 uy ¥ ! ] ® =z < = S: ? TO DRAIN TO DRAIN - FILL = = ! — LINE 1P Si @ Iz - o 4 - 1 - S I - 4 He = i 4 2 a I Lo ; ENED = x . I ! i & ”P ik | Lo —>a 1 ' TANK NO. 3 TANK NO. i : TANK NO. 4 TANK NO.5 TANK NO, & L Mok FLEL CARRIER ; KoK (o) NaK NoK i i e fe - ! ; T ’ @ He i @ DUMP TANK ! : i 3 i i : : 7\ Y% SUPPLY HEADER Z fi- ‘ % 1 | : s ~ ® . L& t l o % MAXE-UP HEADER ol f | | E ) i e o ef I He oy R FILL AND pqfFILL AND " DUNMP LINE DUMP LiKE NOTES { : i FROM He SUPPLY TRAILER THe SCRUBBER RESERVE MANIFOLD 12 He BOTTLES FLOW IN gpm SO0 S FLOW IN cim ¢ Fig. PRESSURE IN ps.g TEMPERATURE i °F i. 1. PRESSURE IN INCHES OF WATER, GAGE Fluid-Circuit FUEL NoK HELIUM WATER GLYCOL INERT SALTS VAPOR TRAR NORMAL OPERATING POSITION OF VALVES ~—=3— OPEN ——»— CLOSED ————=— THROTTLING Flow Sheet. FLOW CONDITIONS ARE BASED ON THE ASSUMPTION THAT THE COOLANT HAS THE FOLLOWING PROPERTIES: o =187 brett 1= 7 TO 3 cp AT OPERATING CONDITIONS Cp=0.26 Btu/b°F VOLUME OF MAIN SYSTEM (APPROX.): INTERNAL: 1.5 13 EXTERNAL: 6.0 f+3 TCTAL 7.5¢13 in the hot condition corresponds to a maximum creep, or deformation, of 0.5%. REACTOR The reactor design, with the ex- ception of very minor changes, remains as previously described. All detailed drawings have been released to the shop. The beryllium oxide blocks have been sized and are ready for assembly into the core. The pressure shell has been received from Lukenweld, ¢*’ the reinforcing segments for the head have been welded in place, and the head holes have been bored. The various core pressure-shell components are currently being fabricated and as- sembled. INSTRUMENTATION R. G. Affel, ANP Division Installation of all instrument panels has been completed. Approxi- mately 80% of the process instruments have been mounted and supplied with electric power and/or compressed ailr. The remalning instruments should be installed by January 15, 1953. Minor instrumentation changes have been made to accommodate the design changes in the pump seal. All major process instrumentation components are de- tailed and either on hand or on order. It is planned to complete the instal- lation of instruments on the panels so that as work in the pits proceeds, the sensing elements, when installed, may be checked directly to the panels. To date, 21 of a series of instru- mentation prints have been issued and shop fabrication started. The series includes such items as the fuel circuit flowmeter, the reflector- cooling system (NaK) electromagnetic flowmeter, the NaK purification system electromagnetic flowmeter, the ta- chometer mountings for the reflector coolant and fuel helium fans, and the liguid-level indicators for the re- flector coolant and fuel surge tanks. (3’The Lukenweld Division of The Lukens Steel Co. Detailed prints of the vapor traps required by the ZrF, condensate (cf., sec. 2, “Experimental Reactor Engi- neering’”) for the surge tanks and the hot fuel dump tank have been issued and sent to the shops for fabrication. Location of thermocouples on the system has proceeded at a satisfactory pace. Two prints showing thermocouple construction have been issued and sent to the shops. Since the system will require approximately 750 thermo- couples, every effort is being made to run the thermocouple extension wires to their approximate pit locations before the pits have major components placed within them. It is believed that this procedure will expedite final installation and test of the temperature instrumentation. OFF-GAS SYSTEM S. A, Hluchan, Instrument Department H. L. F. Enlund, Physics Divasion The previous report(4) described an activated-carbon off-gas scrubber cooled by liquid nitrogen. Further analyses have shown that the liquid nitrogen consumption would be 1in excess of 1000 1b/day because of the decay heat of xenon and krypton 1f the gases were held for less than 100 min before reaching the scrubber. The nitrogen consumption did not become reasonable until the gases were held up for many hours before admittance to the scrubber. In fact, with little additional difficulty, the gases could be held up until they decayed suf- ficiently to be discharged from the stack and the need for the scrubber would be obviated. Accordingly, it has been decided to abandon the carbon scrubber in favor of mechanical re- tention. Description of the System, A helium atmosphere is maintained over the surge tanks in the fuel system and the fuel dump tanks. This helium (4)T. Boseberry, ANP (Quar, Prog. Rep. Sept. 10, 1952, ORNL-1375, p. 12. ) ' 11 ANP PROJECT QUARTERLY PROGRESS REPORT gas, which will contain the volatile fission products (Be, I, Xe, and Kr), ¢5) passes through a NaK vapor trap (where the Be and I are removed), then into two holdup tanks (to permit the decay of Xe and Kr), and is then released in the stack. However, the release of gases to the stack 1is dependent upon two conditions: the wind velocity is greater than 5 mph and the activity, sensed by a monitor, is less than an established maximum value. The monitor is located between the two storage tanks, which are connected 1in series. Provision is also made to exhaust the reactor pits through the holdup tanks in the off- gas system at a rate of 27 cfm (the limit of the exhaust system). The off-gas system 1s shown schematically in Fig, 1.2. With a static helium atmosphere in the surge and dump tanks, the volu- metric flow rate of fission gases 1is a maximum of 0.0014 cfm. In order to have a measurable flow of gas, the fission gases are mixed with a fixed air bleed of 10 cfm between the first holdup tank and the monitors. The minimum flow rate past the monitors then 1s 10 cfm, and the maximum is 37 ¢fm (that 1s, 10 c¢fm from the fixed air bleed plus 27 c¢fm 1f the room 1is being exhausted at the same time). The monitor setting can then be based on the premise that the flow 1s 37 cfm, and the setting will be conservative by a factor of 3.7:1 wher the minimum flow rate prevails. The second holdup tank 1s placed between the monitors and the stack valve to increase the gas transit time between the monitor and the valve to ensure that the valve will have time to close after the monitor signals the presence of excess activity. Maximum Activity of Stack Gases, The maximum activity of the stack gases has been calculated by assuming (SJM. M. Mills, A Study of Reactor Hazards, NAA-3R-31 (Dec. 7, 1949), 12 that the average energy of disinte- gration is equal to 1 Mev.*? The design of the off-gas system includes two vacuum pumps that deliver a maximum of 27 c¢fm and a blower that discharges 10 ¢cfm to give a total of 37 cim maximum discharge through the monitor, The maximum permissible ground concen- tration for the 1-Mev fission-product activity 1s MPC = 1.6 x 10°% ue/cm® . At 37 cfm, or 1.05 x 105 cm?®/min, and with a permissible activity discharge rate of 0.832 curie/min, which produces the above MPC, the activity per cubic centimeter should not exceed m_g;gégm__: 0.8 Mc/cms ’ 1.05 x 10° as determined by the radiation moni- tor. The monitors that control the positions of the stack valve will be set to prevent discharge as soon as the activity of the gas rises above a predetermined level. The discharge rate of xenon and krypton fission products to the atmos- phere must be such that the activity 1is within the above limit. The effective system holdup, before the monitors, is 11.4 ft3, or 3.53 x 10°% cm?® (the volume of one tank plus piping). If it can be assumed that the decay time of the fission products is equal to the system volume divided by the flow rate, the total energy at a particular time can be calculated. This energy must be converted to disintegrations per unit time by considering effective energy changes in relation to the variation of 1so- topic concentrations with time. The values of permissible and calculated stack activity have been plotted in Fig. 1.3, together with the permissible discharge rate, as determined by the National Committee on Radiation Pro- These data, together with K. Z. Morgan (Chairmen), Maximum Permissible Armounts of Radioisotopes in the Human Body and Hax imum Permissible Concentrations in Air and Kater, NBS Handbook No. 52 (to be published). €T 214 el ‘@3 sAS fesodsyd se9-3JJO cka FROM PiTS HF DY Y UNCLASSIFIED DWG. 16957 AR FROM BASEMENT —b—g 10 ctm BLOWER SHIELDING WALL ;% 7 mt} FILL TANKS B LINE VOLUME APPROX 2 ft3 (GAS) G. Y4-in. BOURDON RESTRICTOR - { VALVES £ He SUPPLY o o & FUEL o COOLING E ) SURGE TANK o N 054 3 GAS OR £ REFLECTOR GOOLANT VAGUUM PUMP | R ADIATION LIQUID VOLUMES o SURGE. TANK MONITORS Ys~in. BOURDON RESTRICTOR VALVES He SUPPLY VAPOR TRAP FUEL SURGE TARK 054 13 GAS OR LIQUID VOLUMES REFLECTOR COOLANT SURGE TANK NaK VAPOR TRAP AND STORAGE TANK === NORMAL VENT PATH o e~ HOT GAS BY-PASS 3 VACUUM PUMP VACUUM DISCHARGE PATH \_ e VALVE CONTROLLED ¥ BY ANEMOMETER & ¢S6T ‘01 ¥IAWADIA ONIGNA (0T HAd Vi A4 ‘€T ‘axoydsouw}y 94l 03 AJrAIIOY wWoRrdAI) pue uoudx jJo IFIBYISIQ DISCHARGE RATE {curies/min} 1000 500 200 t00 50 20 | ! REF., BU. STDS HANDBOOK NO 52 {PREPUBLICATION) K.Z. MORGAN, COMMITTEE CHAIRMAN REACTOR POWER, 3mv OPERATING TIME, 200 hr I {APPROX SATURATION) DWG. 15958 | DISCHARGE ACTIVITY {curies /min) TOTAL DISCHARGE RATE (41.6 ¢¢/min) PER RESTRICTOR (208 cc/min) DISCHARGE RATE TO YIELD MAXIMUM PERMISSIBLE . GROUND CONCENTRATION ACCORDING TC REF. | 20 50 100 200 HOLDUP TIME {min) 5.9 days = 8500 min 500 1000 2000 5000 10,000 H90Ud ATHALYVNO L3AL0Hd JdNV L LHOdHd SS the disintegration rates and energies involved, are tabulated in Table 1.1. It will be noted that after 8500 min of holdup, corresponding to a discharge rate of 20.8 cm®/min through each restrictor, the ground tolerance will not be exceeded. : } Normal Discharge from the Surge Tank. The maximum pressure within the surge tank is limited by a 5-psig pressure regulator in the gas supply system. The maximum discharge rate from the surge tank is limited by a Bourdon restrictor to 20 cm®/min with a 3-psi pressure differential. At this flow rate through each of two restrictors, the holdup volume of the system 1s such that it will allow sufficient decay time, as required by the above calculation, to permit the discharge of the off-gas directly up the stack. The change of effective energy owlng tc the persistence of the longer lived isotopes has been ac- counted for when ground concentration of this gas is considered. Gas Vented from the Fuel Dump Tank During Dumping. In considering waste gases from the surge tanks, 1t has been assumed that all gaseous products escape 1nto the surge tanks during operation. Actually, 1t is expected that some portion of the fission- product gases will remain in the fuel and that some fraction of this portion PERIOD ENDING DECEMBER 10, 1952 will be released when the fuel is admitted to the radicactive-fuel dump tank. When fuel i1s admitted to the fuel dump tank, 1t is expected that helium will be displaced at a rate of the order of 5 ¢fm. This helium, after passing through the NaK scrubber and the first holdup tank, will be admitted to the monitors. Should the monlitors sense excess activity, the stack valve will prevent discharge, and the vacuum pumps will permit recirculation through the holdup tanks and monitors. The recirculation should homogenize the gases and ensure that the monitor i1s sensing a repre- sentative sample. When the gases have decayed sufficiently to permit release, the monitor-controlled interlock will open the stack valve. REACTOR CONTROL SYSTEM E. P. Epler Research Director’s Division The high-temperature chamber, without U?3% plating, has completed 1000 hours at 800°F., The temperature will now be raised at the rate of 50°F per week to determine the high-temperature characteristics of the MgO,*Si10, insulator. The fission chambers to be used for the ARE startup are scheduled for delivery February 1, 1953, and will be tested at 800°F. fission TABLE 1. 1. ACTIVITY OF XENOXN AND KRYPTON AS A FUNCTION OF HOLDUP TIME STACK DISCHARGE RATE | EFFECTIVE | DISINTEGRATION : : AOLDUP TINE (curies/min) ENERGY RATE DECAY POWER pc IN ;IB Days ¥Minutes | Calcul ated MPC {Mev) (dps) Watts Mev/sec (uefem™) : Y% 720 344 2 0. 41 9.15 x 1015 500 3.75 x 10%% [ 3.9 x 10-8 1 1, 440 110 2. 45 0.34 5.88 x 101° 320 2.00 x 10% | 4.71 x 10-6 2 2, 880 39.6 3.51 0.237 4.92 x 1018 160 1.00 x 10*% | 6.75 x 10~ 3 3, 320 28.5 3.94 0.211 3.79 x 1013 128 8.00 x 109 | 7.58 x 10-® 15 15 6 5 7, 200 6.91 4. 54 0.183 1.84 x 10 54 3.38 x 10 B.74 x 10 7 10,080 3.02 4. 54 0.183 1,13 x 1015 33 2.06 x 10%% | 8.74 x 10-8 15 ANP PROJECT QUARTERLY PROGRESS REPORT The first production model of the servo amplifier has been tested with the OBNL Power Plant Simulator, and it proved to be satisfactory. This test was made with the actual com- ponents, or duplicates, to be used 1in the ARE. A memorandum describing the on-0ff servo for the ARE 1is being prepared.(7) 16 The wiring diagram for the control system has been completed and working drawings for the relay panels, con- sole, and chamber installation have -been issued to the field. (T)E. R. Menn, J. J. Stone, and S, H, Hanover, An On-Off Servo for the ARE, ORNL CF-52.11-228 (to be published). PERIOD ENDING DECEMBER 10, 1952 2. EXPERIMENTAL REACTOR ENGINEERING H. W. Savage, ANP Division Developmental work on components for high-temperature dynamic fluid systems has continued, with the effort - being primarily on pumps, seals, heat “exchangers, and instrumen tation. Centrifugal pumps with both gas seals and frozen seals have operated suc- cessfully over the temperature range of 1200 to above 1500°F, and operational dif ficulties with these pumps have - become less frequent. Techniques have been developed for remotely stopping ~and restarting pumps 1lncorporating a frozen-fluoride seal. Emphasis has also been placed on seal research 1n an effort to find better materials for packing rotating- shaft seals and valve-stem seals. In the search for materials that will ~have negligible change in physical properties at high temperatures and will furnish some lubrication to the - shaft at these temperatures, several promising materials were found. A . program is under way to develop a face seal that will seal high-temper- ature fluids against a gaseous atmos- " phere, with the minimum leakage. Various rotating-shaft seals for containing high-temperature liquids have been tested. To date, the best results have been obtained with a - packed seal in which the pumped liquid ~may be frozen. A program is under way for developing a special type of seal ~in which a material different from " the liquid being pumped and having a higher melting temperature 1s injected 1nto the seal and frozen. Tests conducted to date indicate that this type of seal shows promise. Heat transfer tests have been conducted with the sodium-to-air ~radiator, and the sodium inlet temper- " ature has been increased to 1700°F. The radiator tested had 15 fins per inch, which were sectioned every 2 inches. This gave a net improvement ~of 20% in the over-all heat transfer coefficient, as compared with that for an unsectioned radiator, A bi-fluid heat transfer system has been con- structed, and shake-down tests have been conducted satisfactorily. The rotameter type of flowmeter that uses a tapered core riding inside an induction coil as the float-position sensing element has given very satis- factory performance.’ This type of flowmeter will be used in the ARE. The Moore Nullmatic pressure trans- mitters, modified for high-temperature operation, have given trouble-free performance during several hundred hours of operation with pressure transmitter temperatures as high as 1400°F. Pressures up to 70 psi were measured. Techniques for the vacuum distil- lation of small guantities of Nak fromliquid systems arebeing developed, since all the NaK used for cleaning the ARE fuel system cannot otherwise be removed. Tests have continued for determining the temperature-dependence of gas line plugs above systems employing a ZrF, -bearing fluoride mixture. Vapor condensation traps for this ZrF, vapor, in which the vapor is bubbled through the eutectic NaF-KF-LiF, have been satisfactorily tested. _ Improvements made in the plant facilities are the installation of a helium distribution system, the expansion of the fabrication shop facilities, the completion of the instrument shop facilities, and the installationof six gas-fired furnaces. PUMPS FOR HIGH-TEMPERATURE FLUIDS W. B. McDonald G. D. Whitman W. G. Cobb W. R. Huntley A. G. Grindell J. M. Trummel ANP Division Pump with Combination Packed and Frozen Seal. In the first test, the pump with the combination packed 17 ANP PROJECT QUARTERLY PROGRESS REPORT and frozen seal ran for 550 hr befare 1t had to be stopped because of a valve failure in the loop. Average operating conditions during this run were: Pump suction pressure 5 to 15 psig 35 to 50 psig 1500 rpm 15 gpm 750 to 1050°F Pump discharge pressure Shaft speed Flow Packing temperature Temperature at extreme end of frozen seal 600 to 800°F The packing of the pump was made up of Inconel braid with mixtures of graphite powder and nickel powder between the layers of braid. The pump shaft was coated with Stellite No. 6. Operation of the pump was charac- terized by frequent power surges of the driving motor because of shaft seizing in the seal area. Tricresyl phosphate and lead glass were periodi- cally injected into the seal as lubricants, with indeterminant results, Postrun examination of the shaft showed very severe scoring in the frozen seal region (0.036 in. on the diameter of the 1 1/2-in, shaft). The second run of this pump was of 600 -hr duration, Loop shutdown was caused by leakage of the pump flange. Changes made 1in the pump and in the operating procedure before this run wer e: 1. pump shaft resurfaced to remove scoring of first run, 2. packing changed to nickel-foil wrapped braid with graphite powder be tween packing layers, 3. no lubricants injected. Operation was much smoother than that of the first run. This seemed to be primarily the result of closer temperature regulation of the frozen- seal area. 1t was found that 750 to BOO°F was the most satisfactory range for relatively smooth operation. lLeakage of solid fluoride from the seal at these temperatures varied approximately from 1 to 3 g/day. The packing temperature was maintained at 1050°F. 18 A stop-start technique for the frozen seal was developed during this second run. Upon turning off the motor power, the pump coasts freely to a stop. However, the shaft becomes immovable in approximately 30 seconds. Therefore calrod heating is applied to the frozen seal area and the tempera- ature brought to an indicated 850°F, The seal then loosens, and the operation may be resumed with no leakage. Timing 1s important, since the application of too much heat may result in heavy seal leakage. A quick means of cooling the seal, such as an air blast, must be used i1f the frozen seal is completely removed, A second Durco pump has been modified to i1nclude a combination packed and frozen seal. This pump has accumulated 84 hr of operation at 1200°F and flow rates up to 60 gpm. Operation of this pump has been very difficult because of unexplained sei1zing 1in the seal area. Temperature rises along the seal area indicate that the taking place 1in the packing area of the seal. This cannot be definitely concluded, since the shaft has not been examined in that area. Some stop-start data were obtained during one of the runs. It appeared that a very definite temperature range (750 to 820°F in this case) was needed for remote loosening of the shaft and subsequent startup without leakage,. The start-stop procedure was repeated five times, and successful operation followed each trial, However, this performance could not be duplicated in later trials. Part of this incon- sistency 1is thought to be caused by the chip retainer, which 1s being removed for the next run. seizing 1s however, One other change 1s being made in the seal geometry in an attempt to obtain more consistent operation. The radial clearance between shaft and wall in the frozen seal region is being increased from 0.010 to 0,040 in. to more closely duplicate the design of the first combination seal "pump, discussed above, which ran satisfactorily. ‘ : Pump with Frozen-Sodium Seal. Approximately 4000 hr of operation had been accumulated when the test of the pump with the frozen-sodium seal had to be terminated because of leaking flanges and failure of a thermocouple well. The final run was of 1000-hr duration at a pump temperature of 1100°F, ' Postrun examination of the pump showed no measurable wear of the shaft in the frozen-seal area. Scoring of the rear face of the impeller, - which indicated inter ference with the housing, was very severe and was probably the source of pump noises during the last run. ' : Allis-Chalmers Pump. During this quarter the Allis-Chalmers pump that has a hydrostatic bearing was tested with NaK as the system fluid. When this pump was first tested, the shaft gas seal provided by Allis-Chalmers was used. The seal consisted of three Graphitar rings, each of which had three 120 ~deg segments. The room- temperaturediametral clearance between shaft seal rings was designed to be between 0.0065 and 0.008 inch. At operating conditions (approximately 170 gpm, 45-ft head, and elevated temperature), the diametral clearance and the gas leakage to atmosphere past these rings were to approach zero. In the first test, the gas leakage past the seal was excessive, and a large amount of gas was entrained in the system fluid. Therefore two modifications were made to the pump: a rotary face seal was added to decrease gas leakage to atmosphere, and additional baffling, suggested by Allis-Chalmers, was placed in the region above the pump impeller to reduce gas entrainmentin system fluid. The second test revealed that the additional baffling did materially reduced gas entrainment in the system fluid and also that the rotary face PERIOD ENDING DECEMBER 10, 1952 seal reduced gas leakage toa tolerable level. The unlubricated rotary face seal, however, squealed and chattered aftera very short period of operation. Further testing indicated that the seal operating temperature was sensitive to changes in pump suction pressure, a condition that may be overcome by using a balanced bellows seal. These tests indicate that this pump will give satisfactory performance when a good gas seal is incorporated in the design. A frozen-sodium gas seal 1is presently being fabricated for test in this pump. Laboratory-Size Pump with Gas Seal. The laboratory-size centrifugal pump with a gas seal, described previ- ously,(1) has been operated for a total of 1275 hr with the fluoride fuel NaF-ZrF -UF, (46-50-4 mole %) at temperatures up to 1500°F. The average fluid temperature during this period was approximately 1350°F. The satis- factory performance data obtained are presented in Fig. 2.1. The pump discharge pressure and pressure drop across the venturi were measured by means of the null-balance level- indicator systen. The initial difficulty of liquid- level detection in the pump bowl at high shaft speeds has been overcome. The turbulence in the liquid surface has been reduced by additional baffling, and the action of the probes used for level detection has been quite satisfactory up to shaft speeds of 4400 rpm. The rotary gas seal ~ Graphitar No. 30 lubricated with spindle o0il running against hardened tool steel - has functioned with ‘extremely small gas leakage and without maintenance or appreciable wear during the total running time. Oil leakage past the seal assembly was collected, and 1t was found to amount to less than 1 ¢m?® per 24-hr period. The only (1y. 6. Cobb, P. W. Taylor, and G. D. Whitman, ANP Quer. Prog. Rep. Sept. 10, 1952, ORNL-1375, p. 1lé. 19 ANP PROJECT QUARTERLY PROGRESS REPORT Fig. 2.1, mole %) at 1300°F. mechanical failures in this pump have been broken guide vanes in the dis- charge case. These vanes were origi- nally held in place by small tack welds, which have now been reinforced, and additional welds have been added. 20 M 20 ] DWG. 17439 DENSITY ~ 195 Ib/ft3 80 - — - 4300 rpm -‘MN M""""—-_ Mr_"“-«. I, "? O ....... A — . I 4000 rom e iy 6 O I R e — 50 2 ~— o b=, T 40 \g 30 - IR R 30 | EFFICIENCY AT 3600 rpm 2200 rpm /‘ ------ i 20 e b 20 L~ ™ o T T & S . . {0 / 10 W ////f//? 1250 rpm 0 z’// 0 O 2 4 & 8 10 12 14 16 FLOW (gpm) Performance Curves for Centrifugal Pump with NaF-ZrF, -UF, (46-50-4 Density of fluoride mixture is about 195 1b/ fe 3. A second pump has been fabricated and installed in the fluoride loop of a bi-fluid heat exchanger system. No radical changes have been planned in the present design. However, some effort has been put forth to simplify the construction of the shaft and radiation heat shields. ARE Pump. It is now planned that the pumps for the ARE fuel circuit are to be similar to the ANP experimental engineering model FP. Figure 2.2 shows an assembly-section view of the pump. A standard commercial pump base with ball bearings that support a horizontal, overhung shaft provides the foundation., The pump casing is supported through the sealing head and casing extension. The sealing head 1s sealed to the pump casing with a commercial oval-ring gasket in a bolted flange joint, By removing this Joint from the hot region near the pumped liguid and away from regions requiring preheating, satisfactory sealing 1s readily accomplished. ' Pump suction and discharge con- nections to the circulating system are made by welding. The pump impeller is an Inconel casting from standard Worthington Pump Co. The discharge case 1s machined from heavy Inconel forgings and has a concentric volute and a welded tangential dis- charge. The impeller is double-keyed to the overhung shaft and i1s held in place by a thrust nut and a locking screw. Normal radial clearances are employed between the impeller hubs and the sealing labyrinths, and an axial clearance of 5/32 in. 1in either direction prevents jamming resulting from differential thermal expansion, The shaft seal is of the frozen-packed design; the gland for the stuffing box provides the region for the frozen seal. To prevenl cracking or checking of the hard surface material on the shaft, the material is applied as a loose-fitting, prefabricated sleeve, The concentricity between seal and shaft and the differential expansion are controlled by angle-beveling the inside of both ends to the geometrical angle of the sleeve. A cartridge type of electric heater ~1s provided in the center of the shaft for control of temperatures. A turbo- patterns. PERIOD. ENDING DECEMBER 10, 1952 slinger arrangement is provided just outboard of the seal gland to maintain a suitable temperature on the oil seals and bearing. Two independent heaters are provided on the outer surface of the seal shell for further control of the temperatures in the seal region. Provision is made for the circulation of a coolant through selected portions of the shaft. Circu- lation of lubricating o1l through the bearing housing 1s provided to minimize effects of radiation damage to the lubricant. The pump (Fig. 2.2) provides a seal for NaK for system cleaning by maintaining molten sodium in the gland groove and freezing on both sides of the annulus. During operation with fluorides, this annulus will serve as a shield to prevent the loss of enriched material by guiding the expected slight leakage to a con- tainer. The coolant for freezing the sodium is to be kerosene at approxi- mately S0°F, A beveled surface on the gland makes a metal-to-metal s'eal against the inner edge of the seal shell to form a NaK-tight seal around the outer surface of the gland. This frozen-sodium seal also seals the system during vacuum removal of the NaK. During operation with NaK, the cartridge heater is removed from the center of the shaft, and a squirt- tube arrangement is inserted to circu- late cooled kerosene. The only alteration necessary to make the pump suitable for circulating NaK as a moderator and reflector coolant is the elimination of the shaft sleeve and the seal heaters. ROTATING SHAFT AND VALVE STEM SEAL DEVELOPMENT McDonald -R. N. Mason - Tunnell P. G. Smrth - W. R. Huntley ANP Division W. B. w. C. Screening Tests forPacking Materials and Lubricants. Work has been done 21 GG UNCLASSIFIED DWG. 17440 SHAFT SLEEVE GLAND GROOVE SEALING HEAD SEALING GLAND PAGKING TURBO-SLINGER .~ TUBULAR HEATERS COMMERCIAL PUMP BASE CASING IMPELLER '}« \m\xw\wm\\m\“w“\“w.\ .\\M\M i) A = b~ s i T DiSCHARGE CARTRIDGE HEATER Fig. 2.2. Assembly of ARE Pump. Sectional view. ~ L 904d ATYALYVN0 LOIdl0¥d dNV LY0dAd SS on packed seals for pumps and valves, and screening tests have been made on a number of packing materials for possible use as lubricants. The test consisted of heating the material under compression to 1500°F for a period of time and then comparing the heated material with the original material. The materials tested included C (graphite), PbO, Ni,0,, Ni,0, + PbO, PbO + Mo, Ni,O, + Mo, CrF,, Ni,0, +C, PbD + C, Pb,(OH),CrO,, MoS,, Ni, 0, +MeS,, MeS, + Mo, BN+ MoS,, BN, Ni,0, + BN, BN + C, ZnS, CeQ,, and CaF,. The tests indicated that the following materials may possibly be useful as high-temperature lubricants: C (graphite), N1203,~Ni203 + Mo, Ni203 + C, MoSz, MoS2 + Mo, MoS2 + BN, and BN + C. CeO, may be a fine abrasive. It 1s planned to further test these materials in contact with fluorides, One test apparatus for screening materials has been built and operated that consists of a fluoride pot with stuffing boxes on the top and bottom. A single shaft is inserted through both the stuffing boxes, and the material to be tested 1s conhtained in the spring-loaded glands. The shaft 1s reciprocated by an air cylinder, and the power requirements can be measured. Graphite and MoS, have been vested at 1000°F in this device with no fluoride leakage out of the stuffing boxes. However, the fluoride wets the surface of the shaft and 1is carried i1into the packing where it causes the shaft to bind with the packing, and the power reguirement becomes excessive. Mixtures of graphite and MoS, with powdered fluoride have also been tried in these glands, but there was no fluoride in the pot. The results were similar 1n that the powdered fluoride melted and caused the gland walls and the - shaft surface to bind. _ One other test device that is being assembled has 1dentical packings located at each end of a lantern gland PERIOD ENDING DECEMBER 10, 1952 in a heated container with a rotating shaft through the assembly. The equipment is designed so that liquids, such as fluorides or lubricants, can be introduced under pressure into the lantern gland. This assembly 1is mounted so that spring tension prevents rotation, and the torque required for operation can be measured. Packing Compression Tests, As reported previously,(?? experience with high-temperature packing materials indicates thatin almost every instance stuffing boxes have required re- tightening after they reached operating temperature. Therefore a series of tests have been run onvarious materials to determine their compression charac- teristics. A dial indicator for measuring the expansion or contraction of the material being tested was mounted on the test apparatus. In the tests, a l-in.-thick layer of the material being tested was subjected to a compressive force of 75 psi and the compression was measured. The material was then heated to 1500°F and held at that temperature until the dial indicator showed no further change. After reachingthis equilibrium condition, the material was held at 1500°F for a further period of 1 hr, and the compression was again measured. The change in compression, that is, the difference between the compression before heating and the compression after heating, 1s given in Table 2.1. This test procedure was repeated several times for each material. In all tests thus far, with the exception of the test of nickelic oxide, there was little, 1f any, further dimensional change after the initial heating. Packing Penetration Tests. A series of tests has been run to determine the wetting susceptibility of various materials. The materaal to be tested is compressed by a heavy washer and screw in a contailner. (2)9. R. Ward, H. R. Johnson, aend R. N. Mason, ANP Quar. Prog. Rep. Sept. 10, 1952, ORNL-1375, p. 19. 23 ANP PROJECT QUARTERLY PROGRESS REPORT TABLE 2.1. COMPRESSION TESTS OF VARIQUS PACKING MATERIALS AT 1300°F AND 75 psi REMARKS COMPRESSION DUE TO - HEATING MATERI AL THERMAL EFFECT CYCLE (in.) Graphite 1 0.038 0.009 3 0.005 Boron nitride 1 0.071 2 0.003 3 0.003 4 0.002 Nickelic oxide 1 0.012 2 0.004 3 0.003 4 0.002 Molybdenum disulfide 1 0.058 2 0.008 3 0.007 4 0.001 5 0.002 6 0.000 10% Graphite plus 1 0.165 90% nickel powder (by weight) 25% Aluminum powder 1 0. 165 plus 75% iron powder (by weight) Material was easily removed from the apparatus and was apparently unchanged. Material was easily removed from the apparatus and was apparently unchanged. Material was easily removed from the apparatus although a large force (4 tons) was required to pusE the stem through the packing material in order to disassemble the apparatus. The material contracted several thousandths of an inch when cooled after each heating period. Upon the fourth heating, thematerial expanded sTightly. Material was easily removed from the apparatus and was apparently unchanged. Material had to be chiseled from the apparatus. Material had to be chiseled from the aspparatus. Fluoride 1s introduced above the material being tested, and gas pressure 1s applied to drive the fluoride through the material. Graphite, when compressed, was not gas tight, and when the fluoride was loaded there appeared to be a definite interface between the fluoride and graphite, which indicated that the graphite was not wetted by the fluoride. The test ran 240 hr with a pressure of 30 psi above the fluoride. Boron nitride, when compressed, also was not gas tight; however, after the fluoride was loaded the test ran 26 hr with 5-psi pressure above the 24 fluoride without leakage of the fluoride i1nto the boron nitrade. The pressure was then increased to 10 psi and leakage began. There was some greenish color a1n the boron nitride. The main leakage path of the fluoride appeared to be along the walls of the container and the screw stem toward the hole 1n the bottom of the container for the screw stem. Stainless steel braid was compressed and heated to the annealing temperature twice and further compressed after each heating. The material permitted free flow of gas before 1t was filled with fluoride. ITmmediately after filling, fluoride leakage occurred at only 1-psi pressure. The leakage soon stopped, and the gas flow was somewhat retarded. When the pressure was increased £o3 psi, most of the fluoride was forced from the container., Exami- nation showed that only a small amount of fluoride had adhered to the braid. Attempts were made to run tests of molybdenum disulfide and nickelic oxide, but these materials were so “fluid” that the container would not hold them. Parts with smaller clear- ances are being fabricated. , Face Seal Tests. Face seals are being considered for high-temperature use with both gases and liquids. All tests have been run in air at room temperature with speeds of about 1600 rpm and pressures of up to 14 psi. The following combinations of materials were tested 1n air, without added lubrication: Carboloy (gréde 779} vs. Carboley {(grade 779) Carboloy {grade 779) vs. graphite (grade C-18) Graphite (grade C-18) vs. graphite {grade C-1§) In the test of Carboloyvs. Carboloy, a loud, grinding noise developed within 5 min, and inspection showed that annular grooves had been worn into each surface. Operation with the other two combinations of materials was satisfactory until chattering developed when a temperature of about 550°F was reached at the seal because of the heat of friction. If graphite depends upon a layer of tightly held moisture for some of its lubrication PERIOD ENDING DECEMBER 10, 1952 qualities,(3*4) then this chattering may be due to the driving-off of surface-held moisture at a more rapid rate than 1t can be supplied by diffusion from the interior of the graphite. The time required for the test seals to reach the chattering stage was usually between 1/2 and 4 hr; however, in one test the Carboloy vs., graphite seal operated satis- factorily for 42 hours. The area of seal contact was 1 1/2 in.? in each test, and the seal contact force was varied from 5 to 20 pounds. Similar results were obtained when Carboloy vs. graphite seals were tested with MoS, and RbOH used as lubricants. Although some seals showed relatively little chattering, therewas, generally, a marked increase in the torque required to overcome the seal frlctlcn as the seals heated up. Combination Packed and Frozen Seal. A seal consisting of a stuffing box packed with powdered graphite in which the slight leakage of fluoride was frozen in the packing compression member was operated for a period of 215 hr at temperatures from 970 to 1500°F with system pressuresthat varied from 16 to 37 ps Leakage rates were measured at_various temper ~ atures and pressures in an attempt to determine the most favorable operating conditions. (E)Pure Carbon Cempany, Inc., Properties of Pure+Bond, Bulletin No. 52, p. § Y)R. H. Savage, J. Appl. Phys. 189, 1-10 (1948). | TABLE 2. 2. LEAKAGE RATES FfiR’COMBINATION PACKED ANP FROZEN SEAL SYSTEM PREEEE&E TEMFERATURE AVERAGE LEAKAGE LEAST AMOUNT OF LEAKAGE (psi) ( °F) (g/hr) (g/hr) | 16 1150 1 | 0.15 30 1200 1 0,4 37 1200 3 0.4 25 ANP PROJECT QUARTERLY PROGRESS REPORT During this test there was no indication of shaft seizing by the seal. Spectrographic analysis of the leakage showed the constituents to be Co, B, Cd, Cr, Fe, K, Ni, and Si, as well as Na, U, and Zr. Chemical analysis of the leakage indicated that the Na, U, and Zr constituents were present in very nearly the same proportions as in the fluoride in the system. A second test, with a similar packing, in which the compression member 1s spring loaded to keep tension on the graphite at all times has been in operation for approximately 350 hr with only small leakage of solid fluoride and with no operational difficulties. ¥rozen-Lead Seal. A test, similar to previous tests with sodium, was conducted to determine the operating characteristics of a frozen seal when lead is used as the system fluid. The equipment consisted of a chrome- plated stainless steel shaft rotating in a finned sleeve in which the frozen seal was formed. A pot to contain the hot lead to supply the seal was attached to the finned section. The finned sleeve was provided with a heater for melting out the frozen seal 1in order to resume operation after a shut-down. A portion of the finned section was shrouded so that a blast of air could be directed across the seal when required. This test operated for a period of 526 hr with leakage occurring when the finned section temperature was permitted to exceed 600°F. The lead temperature in the pot was between 1000 and 1200°F, and the system pressure was 8 ps1. Very smooth operation was experienced, with no tendency toward shaft seizure. The test was terminated when the seal became too hot and caused an excessive loss of lead. This test 1indicates that a lead pump with a frozen-lead seal can be expected to give as satis- factory performance as a sodium pump with a frozen-sodium seal. Frozen-Sodium Seal. Preliminary 26 tests have been conducted to determine the feasibility of using a frozen- sodium seal for sealing a high-temper- ature NaK pump. This design consists of a heated annulus around the shaft to which molten sodium 1s supplied from an attached container. Sodium 1in the annulus i1s kept molten at all times. A coolant passage 1s located on either side of the molten sodium for freezing the sodium around the shaft and preventing sodium leakage from the annulus. The temperature of the NaKis reduced to below the melting point of the sodium at the frozen sodium-to-NaK interface. In the initial tests, some difficulty has been encountered with heat conduction by the solid shaft to the region of the frozen-sodium seal that 1s suf- ficient to melt out the sodium forming the seal when the NaK bath 1is at temperatures greater than 500°F; however, 1t 1s expected that internal cooling of the shaft will eliminate this difficulty. These tests indicate that such an arrangement will satisfactorily seal the rotating shaft of a NaK pump 1f the temperature of the NaK at the NaK-to-sodium interface 1s below the melting point of the sodium and sufficient internal cooling of the shaft 1s provided to prevent the melting of the frozen-sodium seal. This design 1s being incorporated into the pumps for the moderator- cooling circuit of the ARE and also in the pumps for the 1nitial circu- lation of NaK through the ARE {fuel circult. Bellows-Type of Valve Stem Seal (G.M. Adamson, R.S. Crouse, Metallurgy Division). Two, 3-ply, Inconel bellows 2 in. in diameter and 3 1in, long were examined for the Experimental Engineering group. The bellows had been fabricated at the Fulton Sylphon Co. by using a special rolling technique. The first one had been i1mmersed in the fuel mixture NaF-ZrF,-UF, (46-50-4 mole %) for 975 hr and the second one for 1975 hr at 1500°F.¢%> The first bellows examined had fluorides between the outer and center ply and the second one, which was full of fluorides, had failed completely. The most important observation made during this investigation was that the wall thickness of the bellows was much less than that expected. Instead of the thickness being 0.027 in., the average thickness was only 0.022 inch. What was even more serious was that the bends were even thinner. In the first bellows, the bends had been thinned an additional 34% and in the other 21%. In the first bellows, several spots in the outside ply were less than 0.002 in. thick. | The first bellows probably failed through one of the thinned down areas in the outer ply. No definite cause for the complete failure of the second bellows can be given. When examined, this bellows contained many circumfer- ential cracks. Although it i1s certain that some of these cracks were made after the test, 1t is probable that some of them were fabrication cracks and were the cause of the failure. In both these bellows, considerable self-welding between the plies was found at the bends. _ The manufacturer was contacted, and two similar bellows were obtained for examination in the "“as received” condition. Two other 3-ply bellows 1 3/8 1in. in diameter and 6 in. long were also sent for examination. The two 2-1n. bellows are even thinner than those discussed above. Both these bellows had an average thickness of 0.018 inch. The plies were more nearly uniform and the thinning in the - bends was 16.7 and 12.5%. The two smaller bellows also had an average thickness of 0.018 inch. The reductions - found 1in the bends of these two were 16.7 and 11.1%. No self-welding or fabrication cracks were found in any of these bellows. Sp oy Taylor, ANP Quar. Prog. Rep. Sept. 10, 1952, ORNL-1375, p. 19. PERIOD ENDING DECFMBER 10, 1952 The manufacturer is now attempting to fabricate 4~-ply bellows to obtain the desired wall thickness. The individual plies will be as thick as those of the bellows described above, or thicker, if posszble HEAT EXCHANGERS G. D. Whitman D. F. Salmon ANP Division Sodium-to-Air Radiatoer. The third sodium-to-air radiator performance and endurance test was started during the quarter and ran for 1212 hr before failure., The running time at the varioussodium inlet temperaturee is given in the following: TEMPERATURE RUNNING TIME (°F) (hr) 700 - 24 900 48 1100 . 72 1300 34 1500 _ 655 1600 336 1700 43 Total 1212 Failure occurred at a sodium inlet temperature of 1700°F, and the resulting fire did very little damage because the system was dumped as soon as the leak was indicated by a heavy smoke discharge from the air duct. No fire fighting was necessary, and the sodium outside the system was allowed to burn 1tself out. _ Again, as 1in both of the previous tests, a center tube between the header and top fin on the sodium inlet side of the radiator failed. The tubes 1in this radiator were fabricated from type 316 stainless steel and had 0.025-2n. walls in contrast to the type 304 stainless steel tubes with 0.015-1n. walls used in the previous designs. Since all three failures occurred in the same location, 1t is possible 27 ANP PROJECT QUARTERLY PROGRESS REPORT that a localized stress was set up in the shorter tubes between the header and the fin matrix during the brazing operation. Such stress may be relieved by increasing the spacing between the headers and top fin. Considerable difficulty was en- countered after about 400 hr of operation of this test in keeping the radiator tubes free fromoxide buildup, which would have eventually caused plugging. The plugging that occurred in the cooler sections of the radiator could be temporarily relieved by shuttingoff the air flow and operating under isothermal conditions, at 1200°F, for approximately 1 hour. After normal operation resumed, the plugging would start again, and after several hours a drop 1a heat transfer performance would be observed. A by-pass filter circuit was designed into the loop to prevent such oxide plugging, but 1t was rendered almost inoperable becausecf inadequate flow regulation. A small orifice was used to reduced the flow through the filter caircurt, but the orifice plugged easily at the low flow rates necessary for lowering the fluid temperatures in the filter. A throttling valve was substituted for the orifice, and the fluid entering the filter was held at 600 to 800°F below the main stream temperature, Approximately one-eighth of the total system flow was continuously passed through the filter, and the radiator was cleaned sufficiently to rumn about 500 hr without serious tube plugging. When the temperature of the sodium entering the radiator was raised to 1700°F, some tube plugging started again and had not been satisfactorily cleared before the failure. The radiator was of the same general design as that of previous was models, and the fin spacing was 15 fins per inch. The fins were cut through, interrupted, and slightly in the direction The over-all coefficient of fset every 2 in. of air flow. 28 of heat transfer 1s shown plotted against mass air flow rate per square foot of face area (Fig. 2.3). An improvement of about 20% in the over- all heat transfer coefficient was achieved over the continuous fin exchanger, as shown by the dashed line. The accompanying increase 1in air-pressuredrop was between 10 and 15%. Bifluid Heat Transfer System. Assembly of the bifluid loop reported previously(®) has been completed. The NaK system has been filled and the electromagnetic pump has been checked. Various minor changes were necessary, such as correcting reversed thermo- couples and clearing gas lines. Considerable effort was required to get the electromagnetic pump started. The trouble, however, stemmed entirely from nonwetting or uncleanliness of the pump cell. When the NaK was heated 1n the sump tank so that the pump cell temperature reached 450°F, the pump started i1immediately. A flow rate of 11 gpm at 250 v input to the pump primary coil was achieved. This pump is a G-E model G-3, with a modified cell that has nickel lugs welded into the sides of a type 316 stainless steel throat. The electromagnetic flowmeters will be calibrated against the NaK venturi to complete the shake-down of the NaK system. The fluoride system has been filled with the fluoride fuel, NaF-ZrF4-UF4 (50-46-4 mole %), and check runs are being made before combined operation of the two-fluid systems 1s undertaken. The gas seal of the fluoride pump was operated dry up to 5000 rpm to check for gas or o1l leakage, but none was apparent. Vibration of the pump and support structure at the high speed was slaght, Dynamic corrosion data of interest to the ARE will be obtained in the heat exchanger of this loop (a small- diameter nickel tube). A temperature (G)D. F. Salmen, ANP Quar. Prog. Rep. Sept. 10, 1952 OBNL-1375. p. 21. PERIOD ENDING DECEMBER 10, 1952 ORI DWG. 17441 20 ;h w//// : olw o 0 © -~ = 10 ~ _— C " | © z : i ™~ -~ = P 5 Q’y// ,-K o > - _ -~ CONTINUOUS FINS (TEST NO.2) = - w - (_2 . - 5 ’,/' wl /," Q -~ O il o Na INLET TEMPERATURE (°F) g o 700 1 ® 900 - A 1100 I...- = ¥ 1300 L O 1500 -l e 8 1600 < m {700 i ! = O 1 1000 2000 5000 10,000 Z0,0QO MASS VELOCITY (Ib/ hr -ft2) Fig. 2.3. Heat Coefficients of Sodium-to-Air Radiator with Interrupted Fins. drop of the fluoride passing through the nickel tube in excess of 100°F and Reynold’s numbers above the laminar 'range should be achieved. The 1impeller "of the fluoride pump was fabricated from Inconel to compare its corrosion ‘resistance with that of a type 316 stainless steel 1mpeller that was used in another loop with an identical Spump. INSTRUMENTATION W. B. McDonald P. G. Smith P. W. Tavylor A. L. Southern J. M. Trummel ANP Division Rotameter Type of Flowmeter. It was reported previously¢(’?? that a (U)p, G. Smith and A. L. Southern, ANP Quar. Prog. Rep. Sept. to, 1952, ORNL-1375, p. 23. 29 ANP PROJECT QUARTERLY PROGRESS REPORT rotameter type of flowmeter had been installed in a high-temperature fluoride loap and that 1t had not operated successfully. The difficulty encountered with the flowmeter was binding of the tapered-core position indicator in its housing as a result of thermal distortion. The details of construction of this flowmeter and 1ts principle of operation were given previously.(7) Other such flowmeters have been constructed with increased clearance around the tapered core to prevent binding. One has operated for a period of 600 hr and measured flows up to 17 gpm at 1300°F. The temperature of the static fluoride in which the tapered core operates is 1100°F. Flow measurements have been accurate to within 10%. It was found that such accuracy can be maintained for long periods 1f close control is maintained over the temperature of the fluorides in which the tapered core 1s operated. A similar flowmeter, with a capacity to 60 gpm, has been installed and is operating successfully 1n a larger test loop. This 1instrument can be adapted for ARE use. Rotating-Vane Flowmeter. The rotating-vane flowmeter manufactured by the Potter Instrument Co. and modified by the Experimental Engineering group, as reported previously,(®) has been installed in a high-temperature loop. Attempts to measure flow with this instrument have been unsuccessful. Under loop operating conditions, no signal that can be calibrated in terms of flow can be obtained from the flowmeter., One difficulty ex- perienced i1s that the loop heater circuits cause 1nduced voltages in the pickup coil that are greater than the signal expected from the flowmeter; however, when the heater circuits are turned off for short periods, no useful signal 1s detectable with the present i1nstrumentation. It 1s (8)y. B. McDonald and J. M. Trummel, ANP Quar. Prog. Rep. Sept. 10, 1952, ORNL-1375, p. 24. 30 thought that thermal distortion at this temperature (1300°F) caused the bearings to seize and render the instrument inoperable, This instrument will not be available for examination until tests with the loop in which 1t has been placed have been terminated and the loop has been dismantled. Diaphragm Pressure-Measuring Device. The diaphragm pressure- measuringdevice reported previously{®> which utilizes a linear differential transformer to measure the deflection of a diaphragm, has been i1in operation for more than 100 hr at temperatures up to 1040°F., The diaphragm in this instrument is made of 1/16-in.,, flat, Inconel stock 3 in. in diameter. Preliminary tests indicate that the operation is reliable up to 1000 °F over the range from 0 to 40 psi. To date, the instrument has been tested only with inert gas against the diaphragm; however, it 1s not expected that the introduction of molten fluorides will radically change the operating characteristics of the instrument, The only observable effects of 1ncreased temperature are a shift of the zero point and an increase in the slope of the performance curve (Fig. 2.4). A second instrument 1is being fabricated that will operate with fluorides at 1000 to 1100°F against the Inconel diaphragm. Moore Nullmatic Pressure Trans- mitter. The Moore Nullmatic pressure transmitter reported previously,(19) which was modified to prevent the fluorides from coming 1in contact with the bellows pressure-sensing element, has been installed in a high-tempera- ture fluoride loop and has operated successfully for approximately 200 hours. The pressure-transmitter temperatures have ranged as high as 1400°F, and pressures have been measured up to 70 psi. A slight zero shift has been encountered with 9y, W. Taylor, ANP Quar. Prog. Rep. Sept. 10, 1952, OBRNL-1375, p. 25. S TYP) PERIOD ENDING DECEMBER 10, 1952 UNCLASSIFIED . 1744 580 N DWG .2 . 240 % LLk tl o o i > D - z 200 o < o T o 3 160 0 « 5 e ok = QO Q 5 120 : g - L L) o = S 80 . v T o < a 4C¥ 0 : L , 0 10 . 20 : 30 40 GAGE PRESSURE (psi) Fig., 2.4. Performance Curves for Diaphragm Pressure-Measuring Device, increased temperatures, aswas expected. Accurate temperature control of the instrument should eliminate this source of inaccuracy. , _ Static corrosion tests of 3-ply Inconel bellows 1n the fluoride mixture NaF~ZrF4-UF4 (46-50-4 mole %) at 1500°F indicate that such bellows may be incorporated in the Moore Nullmatic pressure transmitters and operated with the high-temperature fluorides 1in contact with the bellows. Six such instruments, rated at Q0 to 100 psi, have been ordered from the manufacturer. It is also possible that an instru- ment constructed with single-ply type 316 stainless steel, type 347 stainless steel, or nickel bellows may be used with the ZrF,-bearing fluoride fuels, sinceit is possible to maintain the fluid in static condition and to keep the temperaturein the pressure transmitter between 1000 and 1100°F and thus minimize the effects of corrosion. (Results of preliminary 31 ANP PROJECT QUARTERLY PROGRESS REPORT static corrosion tests of stainless steel, Inconel, and nickel 1in these fluorides indicate little corrosion.) The possibility of locating the instrument beneath the loop and completely submerging the bellows 1in a bath of molten lead with a tempera- ture gradient in the lead from 1100°F at the top to Just above the melting point at the bellows is being in- vestigated. This would provide a molten lead - molten fluoride interface that would make possible pressure transmittal from a 1500°F fluoride stream without exposing the bellows to damaging temperatures. Static tests have indicated that the fluoride mixture will remain on top of the lead and will not mix with the lead. HANDLING OF FLUORIDES AND LIQUID METALS L. A, Mann D. R. Ward J. M. Cisar P. W. Taylor W. B. McDonald ANP Division NaK Distillation Test. The use of cutectic NaK alloy (78 wt % K, 22 wt % Na) for cleaning the ARE {fuel circuit 1s planned. It is anticipated that about 95% of the NaK in the entire fuel circuit can be drained and the remainder will be removed by vacuum distillation under heat, An experi- mental unit has been constructed, and the first test of vacuum distillation of NaK has been conducted. 1In this test, approximately 6 1b of eutectic NaK at 1200°F was distilled from a boiler by wusing a small vacuum pump that pulled continuously from the receiver and maintained a pressure of less than 2 mm Hg. A steady flow of approximately 3 scfmof helium was maintained through the system. This operation continued intermittently for approximately three days; however, there was some down time on the system because of gas leaks and other equipment failures. This test indicated that under attainable operating conditions, this quantityof NaK could be distilled 32 from a boiler in somewhat less than 16 hours. Gas-Line Plugging., It was reported previously(1!) that continued tests were being conducted to determine the extent of gas-line plugging from the vapors of a bath of the fuel mixture NaF-ZrF4-UF4 (46 -50-4 mole %) at various elevated temperatures. A summary of the results of the tests, to date, follows: 1. In operation at 1050°F, there wasno gas-line plugging during 1488 hr of testing. 2. 1In operation at 1300°F, all lines partly plugged after 666 hr of operation. Upon examination, the lines appeared to be totally plugged, but the plugs were sufficiently porous to allow the passageof gas at approxi- mately onc-tenth that of the initial flow rate. 3. In operation at 1500°F, all lines plugged solid ain 100 hr of operation. These tests indicate that gas lines may be expected to operate satisfactorily in a system contailning this fuel, providing the free surface of the fuel adjacent to the entry gas lines 1s at a temperature in the range between 1050 and 1100°F. Above these temperatures, some difficulty may be expected. ZrF, Vapor Condensation Test,(12) In the absence of reliable vapor- pressure data for ZrF,, tests were conducted to determine the minimum container-wall temperature needed to minimize or prevent condensation of ZrF, on the walls. Each of four 1-in.-IPS tubes 18 1n. long was charged with approximately 180 g of the fuel mixture NaF-ZrF4-UF4 (46 -50 -4 mole %). The fuel was maintained at 1500°F in each tube, and the portions above the fuel tubes were maintained at different temperatures, ranging ______ for each tube. (Il)w. B. McDonald and P. W. Taylor, ANP Quar. Prog. Rep. Sept. 10, 1952, OBRNL-1375, p. 32. (12)\\(. B. McDonald and J. W. Trummel, ANP Quar. Prog, Rep. Sept. 10, 19592, ORNL-1375, p. 34. ' These conditions were maintained for 300 hours. The tubes were then sectioned and examined for crystal ~deposits of ZrF,. Correlation of “crystal deposits on the inside tube walls with the various tube-wall temperatures during the test indicates that the ZrF, vapor given off by the fuel at 1500°F will condense on any " surface that is at a temperature of 1250°F or lower. When the tube-wall temperature 1s maintalned at a temper- ature greater than 1250°F, no deposits of ZrF, crystals will be formed. These data check reasonably well wath available vapor-pressure data for ZrF, and for the fluoride mixture NaF-ZrF,-UF, (46-50-4 mole %). PROJECT FACILITIES(!®) Helium Distribution. High-purity heliumis now delivered to distribution systems in the experimental engineering laboratories, Building 9201-3, and the Fuels Production Pilot Plant, Building 9928, by pipe line from tank cars through a pressure-reducing station located at a considerable distance from the building. The installation cost for the several thousand feet of pipe line has been offset completely by the saving already accrued from complete elimination of the labor formerly required to carry out the time-consuming process of filling empty ecylinders with helium at the tank car, transporting the cylinders to intermediate storage, performing individual purity tests spectrographically on each cylinder, distributing the cylinders to work locations, and finally returning the empty cylinders to the tank car for refilling. : Fabrication Shop. The shop facili- ties of the Experimental Engineering (13)The fuel production ard purification facilities are described in section 11, “Chemistry of High-Temperature Liguids."” ' PERIOD ENDING DECEMBER 10, 1952 Department, Building 9201-3, have been relocated and consolidated to permit expansion of the machine shop and relocation of every fabrication work area to new locations adjacent to the mechanical stores crib. With the new arrangement, the production of component parts 1s expedited through the various steps of fabrication, handling is reduced, better housekeeping 1is achieved, and a more workable ar- rangement for the shops is obtained. The use of oxygen and acetylene cylinders has been eliminated by installation of piped supplies of these gases to the work benches in the fabrication area from outdoor cylinder-manifold systems. The ventilation system has been expanded to relieve the new shops of smoke, fumes, and the excessive heat generated during fabrication procedures. ‘ Instrument Shop Facility. A new facility in Building 9201-3 has recently been completed to provide a suitable environment for conducting under constant and most rigid external conditions the design, development, adjustment, and calibration of sensitive electronic instruments and equipment, The nonmagnetic laboratory benches are supplied with electric outlets, grounding busses, and piped supplies of helium, natural gas, oxygen, and acetylene. The illumination installed in the area 1s adequate. Installation of an air-conditioningsystem designed to maintain this laboratory at constant temperature and constant humidity will start in the near future. Gas-Fired Furnace Facility. A battery of six gas-fired furnaces, each rated at 68,000 Btu/hr, is being installed on the main track floor of the experimental engineering labo- ratories, Building 9201-3. The furnaces will serve as heat sources for the various experimental programs under way at the present time. 33 ANP PROJECT QUARTERLY PROGRESS REPORT Each furnace 1s provided with positive safety protection and control instrumentation, including purging blowers, high-voltage spark-ignition systems, differential pressure regu- lators with fail-safe and manual 34 reset features, dilution exhaust stacks, and fail-safe interlocking controls with provision for tempera- ture control and automatic shut-down in the event that the associrated experimental equipment fails, PERIOD ENDING DECEMBER 10, 1952 53. GENERAL DESIGN STUDIES A, P. Fraas, ANP Division A program for the development of liguid-to-air radiators for turbojet ~engines has been outlined. Because of the magnitude of the work involved, the Air Force (Wright Air Development Center) is planning a program for the development of radiator fabrication " technigues., The performance of a radiator already tested at ORNL(!? has been extrapolated to that of a full- scale radiator, and the data have been ~used to analyze the performance of a Sapphire turbojet engine incorporating such a radiator. Performance data for ~ both the radiator and engine appear to be very encouraging. Further design and analysis of reflector-moderated reactors(2) have been held in abeyance pending the completion of critical experiments to determine feasibility., Preliminary results of the first critical assembly are described in section 5, “Critical Experiments.” ‘ ; ATIR RADIATOR PROGRAM A. P. Fraas, ANP Division Further analytical and design studies have been carried out on tube- and- fin radiators. The results of this work, coupled with the experimental test results, indicate that 1t 1s not possible to predict the heat transfer pertformance of various radiator core geometries closely enough to ascertain which of the several designs 1is the best one without testing them. A set of rough scrting calculations indi- cates, however, that tests on the cores listed in Table 3.1 should be made, Since this constitutes a con- siderable program of test work that is more closely related to the engine 1 . . . ¢ )See Experimental HReactor Engineering Sections of this and previous guarterly reports, (2)4. p. Fraas, ANP Quar. Prog. Rep. June 10, 1952, OBNL-1294, p. 6. _ ' than to the reactor, the Wright Air Development Center has agreed to try to carry out, through contracts with vendors, part of the program; heat transfer information and endurance life data should thus be obtained, and one or more sources of radiator supply should be established. : RADIATOR PERFORMANCE G. D, Whitman H. J. Stumpf ANP Division Performance calculations show that a radiator core with 30 fins per inch should be very satisfactory even though it would operate at Reynold’s numbers far down in the laminar flow range., Therefore a unit was built and prepared for test, which 1s described as type L in Table 3.1. The performance characteristics of a full-scale radiator were calculated on the basis of test data obtained for the core element described as type C in Table 3.1 (cf., sec. 2, “Experi- mental Reactor Engineering’). Figure 3.1 shows the performance data 1in the form of a chart that gives ‘“heating effectiveness’ as a function of radiator depth in the direction of air flow for a series of air-mass flow rates. Figure 3.2 gives pressure-drop data for this type of radiator for a 12-in. depth in the direction of air flow. Nickel fins were assumed 1instead of stainless steel fins, The ““heating effectiveness’ was taken as the ratio of the air temperature rise to the temperature difference between the air entering the radiator and the sodium entering the radiator, ENGINE PERFOBMANCE H. J. Stumpf, ANP Division Estimated per formance characteristics for a turbojet engine fitted with 35 9¢ TABLE 3.1. 1TYPES OF TUBE AND FIN RADIATOR CORE ELEMENTS PROPOSED FOR DEVELOPMENT TESTING Tube outside diameter, 3/16 in. Tube material, type 316 stainless steel (1f available) Tube spacing transverse to air flow, 2/3 in, Tube spacing in direction of air flow, 2/3 in, Air-passage length, 12 in, Air-inlet face, 2 by 3 1/3 in. RADIATOR NO. OF ' TUBE TYDE FIN DESCRIPTION FINS PER FIN MATERIAL ABRRANGEMENT STATUS OF TEST INCH A Plain plate 10.5 Stainless steel In-line Completed May 1952 B Plain plate 15 Stainless steel In-line Completed June 1952 C Plate interrupted every 2 in. 15 Stainless steel In-line Completed October 28, 1952 D Plate iaterrupted every 2/3 in. 15 Stainless steel In-line Radiator being prepared for testing E Plate interrupted every 2 1in., with electroformed turbulators i5 Nickel In-line Fins being fabricated for ORNL F Disk fins, stamped and ceramic 15 Nickel In-line Fabrication technique being developed coated at ORNL G Disk fins, stamped 15 Stainless steel In-1ine Suggested Wright Field project H Disk fins, stamped 15 Nickel In-line Suggested Wright Field project 1 Disk fins, stamped 15 Nickel Staggered | Suggested Wright Field project J Disk fins, coined 15 Nickel Staggered | Suggested Wright Field project K Disk fins, stamped and chrome plated {possibly 0.0003 in.) 15 Nickel In-line Suggested Wright Field project L Plain plate 30 Nickel In-line In progress LUOdIY SSTYI0Md ATHALHVNO LDA[0Hd dNV 90 85 80O -~ tn ~J < O : Q miaie HEATING EFFECTIVENESS, 7 (%) 0 v n o 40 30 20 PERIGD :ENBING DECEMBER 10, 1952 o 5 o o ) We 0.010-in. NICKEL FINS INTERRUPTED EVERY Zin. A t5 FINS per in. : ¥\g-in~DIA TUBES ON %-in-SQUARE CENTERS. | WEIGHT FILLED WITH Na =801b /3 AIR INLET TEMPERATURE : 400°F Na INLET TEMPERATURE=1600°F | L No TEMPERATURE DROP = 400°F L / /! _\\ NN N 3 " & % .{:?' nY4 I S/ a, o : L2 : q? . A, dG/do = ~-K(c) = 0 and G(®) = 0, it follows that G(o) = 0 for o 2 A. This means, physically, that the power prevailing at t ~ A, has no i1nfluence on the temperature T at time t, for instance, because all the fuel present at time t - A, or earlier, has left the reactor before time t. -~ A is the time at which the reactor power passes through P, and is rising. Eventunally the reactor heats beyond T,, the temperature at which P = 0, and then the power has to start dropping. or earlier, Assume now that ¢ The attainment of the temperature T, and the connected drop in power have to occur at time t, at the latest, because, unless the power drops before 42 t, it will have exceeded P, during the whele time interval t — A to t, and even P, would have been sufficient to raise the temperature to T,. This shows that the power cannot start at P, and rise continuously for a time interval in excess of A, Also, the rate of increase in log P is limited, as can be seen from Eq. 3, where the temperature cannot be less than 0, the inlet temperature, Since both the rate of increase and the time of increase are bounded, the maximum is bounded, too. Furthermore, if the reactor power stays above P, for the time A, it has to drop below P, before it can rise again, because the temperature could not otherwise go below T,, When the power has gone below P, and starts increasing again, the above argument again holds, A similar argument shows that the power has a finite lower limit, Actually, the limits found by the above consideration are far wider than the limit obtained in practice, but they show that there are no antidamped oscillations that would increase to infinity. Periodic Oscillations. It is now of interest to determine under what conditions periodic oscillations of constant amplitude can occur. For this purpose, one multiplies Eqs. 1 and 6: a d d - = = (T ~ T )? = ¢ — log P(t o dt o) 1c Log PLO) P(t) -—f do K(o) P(t - o) | . (1) 0 If Eq. 7 is integrated over a period p of the oscillation, the left side becomes zero because of the periodi- city. The same applies to the integral of d P(t)'g; log P(t) . The remaining integral is transformed by partial integration: x 0 = log P(t) f d;:T K(o) P(t - o) . p . f dt 2L 1o P(1) f do K(o) P(t - o) dt o f "PERIOD ENDING DECEMBER 10, 1952 t=p t=0 p ® d f dt log P(t) J- do K(o)=— P(t - o) . o 0 dt Again, because of the periodicity, the first term on the right has the same value at ¢ = p and t = 0, and hence only the second term remains on the right side. Noting that d plt - o) d Pt ) —_ - = e —— P - dt | dor v and interchanging the order of inte- gration, one transforms ‘this term into o _ ., , : : do K(U)——f dt log P(t) P(t ~ o) 0 . 0 Since K@) = 0 and fi w dK (o) K(0)=-f dr Tl o do the term can also be written f do dK (o) do 0 p f dt log P(t) P(t) o : p | f dt log P(t) P(t - ¢o) | . (8) 0 At this point, it 1is convenient, though not essential, to choose the P ko) [ dt tog P() PG - o) units of P in such a way that log P is always positive throughout the oscillation. This is possible, since P is bounded below. If log P is always positive, a theorem(z) regardlng inequalities becomes applicable. [t has only to be noted that log P 1s a monoton increasing function of P. The theorem states that the expression in the bracket 1s never negative. [t 2ol o=0 fmdodk " dt log P(t) P(t - o) e ___U< o 0 dor J; o8 _ is zero only 1f P(t — o) = P(t) for all t, that is, i1f o is a multiple of the period p. dK/do was assumed to be nonpositive; hence, the whole integral -8 1s £ 0. : It has been shown before that, for any periodic oscillation, the integral over a period of the left side of Eq. 7 is equal to zero. Hence, the integral over the right side, which 1is equal to the integral 8, has to vanish, too. The condition for this is, according to the above, that dK/do vanish, except possibly at the points (2)G. H, Hardy, J. E. Littlewood, and G. Pdlya, Inequalities, 2d ed., p. 278, Theorem 378, Cambridge Univ. Press, 1952. 43 ANP PROJECT QUARTERLY PROGRESS REPORT where the square bracket in integral 8 vanishes, that 1is, at the points where o 1s a multiple of the period. At these points dK/do may even go to ~® without vielating the condition for periodic oscillations., Speci fic Examples. The previously considered case of constant transit time and constant power distribution is obtained from the above general case by giving K(o) the specific values K(og) =1/8 for o <& and K(o) = 0 for o > 6 (compare Eq. 1 with Eq, 2 of ORNL-1227, p. 43,¢!) or Eq. 2 of Y-F10-109, p, 2(!?), dK/do = 0 at all points except o = & (where dK/do = —x), and periodic oscillations persist only if € is a multiple of the period, If the power distribution is only constant in the direction of fuel flow, but not necessarily 1in the direction perpendicular to 1it, and if there are a number of alternate fuel paths with transit times 6, , 8,, ..., ¢ , respectively, then the above n general theory applies with K(o)} = a, for Qi_l < o < Qi’ where 7 = 1, 2, e, n, 8,70, and the a, are positive 1 constants, a. @, 1. Periodic oscillations are only possible i1f all f, are multiples of the period, a condition very unlikely to occur 1in practice, Tt should be mentioned that T. A, Welton of the Physics Division has made significant advances in reactor kinetics by a somewhat different technique.¢3) The above results can also be regarded as special casesof Welton’'s theorems. REACTOR CALCULATIONS(*) R. K. Osborn, Physics Division It was noticed that the method of images can be used to solve some specialized but not unrealistic problems of the slowing down of neutrons. The (3) T. A. Welton, Phys. Quar. Prog. Rep. Sept. 20, 1952, ORNL-1421 (in press), (4)R. K. Osborn, Some Solutions of the Age Y-F10-111 (Nov. 17, 1952). Equation, 44 case considered involves two homo- geneous, semi-infinite spaces of different properties, joined along a plane x =0. A plane, 1sotropic source of monoenergetic neutrons is placed 1in one of the half spaces, say the right half space. Under the conditions set forth below, the left half space, the “reflector,” can then be replaced, as far as the slowing down density in the right half space 1s concerned, by an “image” source located symmetrically to the given source with respect to x=0. The slowing-down density in the reflector can be described by a “refracted’’ source located to the right of x = 0. The image source and the refracted source have the same energy as the given source. Properties of the right half space are denoted by the index 1 and those of the left half space by the index 2, Zs, &, 1, and g are, respectively, the macroscoplic scattering cross section, the average lethargy 1ncrease per collision, the average cosine of the scattering angle, and the slowing-down density; 7 1is the “age’’ in the medium that contains the source. §22§2(1 - fiz) m (1) £,22,(1 - 7)) and £ 222 n = — (2) S1241 are constant with lethargy., Another assumption 1s that the source plane is parallel to x = 0, so its equation can The Fermi age with no absorption, 1is assumed to describe the slowing-down process: be written as x = X, equation, o%q, it Ox 2 9q L S(x - X) S(r) r ’ (3) and 82q2 oq, ou3 - m > =.0 . (4) The assumed boundary conditions are qz(O, T) = n ql(O, ' I (5) and ' 3q2(0, T) Bql(O, T) e et TR Q)] e et Ox ox The solution in the half space x > 0 is then . (6) - | - X)?2 qi(x, T) = (47} % exp |~ ifi——-““ : 4 + X)? | b A exp |- EEOTLL o 47 1 where 1 - = T A = T (8) 1+—n—- o The image source is thus always weaker than the given source. It 1s positive or negative depending on whether b2 n 1 - i, m 1 1 - u, is smaller or greater than 1. The solution in the reflector is given by 1 B 4mrr / (x - Y)? (9) = —_— ex = m——— ], 7 m P 47 m that is, the neutrons seem to come from a “refracted” source of strength 2n I f — (10) s PERIOD ENDING DECEMBER 10, 1952 located at v - 2 (11) I | with the whole space filled waith material that has the same properties as the reflector. The refracted source 1is always positive. That the solutions satisfy, for their respective regions, the dif- ferential equations 3 and 4 and that they also satisfy the boundary con- ditions 5 and 6 can be shown by direct substitution. _ f The constancy of m and n 1s not a bad assumption in many cases, because the scattering cross section and, hence, £ and & are usually constant over a wide lethargy range. The constancy of the scattering cross section is not a necessary condition for the constancy of m and n. For instance, if the £’s and u's are constant and the scattering cross sections in both media vary in such a way that their ratio remains constant, m and n would still remain unchanged. However, there are few practical examples in which m and n are constant and the scattering cross sections vary. The most im- portant, but somewhat trival, example 1s the case i1n which the two media are of the same material and differ only in density. Then the “image source” will have strength zero. The refracted source has the strength 1, and there is the same amount of material between the refracted source and the boundary x = 0 as there is between the actual source and the boundary. If the macroscopic absorption cross section 2 is not zero, then the image method ¢an be applied only in the somewhat trivial and not very realistic case in which 2 2 . 2 (12) z 124, | 278 2 & = If there are several sources, or a continuum of source, the solutions for 45 ANP PROJECT QUARTERLY PROGRESS REPORT the individual sources are merely superimposed, An interesting generalization of the method can be made 1f there are a number of parallel plane layers of different properties, with one of the layers containing the plane 1sotropic, monoenergetic source of strength 1. This generalization can be shown on the example of Fig. 4.1, Here a source 1s located at the center of a slab of thickness 2a. The slab 1is embedded in reflector material, which extends to infinity on both sides; x = 0 1s the source plane. UNCLASSIFIED OWG. {7446 42 A2 4 1 4 42 4 o L I ' | SOU?CL | l I | | I / | | | | | I / | | j L l | | (g4 | | | i L LAl S - ¥ | e e —— a4 e~ L—r———4—~44—60 Lag—a—44-4‘A60~—w ~vm~n+J Fig. 4.1. Neutron Seceurce and Its Images pescribing Slowing-pown Density Inside Slab, If the left reflector were replaced by the material of the slab, the so- lution in the slab would simply be generated by the two sources - the original source, and the image source of strength A at 2a. However, in order to satisfy the conditions at the 2 -1 NzB . ~hy(v-vy) /(1+] hz} S (v,T) = + v , 1 2vel]l + — Fh2> left boundary with the two sources present, one has to 1introduce two additional sources -~ one of strength A N A 46 jlay,y) == at -2a and one of strength A% at —4a, Now, in order tosatisfy the conditions at the right boundary for the additional sources, two one has to put a source A? at +4a and a source 4% at t6a. 1f this procedure 1s continued, 1t becomes evident that the solution applicable to the inside of the slab 1s obtained by placing sources of strength A' at planes x =*2ia, where 0, 1, 2, .... The solution 1in, the right side reflector, is described by sources of strength BA? located at distances (21 + 1)a/J% Lo 1 = say, the left of the interface x = a, where I‘- = O’ 1 ¥ 2 ¥ 4 5 3 TEMPERATURE DEPENDENCE OF A CROSS SECTION EXHIBITING A RESONANCE®) R. K. Osbern, Physics Division The explicit energy and temperature dependence of a macroscopic absorption cross section exhibiting a resonance was calculated on the assumptions that the microscopic cross section 1s of the form ~ogol o NYT . _B ofi(fvl2|) = Ae o | 12 3 and that the atoms are in a Maxwell- Boltzmann velocity distribution. In the definition of o above, A, B, and [ are adjustable parameters and v,, is the relative velocity between neutrons The guantity v,, 1s the relative velocity that in the and atoms. particular corresponds to 3a resonance cross section, The expression for the cross section is: ~hg(utug)?/ (147 hy) & 2 ._l_ 2011 + {S)B. K. Osborn, The Temperature Dependence of a Cross-Section Exhibiting a Resonance, Y-F10-112 (Nov. 17, 1952). N ,A jla,,¥) PERIOD ENDING DECEMBER 10, 1952 where . vy t [h,v N, = number of atoms per cubic 1 1 + th centimeter, _ _ : : ve = Thyv v = velocity of the neutrons, a, # i ' 1+ l_'h2 m | h = 2, + [h 2 2T Y o= ~l_.._...__2_’ r m, = atomic weight of the atoms, ' 2 ' ) 2 1 ae 7° ey jla,y) = {a +-—-[1+er-f Ny a)] + Vo = |v10| ) 2y, A\ 47 ANP PROJECT QUARTERLY PROGHRESS REPORT 5. CRITICAL EXPERIMENTS A, D, Callihan, Physics Division During the past guarter some inaugural experiments were done on a critical mockup of the proposed reflector-moderated aircraft propulsion reactor, ! and the preliminary results are reported. The initial experiment on the reflector-moderated arrangement was assembled from on-hand materials and is a correspondingly poor simulation of the actual reactor., Nevertheless, the assembly became critical with a critical mass of 13.5 kg, The flux distributions obtained show the ex- pected high thermal flux in the moderator island and reflector. A more realistic mockup of the reflector- moderated reactor sembled. The program of measurements on a critical assembly simulating the ARE reactor, described earlier, was com- pleted, and some of the results are reported. rods have is now being as- The regulating and safety been caltibrated, and a comparison has been uade of the con- tribution to reactivity of various core components. Considerable data from the ARE program have yet to be evaluated and will be presented in subsequent progress reports, REFLECTOR-MODERATED CIBCULATING-FUEL REACTOR ASSEMBLY D. V. P, Wailliams R. C. Keen J. J. Lynn Physiecs Division D, Scott C, B, Mills ANP Division A preliminary study of some of the nuclear characteristics of the re- flector-moderated circulating-fuel reactor(?) has been made with an (l)A. P. Fraas, ANP Quar. Prag., Rep. June 10, 1952, ORNL-1294, p. 6. (2)C. B. Mills, The Fireball, A Reflector Moderuted Circulating-Fuel Reactor, Y-F10-104 {June 20, 1952). 48 assembly comprising component materials that were readily available. The arrangement of the assembly was first (3) 1ts critical on November 1 with a mass of about 13.5 kg of U?3°%, In present form, to be described below, the components were symmetrically located and the loading was 15.0 kg of UZSS. The critical assembly consisted of a central 12-in. cube of metallic beryllium that was almost completely enclosed by a 3-in.-thick fuel layer. Surrounding the fuel was a composite reflector consisting of a 12-in.-thick layer of beryllium and an outer of graphite., The graphite was inner layer 8 1in. 6 in. thick on two opposite sides and thick on the other ones. These materials were arranged in the matrix of 3-in, sguare aluminum tubing, which has been described in previous re- ports.¢*) The loading at the mid-plane of the reactor model 1s shown 1in Fig, 5.1. The fuel consisted of alternate layers of uranium and sodium; the uranium was in disks about 3 1in. in diameter and 0.01 in. thick, and the sodium metal was canned 1n stain- less steel boxes 2 7/8 by 2 7/8 by 1 inch., The wall thickness of the boxes 8 mils. Two disks were placed between adjacent cans of sodium, section was The long dimensions of these 1tems were parallel to the reactormid-plane, The fuel region covered four sides of the beryllium core completely and extended partly over each end, with all but the center 6- by 6-in. section end being enclosed. This 1is of each (3)It is to be emphasized that the critical mass of this assembly is strongly dependent upon the arrangement of the components. For example, the mass was changed by as much as 15% by very minor alterations in the structure, (4]A. D. Callihan, ANP Quar. Prog. Rep. Dec, 10, 1951, ORNL-1170, p. 35; and ANP Quar. Prog. Rep. Mar. 10, 1952, ORNL-1227, p. 59. PERTIOD ENDING DECEMBER o 16, 1952 DWG. 17447 v%a // 7 M/' § \ vt gt o, e u W a s e e et ea e o B T e T e T T e e e Pttt et e Wt e +28%Je%e™0u a - ale et ettt el et sl e et ettt st atatn - » - - B_% 3 8 Ll k& 4 P s B Sln & e W e - - s - - - - - - - - - nta%el0%et a®s a a?sta atata ettt it ntaa s Bt T et e T - - - a . - -' - - “....— ................. - - & ’.fl - ..' I. - I.. woe, P s ettt e ettt al ettt e et ettt '-'s:-'. a*e s 'c.-'-' - - - - - I". ‘..-*fl. "".. ".‘ -‘ «%a 2%a®u *a Attt et et eta 0 s e ...’..- .'.‘ ‘I.‘. - el Ma Pt WA DL ket e s 'U-O‘. .. ..... TelaaNaa 4. e ata®adn*a” e . ot o 0 ------- ar ar et patelelat el et ATt t0 . . atae -t s ot s ettt e et et - . - - - - - . - ' & . ....... . - - - o " s 4 s A me e o & . a’a’e sletn . a®atelatet,* st ettt et e TR %0, *«a to st st te e st . s et at u T a Tt Ty a"aNe - A - - - * n ° o - » L - 9 - - " & =T s ]l® & _ @ N w ¥ _a _ i» - » coalalesaletats . . h‘ N IS tereratelateTatd el e ety el ultel . * 2 el 4 v atn’e o ga ", s et atulata A"t a® s leltws . - // v 1 mlatvnelnl, ¥ . et . - ~ sta"a "R a0, td Tl -9 * - - e - - - - » - > - - - - > - - - - - -l -t 2 s "2Ta"s"a -"n »| o WAt et et et eoqtasl /// /A /// MRS P : ot - - - . p_* - - - » - - . cadlel ata / Setarhiizis - L - Laleozomoslel . * » = et N\ FUEL 11 7 12 ) 7 7 ERYLUUM W e bR e bRMEDN NI OTFBG LA R A EERER SRR ERRN SRS N , . o : e : oy j?//?%;f %/ ////// / : - . S i ”Eéf%@@%%fi%%@%@@%i? Qe e i e e o, S 2! mfl"fQA'éééznifiifé’{.;fiisziiqfiizifig;uq.. ........ i gi' | -~ Fig. 5.1. Moderated Reactor Assembly. 5.2, shown in Fig, above. to preserve symmetry, which 1s a vertical section through the reactor perpen - dicular to the mid-plane referred to It is noted that the graphite end-reflectors were not complete and, the sections of the fuel at the mid-plane were separated by two 1/2-in. fuel shell, reactivity change, that from the effective fraction of delayed neutrons. Vertical Section Normal to Axis'at Mid-plane of Reflector- thicknesses of aluminum. The control and safety rods were reflector elements located ocutside: the Each corresponded, in to about 30% of 49 ANP PROJECT QUARTERLY PROGRESS REPORT SIT DWG. 17448 et Lelels v o = o ofete’. efete’e - s atats -------- ------------ etes - e "a"a's -------- . N\ NN N N &\\X\\T.:.Z.:.'. .'.'.'.‘.:.. NN . 0 00000 BERYLLIUM §§§§§§ DN NN \ N\ N N\ N\ \ \ \ \ NN o b ag o snfageinidrel proiesetelels N \ NN X \ s ] L \ NN NN &\\ NN N N N N 7 %?U EL /7 9000 .............. .. .... . saasasasnseprervedontorns sisanssabhrasnnnalvvwrerinrrese B A SO A OO0 DXONNS SO 00N 0000 \FC\Q\:C\DQFC\ DN N :j/’ 77 A X NN NN N \ N\ i - 0 ?fi;g%%%%%%%% —om= 3in. = j;ng_ X §§§§ 25 AN . D 111111 ------ PR s e, - ooooo o, . o e e aale «Teqse - . - e v _e e sfa®a®s PR L M L aMatae e ettt et at et 4 2 e " e e e e e s ol 2" o rl et e et a el 0o s e e teleT et T d e - et el et et ettt et et T L e "atale’s w«Ma®as e el e e a0 . e et a e al el et u . . o et h ettt e e s s 2%atal et aMe’u s et sfe et q al el o e s et el et e s a0 el o ol . o ----------- LI «MeT 2" --------------- aaTe e s el e e » - o fFig. 9.2, Some measurements have been made that indicate the neutron flux and power distributions 1in various parts of the array. The flux was measured in the usual manner with bare- and cadmium-covered-indium foils and the power or fission-rate data were derived from fission fragments collected on aluminum foils placed in contact with the uranium. 50 Vertical Section Along Axis of Reflector-Moderated Reactor Assembly. In Fig, 5.3 are shown neutron-flux traverses measured horizontally along row 12 in the mid-plane of the reactor, and in Fig. 5.4 are the data obtained along a central traverse of cell 0-12, perpendicular to the mid-plane. In both cases, the activations of bare- and cadmium-covered-indium foils and These results are typical of those obtained their difference are shown. PERIOD ENDING DECEMBER 10, 1952 45 DWG. 17449 | l } | TRAVERSE FROM CELL 042 TO X—42 40 . ~BERYLLIUM FUEL BERYLLIUM REFLECTOR GRAPHITE - ISLAND ~ . . " o > ];I:‘J . - — 5 BARE INDIUM ACTIVATION = o i : N ¢ // o = 2 [ 2 e e TN - DIFFERENCE BETWEEN BARE AND N CADMIUM - COVERED ACTIVATIONS / \YK \\ ™ i:\\ M CADMIUM - COVERED bj\ INDIUM ACTIVATION -1 e - G 5 10 Fi_ g. 5.3. along other traverses, and they confirm the theoretical prediction of high- neutron flux in the moderator 1sland and reflector., This effect is, as theoretically expected, particularly pronounced for thermal neutrons (the dashed curve, Fig. 5.3). The cadmium fraction, derived from the indium-foil activation data and de fined as the ratio of the activation by neutrons of energy below the cadmium cut-of f to the activation by all neutrons, is plotted in Fig. 5.5 for the horizontal traverse of Fig. 5.3. The values of this cadmium fraction, as calculated from the IBM multigroup computations, are also plotted in Fig, 15 20 25 30 DISTANCE FROM REACTOR AXIS (in) Indium Traverse Radially in Mid-plane of Reactor. 5.5. The theoretical and experimental values practically coincide in the center of the fuel and in the bulk of the reflector. The discrepancy at the fuel surface is not surprising, since all practical calculation methods, including the “age’’ multigroup method, are not exactly valid near boundaries. The relative fission rates at the surface of the uranium metal in cell Q-13 are shown in Fig. 5.6, where the two points at 9 1/2 in. were measured on opposite sides of the uranium disk adjacent to the beryllium reflector. In another experiment, the fuel disks, with aluminum foils adjacent, were wrapped in cadmium sheet, The 51 ANP PROJECT QUARTERLY PROGRESS REPORT DWG. 17450 45 1 35-0-__ 40 --m—BERYt_uUM——-—+-—FUE_L—-}-«-—BERYLUUM------~~———~—-—~ -l- ————— ~— GRAPHITE -J! | | | W O A l TRAVERSE ALONG CELL O-12 ‘ — “\ M—:fi\ iUM-COVERED . . CADM cO w v # / INDIUM ACTIVATION COUNTS PER MINUTE x4073 ™ o ~ . ~ -’ L -7 N\ - ~ - " z:;//’ ST C BARE INDIUM ACTIVATION MINUS CADMIUM-COVERED 5} — . ACTIVATION 0 i ! 0 5 10 15 DISTANCE FROM REACTCOR MID-PLANE (in) Fig. 5. 4. Indium-Foil Activation Along Axis of Reactor. resul tant activities collected on the foils are a measure of the fission rate caused by the higher energy neutrons. From these and the data from the preceding experiment,it 1s observed that about 70% of the fissions are produced by thermal neutrons., Two, adjacent, 10-mil-thick uranium pieces were replaced by ten pieces that were each 2 mils thick and separated by aluminum foils. From the observed distribution of activity across this composite fuel element, the self-shielding of the 20-mil-thick uranium 1is found to be 34%, that 1is, only 66% of the uranium 1s effective, This figure of 66% is in satisfactory 52 agreement with a figure of 63% computed from the multigroup data., Of course, the orientation of the disks, parallel to the neutron current from the re- flector, and the nonuniform power distribution make the theoretical calculation difficult and somewhat uncertain, ARE CRITICAL ASSEMBLY D. Scott C. B, Mills ANP Division J. F, Ellis D, V., P, Williams Physics Division The preliminary assembly of the ARE, which has been described in previous PERTOD ENDING DECEMBER 10, 1952 DWG. 17454 ——BERYLLIUM FUE%f - BERYLLIUM -GRAPHHE 1.0 — 0.8 = e = o — (% A e > F o150 <{ it A z g A & 100 — O ] A O A 50 o 0 0 & 2 . 4 8 8 10 12 14 18 18 RADIAL POSITION (in.) Fig. 5.7. Ak of Stainless Steel Fuel Tube at Various Points Along Reactor Radius. ‘ neutron reflection by 1ts stainless steel container in an otherwise un- reflected or partly reflected region, The rod referred to here was a “weaker” rod than the others designed for the ARE. Tt was 2 in. in diameter, 30 in, long, and it contained 0,145 g of B4C per linear inch. Tts complete in- sertion decreased the reactivity b about $1.25. | ' Because of insufficient available excess reactivity, 1t was necessary to obtain an estimate of the poisoning by a second ABRE regulating rod and by the ARE safety rod by the “rod drop” method, which utilizes the prompt transient of a sudden reactivity decrease and gives the result in terms of the effective delayed-neutron fraction. The rod assembly was mounted 7 1/2 in., from the center of the core, and both the regulating rods and the safety rod were measured there. The following results were obtained: “weak” regulating rod (0.145 g of B,C per linear inch), $0.80; “strong” regulating rod (0.68 g of B,C per linear inch), $1.60; safety rod, $5.50. _ In the Aircraft Reactor Experiment Hazards Summary Report(®) it was assumed that the regulating rod in the center of the core would be worth 0.4% in Ak/k, and that the safety rod at a position 7 1/2 in. from the center of the core would be worth 5% in Ak/k. Hence, the regulating rod seems to be somewhat more effective thannecessary. The safety rod is somewhat less effective than was previously assumed, (6)J. H. Buck and W. B, Cottrell, Aircraft: Reactor Experiment Hazards Summary Report, ORNL- 1407, p. 24 and 27 (Nov. 24, 1952). 55 ANP PROJECT QUARTERLY PROGRESS REPORT 120 DWG. 17454 — =~ 110 100 20 80 70 60 |- ROD VALUE {cents) 50 i ? / 40 } 30 | P 4 16 18 20 22 24 26 28 30 32 34 ROD POSITION (in)) Fig. 3.8, but it 1s still regarded as adeqguate., A comparison was made of the two fuels used in these experiments by substituting tubes containing fuel of the first loading (0.163 gof U23%/cm?) for tubes containing fuel of the second loading (0.214 g of U235/¢cm3) at various points 1in the reactor core when it was otherwise loaded with the second fuel mixture. The losses 1in 56 Calibration Curve of ARE Regulating Rod (weak). reactivity incurred by this sub- stitution are shown in Table 5,1. For a similar experiment, an Inconel tube was loaded with the second mixture and substituted for an identically loaded stainless steel tube. The losses caused by the Inconel are also shown in Table 5.1. This comparison 1is important since the ARE fuel tubes are fabricated of Inconel. PERIOD ENDING DECEMBER 10, 1952 TABLE 5.1. LOSS IN REACTIVITY AT VARIOUS RADIAL POSITIONS CAUSED BY CHANGES IN CORE CDMPONENTS RADIAL POSITION (in.) REACTIVITY OF LOW DENSITY FUEL TUBE V3. NORMAL FUEL TUBE REACTIVITY OF INCONEL FUEL TUBE VS. STAINLESS STEEL FUEL TUBE (cents) {(cents) 3.7 29.0 27.9 7.5 21.1 24.8 11.3 14.5 17.2 15 9.0 10.1 57 SUMMARY AND INTRODUCTION E, P. Blizard J. L, Meem, Associate Physics Division The Lid Tank Facility has been applied directly in experiments needed to solve problems of immediate interest in the design of the air ducts through the reactor shield of the GE-Convair airplane (sec. 6). These experiments are essential, since the configuration is so complicated thatit ispractically impossible to calculate., Neutron and gamma 1sodoses around mockups of the GE-ANP inlet and outlet ducts have been obtained. The data obtained provide the information necessary for specifi- cation of the duct shields. In addition, some measurements have been made to determine the induced activities around the duct. The leakage around an alternate ducting arrangement is also being measured. | The Bulk Shielding Facility (sec.7) has been applied, in part, to further alr-scattering experiments. Although these experiments are not yet con- clusive, indications are that the earlier experiments gave doses that were too high; but the designs of the 1950 Shielding Board are not yet com- pletely vindicated. The BSF has also been used to extend the spectral and dose measurements on the NEPA divided- shield mockup. These data will now be used to improve the calculation of the dose at the crew position, Additional experiments now under way at the BSF include the irradiation of animals and the measurement of the energy release per U**° fission, | The Tower Shielding Facility (sec., 8) has been approved and the Laboratory is committed to a schedule that calls for completion of comstruction in November 1953, Detailed engineering design has been contracted to the architectural firm of Knappen, Tippetts, Abbett, McCarthy, who have revised the tower design to eliminate cantilever trusses., lhe new design had a signifi- cantly higher neutron-scattering back- ground than earlier designs; conse- quently, alternate designs are now being studied. Initial tests with the completed facility, whichwill probably make use of the GE-Convair shield design, are scheduled to commence 1in 1954, ] The nuclear measurement (sec. 10) studies include an experiment to determine the angular distribution of neutrons scattered from nitrogen and a new calibration of the fast-neutron dosimeter. The angular distribution of neutrons was measured by utilizing the 5-Mev Van de Graaff accelerator. Analyses of the pulse-height distri- butions of the nitrogen recoils indi- cate a definite change in the dif- ferential cross section of nitrogen that is associated with the resonance value and an increase in the forward scattering. The fast-neutron dosimeter was ‘“calibrated,” in a bioclogical sense, at the Zero Power Reactor at Argonne National Laboratory by taking advantage of a situation in which a high fast-neutron dose wasaccidentally received by an individual. Tt was found that the ZPR leakage fluxes and fast-neutron dose readings 1in the water reflector were quite similar to those expected from a comparison with the BSF data. 61 ANP PROJECT QUARTERLY PROGRESS REPORT 6. DUCT TESTS IN LID TANK FACILITY J. D. Flynn G, T. Chapman J. M. Miller F. N. Watson Physics Division C. L. Storrs, GE-ANP The Lid Tank Facility has been applied primarily to a study of air ducting for the GE-ANP reactor. Partial mockups of i1nlet and outlet “annular” ducts have been tested for neutron and gamma attenuation, The isodoses wmeasured arocund the ducts indicate the proper shield shape in the presence of the ducts., In addition, some experiments have been carried out to determine the activation of engines, structure, etc. to be expected from neutrons that leak out via the ducts., Possible methods of improving the situation were ex- plored when 1t was seen that the activation could be excessive. Multiple ““wavy’ cylindrical pipes were also tested as an alternate duct design. Although these are no doubt superior to the “annular’ ducts as far as shielding is concerned, they present more difficult engineering problems. G-E OUTLET AIR DUCT Neutron Dose Measurements. With the determination of the effect of the transition section on the fast-neutron dose and the thermal flux, the measure- ments on the G-E outlet air duct have been completed.(!) Figures 6.1 and 6.2 show thermal isodoses made with a BF, counter and the automatic plotter. Figure 6.3 gives the results of center- line measurements with this counter. Fast-neutron measurements are exhibited in Figs. 6.4, 6.5, 6.6, and 6.7, There is a slight discrepancy between the measurements of thermal and fast neutrons. The center-line data should coincide when the relaxation length exceeds 7.5 cm. The discrepancy has been attributed to (1) Rep. Sept. 10, 1952, OBNL-1375, p. 48, changing 62 Farlier results ave given in ANP Quar, Prog. sensitivity of the BF; counter during the month-long series of readings. Unlike the fast neutron dosimeter, this counter was not recalibrated during the thermal-neutron experiment. Despite the suspected slow drift in sensitivity, the shape of the 1sodoses should be reliable and should furnish adequate information on the effect of the transition section. Two additional sources of error should be mentioned. The relays that operated the 1isodose plotter introduced a few spurious counts, which caused the plotter to operate 1 to 2 cm further from the source than it should Besides this, the effective center of counting moved about inside the detectors, depending upon the direction of the flux gradient, and introduced an error in position esti- have. mated at not more than 2 cm over the range from the center line to the side of the duct. In repositioning the duct after changing the transition section, 1t was inevitable that a slight variation in the distance from the source axis should occur. Table 6.1, which gives the actual coordinates of four points on the duct identified in Fig. 6.1, may be used in making precise calcu- lations - the drawings give only average position. Calculated Neutron Dose. A calcu- lation of the effect of the duct with no transition section on the center- line dose has been made with some success. As can be inferred from the isodose plots, the center-line dose 1s not affected much by the side arm of the duct. The calculation therefore deals with an 8 1/2-in. air space (essentially a void) in front of the source plate. £9 160 150 40 | 130 £20 110 100 SO BO 70 60 40 30 DISTANCE FROM FRONT OF DUCT (cm) 20 -0 -20 ~30 -40 -30 160 150 140 DWG. 16285A NO TRANSITION SECTION o e $8-1, TRANSITION SECTION FUMBERS CURVES ARE THERMAL NEUTRON FLUX NORMALIZED TO NEUTRON DOSIMETER SOURCE WiTH NO TION SQURCE WITH 18-in. TRANSITION SECTION 130 120 WO 100G 20 B8O 7O 60 5C 40 30 20 (0 Q 10 20 30 40 50 &80 70 80 90 WO WO 120 150 140 180 DISTANCE FROM CENTER LINE {cm) Fig. 6.1. Thermal-Neutron Isodoses Around G-E Outlet Air Duct (Shutter Open). ‘0T HJHWEOAO HNIOGNA doX¥dd 26T ¥9 DISTANCE FROM FRONT OF DUCT {cm) 160 150 140 130 120 VG 300 90 80 70 60 50 40 30 20 150 140 130 Fi 120 g. Sy OWG 16220A —_— B-in TRANSITION SECTION — e 1 2 - . TRANSITION SECTION NUMBERS ON CURVES ARE THERMAL NEUTRON FLUX NORMALIZED TO NEUTRON DOSIMETER SOURCE WITH 6-1n. TRANSITION SECTION SECTION "o 100 90 80 7O 80 850 40 30 20 10 o 10 20 30 40 5C¢ 60 TO B8O S0 100 110 120 430 140 150 6.2. DISTANCE FROM CENTER LINE {cm) Thermal-Neutron Isodoses Around G-E (utlet Air Puct (Shutter Open). L0444 SSHU90Ud XTHALHVNO LDAT0¥d dNV THERMAL NEUTRON FLUX, NORMALIZED TO NEUTRON DOSIMETER (mrep/hr) Fig. Duct 2 X10° PERTOD ENDING DECEMBER 10, 3X10 18-in. TRANSITION SECTION —~12-in. TRANSITION SECTION 1952 DW!. 1629148 ¢ s—m.TRANsnvom SECTION NO TRANSITION SECTION 3 72 B4 96 108 120 132 Z, DISTANCE FROM SOURCE (cm) 144 e.3. {Shutter Open). 156 68 180 Thermal-Neutron Centef-Line Measurements Behind G-E Outlet Air - 65 ANP PROJECT QUARTERLY PROGRESS &-in. TRANSITION SECTION z2=125 cm FAST NEUTRON DQSE (mrep/hr) S 18-1n. Z=1442 cm 12-in, TRANSITION SECTIO Z =140 cm 24 36 48 REPORT DWG. 17370 NO TRANSITION SECTION Z2=99cm 6-in. TRANSITION SECTION z=143cm TRANSITION SECTION z=109 cm 12-in. TRANSITION SECTION Z2=130 ¢m RN 12-in. TRANSITION SECTION Z=135cm 18+4n. TRANSITION SECTION Z =1474 cm 60 Te B4 96 408 y, HORIZONTAL DISTANCE FROM SOURCE AXIS (cm) Fig. 6. 4. 66 Fast-Neutron Dose at End of G-E Outlet Air Duct. FAST NEUTRON DOSE (mrep/hr) PERIOD ENDING DECEMBER 10, 1952 DWG. 162244 NO TRANSITION SECTION y29892 cm ' B-in. TRANSITION SECTION ¥=92.9 cm 12-1n. TRANSITION SECTION ¥=947cm 1840 TRANSITION SECTHON y=933cm 0 12 24 36 48 60 72 84 26 108 120 2z, DISTANCE FROM SOURCE (cm) ' Fig. 6.5. Fast-Neutron Dose at Side of G-E Outlet Air Duct, | 92 < Y < 93.3. 67 ANP PROJECT QUARTERLY PROGRESS REPORT FAST NEUTRON DOSE (mrep/hr) 68 NO TRANSITION SEGTION =102 cm 12-in. TRANSITION SECTION Y=1047 c¢m 18-in. TRANSITION SECTION ¥=103.3 ¢cm 12 24 36 48 60 72 84 96 108 120 Z, DISTANCE FROM SOURCE (em} Fig. 6.6. Fast-Neutron Dose at Side of G-E Outlet Air Duct, 102 < Y = 104.7. PERIOD ENDING DECEMBER 10, 1952 2x10° FAST NEUTRON DOSE (mrep/hr} EXPERIMENTAL DATA: 24 36 48 60 T2 B4 96 108 z, DISTANCE FROM SOURCE {cm) Fig. 6.7. Fast-Neutron Center-Line Measurements and Various Transition Sections. 120 132 144 with G-E Outlet Air Duct 69 ANP PROJECT QUARTERLY PROGRESS REPORT TABLE 6. 1. COORDINATES 0OF FIDUCIAL POGINTS FOR FIG. 6.1 LENGTH OF POSITION I 1Y 11X 1V TRANSITION SECTION (in.) Y{em) z(cm) Y{cm) Y(em) Y{ cm) z( cm) 0 43.1 97.0 61.0 90.9 45.9 23.3 6 44.8 111. 3 62.4 91.9 45.1 40,2 12 46.0 128.7 63.7 93.1 43.4 55.5 18 45,4 144.2 62.3 92,2 44,5 71.5 The neutron dose for this con- figuration has been obtained from the data with water alone by using asimple assumption, The dose at a distance r in water froman isotropic point-source of strength dS{(%) js G(r) 2 d D(r) = dS A2 where G(r) is an undetermined function of r. Integration of this expression over a source disk of radius a gives, for a point on the axis at a distance Z from the source, A d(Z) -EfG(r)dr , 2 . r where o is the specific source strength in neutrons/cm?*sec, and R is the distance from the edge of the source to the detector. Now, consider the case in which there 1s a plane-bounded void of thickness (r-r’') between source and detector, which are sti1ll separated by a distance r. For a point source, assume the dose to be G(r') dD (r,r') = dS T 4771 Integrating this as before gives R D (z.7') - o G(r') vt S 9 r zZ Since the ratio of r to r’' is a con- (Z)This caleculation is mainly based on the work of E. P. Blizard, Introduction to Shield Design, Part I, ORNL CF-51-10-70 (Jan. 30, 1952), 70 stant throughout this integration, Hl o o G(r') Dr(Z,Z ) :“E — ! - dr’ r Zl where R’ 1s the distance, between the edge of the source and the detector. By referring to a sketch of the geometry, Fig. 6.8, and to the previous integral, it 1s immediately apparent that this expression 1s just the dose at a distance Z' 1in water alone from a source of reduced radius in water, a', where a' 1s given simply by the ratio ! t a z R a z To find the dose that would be measured with a source of different radius, an approximation given by Blizard to the Hurwitz transformation from a disk to an i1nfinite plane source 1s used; that 1s, the trans- formation is made frow the data for water alone and the actual source radius, to an 1nfinite plane source, and from this back to a source of smaller radius. The approximate ratio of dose with i1infirite source to that with source of radius a 1is D(Z' , ) L1 e > — t a , D(Z', a) 2 2>\.2 fr X4 + 1 a? A ’ where A 1s the relaxation length of the water. PERTOD ENDING DECEMBER 10, 1952 DWG. 17371 VIRTUAL SOURCE DETECTOR AN "o e Fig. 6.8. With the obvious substitutions, the dose at a distance Z with a VOld of - thickness Z - Z' becomes . | D (Z) = D(z') 22 v - 1+ 22’ , 2)\2 \ al Z! o = — + 1 ’ TTEF T a'? A / a Z where D (Z) is the dose with a void and " D(Z) is the dose with water alone. The ~curve in Fig, 6.7, labeled “no transitioen section]’ was calculated by using this formula, The experimental points are also indicated, and it can be seen ~that the agreement between experimental ~data and the calculations isexcellent. Some very rough calculations have " been made to explain the effect of the transition sections on the center-line ~data. If the water sections are assumed to be opague to neutrons, the calculated dose 1s lower than the . observed dose. More accurate calcu- ~lations are yet to be made. ‘ N= e PURE WATER —— o] Geometry for Calculating the Effect of a Void on Neutron Dose. G-E INLET AIR DUCT A mockup of the G-E inlet air duct has been tested in the Lid Tank Facilitw Some gamma shielding in the form of slabs of 7/8 in. of iron and 1 1/2 in. of lead was used to simulate the design shield along the center line. In spite of care in choosing from available slabs of iron and lead, it was 1mpossible to make the mockup simulate the actual situation very closely, As a consequence, caution should be used in applying the gamma data to the design. Thermal- and fast-nentron and gamma data were taken with the standard Lid Tank instruments, and the results have been converted into isodose plots, Figs., 6.9 and 6.10. It is unfortunate that the source strength was completely inadequate to enable measurement of the fast-neutron dose at the end of the duct, * The final step in this experiment was to study the attenuation of the 71 Gl Zz, DISTANCE FROM SOURCE {cm) 200 180 1e0 $40 120 100 80 60 40 20 160 40 1098 /7 1005 10t 120 Fig. 100 6.9. 80 60 4Q 20 . SDURCE =0 .. . 3\~ N “ | ; '} : 5 \\ \\\E"\\.\ \b\ o i | ! v 0 -140 20 0 -20 ¥y, HORIZONTAL DISTANCE FROM SOURCE AXIS (cm} -40 ~80 -80 - Gamma-Isodose Measurements Around G-E Inlet Air Duct Mockup. -120 ‘0T MAGWIDIU INIANI aolydd cbo6l ANP PROJECT QUARTERLY PROGRESS REPORT gamma shield, Center-line traverses werec made as the shielding slabs were successively removed. The results appear 1in Fig. 6.11. INDUCED ACTIVITY AROUND A DUCT An experiment has been performed 1n the Lid Tank Facility with the primary object of determining the order of magnitude of the induced radioactivity to be expected outside the air ducts in the GE-ANP initial engine shield. In addition, 1t was desired to estimate the value of thin boron shields in lowering this activity, to investigate the utility of BF,-counter measurements in predicting activation, and to determine the effect of borating the shield water around the ducts, The mockup of the G-E outlet azir duct that had been previously tested(®) was modified by the addition of a tank so that borated water could be placed around the duct. Figure 6,12 shows the configuration. The outside of this tank simulated the outside of the design shield. Measurements were made at the end and the side of the duct, as indicated in Fig. 6.12. Two types of measurements were undertaken: samples of cobalt and manganese were exposed and their activities measured, and traverses were made with a BF3 counter. In all cases, various thermal-neutron shields were used, and the results were com- pared with unshielded measurements, Data were obtained with both pure and borated water around the duct. The induced activities under various conditions are tabulated in Table 6.2, and the results of the counter traverses are presented graphically in Figs. 6.13, 6.14, 6.15, and 6.16. Figure 6.17 depicts the results of center- line traverses with no duct in the tank but with various thermal shields around the counter. (B)ANP Quar. Prog. Rep. June 10, ORNL- 1294, p. 72, 1852, 74 Since the activation measurements were of an exploratory nature, a com- plete investigation ofall combinations of parameters was not attempted. The samples were prepared hurriedly, and therefore errors of 30% are to be expected from differences in the geometry of exposure and counting. In the low flux available in this experi- ment, the cobalt did not become radio- active enough to afford an accurate measurement of its activity, The various ratios of counting rates are given in Tables 6.3, 6.4, and 6.5, which show, respectively, the effect of thermal shields, acomparison between the counting rates at the side and end of the duct, and the effect of borating the shield water. It is apparent that a thin boron layer is far more effective 1in shield- ing the boron counter than inshielding either manganese or cobalt. This 1is to be expected, since an 1important part of the activation of the latter is due to resonance absorption at epithermal energies where the boron cross secticn is relatively low, The variously shielded detectors are senslitive to different neutron energies, and therefore an indication of the comparative neutron spectra at the side and the end of the duct can be obtained by comparing the counting rates under these conditions. When the expected experimental errors are con- sidered, there does not seem to be evidence of significant differences 1in the spectra at these two positions. With pure water in the tank, there are more epithermal neutrons than thermal neutrons; or looking at the situation from the opposite viewpoint, the ducts increased the thermal flux. Under these conditions, a conservative estimate can be made of the expected activation around a ducted shield from the readings of a BF, counter, provided an experimental comparison has been made at some point without ducts. It was at first a surprise to find that adding boron to the shield water GAMMA DOSE {mr/shr) PERIOD ENDING DECEMBER 10, 1952 10% 1 I ........ — e e e . h amrem e s aaaaafanmmmm e M —— . mmmmmm e i 4 o ememeeeemiaeef 5 S 2 103 Lol 5 2 10? g 2 ........ .1 10 s e N A e g e e e \‘ . l?\ Bl — AS SHOWN ABOVE 5 , : : \\‘m A— 4in. x 4in. IRON AND FIRST LEAD PLATE REMOVED ] ® — 4in x 4in. IRON AND BOTH LEAD PLATES REMQOVED @— 4in.x 4 in. IRON, BOTH LEAD PLATES AND {RON PLATE REMOVED 2 { i i 60 70 80 90 100 1o 120 130 140 150 160 170 DISTANCE FROM SOURCE (cm) Fig. 6.11. Gamma Center-Line Measurements with G-E Inlet Air Duct. 15 ANP PROJECT QUARTERLY PROGRESS REPORT increased the flux of epithermal neutrons by about 25%. However, calcu- lations of the amount of water dis- placed in adding the boron showed that the result is gquite reasonable. The borated water contained 1.005 wt % boron and 1.7 wt % potassium and had a specific gravity of 1.0403. Thus, there was a displacement of 1.3% of the hydrogen, which resulted in higher epithermal flux. The thermal neutrons were naturally greatly reduced by the boron. However, placing a thin layer of boron at the surface of the shield would eliminate thermal neutrons with- out displacing so much water, RADIATION AROUND AN ABRAY OF CYLINDRICAL DUCTS Previous measurements of the radi- ation around mockups of the annular air ducts for the G-E reactor showed that these ducts will permit the escape of a large flux of fast neutrons through the sides of the shield. Furthermore, this annular duct con- figuration is undesirable because of In view of these it was desired to study the shielding properties of an alternative ducting method, namely, an array of bent cylindrical ducts. its large weight. considerations, DWG. 17153 POSITICN OF MEASUREMENTS BORATED WATER ———f_ BORATED WATER POSITION OF MEASUREMENTS AIR-FILLED DUCT TRANSITION SECTION ————= SOURCE -——“-1/ // Configuration for Induced-Activity Measurements on G-~E Qutlet Fig. 6.12. Air Duct. 76 . Figure 6.18 is a photograph of the bent cylindrical ducts in position in the Lid Tank Facility. There are 19, round, aluminum pipes in a hexagonal array. FEach pipe has an outside diameter of 3 15/16 in. and 1/16-1in. walls. The pipes have three straight sections 22 1in. long connected with 45-deg bends. 1In the plane of the source plate, the centers of the pipes define equilateral triangles with sides 7.33 1in. long. Since the ducts leave the source plate at an angle of 22.5 deg to the normal, the array 1s not symmetrical about the source axis. With this arrangement, the fractions of the total volume that are alr, water, and aluminum are 26.6, 71.8, and 1.6%, respectively, 4 The radiation measurements around this array have been obtained in con- siderable detail. An analysis of the results shows that the gamma dose can PERIOD ENDING DECEMBER 10, 1952 be accurately computed by considering the ducts and water to be a homogeneous shield of appropriately reduced density. The neutrons, however, stream through the ducts in sufficient numbers to increase the flux at the end to one or two orders of magnitude greater than that predicted on a reduced density basis. This is in accordance with the duct theory proposed by Simon and Clifford, that is, geometrical attenu- ation along the straight sections and inverse sine reflection at the bends. The design of this particular array is not optimum, since the attenuation through the ducts is not high enough to exceed that through the equivalent amount of water, An optimum design might have another bend in the ducts to 1ncrease their attenuation, or closer spacing between ducts to further reduce the density of the equivalent homogeneous shield. TABLE 6.2. SUMMARY OF ACTIVITIES INDUCED IN THE LID TANK:FACILITY f ACTIVITY INDUCED SAMPLE NEUTRON SHIELD POSITION. WATER AROUND DUCT (me/ g) : : me/ g Outlet Duce Cobalt None End Borat%d 58.1 t 9.6 x "1t Boron cover End Borated 5.5 9.1 x 10710 None Side Borated 138.3 + 10.1 x 1071 Boron cover Side Borated 18.3 + 9.3 x 1p~10 Manganese None End Plain - 178.5 + 1.5 x 10”8 Boron cover End Plain 4.64 + 0.17 x 1078 Boron backing End Borated 68.3 t 1.0 x 10°® Boron cover End Borated 3.16 + 0.16 X 10°8 Boron backing Side Borated 124.3 + 0.8 x 108 Boron cover Side Borated 11.7 £+ 0.3 x 10°8 Inlét Duct Manganese None End Plain 1.04 + 0.15 x 107 None Side Plain 2.57 + 0.02 x 10°* Notes: (1) Manganese activated to saturation at 6-watt source strength. (2) Cobalt activated 100 hr at 6 watts. (3) clude systematic errors. The erfor factors given are standard deviation of counts taken and do not in- 17 ANP PROJECT QUARTERLY PROGRESS REPORT TABLE 6. 3. EFFECT OF THEGMAL SHIELDS ON EXTERIOR ACTIVATION RATIO OF COUNTS DETECTOR POSITION RATIO MEASURED In Plain Water In Borated Water Boron Side Bare to Cd covered 57 26 Bare to B covered 250 130 Cd covered to B covered 4.4 5.0 End Bare to Cd covered 41 26 Bare to B covered 230 150 Cd covered to B covered 5.6 5.7 No ducts Bare to Cd covered 40 Bare to B covered 180 Cd covered to B covered 4.4 Cobalt Side Bare to B covered 5 to 15 End Bare to B covered 4 to 100 Manganese End Bare to B covered 39 B backed to B covered 22 Side B backed to B covered 11 TABLE 6. 4. RATIO OF EXTERIOR ACTIVATION AT SIDE TO EXTERYOR ACTIVATION AT END RATIO OF COUNTS DETECTCR SHIELD RATIO MEASURED In Plain Water In Borated Water Boron None Side to end 3.4 2.9 Cd cover Side to end 2.5 2.9 B cover Side to end 3.1 3.3 Cobalt None Side to end 2.4 +1 B cover Side to end 3 Manganese B backed Side to end 1.8 B cover Side to end T TABLE 6. 5. EFFECT OF WATER BORATION ON ACTIVATION RATIO OF COUNTS DETECTCR SHIELD RATIO MEASUBRED 1' At Side of Duct At End of Duct Boron None Plain to borated 1.4 1.2 Cd cover Plain to borated 0.64 0.75 B cover Plain to borated 0.73 0.77 Manganese B cover Plain to borated 0.73 1.5 78 counts /min PERIOD ENDING DECEMBER 10, 1952 SO DWG. 17154 COVER Zgp#13830m} UM COVER Zgo7136.3 cm COVER £go7136.3 em ~(—— PURE WATER AROUND DUCT —A—— BORATED WATER AROUND DUCT Z,136.3 cm | a0 45 50 55 60 65 70 ¥, HORIZONTAL DISTANCE FROM SOURCE AXIS (cm) Fig. 6.13. Boron-Counter Measurcments at End of G-E Outlet Air Duct. 79 ANP PROJECT QUARTERLY PROGRESS REPORT 3x108 remsmae e PURE WATER AROUND DUCT (s — BORATED WATER AROUND DUCT 108 - y=1145 em___ | T R NO COVER - counts /min R\ CADMIUM COVER q BORON COVER 30 40 50 60 70 80 20 100 110 {20 130 14Q 2, DISTANCE FROM SOURCE {cm) Fig. 6.14. Boron-Counter Measurements at Side of G-E Outlet Air Duct. 80 PERIOD ENDING DECEMBER 10, 1952 DWG. 17156 PURE WATER ARCUND TANK —— e —e BORATED WATER AROUND TANK 5 = & e £ 1) - 2 2136.3¢m w 2 - A D2 et A o 2z O o = -1 o 10 =z — [7p] 2 i [T - 2 é 10 [ee i_‘ = Ll = Z2=156.3 cm < 5 S = N o ¥ N '.._ z 107 5 %104 -0 0 1o 1 20 30 40 20 60 70 30 20 100 y. DISTANCE FROM SOQURCE-CENTER LINE (cm) ? Fig. 6.15. Thermal -Neutron Measurements at End of G-E Outlet Air Duct. 81 ANP PROJECT THERMAL NEUTRON FLUX NORMALIZED TO FAST NEUTRON DOSE {mrep/hr) Fig. 6.16. 82 QUARTERLY PROGRESS REPORT DWG. 17157 ——PURE WATER AROUND DUCT —~=BORATED WATER AROUND DUCT 40 60 80 100 120 140 160 z, DISTANCE FROM SOURCE (cm) Thermal ~-Neutron Measurements at Side of G-E Outlet Air Duct. counts / min PERIOD ENDING DECEMBER 10, 1952 DWG. 17158 NO COVER CADMIUM COVER 2 BORON COVER 10° 5 2 10% : 12 24 36, a8 60 72 B4 96 108 120 2, DISTANCE FROM SOURCE (em) #i9.6. Boron Counter Centerline Meosurements in Pure Water. Fig. 6.17. BoronFCounter Center-Line Measurements in Pure Water. 83 ¥8 Fig. 6' 18- Multiple Cylindrical Ducts in the Lid Tank Facility. t phoTO 10289 1 " ;;e,«,y:‘v‘m?; ] LHOdAY SSHY90Hd ATHALYVNO LOAf0Yd dNV 7 J. L. Meem R, G. Cochran M. P. Haydon K. M. Henry H. E. Hungerford Physics Gamma-ray spectral measurements on the divided-shield mockup have been extended, and the neutron and gamma dose measurements on the shield mockup are reported. The air-scattering experiments with the reactor at 100 kw are now under way, and the program of irradiating monkeys with the reactor has been started. MEASUREMENTS WITH THE DIVIDED-SHIELD MOCKUP Two further sets of measurements of gamma-Tay energy spectra and angular distributions from the divided-shield mockup (with lead disks) were made after a preliminary attempt by the NDA group to calculate the dose to be expected at the crew position. The measurements were made at iy = 60 deg, 6 = variable, (!’ and ¥ = 60 deg, ¢ = variable., The energy spectra obtained are shown in Figs, 7.1 and 7.2, and the angular distribution for the angle g is in Fig. 7.3. For all measurements, the spectrometer col- limator remained horizontal, Table 7.1 shows all gamma-ray spectral measurements completed since the last tabular summary.(?) It 1s ex- pected that the information is now sufficiently complete to enable an accurate calculation of gamma dose at the crew position. shown Since the collimator 1s always kept horizontal in the measurements, Y, @, and 0 are sufficient to specify the (I)For a definition of angles Y, ¢, and F see Table 7.1, For a discussion of the experimental setup, see F. C, Maienschein, Gamma-Ray Spectral Meesurements with the Divided-Shield Mockup, Paert I, ORNL-CF-52-3-1, Part II, ORNL-CF-52-7-1, Part II'I, ORNL-CF-52-8-38, (2)ANP Quar. Prog. Rep. June 10, 1952, ORNL- 1294, p. 45. PERIOD ENDING DECEMBER 10, 1952 . BULK SHIELDING FACILITY E. B. Johnson J. K. Leslie T. A. Love F. C. Maienschein G. M. McCammon Division position and orientation of the spec- trometer. The angle & for the measure- ments with ¢ = 60 deg and ¥ = 0 was determined so that the spectrometer collimator would always look at the edge of the lead disks in the divided- shield mockup. Center-line measurements of gamma- ray and fast-neutron dosages and also thermal-neutron flux have been com- pleted and are shown in Figs. 7.4, 7.5, and 7.6. The attenuation curves are shown with and without the shield in place. It should be remembered that for these measurements the reactor had a beryllium oxide reflector. (3’ The dashed curves on Figs. 7.4, 7.5, and 7.6 represent the center-line data(*’ with the water-reflected reactor. AIR-SCATTERING EXPERIMENTS The air-scattering experiments with the reactor at a power of 100 kw are well under way, Indications are that the previous measurements, reported last quarter, were somewhat pessimistic, but confirmation of the ANP-53 shield design{®) is not yet clear. It is to be expected that these experiments will soon be concluded, since the BSF 1s poorly adapted to air-scattering measurements. IRRADIATION OF ANIMALS(®? The program of irradiating monkeys by using the reactor, as outlined in (B)ANP Quar. ORNL-1227, p. 76. {4)ANP Quar. Prog. Rep. June 10, 1951, ANP.65, p. 110, (S)Repart of the Shielding Board for the Air- craft Nuclear Propulsion Program, ANP-53 (Oct. 16, 1950). (G)This is a joint program in which the USAF School of Aviation Medicine, Consolidated Vultee Aircraft Corporation, and Wright Air Development Center, as well as ORBRNL, are participating. - Prog. Rep. March 10, 1852, 85 ANP PROJECT QUARTERLY PROGRESS REPORT Y =60° 8 = VARIABLE GAMMA-RAY FLUX (gammas/cm@/sec/Mev/watt/steradion) 0 2 4 6 8 10 GAMMA-RAY ENERGY (Mev) Fig. 17.1. Gamma-Ray Flux at Edge of Lead 86 Disk. DWG. 16777 PERIOD ENDING DECEMBER 10, 1952 T DWG. 16776 GAMMA-RAY FLUX (gammas/eme/sec/Mev/watt/steradian) "0 2 4 6 8 10 2 14 GAMMA-RAY ENERGY (Mev) Fig. 7.2. Gamma-Ray Flux at Edge of Lead Disk as a Function of the Azimuth Angle. 87 ANP PROJECT QUARTERLY PROGRESS REPORT e SO DWG. 16778 >« HYPOTHETICAL SHIELD \ BOUNDARY N\ \ DIVIDED SHIELD MOCKUP LEAD SHADOW DISKS d'\o'(\\ owsxef DIVIDED SHIELD | o o AND REACTOR ¢ 80° 70° 60° 50° a0° rFig. 7.3. Gamma-Ray Flux as a Function of Angle for Energies as Shown (BSML, ¥ = 60°). 88 PERIOD ENDING DECEMBER 10, 1952 103 g _ ,,V_A,V,J._.___”_..,J,,,,_ b |~ Be0 REFLECTOR FOR ! * (. DIVIDED-SHIELD REAGTOR ® - EXP.6. MEASUREMENTS MADE ON BeO-REFLEGTED DIVIDED- e SHIELD REACTOR IN OPEN WATER - T — Jeee A P . MEASUREMENTS MADE WITH REAGTOR IN POSITION IN - DIVIDED--SHIELD MOCKUP, 0.4 %, -BORATED WATER, NO SHADOW SHIELD . MEASUREMENTS MADE WITH REAGTOR IN POSITION 1IN | DIVIDED~SHIELD MOCKUP, 0.4 % - BORATED WATER, WITH LEAD SHADOW SHIELD S e IO IR 10 1 1o 5 3 = S ; = REAR PERIPHERY OF W 1072 | DIVIDED-SHIELD ---- - g [~ MOCKUP { EXP. 7) 2 a i I 3 — } | : ! © | J_--_..“._L _______ Tol S r -------- Y- e / o S | ' Ny oL bt ] i 1 L 5% N L i e I EaD SHADOW-SHIELD - S — - CISKS iN POSITION “"— B — 10"5 e R 1078 | 1077 0 40 80 120 is0 200 240 2P0 CENTER-LINE DISTANCE FROM ACTIVE CORE {cm) Fig. 7.4. Gamma-Radiation Measurements Along Center Line of the Divided- Shield Mockup in the Bulk shielding Facility. 89 ANP PROJECT QUARTERLY PROGRESS REPORT 106 o I ot e ----- . — BeQ REFLECTOR FOR — 5 / DIVIDED-SHIELD REAG . T @ — EXP. 6 MEASUREMENTS MA REAGTOR IN OPEN WATER o T @ —ExP 6 MEASUREMENTS MADE WITH DIVIDED-SHIELD | 0% Zi . ; REACTOR IN OPEN WATER, 4% in OF LEAD — e INTERPOSED {0 cm FROM REACTOR TO DECREASE F—— PR —— — GAaMMA FLUX ] AN T 1 A——EXP B MEASUREMENTS MADE WITH DIVIDED-SHIELD Lo //,- REACTOR IN OPEN WATER, 8in OF BISMUTH — Aéé INTERPOSED 20 cm FROM REAGTCR TO DECREASE e ‘ GAMMA FLUX _ ' MEASUREMENTS MADE WiTH REAGTOR IN fiééi POSITION IN 0.4 %-BCRATED-WATER DIVIDED~ |-~ SHIELD MOGKUP, NO SHADOW SHIELD [— MEASUREMENTS MADE WITH REAGTOR IN o] FOSITION IN 0.4 % - BORATED-WATER DIVIDED- t SHIEL MOCKUP, WITH LEAD SHADCW SHIELD N POSITION - N - DATA FOR WATER-REFLECTED REACTOR, CENTER- - e LINE MEASUREMENTS IN WATER S .6 ——— b L . L : o FE = T 10 . AT;_ & - - S o @ E wJ 8 0 = Q o — o st = .\I— 10_.1 s b |15 = = 102 = 1 Ny o=t e A e 1 . ..,J,_*‘._._..v—,,,,d,.*j fFooo _ | - ot ——REAR PERIPHERY OF V% 3 J DIVIDED-SHIELD MOCKUP % 10 —— if"“f’::'..T'..___.__,ff\._:Jf.__':;_L ~T 3 o ;’_ W b b b e e N e L e L o \‘.:i\‘ ) ] _____ ] | : L - — TR 10_5 103e- IiIprTI— & — A'—_~J coiiz ~ o i l 0 20 40 60 80 100 120 140 180 180 CENTER-LINE DISTANGE FROM ACTIVE CCRE (cm) Fig. 7.5. Fast-Neutron Dose Measurements Along Center Line of the Divided- shield Mockup in the Bulk Shielding Facility. 90 PERIOD ENDING DECEMBER 10, 1952 REFLECTCR FOR DIVIBED-S ® — EX REACTOR IN OPEN WATER 108 o sl ©o— EXP 6 MEASUREMENTS MAGE WITH DIVIDED-SHIELD e REACTOR IN OPEN WATER, 4 ' in. OF |EAD INTERPOSED 10 em FROM REACTOR TQ DECREASE GAMMA FLUX MEASUREMENTS MADE WiTH REACTOR IN POSITION IN DIVIDED-SHIELD MOCKUP, NO SHADOW SHIELD MEASUREMENTS MADE BEHIND DIVIDED-SHIELD MOGKUP, WiTH L EAD SHADOW DISKS IN POSITION AND 7. IN-FOIL MEASUREMENTS DATA FOR WATER-REFLECTED REACTOR 107 102 THERMAL-NEUTRON FLUX (n%/wm‘f) 12 g3 1974 ] 10 0 20 40 60 80 100 120 140 160 180 200 CENTER-LINE DISTANCE FROM ACTIVE GORE (cm) Fig. 17.6. Thermal - Neutron Measurements Along Center Line of the Divided- Shield Mockup in the Bulk Shielding Facility. 91 the last quarterly report, (7? has been started., A plan view of the instal- lation is shown 1in Fig. 7.7. The animals are contained in watertight cages that are lowered under water into positioning frames on either side of the reactor as shown. The cages are located 50 5/8 in. from the center of the reactor with 7 1/2 in. of lead between the reactor and the cages. The animal irradiation is done only on the week end, and the reactor 1is free to be moved forward or backward for shielding experiments during the week, In cooperation with the Health Physics Division, an extensive set of (T)ANP Quar. Prog. Rep. Sept. 10, 1852, ORNL- 1375, p. 66, TABLE 7.1. dosimetry measurements in the cages has been completed. The results will be reported later, OTHER EXPERTIMENTS A report on the results obtained from the irradiation of electronic equipment has been issued.(®? The experiment for determining the energy released per U233 fission has been completed, but the calculations have not yet been finished. Because of low prioerity on reactor time, no pProgress has been made on measuring neutron spectra or capture gamma-ray spectra., (B)A. N. Good and W, T. Price, Effects of Nuclear Bediation on Electronic Components and Systems, WADC-TR-187 (Aug. 18, 1952). SPECTROMETER POSITIONS FOR GAMMA-RAY SPECTRAL MEASUREMENTS WITH THE DPIVIDED-SHIELD MOCKUP (WITH LEAD DISKS) yr Pt G » (deg) (deg) (deg) 0 0 0, 10, 20, 30, 40, 50 50 0 ~20, -10, 0, +10, +20, +30, +40, +50, +60, +70 60 0 ~30, -20, -10, O, t10, +20, +30, +40, +50, +60, +70, 180 60 5, 10, 15, 20, 25, 30 See footnote " nose of the spectrometer collimator. ¢’is the angle between the aircraft axis and a line connecting the pseudo reactor cemter with the *s> is the angle between the horizontal plene anda plane that includes the aircraft axis and thenose of the aspectrometer collimator. ss¢@ js the angle between the spectrometer collimator and the line joining the pseudo reactorcenter and the nose of the spectrometer collimator. 92 UNCLASSIFIED OwWG. £-13262 1L . ] || 7 ET= Seg!h S, £ EPr ~ aF e I g_ Cw TLET e[ 66 in. WIDE x 59% in. HIGH x 1Y% in. YHICK LEAD PLATES v S5 gp oW 95T \ SET IN POSITIONING FRAME AS SHOWN o ] ‘-h‘h\‘g MELTING POINT 5 . w )\\ é 400 @\\“*%z ------ o . = = 300 G >-§-.-.?s.h,-_~§~( PHASE TRANSITION — 7 \\ o clf’Q”{) 200t T 4] & / 5 100 KBE, 10 20 30 40 50 60 70 80 90 NaBE, NaBF, {rnole %) Fig. 10.3. The System NaBF -KBF,. 110 through a minimum at about 90% NaBF,. Halts at the minimum melting tempera- ture of 360°C were not observed for other compositions; apparently these materials are completely miscible in the solid state. : Attempts have been made to obtain phase equilibrium data in the NaBF,- NaUF, and NaBF, -NaZrF, systems, with little success. Mixtures of these materials were heated, in each experi- ment, to temperatures up to 800°C, where BF, pressures were about 100 psi, before the cooling curves were recorded. Although the data are quite incomplete, 1t appears that more than 5 mole % of either compound raises the melting point of NaBF, considerably. There is some evidence for eutectics at about 360°C in each system at quite low uranium and zirconium concen- trations. Actual compositions of the eutectics have not been established. DIFFERENTIAL THERMAL ANALYSIS R. E. Traber, Jr. Materials Chemistry Division The differential thermal analysis apparatus for l- to 2-g samples was used regularly during the quarter for the careful examination of important compositions, for testing samples that TABLE 10. 2. THERMAL EFFECTS OBSERVED PERIOD ENDING DECEMBER 10, 1952 were availableonly in small quantities, and for searching for thermal effects that are difficult to find with the coocling-curve technigue. The apparatus has been found to have limited appli- cationin the study of reduced systems, such as those containing UF,. Although a flowof purified heliumwas maintained in the apparatus, the erratic behavior of the differential trace obtained when the reduced samples were heated was appavently due to oxidation, Examination of the solid phases re- maining at the end of the tests showed that oxidation had occurred. Some difficulties that were experienced with the electrical system may be attributed, at least in part, to the high sensitivity of the system. Table 10.2 summarizes the thermal effects observed with differential apparatus for a number of compositions of current interest. The temperatures at which the differential trace begins to leave the base line, reaches a peak, and returns to the base line are recorded. Where more than one “hump” was observed in the differential trace, only that at the higher temper- ature is included in the table. 1t should be noted that the temperature at which the differential trace returns to the base line on the heating curve WITH DIFFERENTIAL THERMAL APPARATUS l 1 THERMAL EFFECTS (°C) COMPOSITION (mole %) ' Start Peak (m.p.) End 50 NaF-50 UF, 600 685 705 54 NaF-41 BeF,-5 UF, 310 340 360 55 NaF-40 BeF ,-5 UF,- (light-green layer) 320 360 400 55 NaF-40 BeF -5 UF, (dark-green layer) 310 355 375 57 NaF-43 BeF, 310 340 350 50 NaF-25 UF,-25 ZrF, 500 575 625 50 NaF-50 ZrF, 490 520 535 111 ANP PROJECT QUARTERLY PROGRESS REPORT is usually higher than the melting point of the composition determined from the cooling curve. This may be due to the time required to melt all the sample, and the difference between the two values 1s probably a function of the heating rate. An effort is under way to increase the sensitivity of the differential thermocouple arrangement so that a very slight thermal effect may be found, such as that which apparently was overlooked in the NakF-BeF, -UF, fuel mixture (discussed previously in this chapter). SIMULATED FUEL FOR COLD CRITICAL EXPERIMENT D. R. Cuneo J. D. Redman .. G. Overholser Materials Chemistry Division Filling the fuel tubes with homo- geneous powder containing Z4r0,, NaF, UF,, and graphite was accomplished in the manner described previously.(3) One tube was required, however, 1in which the fuel density was uniform and at least equal to the ARE fuel and in which the fuel had the proper Na:Zr:U ratio. Attempts to cast slugs of this material by heating premelted powder of the proper composition under inert atmospheres 1in graphite molds were not successful. Only the bottom 1l to 2 in. of an B8-in. section so formed was free from “pipes.” Re-use of the material from the porous sections led to considerable fractionation because of segregation during the slow cooling. The slugs were prepared 1in Building 9212 by melting the premelted fuel by induction heating under an 1nert atmosphere, pouring the liquid into 10 -in. molds, and rapidly cooling the casting, Slugs prepared in this fashion were free from pipes over about 8 in, of length and had uniform (S)D. R. Cuneo and I.. G, Overholser, ANP Quar,. Prog. Rep. Sept. 10, 1952, ORNL-1375, p. 87, 112 uranium concentrations over the entire length, The slugs were cut with an electri- cally heated knife and wrapped 1in 0.25-m1i]1] aluminum foil. A total of 41.5 in. of this material, which contained (by weight) 74.0% ZrF,, 17.2% NaF, and 8.82% UF,, was supplied to the Critical Experiment group. The material had a density of 3.75 g/cm? at room temperature. In addition, tubes were filled with $10,, NaF, KF, and Cr for danger coefficient measurements. COOLANT DEVELOPMENT L. M. Bratcher C. J. Barton Materials Chemistry Division No new coolant components were considered during the quarter except Ban,which proved unattractive because of the high melting point of the eutectic in the one system studied. Studies of systems containing AlF,, ZrF,, and BeF, continuned. NaF-Zrf,. Study of the complicated and important binary system NaF-ZrF, has been in progress for some time. Early studies were complicated by the formation of oxide that caused error in the calculation of compositions and resulted in the appearance of thermal effects above the melting points of the pure fluoride mixtures, Some data on this system have been presented 1in previous reports, (8 Although further study i1s necessary to more clearly define the composition of the solid phases in certain portions of the system, the location of the liguidus line 1s believed to be sufficiently well established to justify the publication ofthe tentative equilibrium diagram for the system, as shown in Fig. 10.4. Some of the gquestions remaining to be explained about this system are: (1) the (6)L. M. Bratcher, R. E. Traber, Jr., and C, J. Barton, ANP Quar. Prog. Rep. June 10, 1852, ORNL-1294, p. 90; and ANP Quar. Prog. Rep. Sept. 10, 1952, ORNL-1375, p. 89. PERIOD ENDING DECEMBER 10, 1952 oo OWG. 17405 10O : 1000 o 200 \C\ ~ e PR -~ s 7 o f\\ < $ 800 2 £ Wi O £ & oo"wfl o /fi)y L) o o o < 700 A " = 0oy 00 o Qoo 500 400 - NoF 10 20 30 40 50 &0 70 80 20 2rFy, NagZrf, No,ZrFg NaZrf, NaZraFg(?) Zrf, (mole %) Fig. 10.4. " composition of the compound that is - believed to exist between NaZrF_, and ZrF,; (2) the possible solid solution formation between NaZrF_ and Na,ZrF,; (3) the significance of the thermal effect at 525°C in the 33 to 38 mole % ZrF, region, which may indicate polymorphism of Na,ZrF, or, possibly, a compound such as NajZ2r,F ,; (4) the peculiar behavior {marked expansion on freezing) of mixtures in the region of the eutectic at 43 mole % ZrF,. _ LiF-ZrF_ . Study of the LiF-ZrF, system has been attended by some of thedifficulties mentioned in connection with the NaF-ZrF, system. Although The System NaF-ZrF,. thermal data have been obtained for a number of compositions in the 10 to 70 mole % ZrF, range, the melting points of some compositions are still uncertain. It is clear, however, that this systemis quite different from the other alkali fluoride-zirconium fluoride systems that have been studied. The minimum-melting-point composition appears to be close to 50 mole % ZrF,, with a melting point of about 510°C. The solid phases in this system have received little attention, as vet, NaF-KF-Al1F,. The lowest melting- point compositions in the binary 113 ANP PROJECT QUARTERLY PROGRESS REPGRT system NaF-AlF; and KF-AlF; reported in the literature’? are 685 and 570°C, respectively. The tentative equilibrium diagram shown in Fig. 10.5 indicates that in the ternary system no melting points lower than 570°C are available. NaF-BeF,-ZrF,. Thermal data were obtained from cooling curves for about 25 compositions in the NaF-BeF,-ZrF, system. Many of the compositions studied were within the NaF-NaZrF, - NaBeF, part of the diagram. The lowest melting point observed was (T)F. T. Hall and H. Insley, J. Amn. Ceraa. Soc. Nov. 1947, Supplement. AlFs p 2 / i <,Aé274 ! T 4’i¢/%fiéfié/{ LLNOT 375°C for a mixture containing 5 mole % ZrF,, 40 mole % BeF,, and 55 mole % NaF. It appears that a Bel, concen- tration of approximately 20 mole % 1is needed to obtain a melting point substantially lower than that of NaZrF, (510°C). NaF-LiF-ZrF,. The NaF-LiF-ZrF, system has been studied fairly in- tensively, especially in the 30 to 50 mole % ZrF, range in which the lowest melting points occur. The lowest melting point obtained was 426°C for the mixture containing 20 mole % LaiF, 40 mole % NaF, and 40 mole % ZrF, . Isotherms cannot be prepared for this DWG. 7406 7 685°C 570°C <7 b="" - ' e gpoteATTTTTTTT A \ LN\ \\ 900°¢ K3AlFg \\ \ . NazAlFg 1025°C \ \/ 500 0%\ 1020°C / O e N N o 1000 / AN 950°C # _ °C 840°C o | 80070~ O° .—?5000 / KF > N N / NoF 710°G Fig. 10.5. The System NaF-KF-AlF,. 114 system until the LiF.ZrF, system is clarified. _ NaF-BaF,. The alkaline earth fluorides have received comparatively little consideration as possible components of fuels and coolants, mainly because of their high melting points Since data on the NaF-BaF, system apparently have not been published, a few compositions were tested to determine the minimum melting point. The data indicate that this is a simple eutectic system; the eutectic at approximately 35 mole % BaF, melts at about 820°C. This is much too high to be of interest. The KF-BaF, eutectic has been reported to melt at 750°C. Therefore the NaF-KF-BaF, ternary seems unlikely to yield usefully low melting points. NaF -KF-~LiF-ZrF, Increasing amounts of ZrF, were added to the NaF-KF-LiF eutectic (11.5, 42.0, and 46.5 mole %, respectively). After a slight initial decrease 1in melting point of about 7°C at 2 mole % ZrF,, the melting point increased quite rapidly to 680°C at 10 mole % and reached a maximum of 715°C at 20 mole % ZrF, This indicates that if molten NaF-KF-~ LiF eutectic 1s used to trap ZrF, vapors from the ARE, as has been suggested, either the concentration of ZrF, would have to be kept low or the temperature would have to be maintained above 700°C to keep solids from forming. _ . . NaF-RbF-AIF, Meltlng points of all the compos1t10ns tested in the NaF-RbF-AlF, system (about 40) were substantlally higher than the minimum melting point observed in the RbF-AlF, system (525°C). STUDIES OF COMPLEX FLUORIDE PHASES Several new complex fluorides have been prepared to assist in the identi- fication of various materials found at the conclusion of static and dynamic corrosion tests. The complexes of the alkali fluorides with trivalent chromium have been studied in detail PERIOD ENDING DECEMBER 16, 1952 because one such complex, K,NaCr¥,, had been previously identified as being present in a loop test. The complex fluorides synthesized in these studies have been i1dentified or characterized by chemical analyses, x~-ray diffraction patterns, and optical crystallographic data. Although in most instances the sealed capsule technique was used for the preparation of these samples, 1n some cases welded tubes similar to those used for static corrosion tests were employed, with a concomitant reduction in oxide for- mation. The density and solubility of several of the complexes have been determined, and the data are given in Table 10.3. K,CrF -Na,CrF -Li CrF and L. G. Overholser, Materials Chemistry Divisien). The identi- fication of compounds in the system K,CrF -Na;CrF,-L1,Cr¥F, has been virtually completed. A constitution diagram based on x-ray diffraction data supplied by H. Dunn and interpreted with help from A. G, H, Andersen is given in Fig. 10.6. Apparently Na,CrF, and Na,LiCrF, are the limits of one solid solutlon region, and K,NaCrF_, K3Na3(CrP6)2 and KNaLiCrF, are the limits of another such area. The corrosion products found in loops in which NaF-LiF-KF-UF, had been circulated have been in the region between K, NaCrF, and K ,Na,(CrF_ ), except in one case in whlch the product resembled KNaLiCrF So0lid Phases 1n NaF-BeFQ»UF4 and NaF-ZrF, Systems (A. G. H. Andersen, ANP Division). Work done by Andersen on the solid phases in NaF-BeF,-UF, and NaF-ZrF, systems was summarlzed 1n his final report.(®’ The solid phases in the NaF-BeF, -UF, system will probably be studled further when time 1s available. UF,-ZrF, (V. S. (B. J. Sturm Coleman, cC. J. Barton, Materials Chemistry Division; T. N. McVay, Consultant, Metallurgy (B)A G. H. Andersen, The Solid Phases of Alkali and Uranium Fluoride Systems, Y-F33-3 {Det. 1, 1952}, 115 ANP PROJECT QUARTERLY PROGRESS REPORT TABLE 10,3, PHYSICAL PROPERTIES OF FLUOCOMPLEXES OF CHROMIUM, IRON, AND NICKEL COMPOUND OPTICAL DATA MES:::G SOLUBILITY IN WATER ) DENSITY (o) (g/ml) (o cu’) K4CrFy Cubic,** n = 1.422 1055 2.5 x 1073 at 290°C | 2.69 NayCrF, Cubic,** n = 1.411 880 4.0 x 10°% ar 250°C LisCrF, Biaxial,** (=), a = 1.444, 672 3.16 2V = about 40°, a = 1. 464 K,NaCrFy Cubie,** n = 1,422 1006 2.9 x 10°% 3.07 K,LiCrFg Cubic, n = 1.422 952 K,Na,(CrFy) , Cubic, n = 1,418 1000 MNaLiCrF, Cubic, n = 1,418 875 Li,KCrFg Anisotropic 791 LiyNaCrFg Anisotropic Na,LiCrFg Cubic, n = 1.400 8 30 Rb,CrFg Anisotropic Cs;CrF Biaxial, (+), avg. n = 1,520%** K,RbCrF Cubic K,CsCrFy Cubie, n = 1.457 K FeFg Cubic, n = 1.414 Na,FeF Cubic K,NaFeF, Cubic, n = 1,414 965 3,19 (solid solution) K,NiF, . Anisotropic, avg. n = 1,423 9 40 Na,NiF, 805 KNaNiF, 785 *Most of the melting point data were obtained by C. J. Barton, R, J. Sheil, R. E. Traber, and L. M. Bratcher. **Data from T. N. McYay, ***Data from G, D. White. 116 Nc]:,_l‘Cr'F6 0 X-RAY PATTERN OBTAINED AT THESE PERIOD ENDING DECEMBER 10, 1952 AN DWG. 17407 MPOSITION COMPO : S SOLID SOLUTION o NajLiCrF, K NO (Cr o SOLID SOLUTION Ko NaCrFg 7 LizNaCrfy A _ K3CrFG K'?_LiCrFG Fig. 10.86. Division). heating UF, The samples prepared by with ZrF,, with and - without NaF, show a complex compound UF,*2ZrF,, which is an orange-red crystalline solid that is occasionally found as a reduction product of ZrF,-bearing fuels. When this material is heated with NaF at 850°C or when UF, and ZrF, in proper ratio are heated with NaF, the products include UF,, some UF,-2ZrF,, and some NaZrF,. The latter compound usually contains LigCrig L.ial'(CrF'6 The Syste@ Kschfi-Naachfi—LiSCrFe. some NaUF; in solid solution, presumably formed by traces of ox1dants in the system. Since NaF can "steal” ZrF, from UF -2ZrF,, apparently NaZrFs is a more stable compound than the UF;'2ZrF, complex. The 2ZrF, -UF, compound has been found in loops in which there was severe reduction of the UF, in the fuel because of the injection of Nak, and alsoin capsules in which zirconium metal or NaK had been added to the fuel. 117 ANP PROJECT QUARTERLY PROGRESS REPORT NaF-Zr¥, (P. A. Agron, Materials Chemistry Division). The x=-ray studies of the NaF-ZrF, system(?) have been extended to the region of 75 mole % of ZrF,. The crystal structures of the solid phases Na,ZrF, and NaZrF, have been reported previously.(1?) Studies of the behavior of the phases that appear in compositions lying between these two compounds and of those that lie beyond the NaZrF, compositions are being made; considerable additional study will be required, since the system 1s an exceedingly complex one. Other Fluoride Complexes (B. J. Sturm and .. G. Overholser, Materials Chemistry Division). It was previously noted that a preparation corresponding to K,NaFeF, was thought to be iso- morphous with K,NaCrF . Further study has shown that Na,FeF_, and K,Fel, apparently form solid solutions over a wide range, probably 1nall proportions. X-ray patterns for materials corre- sponding to K, FeF,, K,NaFeF, K, Na(Feky),, and KNa ,FeF_ differ only by slight shifts 1n lines. Fusion of equal wolar proportions of KHF,, NaHF,, and NiF, -4H,0 at 850°C resulted ina yellow compound, probably KNaNiF,. A fusion in the proportions corresponding to K,Na(NiF,), gave a mixture of K,NiF, and KNaNiF,. Heating a mixture of KNiF;+1%H,0 (prepared from aqueous solution) and NH,F, at 700°C yielded a product that agrees with the ASTM x-ray diffraction data for anhydrous KNiF,, Interaction of chromium metal with K,NiF, at 850°C for 5 hr resulted in the formation of K,CrF_ by the following reaction: 3K,NaF, + 2Cr —> 2K CrF, + 3Ni This behavior is comparable to that previously noted for displacement of Fe from K,NaFeF, by Cr, (g)L. M. Brateher and C. J. Barten, "Coolant Development, ' this chapter. (IO)P. Agron, ANP Quar. Prog. Rep. Sept. 10, 1952, ORML-1375, p. BS. 118 REACTIONS OF FLUORIDE MIXTURES WITH REDUCING AGENTS W. R, Grimes Materials Chemistry Division L. A. Mann ANP Division The reactions of possible ARE fuel mixtures with reducing agents were first examined in an effort to evaluate the damage that would result i1f NaK were inadvertently admitted to the fuel circuit during operation. Identi- of the products 1n these complex mixtures was shown to bea very difficult problem. Hecently, however, it has been demonstrated that addition of reducing agents to the fluoride melts decreases the corrosion by these materials. Since production of UF, and the consequent precipitation of uranium at high temperature can result from excessive addition of reductant, a careful studyof the fluoride systems under reducing conditions has been undertaken. Reducing Power of Various Additives (J. C, White, Analytical Chemistry Division). The total reducing power of reaction products resulting from the addition of NaK to such materials as ZrF,, NalF, and UF, and such mixtures as Nab-ZrF, -UF, and NaF-ZrF, has been measured by two methods: (1) oxi- dation with standard ceric sulfate solution and (2) hydrogen evolution from dissolution in mineral acid. The validity of these procedures has been verified by using control samples, such as UF; and Zr. 1In practically none of the NaK addition tests, however, has a reducing action eqguiva- lent to the amount of NaK added been observed. This reduction phenomenon has also been obhserved when UF, has been added to NaF and ZrF, and treated as in fuel preparation. One compound, Na,U)F,, gave nearly the theoretical amount of UF, added. Several samples of fuels that had undergone corrosion testing were fication arbitrarily selected and the total reducing power determined by the ceric sulfate oxidation procedure, Since UF, was the only reductant (with respect to ceric sulfate) known to be present in these fuels, the reducing power was calculated as total uranium and compared with the value obtained from oxidation with ferric sulfate solution. All the values obtained by ceric{IV) oxidation are higher than those ob- tained by ferric(III) oxidation. Since ferric(IIIl) oxidizes only uranium(IV) in this instance, other oxidizable species that have not been identified satisfactorily must be present in rather appreciable quanti- ties. ' | Identificationof Reduction Products (F. F. Blankenship, D. C. Hoffman, Materials Chemistry Division; K. J. Kelly, Pratt and Whitney Aircraft Corporation; T. N, McVay, Consultant, Metallurgy Division). HBeduction products have been obtained by sealing the fluoride mixture to be tested, usually either the ARE fuel (50 mole % NaF, 46 mole % ZrF,, 4 mole % UF,) or NaZrFS, in capsules of type 316 stainless steel with the desired quantity of reducing agent and heating the capsules for 16 hr in the tilting furnace. 1In these tests, NaK, Zr, and ZrH2 were added in 0.2, 0.4, and 0.8 equivalents (1 equivalentis the amount required in theory to reduce the UF, to UF,). All samples were rocked with the hot end of the capsule at 800°C and the cold end at 650°C, After this heating, they were heated to 800°C while in a vertical position for2 to 6 hrto encourage sedimentation of any 1nsoluble material. Although 1t is not yet possible to explain all the processes that take place in these systems, some of the qualitative results observed may be summarized as follows: 1. Little change in the over-all appearance of the NaZrF, samples was produced with any of the reducing PERIOD ENDING DECEMBER 10, 1952 agents. Some NaZrF,, together with colorless anisotropic crystals of a continuous range of lower indexes of refraction, was present, which suggests possible solid solutions of NairF,, Na,ZrF,, and NajZrF,. " 2. A gradual change of the ARE fuel from bright green to a darker color with vellow to brown to red portions could be observed as more reducing agent was added. A brown (olive-drab) pleochroie crystal (average index = 1.558) was found 1in all the 0.2-eq. additions. With 0.4 eq., more of the brown crystal, togetherwith partly hieachedNaZr(U)Fy was present, A trace of a red-orange phase was also found in the 0.4-eq. NaK addition. With 0.8 eq. of NaK, a small amount of UF,, more red-orange phase, some yellow-to-bleached NaZr(U)F, and a little opaque material (possibly metal) were found. 1In 0.8-eq. ZrH, or Zr additions, no UF, was present, although a yvellow-to-orange phase was beginning to grow in and separate from the nearly bleached crystal solution; the brown crystals were present. The Zr addition seemed to show more reduction products, as well as a small amount of opaque material. In all the tests, the concentration of the brown, red-orange, and UF, crystals appeared to be highest 1n the bottom portion of the capsule. 3. The NaF—ZrF4—UF4 (50-46 -4 mole %) fluoride fuel run as a control sample with these tests appeared normal, with only a slight trace of a brown coloration in some crystal solution fromthe bottom of the capsule. The orange-red crystalline phase has been prepared by heating UF; and ZrF4 (1:2 mole ratio) in sealed capsules at B850 to 900°C. This complex, which 1s almost certainly UF, 2Zr¥F,, appears to be fairly uniform; however, variations in the index of refraction indicate that the UF,-to-ZrF, ratio is not constant. By heating equimolar mixtures of ZrF, and UF,, a yellow-brown crystal is 119 ANP PROJECT QUARTERLY PROGRESS REPORT formed; however, remains, When mixtures corresponding to NaF-UF, -2ZrF, are heated, the red- orange phase 1s predominant, but free UF,, NaZrF,, and a trace of a colorless phase are present. [If preparations containing NaF + (UF,-2Z:F,) are ‘agitated to ensure equilibrium during the heating period, the olive~drab phase, brown phase, along with NaZrF, appear. When the composition is NaF + 2(UF, +2ZrF,), the red-orange phase predominates, with some green- to-olive-drab phase growing in it; some UF;, NaZrF.,, and a trace of colorless crystals (not ZrOz) appear. It seems that NaK produces some free UF, in the ARE fuel, whereas ZrH, and Zr do not. These phenomena may have the following explanation: The (NaK)F formed can remove ZrF, fromthe UF,*2ZrF,, or similar compound, with the ultimate formation of free UF; when it no longer has enough ZrF, with which to combine. On the other hand, the ZrF, formed by the ZrH, and Zr additions will be able to hold more UF,. (Large encugh additions of ZrH, or Zr to produce free UF, have not yet been obtained.) This suggests, however, that the ARE fuel is in very delicate balance with regard to reductants, and on this point alone fuels with higher ratios of zirconium to alkali metal might be preferred. Reaction of Fluoride Mixtures with NaX (L. A, Mann, J. M, Cisar, F. M, Grizzell, ANP Division). A series of four tests was run by the Experimental Engineering group, in which various amounts of NaK were allowed to react with a fluoride fuel mixture to determine how much NaK canbe tolerated in the fuel mixture. In these tests, the NaK was added to NaF-ZrF, -UF, (46-50-4 mole %) and allowed to react at high temperatures (1400 to 1500°F), The liquid portion was then pulled through a micrometallic filter, the residue an excess of UF3 some UF;, much of and some reddish and (the portion that was 120 solid at high temperatures) and the filtrate were examined. It was found that the addition of sufficient NakK would reduce enough UF, in the fuel mixture to UF; to cause a solid precipitate at reactor temperatures and, hence, would be detrimental to the proper functioning of the ARE. It was also found, by adding varying amounts of the NaK to a given amount of fuel, that a limited addition of NaK would notcause such precipitation. The maximum amount that could be added was between 0.27 and 0.70 eq. (per equivalent uranium) at 1200 to 1300°F. Additional confirmatory tests, plus tests with other fuel mixtures, are scheduled to be performed by the Materials Chemistry group. Reaction of Na¥F-ZrF,-UF, with Zrii, (J. D. Redman, L. G. Overholser, Materials Chemistry Division). Ad- ditions of small amounts of ZrH, have been shown to be of considerable benefitin decreasing attack on Inconel by fluoride mixtures. Since production of UF; in amounts sufficient to exceed the solubility of this compound at 1100°F might occur as a result of such additions, made studies have been to demonstrate whether such systems are completely liquid at this temperature. The apparatus developed for this purpose is shown in Fig, 10.7. This apparatus will minimize the possibility of oxidation of the mixture. The charge bottle 1s loaded with the required materials, and the apparatus 1s assembled in a dry box. The apparatus 1s then rocked, and after an equilibrium temperature is reached, the rig 1s inverted to permit the charge material to pass through the nickel filter and into the receiver tube. Thermocouple wells are provided for temperature control, and the gas lines permit evacuation of the chamber or maintenance of a particular atmos- phere, as desired. The filter may be removed for examination by disassembling the apparatus. In these studies, a mixture con- taining 30 mole % NaF, 46 mole % ZrF,, and 4 mole % UF, that had been purified in the standard fashion and stored in a sealed bottle in a dry box was treated with varying guantities of ZrH,. BSamples were equilibrated at 800°C for 4 hr under apositive pressure of helium and, afrer 2hr equilibration at 600°C, filtered at the latter temperature. ‘ | When ZrH, was added in the range from 0.2 to 0.7 wt % of the fuel mixture, no evidenceof solid separating from the melt was observed. Chemical analysis of the filtrates in each case revealed the original uranium concentration, and microscopic exami-~ nation of material on the filter revealed no UF;. Although extensive reduction of uranium to UF; 2ZrF, was observed in the filtrate, especially when 0.7% of ZrH, was used, no free UF, could be detected in the specimens examined. . Additional tests will be made to verify this important point and to Closed-system PER 10D ENDING DECEMBER 16, 1952 L2 Batch-Filtration Rig. determine the maximum ZrH, concen- tration tolerable without precipi- tation of the solids. 1t appears, however, that if the temperature is kept at 600°C or above, at least 0.7 wt % of ZrH, may be added to the ARE fuel without difficulty. _ Soelubility of Potassium in the NaF-KF-LiF Eutectic (H. R. Bronstein, M. A, Bredig, Chemistry Division). Additions of alkali metals to fluoride mixtures have demonstrated a capacity for supressing the fluoride attack on container materials. Consequently, an investigation was undertaken to determine the amount of potassium that will remain in equilibrium in the fluoride eutectic NaF-KF-LiF (11.5-42.0-46.5 mole %). The need for separation of the equilibrated liguid salt and liauid metal phases led to the design of aball-check apparatus that consists of a sealed capsule with two outlets, either of which may be sealed by the steel ball within the capsule, The capsule 1s charged with the fluoride, the metal added, and the 121 ANP PROJECT QUARTERLY PROGRESS REPCRT mixture intimately mixed. The capsule is then tilted so that the ball closes the lower valve and isolates the upper part of the salt phase, which is then solidified and analyzed for 1ts potassium content. The data obtained are summarized in Table 10.4. PRODUCTION AND PURIFICATION OF FLUORIDE MIXTURES F. F. Blankenship G. J. Nessle Materials Chemistry Division Use of the hydrogenation-hydro- fluorination process previously described for fuel-sample preparation has been continued on laboratory and pilot scales for production of standard materials for corrosion testing, physical property evaluation, and large-component testing. Construction of the production equipment to furnish 3000 1b of NaZrF, for the ARE is in an advanced stage. Raw materials are being accumulated at a satisfactory rate, A modification of the purification treatment has been adopted for micro- scale processing of samples containing enriched uranium for radiation-damage testing. Aslight modification of the standard procedure has been used successfully to purify mixtures containing 50 mole % NaF, 25 mole % ZrF,, and 25 mole % UF,. Preparation of NaZrl; by direct hydrofluorination of Zr0O, in the presence of NaF has been moderately successful in simple equipment. Further study of this process 1s planned, Laboratory-Scale Fuel Preparation (R. E. Thoma, C, M. Blood, F. P. Boody, Materials Chemistry Division). Fourteen batches of purified molten fluoride compositions, both coolant and fuel, have been prepared for loop tests, measurement of physical properties, and corrosion testing. These were treated 1n essentially the same manner as previously reported, (1) To explore the unlikely possibility that hydrogen reduces UF, or Zr¥,, two of the fuel batches were given an additional hydrogenation for 1 hr following the regular procedure. No evidence of reduced phases in the products from these runs was shown by examination with the petrographic microscope. However, there 1s evidence that the material so prepared was slightly less corrosive in small-scale tests than was the standard fuel. No explanation for this effect has been suggested; however, further study of this behavior is planned. Modifications of techniques of assembling and disassembling apparatus have resulted in less frequent failure than was experienced at the beginning of the hydrofluorination program, Corrosion of the reactors has not yet been a problem when the standard treatment 1s applied to relatively pure fluoride mixtures. Pilot-Scale Fuel Purification (G. J. Nessle, J. E. Eorgan, Materials Chemistry Division). Two apparatus capable of producing up to 3 kg of (1D, M. Blood, F. P. Boody, A. J. Weinberger, and G. J. Nessle, ANP Quar. Prog. Rep. June 10, 19592, ORNL-1294, p. 97. TABLE 10.4. SOLUBILITY OF POTASSIUM IN NaF-KF-Li¥F TEMPERATURE OF NO. OF POTASSIUM CONTENT EXPERIMENT (°C) EXPERIMENTS (mole %) 544 1 3.8 686 1 3.5 920 5 3.7 £ 0.5 10 40 1 3.9 122 purified fuel mixtures andone apparatus capable of handling up to 30 kg of the molten materials are 1in use at present. The small units are es- sentially duplicatesof the laboratory- scale models previously described. The 50-1b equipment, however, was built mainly from existing equipment and utilizes an 8-ft transfer line and a receiver furnace that can be lowered topermit rapid handlingof the product. This apparatus has 3/8-in. nickel tubing in the gas and transfer lines and 10-in.-dia reactor and receivers. Swagelok fittings are used on all tubing connections. A total of 323 kg of fuel has been prepared i1n the equipment, and 1t 1is possible to produce up to 60 kg per week, 1f necessary. Each fuel batch 1s sampled as 1t is transferred under inert gas pressure to the receiver, Except 1n a few instances, the concentrations of Fe, Cr, and Ni have been less than 900, 100, and 900 ppm, respectively. There appear to benodifferences in chemical analysis that can be attributed to the presence or absence of the sintered nickel filter in the transfer line. Since there have been some un- explained differences in corrosion between various batches of fuel prepared in this equipment, it may be necessary to increase the time of treatment in the 50-1b rig. This possibilityis being studiedat present. In general, performance of the pilot-scale equipment has been quite satisfactory. The 50-1b rig would be improved by larger valves in the HF lines, although heating all such lines to 100°F has minimized the difficulty resulting from condensation of HF, No difficulty with faulty vessels of nickel or with corrosion of reactors has been observed. Transfers of material from the l0-in. reactor are remarkably complete; material balances indicate less than 100-g holdup on batches of 50 pounds. PERIOD ENDING DECEMBER 10, 1952 Fuel Production Facility (G. J. Nessle, Materials Chemistry Division). The 3000 1b of NaF-ZrF, (50-50 mole %) for the ARE is to be prepared in 250 -1b batches. Equipment for this purpose 1s being constructed of nickel from scaled-up designs that are very similar to those used for the pilot- scale units. Duplicate units are to be used, and production of 750 to 1000 1b per week should be possible. These units are in the final con- struction stages and should be available by mid-December. The equipment i1s instal led in an area that is convenient for operating personnel and where safety can be maintained during the entire cycle. The process includes storage, transfer, weighing, and blending of the dry solid components; treatmentby melting, fluorinating with hydrogen fluoride, and reducing with hydrogen; transfer of the pure liquid melt to the storage vessel; and storage of the solidified product. All treatment processes at molten temperatures are handled remotely, and the negative-pressure ventilation over the confined process equipment is at a rate of more than one change per minute. The process equipment from outside manufacturers and Y-12 shop fabricators has been delivered and is scheduled for instal- lation, without delay, upon completion of the construction work. The ZrF, for the fuel is low- hafnium material prepared by the Y-12 Production Division by hydrofluori- nation of ZrCl,. The ZrCl4, produced at the Bureau of Mines in Albany, Oregon, has been delivered, and conversion to ZrF, is virtually complete. Table 10.5 shows the chemical analysis of the sublimed ZrF, received fromY-12 and stock-piled for this operation. The NaF of the purity required is available in stock, and HF, H,, and He of the proper purity are available in gquantity. 123 ANP PROJECT QUARTERLY PROGRESS REPORT TABLE 10.5. ANALYSIS OF LOW-HAFNIUM Lr¥, FOR PRODUCTION OPERATION BATCH COMPOSITION (%) HAFNIUM BORON NO. 7r F cl C (ppm) (ppm) B-1 54.8 { 42.8 0.03 0.06 85 B-2 55.2 42.8 0.03 0.12 70 - 43.9 0.01 0. 29 50 1 B-4 43.8 0.01 0. 14 50 0.5 B-5 44.7 0.01 0.07 50 0.5 e Lo . Preparation of Hydrofluorinated Fuel Samples (F. P. Boody, Materials Chemistry Division). Ten small samples containing enriched UF, have been treated in the program for preparing fuels for the cold critical test and for radiation-damage tests in the MTR. The base material was a mixture of NaF and ZrF, that had been hydrofluorinated before the enriched UF, was added. Samples containing 10.8, 16.5, and 35.0 wt % UF, have been prepared for the radiation-damage experiments, The batches of NaF-ZrF,-UF, (46-50-4 mole %) for the cold critical test were treated in the same manner as batches containingnormal UF,. However, the batches required for radiation- damage tests were small (10 to 20 g), and the procedure was modified so that the HF, H,, and He gases were not bubbled through the melt but were applied as an atmosphere. The melt was contained in either a nickel or platinum crucible 1nside the nickel reactor. The reactor was opened and the sample transferred to a gas-tight glass shipping container in a dry box that had an inert atmos- phere that was produced by evacuating and flushing with dry helium three times. A small amount of NaK was included in the sealed glass shipping container to ensure the quality of the inert atmosphere. The formation of a hlack crust on the surface of several of the samples 124 has caused considerable concern. This crust has been examined petro- graphically, spectroscopically, chemically, and by x-ray diffraction. The spectroscopicand x-ray diffraction analyses showed only NaUF; and NaZrF, to be present in appreciable quantity; however, the petrographic microscope indicated small amounts of carbon and UO0,. Chemical analyses indicated 0.06 to 0.20% carbon and approximately 0.2% U0,. Hydrofluorination of Zrx0,-NaF¥ Mixtures (C. M. Blood, R. E. Thoma, Materials Chemistry Division), Efforts to determine the optimum conditions for the smooth and complete hydro- fluorination of NaF-Zr0, mixture to NaZrF; have continued, The successful results obtained during the previous quarter{'?? with the hydrofluorination of small samples (300 to 400 g) encouraged attempts to treat larger batches (2 to 3 kg) without the aid of a mechanical stirrer. Because of the high temperatures (700 to 900°C) involved and the pronounced 1in-~ convenience of mechanical stirring in the presence of HF at this tempera- ature, a technigque was sought that required no more agitation than that provided by gas bubbling through 6 in. of melt 4 in., in diameter. Completion of the reaction by passing HF through a nickel reactor at (12)g F. Blankenship, R. E. Thoma, Jr., F. P. Boody, and C. M, Blood, ANP Quar. Prog. Rep. Sept. 10, 1952, ORNL-1375, p. 91. low temperatures (50 to 150 °C}, at which a liquid reaction medium was obtained through the agency of the low-melting-point polyhydrofluorides of NaF, or at high temperatures {550 to 850°C), at which liquefaction resulted from the melting of the NaZrF,, appeared feasible. The main problem was to find the optimum combination of low- and high-tempera- ture stages. Farlier results indicated that although essentially stoichi- ometric conversion could be obtained at low temperatures, complete neutral- 1zation and removal of water was best ensured by high-temperature treatment of the molten salt. Accordingly, all trials were finished withat least 1 hr of high- -temperature treatment. Difficulties associated with the appearance of insocluble intermediates were encountered at both low and high temperatures. Cements, presumably related to ZrOF,, were developed in the partly reacted mixtures; rapid passage of HF or helium was 1neffecti?e in mixing the cemented portions, and channeling occurred. ' Successful results were achieved 1f long scaking periods (12 to 16 hr) atlow temperatures were used, followed by high-temperature hydrofluorination; when 25% of the charge material was the previously prepared NaZrF., the high-temperature treatment alone was sufficient. Both petrographic exami-~ nation and x-ray analysis indicate that even in those samples in which the material balance i1s 100% there occurs a trace amount of Na,ZrF,, and as a result the refractive index or the x-ray crystal pattern deviates slightly from the exact standard for NaZrF, . The feasibility of making ZrF, directly from ZrO, and NaF has been demonstrated from a laboratory stand- point; the practical application of theprocess requ1resfurther'englneerlng development, PERTOD ENDING DECEMBER 10, 1952 PURIFICATION OF HYDROXIDES E. E. Ketchen I.. G. Overholser Materials Chemistry Division The purification of hydroxides has continued, but at a further decreased rate, An increased interest 1in handling alkali metals, especially the alloy NaK, made it necessary to condition the vacuum dry box and perform numerous loadings and un- loadings, which cut heavily into the time allotted for hydroxide purifi- cation. sufficient NaOH has been purified to maintain an inventory large enough to fill all requirements for this material. However, The method previously given, ('3¢1%) which involves the removal of Na,CO, from a 50 wt % solution of NaOH and subsequent dehydration at 450°C under vacuum, was used for all NaOH purifi- cation., Nine batches averaging 1 1/21b per batch were prepared during the period. The purified product continues to meet the specification of 0.1 wt % for both Na,CO, and t,0. Additional pure KOH has been prepared by the method previously describedt 1319 namely, the interaction of pure potassium with water, followed by dehydration at 450°C under vacuum. The K,CO; content has ranged from 0.04 to 0.12 wt % and the water content has been 0.1 wt % or less. Approximately 2 1b of KOH was prepared during the period, and the inventory was thus increased to about 5 pounds. At present, the demand for pure KOH is virtually nonexistent, and unless some unforeseen demand arises 1t 1s not planned to react more than. an additional pound of potassium. Two batchesofSr(Ofl)2 were purlfled by the method previously described (13)g. g Quar. Ketchen and L.: G. Overholser, ANP Prog. Rep. June 19, 1952, OBNL-1294, p. 89. (14)D.lL Cuneo, E. E. Ketchen, D. E. Nicholson, and L, G. Overholser, ANP Quar. Prog. Rep. March 10, 19532, ORNL-~1227, p. 104, : 125 ANP PROJECT QUARTERLY PROGRESS REPORT in detail.{'%) This material is not being used for experimental purposes (IS)L. G. Overholser, D, E. Nichclson, E. E. Ketchen, and D. R. Cumeo, ANP Quar. Prog. Rep. Dec. 10, 1951, ORNL-1170, p. B84. 126 at present; consequently, no further significant production is anticipated. No LiOH was purified during the period. Present requirements are being met by dehydration of the commercial monohydrate, PERYOD ENDING DECEMBER 10, 1952 11. CORROSION RESEARCH W. R, Grimes, Materials Chemistry Division W. D. Manly, Metallurgy Division H. W. Savage, ANP Division Most of the effort on corrosion was expended in dynamic tests of the ZrF, - bearing fluoride melts. These studlea have been primarily concerned with the effect of various additives to the melt on the corrosion behavior of Inconel, It was found that additions of ZrH, and NaK to the fuel mixture inhibit the corrosive attack. Other tests of fluoride corrosion have been performed to determine the effect of crevices, temperature, and pretreatment of the fluoride and the resistance of various oxide coatings and ceramic bodies. Several Inconel loops circulating the fuel mixture NaF-ZrF, -UF, (46-50-4 mole %) exhibited more severe corrosion than was previously encountered 1in such tests; this is believed to be due to the lower purity of the fluoride mixtures recently prepared in large- batch apparatus, Temperature-dependence tests and experiments on the effects of various additions on the corrosion behavior of the hydroxides were carried out. How- ever, the maintenance of a hydrogen atmosphere 1is the only proved means of controlling hydroxide corrosion. The work on liquid metal corrosion was concentrated on the operation of thermal convection loops of two types to study the mass transfer properties of lead. One of the most critical variables in lead corrosion was found to be the cleanliness of the lead and the container., However, even the purest lead prepared to date cannot be satisfactorily contained in Inconel at temperatures above 500°C., The in- vestigation of the stability of BeO 1n NaK was continued, but additional ex- perimentation is required to make an . evaluation, . FLUORIDE CORROSION IN STATIC AND SEESAW TESTS D, C, Vreeland L. R. Trotter E. E. Hof{iman J. E. Pope Metallurgy Division F. Kertesz C. BR. Croeft H. J. Buttram R. E. Meadows Materials Chemistry Division Oxide Additives. Static tests were run in Inconel tubes for 100 hr at 816°C with the fluoride mixture NaF-KF-LiF-UF, (10.9-43.5-44.5-1.1 mole %) plus approx1mately 10% additions of ferric oxide, nickel oxide, and chromic oxide. These'tests'were run to determine whether the presence of these oxides, which may also be present on Inconel, would increase the cor- rosion by fluorides. 1TIn these tests, the nickel oxide and ferric oxide had little or no effect on the extent of corrosion. The addition of chromic oxide apparently increased corrosion. The results are summarized in Table 11.1. Similar tests are being run with oxidized Inconel specimens to determine whether increased corrosion can be expected on oxidized Inconel, Comparison of Liguid- and Vapor- Phase Corrosion. Sections of the testing tube used in some of the tests run with the fluoride mixture NaF-KF- LiF-UF, (10.9-43.5-44,5-1.1 mole %) for 100 hr at 816°C were removed, both from above and from below the bath level, for metallographic examination. The corrosive attack noted on all sections examined would seem to indi- cate that attack can be expected on metals exposed to the vapor phase of the fluoride mixture. The sections of type 304 stainless steel exposed to the vapor phase appeared to be attacked 127 ANP PROJECT QUARTERLY PROGRESS REPORT more severely than those exposed to the liquid phase. Inconel, type 309 stainless steel, and type 316 stainless steel appeared to be attacked by the vapor phase to approximately the same extent as by the liquid phase of the molten fluoride salt., Figures 11.1 and 11.2 compare type 304 stainless steel as exposed to the liquid phase and to the vapor phase of the fluoride. Details of these tests are presented in Table 11.2. Crevice Corrosion. Some concern had been expressed about the possibility of crevice corrosion in materials used to contain the molten fluorides. In order to check this possibility, tests were set up with specially prepared crevices. Ordinary static corrosion tubes were employed, and the lower section of the tube above the bottom weld was partly crimped so that a crevice about 1 in. long and approxi- mately 1/16 in. wide was obtained. After being exposed for 100 hr at 816°C to the fluoride mixture NaF-KF- LiF-UF, (10.9-43.5-44.5-1.1 mole %), the tubes were cut longitudinally through the partly crimped section and examined for evidence of accelerated corrosion. The crimped ends of several ordinary static corrosion test tubes were also examined for accelerated corrosion. Corrosion in these crevices appeared to be somewhat erratic, with some sections being unattacked. How- ever, even in the sections that were attacked, the depth of penetration did not exceed that normally expected for these materials after exposure to fluorides. Details of these tests are presented in Table 11.3, TABLE 11.1. RESULTS OF STATIC CORROSION TESTS OF INCONEL IN NaF-KF-LiF-UF, WITH VARIOUS ADDITIVES FOR 100 hr AT 816°C ADDITIVE METALLOGRAPHIC NOTES 10% ferric oxide 10% nickel oxide 10% chromic oxide Attack to 2 mils on specimen and tube Attack to 1 mil on specimen and tube Attack to 5 mils on specimen and 2 to 10 mils on tube TABLE 11.2. RESULTS OF EXAMINATIONS OF VARIOUS MATERIALS EXPOSED TO LIQUID AND VAPOR PHASES OF NaF-KF-LiF-UF, FOR 100 hr at 816°C METALLOGRAPHIC NOTES MATERXAL }+H————rrorovooo o LIQUID-PHASE EXPOSURE VAPOR-PHASE EXPOSURE Inconel Erratic attack, subsurface voids Erratic attack, subsurface voids to to 1.5 mils 1 mil Type 304 Erratic attack, intergranular Intergranular attack to 5 mils stainless steel Type 309 stainless steel Subsurface voids to 3 mils Type 316 stainless steel with some subsurface voids to 1 mil Intergranular penetration of 1 mil Subsurface voids to 3 mils Some slight evidence of attack, less than 0.5 mil penetration 128 PERYOD ENDING DECEMBER 16, 1952 Fig. 11.1. Type 304 Stainless Steel Exposed to Attack by Ligquid Phase of NaF-KF-LiF-UF, for 100 hr at 816°C. 250X. | | | P UNCLASSIFIED © ' . ° & o, ‘ : i . - , . S . o | T ! - - . £ i - - ; - Foo . ® . K s 5 . . 3 ; i . . | e e . A i : . 5, ' o . %, P : % . g acu s, 7 s, . S b * . s 4 Ll T . : . v ‘ . St . : \ \ o 5 . - i . : : : L - C . { ; e 05 ¢ "’““w.v// T | 'é . - e {; Fig. 11.2. Type 304 Stainless Steel Exposed to Attack by vapor Phase of NaF-KF-LiF-UF, for 106 hr at 816°¢C. 250X, | 129 ANP PROJECT QUARTERLY PROGRESS REPORT TABLE 11.3. RESULTS COF EXAMINATION FOR ACCELERATED CREVICE CORROSION IN Inconel (specially prepared crevice) Type 304 stainless steel (specially prepared crevice) Type 316 stainless steel (specially prepared crevice) Incone! (regular static test) Type 304 stainless steel (regular static test) Type 309 stainless steel (regular static test) Carboloy and Stellite Alloys., Several Carboloy and Haynes Stellite alloys that might possibly be used as valve seat and facing materials have been subjected to static corrosion tests with the fluorides. Carboloy 44A and 55A were apparently unattacked in fluoride mixture NaF-ZrF,-UF, (46- 50-4 mole %). The Stellites tested were attacked much more severely by this fluoride mixture than by NaF-KF- LiF-UF, (10.9-43.5-44.5-1.1 mole %). These materials were exposed for 100 hr at 816°C in evacuated Inconel tubes. The test results are presented in Table 11.4. Reducing Agents. with various reducing agents were exposed in the tilting furnace for 100 hr with 4 cpm between 650 and 800°C., Data were obtained by addition of 1 wt % of Zr or ZrH, to fuel con- taining NaF-ZrF, -UF, (50-46-4 mole %). Chemical analyses of the fluoride, without and with the additives, indi- cate that with the additives the amount of structural elements dissolved is drastically reduced. tration Fluoride samples The concen- of nickel in the fuel is con- siderably increased, whereas the iron content remains essentially constant; 130 METALLOGRAPHIC NOTES ¥ Subsurface voids to a maximum of 2 mils Subsurface voids to a maximum of 2 mils Subsurface voids to a wmaximum of 1 mil Subsurface voids to a maximum of 2.5 mils Very little attack, a few subsurface voids to 0.5 mil Subsurface voids to a maximum of 1.5 mils the dissolution of chromium, however, 1is reduced to negligible proportions. It appears that this technique may alleviate the difficult problem of selective leaching of chromium from Inconel and stainless steel. Metal- lographic examinations of these tubes indicate that addition of Zr or ZrH, reduces penetration of the fuel into the metal. Tests still in progress indicate that addition of these agents to the extent of an 0.8 equivalent of Zr or ZrH, (based on reduction of UF, to UF;) causes formation of an orange-brown compound and that addition of an 0.8 egquivalent of NaK causes some reduction to UF;. At lower concentrations, that is, below 0.4 equivalent, no free UF, 1s detected. The range between 0.4 and 0.8 is being investigated, Examination of Inconel tubes 1in which varying amounts of NaK were added to NaF-ZrF,-UF, (50-46-4 mole %) and NaF-Zr¥F, (50-50 mole %) showed that in the tubes containing NaF-ZrF, - UF, there was a nonmetallic deposit and some pitting at the deposit-metal inter face. The tubes containing NakF- ZrF, appeared to be attacked similarly, but there was somewhat heavier pitting. Additions of NaK cannot be recommended at present. ' Fluoride Treatment. Static cor- - rosion tesfls were made on a special batch of the fluoride mixture NaF-ZrF,- UF, (50-46-4 mole %), which was pre- pared by starting with ZrO, and hydro- fluorinatirig the mixture to obtain ZrF,. The tests indicated that this mixture 1s no more corrosive than material prepared by the hydrogenation- hydrofluorination process in which - ZrF, is used as the startingmaterial. The effect of a hydrofluorination treatment for the fluoride mixture NaF-KF-UF, (46.5-26-27.5 mole %) was PERIOD ENDING DECEVBER 16, 1952 determined in a tilting-furnace cor- rosion test in which the hot end was at 800°C and the cold end at 650°C, The duration of the test was 100 hours. It was found that Inconel suffered approximately the same degree of attack as when exposed to untreated fluorides of the same composition, that is, 1 to 6 mils of penetration. The results of exposure of type 316 stainless steel indicated approximately the same severity of attack, but slightly less penetration, as when untreated material ‘was used. It appears that the purification treat- ment should be extended for longer TABLE 11.4., RESULTS OF TESTS OF SEVERAL CARBOLOY AND HAYNES STELLITE ALLOYS EXPOSED T0 FLUORIDE MIXTURES FOR 100 hr AT B16°C IN INCONEL TUBES FLUORIDE - TER - METALLOGRAPHIC NOTES MATERIAL BATH NO. | | Carboloy 44A 27(@) No apparent attack Carboloy 55A 27 No apparént attack Carboloy 608 27 General roughening of surface, 1 to 2 mils ‘ Carboloy 779 27 Some surface spalling to a depth of 1 mil, which may have occurred in grinding : Carboley 907 27 Some surface spalling to a depth of 1 to 3 mils, which may have occurred in grinding Haynes Stellite 3 14® Light attack of what appears to be a carbide phase, 1 mil in depth Haynes Stellite 3 27 Selective attack of what appears to be a carbide phase, 4 ' maximum depth 22 wils, minimum 12 mils, average 15 mils Haynes Stellite 6 14 Selective attack of what appears to be a carbide phase, {specimen A) maximum depth 6 mils, minimum 2 mils, average 4 mils Haynes Stellite 6 27 Selective attack of what appears to be a carbide phase, (specimen A) maximum depth 24 mils, minimum 12 mils, average 15 mils Haynes Stellite 6 14 Selective attack of what appears to be a carbide phase, (apecimen B) : maximum depth 3 mils, minimum 1 mil, average 2 mils Haynes Stellite 6 27 Selective attack of what appears to be a carbide phase, (specimen B} 4 maximum depth 29 mils, minimum 8 mils, average 1l mils Haynes Stellite 19 14 Scattered attack to 2 mils in depth Haynes Stellite 19 27 Selective attack of what appears to be a carbide phase, maximum depth 29 mils, minimum 10 mils, average 20 mils (a) a ) . . Composition: (b)Composition: NaF-ZrF,-UF,, 46-50-4 mole %. NaF—éfF.LiF;UF4, 10,9-43,5-44.5-1.1 mole %. 131 ANP PROJECT QUARTERLY PROGRESS REPORT times when high uranium concentrations are used. A test was run in the tilting furnace under standard conditiomns of time and temperature with NaF-ZrF, -UF, (50-46-4 mole %) that had been treated with hydrogen after purification by the normal hydrogenation-hydrofluori- nation method. Type 316 stainless steel showed somewhat less attack when subjected to the hydrogen-treated material than when exposed to material prepared in the standard fashion. The Inconel tubes were found to be lightly attacked (0.5- to 1-mil penetration) when in contact with the hydrofluorin- ated material, but they evidenced no attack when exposed to the hydrogen- treated material. These preliminary tests indicate that a final hydrogen treatment of the fuel would be bene- ficial, Additional tests are scheduled. Temperature Dependence. Although the immediate application of the fluoride fuel NaF-ZrF4-UF4 (50-46-4 mole %) is to be limited to a tempera- ture of 1500°F, some corrosion tests under static conditions were performed at considerably higher temperatures to determine the temperature-dependence of the corrosiveness of this fuel. As the data in Table 11.5 indicate, penetration of the Inconel by the fluorides in these 100 hr tests in- creased slightly, 1f at all, over the temperature range 800 to 1200°C, It 1s i1interesting to note that Inconel seems to lose weight at 1200°C instead of gaining weight as is usual at the lower temperatures, No expla- nation for the behavior athigh temper- atures 1s suggested, Ceramic Materials. Two specimens of beryllium oxide blocks with approxi- mate dimensions 0.25 by 0,25 by 0,50 in., were exposed to NaF-BeF, (57-43 mole %) for 100 hr (24,000 cycles) in the tilting furnace with the hot end (beryllium oxide mechanically held at hot end) at 800°C, and the cold end at TABLE 11.5. CORROSION(H?INCGNEI,BYNaFVZrF4-UE1AT TEMPERATURES FROM 880 70 1200°C RUN NO TEMPERATURE WEIGHT CHANGE PENETRATION CHEMICAL ANALYSIS (ppm) ' (°C) (mg/dm?/day) (mils) Fe Cr Ni 299(a) 800 +4 0.5 to 1 170 90 20 +8 0.5 to 1 180 1860 45 -1 0.5 to 1 440 2100 20 234(2) 1000 +292 1 to 2 185 2700 20 +9 1 to 4 100 3000 20 +12 1 to 4 90 2600 20 255(%) 1100 0 0.5 to 2 95 980 20 +6 0.5 to 2 100 1000 20 258(¢) 1200 -13 0.5 to 2 200 1030 75 ~31 0.5 to 1 290 670 110 {a) Prerun analyses of fuel: (&) Prerun analyses of fuel: {c) Prerun analyses of fuel: 132 3000 ppm Fe, 980 ppm Cr, 230 ppm Ni. 720 ppm Fe, >20 ppm Cr, 135 ppm Ni. 340 ppm Fe, 220 ppm Cr, 580 ppm Ni. 650°C, One specimen came out with ~clean surfaces and showed a 2.0% weight loss, whereas the other was found to have a 4.6% weight gain as a result of a magnetic oxide layer on one side. This oxide was probably due to iron and/or nickel from the tube walls, Several ceramic materials with approximate dimensions 0.25 by 0.25 by 0.50 in. were tested 1n the fluoride mixture NaF—ZrF4 50-50 mole %) under static conditions, and the following information was obtained: ' SPECIMEN WEIGHT CHANGE (%) SiC i +35 TiO2 - - 17 ZJ."O2 {stabilized) - -51 Zr02 Dissolved MgO Dissolved Al ,0, - 317 The weight gain shown by the silicon carbide may be due to soaking up of the fluorides; if this is the case, there is indication that silicon carbide resists attack by this melt. FLUORIDE CORROSION IN THERMAL CONVECTION LOOPS G. M. Adamson, Metallurgy Divisioni Several Inconel loops were operated with NaF-Zr¥F,-UF, (46-50-4 mole %) under standard conditions, and in every case the depth of attack was slightly greater than had been encountered previously., The fluoride charges for these loops were all prepared in large batches. The inhibiting effect of zirconium hydride was confirmed in a test with NaF-KF-LiF-UF, (10.9-43.5- 44.5-1.1 mole %). The inhibiting effect was also observed with ZrF - bearing fluorides, but 1t was not quite so effective and caused changes to take place in the fuel. NaK also has an inhibiting effect on both these fluorides but causes even greater changes to take place. It was noted that the fluorides possess a self- PERIOD ENDING DECEMBER 10, 1952 insulating property that makes plugging a flowing system more difficult than would be expected, | The results obtained during this period with the Inconel loops in which fluorides were circulated are summarized in Table 11.6. This table is a con- tinuation of Table 15 in the previous report. ?) Table 11.6 should be referred to in reading the following discussion because i1t presents the individual test data not given in the specific sections. All loop tests, except one that terminated prematurely because of a power failure, operated for 500 hr with a hot leg temperature of 1500°F, Mixtures Containing ZrF, . as yet undetermined reason, the attack found in the TIncomnel loops in which fluorides containing ZrF, have been circulated is increasing, The attack by these fluorides had been reduced to a depth of about 5 mils maximum after 500 hr at 1500°F, For some but i1n recent tLtests the attack has been significantly greater, that is, from 9 to 12 mils. Although some of the earlier loops were attacked to a depth of 10 mils, the attack could be attributed to the cleaning cycle, since 1t has heen shown (both with other fluorides(?’ and with lead) that the cleaning methods pre- viously used caused an increase in attack. The new attack is actually as deep as, or deeper than, the attack in all the earlier tests, cleaning variables are i1ncluded. Figures 11,3, 11.4, and 11.5 show typical hot leg sections from these loops. Figures 11.3 and 11.4 permit a comparison of the earlier and the recent attack of NaF-ZrF _ -UF, on Inconel. Figure 11.5 shows a hydrogen- fired loop of the earlier group. One other point of interest is that an as vet unidentified brown material 1is found in the fluorides from the recent even when the (I)G. M. Adamson, ANP Quar. Prog. Rep. Sept. 10, 1952, OBNL-1375%, p. 105, (ypid., p. 104, 133 el TABLE 11. 6. CORROSION DATA FROM INCONEL THERMAL CONVECTION LOOPS IN WERE CIRCULATED FOR 500 hr{e) AT 1500°F WHICH FLUORIDE MIXTURES LOoOP NO. CLEANING PAGCEGURE FLUCRIDE METALLOGRAPHIC NOTES MTXTUR$E Hot Leg Cold Leg CHYMICAL NOTES 238 223 241 235 240 239 243 242 244 246 245 247 249 255 256 NaK Nak Degreased Degreased Degreased Degreased Degreased Degreased Degreased Degreased Degreased Degreased Degreased NaF-KF-LiF-UF 10.9-43.5-44.5-1. 1 mole % NaF-KF-LiF-UF, 10.9-43.5-44.5-1. 1 mole % NaF-ZrF -UF 46-50-4 mole % + 0.5 wg % NaK NaF-KF-LiF-UF. 10.9-43.5-44.5-1. 1 mole & + 0.5 we % Cr NaF-KF-LiF-UF, 10.9-43.5-44.5-1.1 mole % NaF-ZrF,-UF 45-50-4 muIe % NaF-Zrf - UF, 46-50-4 mole % +0.5 we % Ll NaF-KF-LiF-UF 10.9-43,5-44.5-1. 1 mole % + 0.5 wt % ZrH2 NaF-ZrF‘-UF‘ 46-50-4 mole % NaF-ZzF, - UF, 52-48 mole % NaF-ZrF, - UF 46-50-4 mole % NaF-KF-LiF-UF, 10,9-43.5-44.5-1. 1 mole % + 0.5 wt % Cr Hydrafluorinated NaF-KF-LiF-UFi 10.9-43.5-44.5-1.1 mole % NaF-KF-LiF-UF, 10.9-43.5-44.5-1.1 mole % Hydrofiuorinated NeF-KF-LiF-UF 16.9-43.5-44.5-1, 1 mole % Moderate general and intergranular attack, maximum 12 mils, average 7 mils Typical Inconel attack, 8 to 10 mils; depth slightly deeper in crevice, but twice usual amount found!®! Light pitting and intergranular attack, maximum 4 mils, average 15 mils Typical Inconel attack, more grain boundary preference, maximum 13 mils, average 8 mils Moderate attack, up to 11 mils, sample attacked only 3 milsfe) Moderate te heavy attack, 9 to 17 mils deep, sample attacked only I miltd? Widely scattered attack, 1 to 4 mils Widely scattered attack, 1 mil; occasional depozits in some grain boundaries Moderate Inconel attack, maximum % mils, average 5 mils Scattered intergranular attack, up to B8 mils in top section; pitting, 1 mil, with some areas up to 6 mils in lower part of hot leg Moderate to heavy Incanel artack, maximum 12 mils, average § mils Light to moderate intergranular attack, 1 to 7 mils deep Very heavy Inconel attack, average 18 to 20 mils, maximum 30 mils Moderate intergranular atcack, to 20 miis in bath sections, ne evi- dence of chrome plate!®! Maximum penetration 18 miis, average 10 mils, not so much in lower section Thin noametallic layer Thin nonmetaliic deposit Metallic deposit and needle- like metallic crystals Thin nonmetallic surface layer that follows surface contours Thin surface deposit Light, spotty deposit with some metallic erystals Very thin surface deposit anrd de- posits of crystals Metaliic layer with nonmetallic particies occluded No deposit No depesit Occasicnal nonmetallic particles Thin layer that appears to be metallic with some nonmetallic particles embedded in it Tightly adhering metallic layer of L mil, surface rough with some nonmetallic particles Heavy, light-colored deposit throughout leg, varies from 0.25 to 0.75 mil in thickness Heavy metallie layer with some attached crystals, up to 0.004 in. long Fe and U decreased, Cr increased slightly Fe and U decreased, Cr increased Zr and Fe decreased, U, Cr, and Ni vary Cr added still in top pot, Fe and U slightly lower than origi- nal U varies widely, Cr increased, Fe decreased U increased but varies, Zr de- creased about 3%, Cr increased, Fe decreased U fairly constant but 3% above original, Zr decreased, Fe varies, Cr increased U and F decreased siightly, Cr and Fe vary but decreased U increased about 1%, Zr de- creagsed 2.5%, Fe and Ni de- creased slightly, Cr increased Cr and U increased, Fe and Ni decreased Cr and U increased, Fe and Ni de- creased, all high in original analysis (')Operltion cf each loop was terminated (b)Llp Jjoint in hot leg U¢)Sample in hot Leg. (‘)Slmpie in top of hot leg (e} gix-inch chrome-plated saction welded inta hot leg. at 500 hr, as scheduled, except loop 235, which was terminsted at 455 hr becavee of « power failure. LHOdAY SSAYO0Ud ATHALHYNO LOALOMd dNV PERIOD ENDING DECEMBER 10, 1952 Fig- 1i1-3- NaF-ZrF4~UF4 Prepared in 5-1b Batches. tests that was not found in fluorides from the earlier tests. The major difference in these tests is that the earlier loops were filled from small batches of fluorides made in the laboratory, whereas the later ones were filled from 50-1b batches made in a production operation. The attack now being measured is not serious, since it 1s comparable to that normally found with NaF-KF-LiF- UF, (10.9-43.5-44.5-1.1 mole %), but the trend may be serious. The actual fuel material for the reactor will be produced in 250-1b batches instead of the 50-1b batches being produced at present. A joint chemical, experimental engineering, and metallurgical program is under way to determine whether the increase in batch size affects the the Hot Leg of Inconel Loop Tested for 500 hr at 816°C with 250X. corrosion or whether the increase 1n corrosion is the result of some change in handling procedure. Most of the postrun examlnatlons(g) of the fuels from thermal convection loops have been confined to petrographic and x-ray examinations. The NaF-ZrF, UF, (46-50-4 mole %) fuel circulated 1n several Inconel and type 316 stainless steel loops was studied, The ple- ochroic, brown or olive-drab phase that has an average refractive index of 1.556 was first noted in a type 316 stainless steel loop, but it has also been found in several Inconel loops containing this mixture, as well as in ZrF,-bearing fluorides treated with NaK, Zr, and ZrH,. In these dynamic (S)Examination of fluoride mixtures were made by D. C. Hoffman, Materials Chemistry Division. 135 ANP PROJECT QUARTERLY PROGRESS REPORT Fig. 11. 4. NaF-ZrF4-UF4 Prepared in 50-1b Batches. corrosion tests, there appears to be some correlation (which did not exist in static tests) between the amount of the olive-drab phase and the extent of corrosion, Hydrofluorinated NaF-KF-LiF-UF,. One other series of tests points to poor production technique as the cause of the trouble discussed above. The attack found in Inconel loops in which NaF-ZrF, -UF, (46-50-4 mole %) was circulated had been only one half of that found with NaF-KF-LiF-UF, (10.9- 43.5-44.5-1.1 mole %). One explanation for this has been the higher purity of the ZrF,-bearing fluoride. During production, the ZrF, -bearing material is purified with both hydrogen and hydrogen fluoride, whereas the NaF-KF- LiF-UF, is not. Two special batches of NaF-KF-LiF-UF, were prepared by the 136 Hot Leg of Imconel Loop Tested for 500 hr at 816°C with 250X, group that makes the NaF-ZrF,-UF,, and the same techniques were used., Un- expectedly, the metal impurities in the specially prepared batches were much higher than in the normal material. In the two special batches, the metal impurities were: BATCH 1 BATCH 2 Chromium, ppm 2200 1280 Iron, ppm 5600 7000 Nickel, ppm 7100 5300 The presence of these impurities has not yet been explained. Metallographic examination after a test with the first batch revealed a wmaximum hot leg attack of 30 mils, with an average of 18 mils. This 1s the deepest attack yet found with any fluoride loop. A loop 1s now being run to PERIOD ENDING DECEMBER 190, 1952 s 5l . ; N e ) . ¢ * . : ‘r & & S - . ¢ I . ‘ b boraen t P e, MILS i ; . T _ fg . ) M e . : ot . L O e T TINGS s N " ol ey ! . .8 : L e A T At "J L, e . . % e i PR et i / L ‘ . j‘ + ..1 2 v \\ . __-f‘f ; ~ ’ %' W ; - F"}*';“' :v- : vy - - » » - o ,.--,’, e '?‘W/ : } » - Lt . . 4 - N e ¢ v o K o ‘ . S « 7 ‘Q, o ts - . J - . - . ¥ - L % 3 o . » » . . o i R N T e B o " ' » &, LT : ; - . '. -~ . Mm .‘;w" . t to . AQ- . » . » . - TR L e . fi.- e P ; ‘ ‘-' . P Fig. 11.5. Hot Leg of Hydrogen-Fired Inconel Loop Tested for 500 hr at 816°C in NaF-ZrF,-UF,. 250X. determine whether the addition of iron and nickel metal powders to NaF-KF-LiF-UF, will cause an increase in attack. The test with hydro- fluorinated fuelswill also be repeated. Corrosion Inhibitors. It was pointed out in the previous report(*’ that the addition of 0.5% ZrH, caused a reduction in the hot leg attack on Inconel by NaF-KF-LiF-UF, (10.9-43.5- 44.5-1.1 mole %) to only 0.5 mil. The test has now been repeated, and the attack found in the second loop was 1 mil., The unidentified material found in many of the grain boundaries in the hot leg section of the first loop was also found here, but only in very small amounts in widely scattered areas. A thin adherent layer that appears to be metallic was found in the cold leg. The fluorides in the loop after the run consisted of (4)9. M. Adémson, op. cit., b. 108. alternating layers of a colorless material and the usual green phase. Petrographically, these two materials seem to be very similar, or even to be the same. No reduced or partly reduced phases were found in the Yoop itself. Since optimistic results were ob- tained with the loops discussed above, two loops were run with zirconium hydride added to NaF-ZrF,-UF, (46-50-4 mole %). Operation of both these loops has been completed, but the results of metallographic examination are availa- ble for only the first one. Scattered attack, with a maximum penetration of 4 mils (average 2 mils), was found. This attack is definitely less than that found in the other NaF-ZrF, -UF, loops run during this period, but the effect of the zirconium hydride 1s not so great as was found with the NaF- KF-LiF-UF, mixture. No grain-boundary 137 ANP PROJECT QUARTERLY PROGRESS REPORT constituent was found in this loop. A considerable change had taken place in the fluorides in both loops, as evidenced by the unidentified brownish material found, along with the green phase, in all sections. No free UF, was produced, although intermediate reduction products similar to those present 1n NaK loops were found. The static corrosion tests had indicated optimistic resnlts when base metals were used as inhibitors., Previously reported work had also shown a reduction in attack when nonuranium-bearing fluorides were circulated. Small amounts (about 10 cm®) of NaK were therefore added to two Inconel loops, one of which contained NalF-ZrF, -UF, and the other NaF-KF-LiF-UF,. In these loops, both the amount and maximum depth of attack were lower than those in comparable loops without the NaK. Although the improvements were not large and could have resulted from the normal spread 1n results, the fact that the metallic impurities in the fluorides were so low would indicate that the im- provements were real. The NaF-ZrF, -UF, (46-50-4 mole %) was changed in appearance and included yellow material that was present both as clumps and as a grain-boundary constituent. This loop also gave considerable difficulty during startup, and it was necessary tostrike the legs frequently with a hammer to wmaintain circulation. Free UF,, as well as intermediates, was produced in the fluoride. the material being leached from the hot leg, the addition of chromium to the fuel could possibly slow down the reaction. It would be necessary to keep the chromium concentration low enough to prevent saturation and deposition in the cold leg, but high enough to reduce the rate of solution in the hot leg. The solu- bility of chromium in the fluorides has not yet been determined. Two loops were operated with a chromium Since chromium 1s 138 addition, but the results are 1in- conclusive since the chromium did not mix with the fluorides. The analysais of the fluorides in both loops showed a chromium concentration in the various loop sections that was even lower than normal, whereas a chromium concen- tration of over 5% was observed 1in the fluorides in the expansion pot of one loop. Inserted Corrosion Samples. Two Inconel loops were operated with small, flat, Inconel samples 1nserted 1in the top of the hot leg. In a loop operated with NaF-ZrF,-UF, (46-50-4 mole %), the wall attack in the hot leg con- sisted of moderate integranular and general attack from 9 to 17 mils deep, which is deeper than normal, The sample in this loop, however, was attacked to adepth of only 1 mil. The second loop, which contained NaF-KF- LiF-UF, (10.9-43.5-44.5-1.1 mole %), showed moderate wall attack from 5 to 11 mils deep, which is average attack for NaF-KF-LiF-UF,. The sample was attacked lightly to only 3 mils 1n depth. Two more loops are now circu- lating with small thin-walled tubes inserted in the hot leg. Thermocouples inserted in these tubes show that a large temperature drop isnot responsi- ble for the lack of attack on the samples. Crevice Corrosion. additional check on the crevice corrosion found at the top weld in the thermal loops and i1n one of the pump loops, a loop was operated with two crevices fabri- cated into the hot leg., NaF-KF-LiF-UF, (10,9-43.5-44.5-1.1 mole %) was circu- lated in this loop at 1500°F. 1In the upper section of the hot leg, the wall attack varied from 4 to 7 mils, whereas in an adjoining crevice, the attvack was from 6 to 8 mils and twice as concentrated. At the lower crevice, the pipe showed only scattered pits, up to 5 mils deep, whereas normal attack, up to 6 mils, was found in the crevice. This loop showed only a slight increase in depth of attack As an in the crevices, but a considerable increase 1n amount. Variation in Loop Wall Composition (J. P, Blakely, Materials Chemistry " Division, G. M. Adamson, Metallurgy - Division). Additional drillings have been made from the inside of the loop - walls, and steps were taken to assure that the pipes were not deformed during the drilling. The chemical analyses of these samples are shown in Table 11.7. TInconel loop 229, in which NaF-KF-LiF-UF, (10.9-43.5-44.5-1.1 mole %) was circulated, and Inconel loop 236, in which NaF-ZrF,-UF, (46- 50-4 mole %) was circulated, were operated under standard conditions. The change of analyses with depth from the surface follows the same general pattern as for the loops discussed in the previous report.(s) ' Self-insulating Properties of Fluorides. An Inconel loop was filled with NaF-KF-LiF-UF, and allowed to circulate in the normal manner at 1500°F. After normal circulation had been established, two helium jets were directed against an area at the bottom of the cold leg. Each jet delivered over 1000 ft3/hr of gas for 18 hr but did not cause the loop to plug. Initially, the cold leg temperature dropped, but the power was increased and the temperatures gradually returned to normal. The helium jets were then replaced by air jets that delivered a sufficient volume to form a black spot about 6 in., long. The loop circu- lated over 1000 hr with these jets operating, but there was apparently no plugging caused by the temperature differences. Air jets were then turned on a section of the loop in the cold leg, and, after a total of 2300 hr, operation was terminated. The fluoride 1in both sections appeared normal upon visual inspection, but in neither section (S)Ibid.. p. 11D, PERTOD ENDING DECEMBER 10, 1952 would the fluoride melt under the conditions normally used for this operation, Other Loop Tests. A type 316 stainless steel loop (No. 117) circu- lated NaF-KF-Li¥F-UF, (10.9-43.5-44.5- 1.1 mole %) for 500 hours. This is only the second type 316 stainless steel loop that has not plugged, and both of these loops were operated under similar conditions, The cold leg of this loop was held above 1500°F by using a hot leg temperature of 1630°F and wrapping the cold leg with asbestos tape. No sign of plugging was evident at 500 hours. At this time, the hot leg temperature was reduced to 1500°F, and the asbestos tape was removed so that the loop would circulate under standard conditions. The loop then plugged after 366 hr at the lower temperature, or a total of 866 hours. A considerable quantity of metallic flakes was observed in the fluorides. The fluoride in the sections of this loop melted at below 1250°F, and it all melted. An Tzett iron loop, which had been cleaned with dry hydrogen, plugged 1in 46 hr of eirculation of NaF-KF-LiF-UF, (10,9-43,5-44.5-1.1 mole %) at 1500°F, The inside surface of the hot leg was very rough, and considerable reduction in wall thickness had taken place. A heavy metallic deposit in the form of large metallic crystals with some non- metallic particles embedded i1n them was found in the cold leg. Inconel loop 246 circulated NaF-ZrF, (52-48 mole %) for 500 hr at 1500°F. Scattered intergranular attack of from 3tp8 mils was found in the top section of the hot leg, The lower section showed general pits of 1 mil, with an occasional patch up to 6 mils deep. No deposit was found in the cold leg, This attack is comparable to that found in the previous tests with fluorides that did not contain uranium. ' 139 0v1 TABLE 11.%. ANALYSES OF LOCGP WALL COMPOSITION DEi;j‘OF COMPOSITION (%) (mile) Fe Ni Cr Fe/Ni NaF* KF* LiF* ZrF,* | Other** Total Hot Leg of Loop 229 3 6.73 81.7 .19 0.083 0.26 0.74 0.74 1.34 69.77 6 6.83 80.9 9.38 0.085 0.26 0.44 0.41 1.19 99.41 10 6.99 79.7 11.1 0.088 0.14 0.30 0.27 1.23 99.73 15 6.98 78.1 13.1 0.089 0.11 0.15 0.22 1.40 100.16 20 6.85 77.8 14.2 0.0C88 0.07 0.12 0.16 1.42 160.62 25 6.91 76.8 15.4 9.090 1.47 100.58 30 6.87 16. 4 15.6 0.089 1.66 100.53 External 6.90 76.5 16.0 0.9090 1.36 100.76 Cold Leg of Loop 229 3 8.46 73.8 16.6 0.114 1.45 106. 31 6 8.15 74.6 16.5 0.110 1.64 100.89 10 7.82 4.4 16.17 0.105 1.75 100.67 15 7.63 74.5 16.6 0.102 1.79 100.52 20 7.72 74.4 16.5 0.104 1.64 100.25 External 7.62 74.6 16.7 0.102 1.65 106,57 Hot Leg of Loop 236 3 11.7 74.8 10.3 6.156 0.14 0.92 1.61 99.47 6 9.44 74.6 13.7 0.126 0.04 0.55 1.49 99.82 10 9.02 74.8 14. 38 0.121 1.75 100. 37 15 7.70 74. 4 16.5 0. 43 1.56 100,16 20 7.70 74.1 16. 6 0.104 1.43 99.83 25 7.63 74.3 16.5 0.102 1.56 89.99 30 7.68 74,2 16.6 0.103 1.56 100.04 External 7.68 74.6 16.6 0.103 1.35 100,23 ‘These values caiculated from spectrographic analysis of the metals by assuming them to be present as fluorides, ‘.Total of Ca, Cu, Si, Al, Mg, Mn, and Ti, from spectrographic analysis. LHGJAM SSAYI08d ATHALYVNO LOACO¥d 4NV HYDROXIDE CORROSION Vreeland L. R, Trotter Hof fman J. E. Pope Metallurgy Division F. Kertesz Materials Chemistry Division Mo et O Corrosion Inhibitors. A survey of the abstracts contained in ORNL-1291¢8) indicated that additions of Ca(Q, Ca(OH)z, NaNO,, NaNO;, and NaClO, might have some effect in inhibiting corrosion by hydroxides, CaQ and Ca(OH), were reported to participate 1n reactions of the following type: Na2C03 + Ca(()H)Q"'“_“> 2NaQOH + CaCOa, Na,CO, + CaO +H,0 ~—> NaOH + 3CaCo, . Reactions for the alkali metal nitrites and nitrates and sodium chlorate were not given, but the reduction of cor- rosion by these additives was stated to be as much as 90% under certain conditions, Static tests of type 316 stainless steel in sodium hydroxide with various additives were run at 816°C for 100 hours., None of these approximately 5% additions seemed to have an effect in inhibiting cor- rosion in these tests. It is believed that the inhibiting effect mentioned in the references may take place at much lower (G)M. Lee, General Information Concerning Hydroxides, ORNL-1291 (April 21, 1952). temperatures than are PERIOD ENDING DECEMBER 10, 1952 employed in these tests. The test results are presented in Table 11.8. Temperature Dependence. A series of tests for determining the effect of temperature on the corrosion resistance of types 304 and 316 stainless steels exposed to sodium hydroxide for 100 hr has been completed. Attack on these materials was not noted until the test temperature was increased to at least 550°C. The results are tabulated in Table 11,9, : Nickel Alloys in NaOH, Static tests in NaOH of an 80% Ni-20% Mo alloy and an B0% Ni-20% Fe alloy were run for 100 hr at 816°C. The 80% Ni-20% Mo alloy showed subsurface voids to a depth of 1 to 2 mils, and the 80% Ni-20% Fe alloy showed 3 to 5 mils of subsurface voids upon metalloegraphic examination. | Compatibility of Be0O in KOH. A sample of BeO was tested in molten KOH contained in an Inconel tube with a hydrogen atmosphere. The hydrogen was purified with a “Deoxo’ unit., The KOH was dehydrated, under vacuum, for 56 hr by gradually raising the tempera- ture to 500°C before introducing the BeO specimen., During the test, a constant flow of hydrogen was maintained through the system, The time of the test was 100 hr and the temperature was B800°C. The BeQ was rather severely attacked, as can be seen from the TABLE 11.8. RESULTS OF STATIC TESTS OF TYPE 316 STAINLESS STEEL ~ IN NaOH WITH VARIOUS ADDITIVES FOR 100 hr AT 816°C ADDITIVE METALLOGRAPHIC NOTES 5% NaClO3 Unattacked material decreased from 33 to 26 mils 5% NaNO2: Unattacked material decreased from 33 te 25 mils 5% NaNO3 Unattacked material decreased from 33.5 to 20 mils: | intergranular penetration of 1 to 2 mils beneath uniform corrosion layer : 5% Ca0 Unattacked material decreased from 33.5 to 26 mils 5% Ca(OH), Unattacked material decreased from 33.5 to 26 mils 141 ANP PROJECT QUARTERLY PROGRESS REPORT TABLE 11.9, RESULTS OF TEMPERATURE-DEPENDENCE TESTS O0F TYPES 304 AND 316 STAINLESS STEELS EXPOSED IN NagH FOR 100 HOURS TEMPERATURE (°C) MATERI AL METALLOGRAPHIC NOTES anype 304 stainless steel 350 No attack . 450 No attack 550 Light intergranular penetration of 1.2 to 1 mal 650 Unattacked material decreased from 34 to 24 mils Type 316 stainless steel 350 No attack 450 No attack - 550 Intergranular attack of 1 to 2 mils welght and dimensional changes listed in the following: BEFORE TEST AFTER TEST Length, in. 0.486 0.413 Width, 1in. 0.263 0.207 Thickness, in. 0.269 0.213 Weight, g 1.5254 0.6882 of the Inconel tube used in this test revealed a 4 to 10-mil oxide layer. Nickel in NaOH Under Hydrogen Atmosphere. Maintenance of a hydrogen pressure from an external source has been shown to minimize corrosion and transfer of nickel in NaOH. Maintenance of an atmosphere of hydrogen in components of a high-temperature reactor would 1ntroduce a number of problems; however, the prospect of containing hydroxides in this fashion has appeared sufficiently promising to justify systematic study of this possibility, In the experiments, sodium hydroxide containing less than 0.1% Na,CO, and less than 0.1% H,0 was used, and all handling of the material was conducted in a dry box that conld be evacuated and flushed with pure, dry helium. The Metallographic examination mass 142 metal to be tested was heated for 30 min at 800°C in pure flowing hydrogen and subsequently handled so that the inner surface of the tube was exposed only to pure helium before the corrosion test., The hydrogen used 1in these experiments was purified by passage through a “Deoxo’ catalytic mass. The water was removed by liguid-nitrogen- cooled traps and by magnesium per- chlorate, In one type of test, the movement of hydroxide was achieved by thermal convection in a single 1/2-in.-dia tube inclined at 45 deg and heated to 800°C at the bottom. A temperature gradient of about 200°C was maintained between the top and bottom of the hydroxide that filled the 18-in. tube to a depth of about 12 inches, Tubes of nickel were placed in an outer jacket of stainless steel designed to contain the furnace assembly so that the hydrogen can bathe the outside walls as well as the contents of the tubes and were exposed to sodium hydroxide for 48 hours. Figure 11.6 indicates the great difference in the behavior of nickel 1n NaOH when hydrogen instead of helium is used in tests of TEMPERATURE GRADIENT 80G°C — BOTTOM 560°C ~ TOP TUBE INCLINED 45° 100-hr TEST " Boo®C BOTTOM Fig. 11.6. this type. Tests conducted in the helium atmosphere show large deposits of nickel crystals at the cold end of the tube, whereas the bottom sections of the tube are highly polished. When hydrogen is used, the bottom sections of the tube show considerable polish, but virtually no crystal deposit is visible at the cold end. When tests are conducted in a similar fashion but with the hydrogen (at atmospheric pressure) applied only to the inside of the tube under test, the beneficial action isstillobtained. The bottom section of the tube shows PERIOD ENDING DECEMBER 10, 1952 PHOTO 11862 LIQUID LEVEL~—0u TOP 56Q°C 580°C Standpipe Test of NaOH in Nickel Capsule with Hydrogen Atmosphere. the typical polished appearance, but no mass transfer to the cooler portions is evident, In another type of test, nickel tubes fitted with a delivery tube for maintenance of the proper atmosphere were exposed in the tilting furnace. The tubes were rocked four times per minute, with the hot end maintained at 800°C and the cold end at 650°C, for 100 hours. Results very similar to those described above were obtained in these studies, as the specimens shown in Fig. 11.7 indicate. Since the hydrogen has ready access to virtually 143 ANP PROJECT QUARTERLY PROGRESS REPORT 800°C 14S1H51 t492H54 HYOROGEN ATMOSPHERE TUBE ONLY DEGREASED HYDROGEN ATMOSPHERE TUBE HYBROGEN-~FIRED BEFORE TEST Fig. 11.7. all parts of the tubes during the test, it is hardly surprising that prior hydrogenation of the specimens did not appear to be beneficial. It is noteworthy that when helium atmospheres were used in these tests, the NaOH recovered was brownish-gray in color and contained about 1500 ppm of nickel. When the hydrogen atmos- pheres were used, the snow-white hydroxide contained 20 to 35 ppm of nickel. (?)A. des Brasunas, G. P. Smith, D, C, Vreeland, and F, Kertesz, ANP Quar. Prog. Rep. Sept. 10, 1952, ORNL-1375, p. 119. 144 PHGTO 11881 650°C 1493H51 147 7H51 HELIUM ATMOSPHERE TUBE HYDROGEN-FIRED HYDROGEN ATMOSPHERE TUBE HYDROGEN-FIRED BEFORE TEST INTERMITTENT VACUUM APPLIED Seesaw Tests of NaQOH in Nickel Capsules After 100 Hours, LIQUID METAL CORROSION D, C. Vreeland J. B, Pope E. E, Hoffman J. V. Cathcart L. R, Trotter G. P. Swmith, Jr. G. M. Adamson Metallurgy Division L. A. Mann J. M. Cisar ANP Division High-Velocity Corrosion by Sodium. A dynamic test, which has become known as the spinner test,’? has been used to check the effect of high-velocity corrosion and erosion in molten sodium on several materials. In this test, relatively high velocities (400 ft/min) are obtained by rotating tubular specimens in a pot containing the molten corrodant under isothermal conditions. Inconel and types 316, 347, and 446 stainless steels have been tested in this apparatus. Greater attack than that obtained in ordinary static cor- rosion tests was noted onall materials tested. Tt should be emphasized that, except in the test of the type 347 stainless steel specimens, these were actually three-component tests because the spinner pot was fabricated of type 347 stainless steel. | The effect of this test on Inconel spun at 400 ft/min for 72 hr at 816°C is shown in Fig. 11.8. A 0.5-mil surface layer, with 0.5 mil of inter- granular voids beneath it, is apparent. This surface layer may be a mass transfer effect caused by the three- component system used during test. The analysis of a portion of the surface layer scraped from the specimen and showed 64% nickel, 27.5% chromium, o - o : : » . a?“: e ?_ 5 - *? Fig. 11.8. Speed of 400 ft/mim. 500X, PERIOD ENDING DECEMBER 10, 1952 8.3% iron. (The composition of Inconel is 80% nickel, 15% chromium, and 5% iron.) The intergranular attack on type 316 stainless steel 1s shown 1in Fig. 11.9. This attack extended to a depth of 1 to 2 mils near the front, or leading edge, of the tubular specimen and, as would be expected, was less severe at the trailing edge, where the depth of attack was 0.5 to 1 mil. The test was conducted at 816°C for 100 hr with a speed of 400 ft/min. Type 347 stainless steel suffered intergranular attack to 2 mils after testing for 74 hr at 816°C with a speed of 400 ft/min. After 53 hr at 816°C at a speed of 400 ft/min, type 446 stainless steel showed slight intergranular attack to a depth of less than 0.5 mil. The results of these tests are summarized in Table 11.10, { UNCL ASSIFIED Y8252 1SURFACE LAYER . ""fiq ATTACHED REGION INCONEL Inconel from Spinner Test with Sodium at 816°C for 72 hr at a 145 ANP PROJECT QUARTERLY PROGRESS Fig. 11.9. for 100 hr at a Speed of 400 ft/min. TABLE 11.180. REPORT | UNCLASSIFIED . Y-8020 Ty, - Type 316 Stainless Steel from Spinner Test with Sodium at 816°C 250X, RESULTS OF SPINNER TESTS RUN AT 400 ft/min AT 816°C TIME OF MATERIAL A TEST (hr) METALLOGRAPHIC NOTES Inconel 72 Sur face layer of 0.5 mil with 0.5 mil of inter- granular voids beneath Type 316 stainless steel 100 Intergranular attack, 1 to 2 mils deep on lead- ing edge and 0.5 to 1 mil deep on trailing edge Type 347 stainless steel 74 Intergranular attack, to 2 mils Type 446 stainless steel 53 Slight intergranular attack, less than 0.5 mil Ceramic Materials in Sodium,. A series of static corrosion tests of various ceramic materials received from the Ceramic laboratory has been run in sodium at 816°C for 100 hr in Inconel tubing, The results are tabulated in Table 11.11 for the materials that did not disintegrate during test. Only two of the specimens were intact after testing (Al,0,; and 146 Spinel). It 1is possible that if the specimens that broke up during testing had been thicker (specimens were approximately 0,020 in, thick), some of them would have remained intact, The specimens that disintegrated into fine powder during the testing included porcelain (A1-576), mica, titanium dioxide (Al-192), 5i0,, barium titanate (A1-T-106), Al1,0, (single crystal), lead PERYIOD ENDING DECEMBER 10, 1952 TABLE 11. 11, RESULTS OF TESTS OF VARIOUS CERAMIC MATERIALS "IN SODIUM FOR 100 hr AT 816°C MATERI AL OBSERVATIONS AFTER TESfl' Al,0, Three-mil increase in thickness, weight increase of 0.01 g/in. 2 | S1C Specimen broken into several pieces, no thick~ ness change ‘ MgO Specimen broken into several pieces, no thick- ness change MgO (single crystal) Specimen broken into several pieces, no thick- ness change Spinel g/in. 2 20, (Al 550) Zircon ness BeO glass, Zr0, (Hf free), ThO,, 2MgO-Si0, (fosterite, Al-243), 2Mg0‘2A1203‘FSiO2 (A1-202), aluminum silicate (Al-A), pyrex glass, zirconium silicate (A]l- 475), HiO,, soda glass, TAM Zr0,, and MgO- 310, . ; Lead in. Metal Convection Loops. The problem of circulating lead has been revived during this quarter. lLoops identical to those being used with the fluorides were first used in this work, The lead used in all the following tests was chemical lead that was further purified by bubbling hydrogen through 1t. Lead was first circulated Inconel loops. The first loop, which had been cleaned with NaK and then evacuated while hot, would not circu- late at all, The second loop was rinsed with water, after the NaK cleaning, before being evacuated. This loop circulated only 2 1/2 hours. After the lead was drained out, plugs were found in both loops in the lower in two No change in thickness, weight loss of 0.006 Specimen shattered, l-mil increase in thickness Specimen shattered, l.5~mil increase in thick- Specimen shattered, 7-mil increase 1n thickness portion of the cold leg. Neither plug would melt at 1575°F. Besides the plug in each loop, ‘amass resembling a vine wound around the inside of the cold leg and occupied about one-fourth of the volume. This mass held 1ts shape where 1t turned into the hot lJeg., The analyses of these masses show them to be high in nickel and lead content; however, the x-ray dif- fraction lines do not fit those from any material in this system. ILead was also circulated 1n a type 430 stainless steel loop that was rinsed with cold nitric acid, washed with water, and then evacuated while hot., This loop circulated 16 1/2 hours. The two cleaning methods were then combined and used on a type 410 stainless steel loop. This loop was NaK cleaned, water washed, cold nitric acid rinsed, water washed, and heated while under vacuum. Tt circulated for 351 hr at 1500°F before plugging. The plugs in both these loops again 147 ANP PROJECT QUARTERLY PROGRESS REPORT appeared to be at the bottom of the cold leg. They remained when the lead was meleced out at 1575°F, The plugs have been submitted for chemical and x-ray diffraction study. Lead in fuartz Convection Loops. The prohibitive amounts of mass trans- fer that occurred 1n lead-Inconel thermal convection loops and in static corrosion tests have prevented the acquisition of significant data on this system. In addition, the results were open toquestion because sufficient care had not been taken to deoxidize the lead and because the Inconel tubing used was covered with a heavy coating of oxide. An apparatus built in which lead could be deoxidized with hydrogen and then brought into contact with Inconel specimens without exposure to an oxidizing atmosphere., This appa- ratus, shown in Fig., 11.10, consisted of a thermal convection loop constructed entirely of 1/2-1in. quartz tubing. Two 6-in. lengths of 7/16-1in. Inconel tubing were mounted in the hot and cold legs of the loop. Before being placed in the loop, the Inconel tubing was scrubbed with cleaning powder and rinsed with alcohol and ether. The lead was deoxidized in a 1 1/2-in, - dia quartz bulb attached above the loop and separated from it by a fritted quartz disk. The lead i1n the de- oxidation bulb was heated to 425°C, and hydrogen was allowed to pass through the fritted quartz disk and bubble up through the lead. When the deoxidation was complete, the lead was forced through the fritted disk and into the loop. Circulation of ‘the lead was maintained by the thermal convection currents thus induced. was This procedure assured that the oxide content of the lead was reduced to a minimum and, in addition, pre- vented re-oxidation of the lead during the loading of the loop. This technique also offered several other advantages. 148 The use of quartz loops rather than the conventional metal loops eliminated many of the difficulties previously encountered with leaks at welds. The new loop required only a small amount of metal tubing, a factor of some importance for cases in which the metal to be tested 1s expensive or in short supply. Since the test specimens were completely enclosed in the quartz tubing of the loop, itwas not necessary to provide a protective atmosphere around the outside of the specimens, as would have been the case 1fordinary metal loops of such reactive metals as molybdenum or columbium had been the solid metal under test. Two tests have been made on Inconel specimens with 0,035-1in. wall thickness in the apparatus described above for circulating lead. Both loops had a hot leg temperature of 800°C; one had a cold leg temperature of 400°C and the other 475°C. The results of the two tests differed only in deta1l. Circulation of the lead in one loop stopped after 125 hr of operation and in the other after 51 hr because of formation of plugs in the cold legs. The depth of attack in the hot leg loop and 3 mils 1in the other loop. In addition to the usual mass transfer, a matrix-like, corroded layer formed on the Inconel. This corroded layer is shown in Fig. 11.11, which is a photograph of a cross section of the Inconel tubing 1in the hot leg of the loop. The corresponding was 10 mils in one cold-leg specimen 1is shown in Fig. 11.12. In a preliminary test, the primary purpose of which was to test loop design, a loop was used that was similar in design to that shown in Fig., 11.8, except that 1t was con- structed of pyrex glass. The hot and cold leg temperatures were 500 and 365°C, respectively. No mass transfer or corrosion was noted in either leg during 96 hr of operation. These results, together with the lack of PERIOD ENBING DECEMBER 190, 1952 UNCLASSIFIED DWG. 17408 TO HYDROGEN AND VACUUM LINES LEAD DEOXIDATION BULB ~————w] 77 iy LEAD-——m—-m&ééégé FRITTED QUARTZ DISK—m= 12in. 'PIPS" TO SUPPORT INCONEL TUBE it Y,-in. QUARTZ TUBING Fig. 11.10. Quartz Thermal Convection Loop. 149 ANP PROJECT QUARTERLY PROGRESS REPORT Ee UNCLASSIFIEDY T Y8120 . .& «gfl@@wfi@*;g% # Wi el F1g. Inconel Specimen in Hot (800°C) Leg of Quartz Loop after Circu- 11.11. lating Lead for 125 Hours. 90X corrosion in the cold leg of the first loop (at 400°C) and only very slight corrosion in the cold leg of the second loop (at 475°C), led to the conclusion that the corrosive attack of liquid lead on Inconel probably began in the neighborhood of 500°C, The chemical analysis of the plugs formed in the guartz loop tests was only slightly different from the nominal composition of Inconel. Tt was therefore concluded that the liquid lead had virtually no selective leaching action on the Inconel speci- mens. It was further concluded that both severe mass transfer and corrosive attack will occur in lead-Inconel thermal convection loops with hot leg temperatures of 800°C, even when the lead has been carefully deoxidized with hydrogen. Compatibility of Be0 in Nak.‘®’ Dynamic tests of BeO in NaK are being (S)The chemical analysis of NaK for beryllium is reported in section 15, “Analytical Studies of Reactor Materials.” 150 A " UNCLASSIFIE Y.8122 3 - ¥ rig. 11.12. Inconel Specimen in Cold (400°€) Legof Quartz Loop After Circu- lating Lead for 125 Hours. 90X, conducted by the Experimental Engi- neering Department. Blocks of BeO approximately 0.25 by 0.25 by 0.50 in. were weighed and measured as received from the shop, heated to a bright red color, reweighed and remeasured, and then placed in a test assembly con- taining eutectic NaK heated to 1400°F. The BeO was fastened to the end of a rotating shaft and rotated at a linear velocity of 0.15 ft/sec. 1In the tests to date, there has been considerable BeO weight loss upon exposure for 100 hr or longer at 1400°F., The test results are summarized in Table 11.12. Since earlier static tests showed no instability of the BeO, additional static and dynamic tests are being carried out, along with an 1investi- gation of cleaning, drying, and similar techniques for obtaining accurate weighing of the BeO before and after exposure to NakK. Sodium in Forced-Convection Loops. Metallurgical analyses of the figure 8 loop in which sodium was circulated have been completed. Samples from the hot, cold, and heat exchanger sections of the loop were examined. Corrosion was negligible, as shown in Table 11.13. FUNDAMENTAL CORROSION RESEARCH W, R. Grimes Materials Chemistry Division W. D. Manly Metallurgy Division The basic research needed for determining corrosion mechanisms has TABLE 11.12, PERIOD ENDING DECEMBER 10, 1952 been continued. Examinations have been made of corrosion products from dynamic corrosion test by making use of chemical and physical means to determine identities of the products, and studies are continuing on high- temperature reactions of various liquids with structural metals, thermal stability of NiO and NiF,, and reactions of molten fluorides under applaed potentials, The preparation of various complex interaction products of structural metals with fluorides and the characterization of these compounds SUMMARY OF BeO-NaK COMPATIBILITY TESTS RUN AND SAMPLE NO. 1(0) 2 3(5) 4_((:) 5 6(:1',6] 7(C,f) B(d,g) g(f,g) Initial weight, g 1.5054 | 1.4196 1.4049 1.2287 1.2736 1.8437 25.3124 [ 29.9273 Initia]area,in.2 0.625 | 0.625 | 0.625 0.623 0. 609 0.455 0.625 4. 60 5.45 Initial volume, in.? 0.0313 | 0.0313 {0.0312 | 0.0307 | 0.0310| 0.0293*)| 0.0378*) | 0.567 | 0.640 Initial density, g/cm’ 2.93 |2.80 2.80 2.60 | 2.65 2.98 2.72 | 2.85 Approximate weight of NaK, g| 90 82 82 82 82 82 82 75 75 Duration of heating, hr 6.4 96 129 203 174 212 212 Final weight, g 1.3320 | 1.1047 1.3653 1.0896 0.9384 1. 4335 Weight loss . In grams 0.1734 }0.3149 0.0396 0.1391| 0.3352 0.4102 In per cent 11.5 22.2 2.81 11.3 26.3 22.3 Final volume, in.” 0.0306 |~0.0263|~0.028"> | 0.031¢® Approximate volume loss, % Negligible | 15 3¢h? 19(") Weight loss per initial unit area, mg/in.2 280 500 60 230 740 670 (aLFemperature cycled from foom temperature to () 1500+"F once and BOO to 1500 F five times; one “’Surface removed irregularly, leaving cornesr chipped off during test. (b)sample in two pieces at end of run; no other pieces found, (C}Hotated 14 hr; static 189 kr. (d)Porous inner section of BeO block {for density, see sec. 12, “Metallurgy and Ceramics®™ ). “*ditches”™ and rounded cormers. (f)Dense outer section of BeO block (for density, see sec. 12, “Metallurgy and Ceramics'’). g)Irreguiar semiwedge shafies. (h)Calculated for irregularly abaped samples; values uncertain, 151 ANP PROJECT QUARTERLY PROGRESS REPORT TABLE 11.13. ANALYSIS OF CORROSIVE ATTACK BY SODIUM IN FIGURE 8 LOOP TEMPERATURE | TIME | VELOCITY ATTACK (°F) (hr) (ft/sec) Heat exchanger 1320 2700 Occasional depressions, to 1 mil deep section 1300 1000 1 Hot section 1350 2700 2 Numerous small depressions, to 0.25 mil deep 1320 1000 1 Cold section 750 2700 No noticeable corrosion or erosion 1100 1000 were also continued 1in an effort to aid in the i1dentification of the corrosion products, Interaction of Fluorides with Structural Metals (H. S. Powers, J. D, Redman, L. G. Overholser, Materials Chemistry Division). Investigation of the reaction of chromium and iron with molten NaF-KF-LiF eutectic has con- tinued. Special emphasis has been placed on the behavior of K2NaCrF6 and K,NaFelF, when contacted with the eutectic in the temperature range from 600 to 1000°C, The filtrates col- lected at various temperatures in the range from 500 to 800°C have been subjected to chemical analysis, as 1n the past, and the residues and filtrates have been examined by x-ray diffraction. In a number of experiments, 3 wt % of K,NaCrF_, was added to samples of the NaF-KF-LiF eutectic. The mixtures were heated at 800 to 1100°C under an atmosphere of helium for several hours and then filtered at various tempera- tures in the range from 500 to 800°C, and the residues and filtrates were examined. Heating of the K,NaCrF, at temperatures up to 1100°C prior to its addition to the eutectic did not affect 1ts solubility, and the temper- ature of equilibration of this compound with the eutectic prior to filtration was unimportant. ever, Solubility was, how- a function of temperature of filtration. The filtrate collected at 500°C contained 400 to 500 ppm Cr, whereas the filtrate obtained at either 152 650 or 800°C contained 2000 to 3000 ppm Cr. Microscopic examination re- vealed that most of the Cr was present as K,NaCrF_., which indicates that this compound 1s appreciably soluble 1in the NaF-KF-LiF eutectic atelevated temper- atures, X-ray examination shows that in some runs, materials other than K,NaCrF_ have been present, including K,CrF,, Cr,0,, and KNaLiCrF, Similar experiments in which Cr was added to the esutectic as metal 1instead of as KzNaCrF6 showed that Cr203, Cr, and K,NaCrF_, were present after the interaction., Additional products that have not yet been i1dentified were also found. A study of the solubility of K NaFeF in the NaF-KF-LiF eutectic and the NaF-KF-LiF-UF, mixture at 600 and 800°C was made. It was found that with 2.5% of K,NaFeF the solubility in both fluoride mixtures and at both temperatures of filtration was 6000 to 7000 ppm. Apparently, all the K,NaFeF, added was dissolved. Since the presence of oxidation products 1in a number of the filtrates indicated that the digestion and filtration apparatus in which a blanket of helium is used does not exclude oxygen completely, two new types of reaction-filtration equipment have been designed and fabricated that should eliminate oxidative effects. Air Oxidation of Fuel Mixtures (R, P. Metcalf, F., F, Blankenship, Materials Chemistry Division). The investigation of the oxidation of fuel mixtures contained in nickel has been complicated by the corrosion of the nickel containers. The corrosion has been studied in a series of experi- ments., In each experiment, fluoride, in a nickel boat, was placed in a “combustion tube’’ consisting of a horizontal 1 1/2-in.-0D stainless steel tube heated by a tube furnace. The inner surface of the steel tube was protected by a sleeve of 5-mil nickel sheet. The tube was evacuated and heated to the desired temperature; dry air was then admitted and passed through at a rate of about 40 cm?/min for about 4 hours. The solid products were examined by x-ray diffraction. No gaseous products were observed, In summary, nickel 1s oxidized severely by dry air when 1in contact with fused fluorides. The oxidation 1s accompanied by creeping of the melt over the entire heated surface of the nickel container. Uranium, when present in the fluoride mixture, reacts to form a yellow product that probably contains oxygen but has not yet been completely 1dentified. It is suggested that the oxidation occurs because the fused fluorides dissolve the adherent protective scale of nickel oxide, which forms absence of the melt. The formation of the greenish- gray nickel oxide observed in several of the experiments appears to be associated with the presence of moisture in the salt employed. EMF Measurements in Fosed Fluorides (L. E. Tepol, L. G, Overholser, Materials ChemistryDivision). Previous sbudies,(g)involving the determination of the decomposition potential of NiF, in molten KF, suggested that a thermal decomposition of NiF, occurred during the experiments and led to a study of the decomposition of NiFZ, N10, and K,NiF, at temperatures from 700 to (9)L.'E. Topol and L. G. Overholser, Prog. BRep. Sept. 10, 1952, 5 to 10 g of in the ANP Quar. ORNL- 1375, p. 123. PERIOD ENDING DECEMBER 10, 1952 900°C in a purified helium atmosphere. The study has been continued and extended to include the possibility of decomposition under vacuum. An attempt has been made to measure the decompo- sition potential of KF on Ni at 8%90°C in a nickel container. Repeated attempts 'to prevent the decomposition of NiQ and NiF, at 750 to 900°C under a pur1fled helium atmosphere were unsuccessful, even when all the rubber tubing was re- placed with glass or copper tubing. In some cases, the weight losses were apparently greater than could be explained by complete decomposition of the NiF, or NiO. An attempt is being made to measure the dissociation of NiF, and Ni0O in vacuum at various temperatures. A vacuum system has been constructed, and a preliminary experiment showed that no apparent decomposition of the Ni0 occurred, even though it had been heated to 1020°C, This absence of dissociation 1is 1in agreement with the findings of Johnson and Marshall,('%) who measured the vapor pressure of NiO at temperatures from 1440 to 1566°K. Studies of the behavior of N10 1in vacuum tinuing. are con- Decomposition potentials have been determined in KF at 890°C with nickel electrodes in various vessels. Measure- ments were made in Norton stabilized- zirconia crucibles (TZ-5601) and in Norton thoria crucibles (LT-7010), although these materials are somewhat permeable to the KF, Subsequent runs were made with a nickel cup as both container and cathode and a 1/16-in.- dia nickel rod as the anode. 1In every case except one, a decomposition potential was observed at 0.7 to 0.9 volt. These values agree with earlier values®®? and with those determined by Neumann and Richter(!!) on graphite. In one run in which higher potentials (10)H. L. Johnson and A. L. Marshall, Chen. Soc. 62, 1382 (1940), (Il)B. Néumann and H., Richter, Z. Elektrochen,. 31, 296 (1925). J. Anm, 153 ANP PROJECT QUARTERLY PROGRESS REPORT were applied, a change in slope was noticed at voltages above 2.5, in addition to the break in the current- voltage curve at 0.8 volt: but, un- fortunately, not enough data were taken at these higher potentials to obtain an accurate determination of the decomposition voltage. In the last experiment, no break in the current- voltage curve was found at 0.8 volt, but a definite break occurred at 2.6 volts., In all cases, the anode was markedly attacked and was surrounded by a black sludge that was somewhat magnetic. Possible explanations of these results are being studied. Preparation of Trivalent Nickel Compounds in the Hydroxides (L. D, Dyer, G. P. Smith, Metallurgy Division). Lithium nickelate(III) and sodium rnickelate(III) have been shown to occur (see previous guarterly reports) in the corresponding hydroxides under highly oxidizing conditions by actually 154 preparing large amounts of these com- pounds in hydroxides, Therefore the preparation of a presumed potassium nickelate(1II) was undertaken to show 1ts occurrence under certain circum- stances in potassium hydroxide, By using molten potassium peroxide as the oxidizing agent on nickel, enough higher valent nickel crystals were prepared to get a single crystal for x-ray study. Because of the apparent instability of the supposed potassium nickelate, the nickel in the compound either lost some oxidizing power when removed from the KOH and K204 with alcohol, or 1t never was completely oxidized in the tube. The separated compound contained only 20% Ni**", whereas the theoretical value for KNIO, is about 45% Ni'**, The experiments are being continued to find the conditions for obtaining more and larger crystals and to refine the separation method. 12. ~W. D. Manly . PERIOD ENDING DECEMBER 10, 1952 METALLURGY AND CERAMICS J. M. Warde Metallurgy Division Additional studies on the cone-arc welding process are under way in an effort to obtain more complete under- standing of the basic principles of the process. Resistance welding of solid fuel elements has been tried, with some degree of success. After the proper electrode force was de- termined, a convenient welding time was selected, and welds made over a considerable current range have been studied. An automatic heliarc welder has been set up for making longi- tudinal welds on stainless steels under very carefully controlled con- ditions sc that the optimum welding conditions for the various structural metals can be determined. The high- temper ature brazing alloy development program is continuing, and results of various corrosion tests in liquid metals, fused fluoride salts, and hydroxides, as well as the results from the various high-temperature tensile tests, are presented. A very marked effect of the en- vironment on the load-carrying abili- ties of Inconel has been observed in tests run at 815°C in atmospheres of air, argon, and hydrogen. The same effect has been seen to a lesser extent 1n creep tests of type 316 stainless steel. Preliminary results obtained at 815°C indicate that the fluorides affect the load-carrying ~abilities appreciably at the lower - stress values. _ An attempt is being made to produce spherical particles of uranium-bearing alloys approximately 0.010 1in. in ~diameter. These particles will re- ceive a protective coating of nickel plating, approximately 0.005 in., prior to being used in a pebble-bed ~type of reactor. The methods being investigated are the following: 1. suspension in refractory powder and heating above the solidus, ' 2. momentary melting by passing through a high-temperature arc, 3. spraying from a metallizing gun. Solid-phase bonding studies are being initiated to determine which materials are easy to bond and which materials are difficult to bond. After this screening operation, the work will be expanded to include a study of ‘the production of solid fuel elements by a hot-pressing operation in which electroformed screens will be filled with a mixture of U0, and stainless steel powder prior to the bonding step. Studies on the reaction of columbium with various gaseous atmos- pheres have been initiated in an attempt to understand the effect of these atmospheres so that the me- chanical properties of columbium and its alloys can be studied. Disks in which a layer of U0, 1s incorporated have been successfully prepared from Cr-Al,0; cermet compo- sitions., A ZrC-Fe cermet has been developed that has possible interest as a material for pump parts, seals, and bearing materials. Work 1s being carried out on SiC-C cermets. A satisfactory dipping technique has been developed for the application of an oxidation-resistant ceramic coating to nickel parts for use in an aircraft type of radiator. A ceramic coating containing 10% boron for possible application in reactor shielding has been successfully flame-sprayed on 20-gage stainless steel. | FABRICATION OF SOLID FUEL IN SPHERES E. S. Bomar J. H. Coobs H. Inouve Metallurgy Division A geometry for the fuel in the Supercritical Water Reactor, suggested by the Pratt & Whitney Alternate Design group, 1s that of spherical 155 ANP PROJECT QUARTERLY PROGRESS REPORT particles 0.010 in. in diameter. After receiving a 0.005-in. protective nickel plate, the particles would be packed 1n beds 1n the reactor core, and cooling water would flow through the interparticle channels. Several methods for preparing the spheres, with the use of both high- and low-melting-point alloys, were given a preliminary examination. The high-melting-point alloy contained 5% uranium in molybdenum, and the low-melting-point alloy contained 5% uranium i1n nickel or copper. The results obtainedbyusing the following methods of preparation were only partly successful: (2) suspension in refractory powder and heating above the solidus, (2) momentary melting by passing through a high-temperature arc, and (3) spraying from a metal- lizing gun. Suspension in Refractory Powder, The U-N1 and U-Cu alloys were swaged and drawn to 0.010 in. in diameter and then cut into short segments. The U-M particles were mixed with Al O, and heated to 1450°C; one sample was heated in hydrogen and another in a vacuum of 3 microns. The U-Cu parti- cles were spread on a refractory plate and heated to 1100°C for 5 min in hydrogen. A surface filwm formed in all three cases and prevented spheroid- 1zation, even though a liquid phase was present. Momentary Melting in a High- Temperature Arc, A rig for housing two water-cooled electrodes and supplying an argon atmosphere was assembled. Both carbon and tungsten electrodes have been used. The U-Na alloy particles, similar to those used in the first method, were dropped through an struck between the electrodes. Alignment proved to be very critical, but the particles that passed through the arc zone did melt. The yi1eld was quite low, however. Particles that passed through the carbon arc were porous, whereas those arc 156 that passed through the tungsten arc were not. Similar U-Ni alloy particles were also dropped through an atomic-hydrogen arc, and a small number of essentially spherical, but porous, particles were formed. Spraying from a Metallizing Gun, A length of 0.057-in. -dia U-N1 alloy wire was fed through a metallizing and the resulting particles were collected in water. As with the other methods, a porous product resulted. Substitution of argon for the normal air blast produced what appeared to be a sound product, with only a superficial surface film. During the process of droppaing segments of wire through the tungsten arc, 1t was noted that small particles were ejected from the electrode at current densities high enough to melt the electrode tip. The bulk of the particles ranged in size from 0.010 to 0.020 inch. These results were duplicated when U-Mo electrodes were substituted for the tungsten elec- trodes. The U-Mo electrodes were prepared by pressing a mixture of the elemental powders and sintering at 1200°C for 5 hr in a vacuum of 0.5 to 1 micron. The spheroidized particles did not give a response on exposure to an alpha counter as did the parent electrodes and U-Ni particles from an earlier spraying experiment. gun, SOLID PHASE BONDING OF METALS E. S. Bomar J. H. Coobs Metallurgy Division The 1nitial tests on the solid- phase bonding of metals, performed essentially as a screening operation, have been completed. These tests were undertaken to determine which materials are easy to bond and which are diffi- cult to bond. The tests were run on both sheet stock and sintered-powder compacts and were performed by stacking wafers 1n a molybdenum-lined graphite die. The laminates were hot pressed for 5 min at 3000 psi at 1150, 1200, and 1250°C in an argon atmosphere. Further tests have been run at 1150°C for 1, 10, and 30 min to determine the effect of time on the extent of "bonding. Evaluation of these tests i1s not complete. Examination of the first group of samples revealed little difference in the degree of bonding at the various .~ temperatures. As was expected, con- siderably more diffusien occurred at - 1250°C than at the lower temperatures, but bonding was only slightly better. In general, the variocus couples may be divided into four groups on the basis of the extent of bonding: ex- cellent, interface almost obliterated, ~inseparable; good, interface well defined, inseparable; fatir, separated with some difficultyj poor, only superficial bonding. The couples studied fall into these categories in the following manner: ' Excellent Nickel to Inconel Nickel to stainless steel Stainless steel to stainless steel Iron to iron ' Good Nickel to iron Nickel to nickel Mol ybdenum to nickel foilto molybdenum Fair . ' Molybdenum to nickel Meclybdenum to Inconel Molybdenum to molybdenum Poor ~ Mol ybdenum to iron Mol ybdenum to stainless steel _ The self-welding of the molybdenum, with or without a nickel foil bonding layer, was poor at 1250°C; so supple- mentary runs were made at 1400 and 1500°C, with results as indicated above. For molybdenum to nickel and mo- lybdenum to Incomel, there was a measurable amount of diffusion but only fair bonding, possibly because of the formation of a third phase of PERIOD ENDING DECEMBER 10, 1952 poor strength at the interface. Ex- tensive diffusion (2 to 3 mils) occurred between molybdenum and iron and molybdenum and stainless steel, but there was even less bonding than was found between mol ybdenum and nickel or between molybdenum and Inconel. - fi Further work in which electro- deposited chromium is used as a bonding layer is being done on the bonding of molybdenum to the other metals. Chromium is reported to be completely miscible with molybdenum and may be more compatible with the other ma- terials. Several small fuel assemblies have been prepared by using the electro- formed nickel screen, filling with mixtures of UD, and stainless steel powder, and pressing rubberstatically. This step is followed by cladding both sides with iron or nickel sheet and by hot pressing at 1250°C. The as- semblies are now being examined for fuel distribution and bond integrity. " COLUMBIUM RESEARCH E. S. Bomar H. Inouye Metallurgy Division Gaseous Reactions. TInvestigation of the reaction of gases with columbi- um was initiated after a literature survey was made that revealed the high reactivity of the metal above 400°C and some preliminary high tem- perature tests made that gave erratic results., Minute quantities of dis- solved gases change the mechanical properties considerably, and hence these reactions must be controlled. The primary interest during this period was in finding a suitable atmosphere i1n which to conduct creep tests, An argon atmosphere was selected, initially, and some of the observations are presented in Table 12.1. Commercial, tank argon was purified by drying with a tower of magnesium perchlorate, followed by 157 ANP PROJECT QUARTERLY PROGRESS REPORT two towers of titanium sponge at 850°C, and finally one tower of titanium sponge at 200°C, Oxidation in Air. It has been reported that columbium oxides evapo- rate between 1200 and 1500°C. Pre- liminary tests of the stability of the oxides show that there is a negligible loss through volatilization up to 1375°C (see Table 12.2). This temperature being above that of the intended investigation, it was decided to measure the course of oxidation directly with time by suspending the sample in the furnace from one arm of an analytical balance. The oxidation rates of columbium 1in dry air have been measured at 600, 800, 1000, and 1200°C. A linear oxidation rate that becomes more rapid with increase in temperature 1is in Table 12.3. The oxidation tests were made in air flowing at 2 liters/min that was dried by anhy- drone and a cold trap of acetone and dry ice mixture prior to entering the furnace. At 400°C, columbium undergoes short periods of rapid oxidation followed by longer periods of relatively slower oxidation up to about 20 hours. Beyond this time, the oxidation rate becomes linear; that 1s, the weight gain is proportional to the time of exposure, The oxide formed on the sample at the endof 3000 min 1s reasonably adherent. shown TABLE 12.1. COLUMBIUM REACTIONS IN PURIFIED ARGON TEMPERATURE TIME OF WEIGHT HARDNESS ( °CA TEST INCREASE | INCREASE REMARKS ) (hr) (g/cn?) (VPN) 600 291 0.0005 48 Film of CbO, 4, = 4.21, ductile 800 67 0.0015 106 Black film, not identified 1000 88 0.0026 416 Black film, brittle 1000 89 0.0006 97 Static argon, 5-in. mMercury pressure 1000 72 0.0002 85 Capsulated sample in static argon TABLE 12.2. STABILITY OF Ch,0, IN AIR (18 hr) TEMPERATURE WEIGHT CHANGE o REMARKS (°cC) (g) 1600 +0.0001 Starting material had a few black specks of a lower oxide 1100 +0.0001 Oxide completely white 1200 0 Oxide changed to a yellow color 1250 0 Oxide yellow 1300 —0.006 Oxide yellow 1350 =-0.0009 Oxide yellow 1375 -0.0009 Oxide yellow 158 TABLE 12.3. COMPARISON OF GXIDATION RATES AT END OF 90 MINUTES TEMPE RATURE WEIGHT GAIN ("C) (g/cm?) 400 0.00003 600 0.0088 800 0.0465 1000 0.0650 1200 0.0915 At 600°C and above, the oxide forma- tion is fairly thick, and some diffi- culty has been experienced in obtain} ing a picture because of the spalling of the oxide within a few seconds after removal {rom the furnace. Attempts to preserve the oxide 1in place have been made by pouring solder or ““castalite’” plastic around the specimen. ' CREEP RUPTURE TESTS OF STRUCTURAL METALS R. B. Oliver K. W. Reber D. A. Douglas J. W. Woods C. W. Weaver Metallurgy Division Inconel in Air. Inconel specimens have been tested 1n an air atmosphere at stresses ranging from 3000 to 4500 psi at 815°C., The results indicate an increase in rupture life by a factor of 10 as compared to tests run in argon in this stress range. It 1is thought that subsurface oxygen and possibly nitrogen may be the elements influencing the creep rate and pro- longing the rupture life. Tests are being designed to investigate the relative effectsof oxygen and nitrogen on the creep-rupture properties., It is postulated at this time that the creep properties of Inconel in en- vironments other than air may be improved by a pretreatment with oxygen or nitrogen. Experiments will be conducted to explore this possibility, PERIOD ENDING DECEMBER 10, 1952 Inconel in Hydrogen. Fine-grained Inconel specimens have been tested in a purified dry hydrogen atmosphere at stresses ranging from 2500 to 7000 psi at 815°C. The results of these tests as compared with those from tests made in an argon atmosphere show a marked decrease in rupture life, ranging from a 75% decrease at the lowest stress to a 55% decrease at the highest stress tested. A similar series 0f tests 1s being made on coarse~grained specimens. Inconel in Molten Fluorides. Tests of Inconel in the fluoride mixture Na¥F-ZrF,-UF, {(46-50-4 mole %) are being made at 815°C at stress levels from 2500 to 7500 psi. Besults to date indicate a marked decrease 1in rupture life that 1s similar in magni- tude to the rupture life obtained in tests made 1n a hydrogen atmosphere., Figure 12.1 1s a summary of the available data for Inconel tested at 815°C (1500°F) in the several environ- ments. {he tentative data for tests in this fluoride and hydrogen are based on two and three tests, spectively, Type 316 Stainless Steel in Argon, Specimens of type 316 stainless steel have been tested at 815°C in argon at stresses from 5300 to 7300 psi. A comparison of these data with those for Inconel tested in argon shows the type 316 stainless steel to have a longer rupture life than that of Inconel by a factor of 10 at the 5000 psi stress level and by a factor of 3 at the 7000 psi stress level. The data from creep-rupture tests of type 316 stainless steel tested 1in air at the Cornell Aeronautical Lab- oratory, together with a few tests 1in an air atmosphere at ORNL, do not indicate any significant difference between the rupture life of type 316 stalnless steel specimens tested in argon and the rupture life of those tested in air. Type 316 Stainless Steel in Molten Fluorides. Tests of type 316 stain- re - 159 091 UNCLASSIFIED OWG. 17409 ! | | | | ot el o N P ! |~ inco-rounD BAR IN AR ! | N i - L] | 1 | N\ | TN i C : VNG IS TN e | | | — ORN_-0.065-1n, SHEET _L-INCO- 0.0483-in NOF-Z!F4“ UF, SHEST IN AIR ! I | | | | 5 | | : | ORNL-0.065- in. SHEET i AN | r | i o N HYDROGEN —— ! oo VN j ‘ | ] | : e NN NS L +ORNL- 0.083~in. SHEET IN | | ARGON ! (WIDE RANGE OF GRAIN SIZES) D 1 1 i | | | STRESS (psi x1000) ] | - 3 ' ] : | B o é | RS | I R - I | " SRR ‘ a | | | L | o | N | | o 0 1 10 100 1,000 10,000 TIME (nn) Fig. 12.1. Summary of Available Rupture Data for Inconel Tested at 815°C (15008°F) in Air, Argon, Hydrogen and the fFused Fluoride Mixture NafF-Zrg,-UF, (46-50-4 mole %). LHOAHY SSHYO0¥d ATHALYVNO 12Af0Md dNV less steel are being made 1in the fluoride mixture NaF-KF-LiF-UF, (10.9~43.5-44.5~-1.1 mole %) at 815°C at stresses ranging from 5000 to 7500 psi. Preliminary results indicate a marked decrease in the rupture I1fe. It will be necessary to complete more tests before a definite evaluation can be made of the effect of the fluorides on the creep properties of type 316 stainless steel. An anoma- ~ lous behavior has been noted in the stress range from 6800 to 7300 psi - the rupture life increases as the stress is increased. This effect has also been seen 1n argon tests, al- though to a lesser degree. Detailed metallographic studies, together with x-ray diffraction and vacuum fusion analyses, will probably be necessary to determine the structural changes that promote this behavior. BRAZING AND WELDING RESEARCH G. M. Slaughter V. G. Lane C. E. Schubert Metallurgy Division ARE Welding. A manual entitled ‘““Joint Design for Inert -Arc Welded Vessels’ was prepared as an aid in construction of the ARE. This manual describes the preferable basic joint design for use i1n pressure vessels that are to be operated at elevated temperatures in a severely corrosive environment., Cone-Arec Welding. A topical, comprehensive report of cone-arc welding research conducted at this laboratory is being written for publi- cation in the Welding Journal Research Supplement. This report will discuss the basic principles of the cone-arc process, the actual physical setup of the apparatus, and the extent of the research on the welding of thin- walled tube-to-header joints. During the research on the cone-arc welding of the 0.100-in.-0OD stainless steel tubes with 0.010-in. wall thick- ness to the 0.125-in. stainless steel PERIOD ENDING DECEMBER 160, 1952 headers, it was noticed that many welds exhibited a two-pass appearance, In order that the mechanism of the cone-arc welding process could be better understood, an investigation was conducted to study this phenomenon. Figure 12.2a¢ shows a microstructure in a cone-arc weld that resembles, ‘in many ways, that resulting from a multiple-pass butt-weld. There were, apparently, two stages of melting, with growth of dendrites across the interface of the two regions. This two-pass effect apparently results from the very rapid melting of the tube during the initial phases of the welding process. With the tube flush against the top header surface, the intense heat of the welding arc is at first centered upon the thin- walled tube. The tube apparently undergoes melting along 1ts length for a short distance until the thermal- insulating capacity of the very fine tube-to-header spacing is overcome. After this occurs, much of the heat is then used in melting the header material. At this time, conditions are reached that approach more nearly the equilibrium state, The lower pass is then that resulting from the initial phase of the welding, and the upper pass, represented by the molten weld pool, remains throughout the major portion of the welding cycle. ' Since it would seem that the arc would play more directly upon the header sheet at the initial point of striking i1f the tube were recessed 1in the hole, this technique was employed in an attempt to eliminate the two- pass weld., Figure 12.2b 1s a photo- micrograph of a cone-arc weld in which the tube was recessed 0.022 inch, Complete welding occurred, and the two-pass effect was eliminated. It should be remembered that the two-pass weld is not considered as detrimental but is merely a characteristic of joints made under certain conditions, Relatively long arc distances also reduce the tendency for this type of 161 ANP PROJECT QUARTERLY PROGRESS REPORT " UNCLASSIFIEDS v-7450 K Fig. 12.2. plate. (b) Tube recessed 0.022 inch. joint, As the arc distance increases, more of the arc beam impinges upon the header sheet, and the drastic heating of the tube wall 1s minimized. Resistance Weldimg. Since 1t 1is desirable to determine the feasibility of electrical -resistance spot welding of stainless steel clad fuel elements to both themselves and to stainless steel sheet, an 1nvestigation 1is being made in which the welding vari- ables are precisely controlled. The goal of the preliminary experiments in this program was merely the produc- tion of sound, high-strength welds under conditions that do not materially harm the core structure of the fuel elements, Welds were made at several values of electrode force to obtain the optimum value, which was considered to be the minimum force that would consistently result in crack-free, nonporous, weld nuggets. DBy using this optimum electrode force and a reasonable weld time, experimental welds were then made over a wide 162 Two-Pass Characteristces of Cone-Arc Welds, Etched with aqua regia. UNCLASSIFIED Y5355 (a) Tube flush with 194X, range of welding current. Examination of metallographic sections of these welds will enable the determination of the permissible range of current over which good welds can be made and also allow the selection of the most satisfactory value of welding current. Any major defects resulting from welding can also be investigated by metal lographic sectioning. A photomicrograph of a sound, high- strength, spot weld made in 0.030-1in,. fuel elements containing cores of 50% U0, and 50% Fe is shown in Fig. 12.3a. The electrode force used was 800 1b, the weld time was 5 cycles, and the welding current was 6300 amp. The dark etching areas in the cores are thought to result from the partial melting of the 1ron portions of the core metal. The lower limit of the permissible current range is exhibited in Fig. 12.3b. The welding conditions in this case are identical to those used in Fig. 12.3a except that the welding current was reduced to 5800 (o) PERIOD ENDING DECEMBER 10, 1952 ELDED SURFAC § b e Fig. 12.3. Spot Wejds of Stainless-steel-¢lad Fuel glements. {a) Wwelding current §300 amp, al penetration. excellent penetration. Etched with aqua regia. (b) Wwelding current 5800 amp, margin- 50X. 163 ANP PROJECT QUARTERLY PROGRESS REPORT amp. The sheet-to-sheet interface line has been nearly removed; as a result, a moderate strength “stick weld” has been produced. It may be noted that melting begins at the stainless steel~core interface instead of at the usual sheet-to-sheet inter- face. Tensile-shear tests on clad fuel elements that were spot welded under optimum conditions indicate that relatively high shear strengths can be obtained. Strengths of 575 1lb per spot weld were recorded when a 3/16-in. restricted-dome electrode was used. Welds in standard stainless sheet of the same type and thickness would be somewhat stronger, but this would be expected because the nugget size would also undoubtedly be larger. Avtomatic Heliarc Machine Welding, A welding program has been originated to study the operation and welding characteristics of a G-E Fillerweld Machine. This machine consists of a standard inert-gas heliarc torch with an auvtomatic filler-wire addition mechanism. When coupled with amachine welding carriage, this equipment presents an excellent means for semi- automatically welding long straight joints or, when used in conjunction with an appropriate cam, joints of irregul ar and intricate shapes. In an investigation of the type to be con- ducted 1n this laboratory, 1t 1s desirable not only to determine abso- lute values of the welding variables but also to study the effects of these variables upon the gquality of the welds produced. o . Preliminary work on this investi- gation first consisted of adapting the basic equipment to conform with the needs of the program. Experiments have been conducted for the purpose of gaining familiarity with the process and for determining the ranges of welding current and travel speed necessary to produce satisfactory welds with various rates of filler- wire addition. All weld beads have 164 been deposited on flat stainless steel sheet 0.090 in. 1n thickness, but later the investigation will be focused upon actual joints in sheet stock of similar thicknesses, Fabrication of Heat Exchanger Units, 1Tt is necessary to develop techniques for successfully brazing large, complicated, heat exchanger test assemblies of a type suitable for aircraft use., An actual unit was assembled in this laboratory and subjected to the Nicrobrazing oper- ation. Figure 12.4 is a photograph of the heat exchanger brazed in dry hydrogen by the canning techniqgue. As can be seen from the photograph, the fins are badly warped and distorted and 1in some cases, even brazed to- gether. After the leak test with helium, 1t was found that there were leaks in the tube-to-fin matrix as UNCLASSIFIED 01 Fig. 12.4. Liguid-te-Air gadiator Nicrobrazed by Canning Techunigue, well as in the tube-to-header joints of the manifold section. The tube-to- header joints could be repaired by rebrazing, but the leaks in the body of the unit are almost impossible to repair successfully. ' Examination of the completed unit revealed several probable causes for the leaks and excessive distortion, This examination has led to techniques for overcoming these flaws in future brazing operations. The tube-to-fin leaks were thought to be caused by excessive use of Nicrobraz alloy, with the resultant dissolving away of the tube walls. al so tended to aggravate this situ- ation by allowing puddling of the molten brazing alloy. The formation of “hot spots’ in the body of the assembly was also thought to be a prevalent condition. ‘A very rapid heating rate was also an important factor in the warpage. ’ Techniques that are planned for incorporation in further brazing operations are the use of lesser quantities of Nicrobraz, the use of several aspilrators to promote more even hydrogen flow between the fins, the build-up of the whole assembly off the can bottom to overcome the drastic inittial heating rate, and the use of a slightly lower brazing temperature. 8razing of Copper to Inconmel. The need for a satisfactory brazing alloy for joining copper fins to Inconel tubing has been emphasized. The resultant braze should have relatively high strength at 1500°F and should also be a diffusion barrier against copper penetration into the Inconel during service. It seems likely that some alloy other than a copper-base alloy would best fill these require- ments. Nicrobrazing at 1900°F is very promising, but the alloy does not completely melt at this temperature. Tt 1s hoped, however, that the use of other alloys very similar in compo- sition to Nicrobraz but of somewhat The bad distortion’ PERIOD ENDING DECEMBER 16, 1952 lower melting point will result in a satisfactory brazed joint. In view of the possibility that it might be advisable to use copper-base alloy for the production of these tube-to-fin joints, several such alloys are being investigated. Small melts of Cu-Be, Cu-5S1, Cu-Sn, and Cu-Mn alloys have been prepared and are to be tested for flowability characteristics, oxidation resistance, and room- and elevated-temperature tensile strengths. ' : EVALUATION TESTS OF BRAZING ALLOYS G. M. Slaughter V. G. Lane C. E, Schubert Metallurgy Division The results of recent high -tempera- ture oxidation tests and static cor - rosion tests in sodium hydroxide, sodium, and lithium are summarized in Table 12.4. The high ~temperature oxidation tests were conducted in a stream of moist air at 1500°F on T specimens of Inconel and type 316 stainless steel brazed with the various alloys. The samples tested in molten sodium hydroxide at 13500°F were A nickel T joints brazed with these alleys. Brazed Inconel and type 316 stainless steel T joints were used as specimens for the corrosion tests in sodium and lithium, The tensile strength nf several brazed joints has been examined at room and 1500°F temperatures. Oxidation of Brazing Alloys. Ex- amination of metallographic sections of the high-temperature oxidation specimens showed the 60% Pd-40% Ni alloy to be the most oxidation re - sistant of the brazing alloys tested. This alloy was unattacked when in contact with the base metals tested; the Inconel joint is shown in Fig. 12.5. An example of severe oxidation is shown in Fig. 12.6, which is the photomicrograph of a type 316 stainless steel joint brazed with the 64% Ag-33% 165 991 TABLE 12, 4. RESULTS OF 104 hr CORROSION TESTS OF BRAZING ALLOYS AT 1500°F BRAZING ALLOY HIGH- TEMPERATURE OXIDATION ON BRAZED INCONEL HIGH- TEMPERATURE OXIDATION ON BRAZED TYPE 316 STATIC CORROSION ON BRAZED A NICKEL IN NaOH STATIC CORROSION BRAZED INCONEL STATIC CORROSION ON BRAZED TYPE 316 STAINLESS STEEL STAINLESS STEEL In Na In Li In Na In Li Nicrobraz Slight None Moderate | Slight Severe 60% Mn-40% Ni Severe Moderate Moderate Moderate Severe 60% Pd=-40% Ni None None None Severe Severe Moderate Severe 16. 5% Cr-10.0% Si- Moderate None Fractured Moderate | Severe None* Slight 73.5% Ni during examination 16, 5% Cr-10,0% S1= Moderate None Fractured Moderate Slight None* Severe 2.5% Mn=71.0% Ni during examination 75% Ag=-20% Pd- 5% Mn Severe Moderate Severe Sevare Severe Severe Severe 64% Ag~-33% Pd- 3% Mn Slight Severe Moderate Severe Severe Severe Severe *Severe cracking present in joint. LUHOdIH SSHUO0¥d ATHILYVIO L13A704d dNV PERIOD ENDING DECEMBER 10, 1952 E UNCLASSIFIED Y7474 Fig. 12.5. Inconel Joint Brazed with 0% l’_d~4fl% Ni Alloy After Oxidation Test for 100 hr at 1500°F. Etched with KCN(NH,),S,0,. 200X. E UNCLASSIFIED Y.7AB2 Fig. 12.6. Type 316 Stainless Steel Joint Brazed with a §0% Ag-33% Pd-3% Mn Alloy After Oxidation Test for 100 hr at 1500°F. Etched with agua regia. 200X, | - 167 ANP PROJECT QUARTERLY PROGRESS REPORT Pd-3% Mn alloy. As a result of this investigation, it was found that a brazing alloy in contact with one base metal may be severely oxidized, whereas it may be relatively unattacked when in contact with another base metal, This might be explained by the fact that the least oxidation -resistant constituents of the brazing alloy may diffuse more readily into certain base metals than inteo others, Corrosion of Brazing Alloys by Sodium Hydroxide. Since A nickel 1is relatively unattacked by molten sodium hydroxide at 1500°F, it serves as a suitable base metal for testing the corrosion resistance of brazing alloys in this medium, Examination of a joint brazed with 60% Pd-40% Ni alloy and tested in NaOH for 100 hr showed e \'.A - ““\ * B Fig' 12@ 70 that no attack is present, Several other alloys were attacked, and the joints brazed with the Cr-Ni-Si-Mn and the Cr-Ni-Si alloys fractured during removal from the test capsule. Corrosion of Brazing Alloys by Sodium and Lithium. Because brazing operations may be proposed for as- sembling fuel plates into subas - semblies for certailn types of reactors, it was of interest to study the static corrosion resistance of brazed joints in contact with sodium or lithium, The 60% Pd-40% Ni alloy, which ex- hibited excellent corrosion resistance to all other media tested, was severely attacked by the liquid metals. The extreme attack of sodium on brazed Inconel 1is illustrated in Fig. 12.7, which is the photomicrograph of a UNCLASS!FEEJ Sodium. 168 Etched with aqua regia. Inconel Brazed with 60% Pd-40% Ni After 150 X. 100 hr at 15300°F in sample tested for 100 hr at 1500°F, As a check on these results, small specimens of the pure braze metal were immersed in the metal baths, The sample tested in sodium had a weight loss of over 50%, and the sample tested in lithium completely dissolved. Figure 12.8 is a photomicrograph of a type 316 stainless steel brazed with the Cr-Si-Ni-Mn alloy and tested in sodium for 100 hr at 1500°F. No attack is exhibited, but the cracking tendencies of this brazing alloy are shown very clearly. It was noted that the cracking of the Cr-Si-Ni-Mn and Cr-Ni-Si alloys was more severe when alloyed with stainless steel than when - alloyed with Inconel. Tensile Strength of Brazed J01nts. Results of the room-temperature ten- sile strength tests of Inconel butt- joints brazed with Nicrobraz alloy seem to indicate that a short brazing time of 10 min or less leads to the Fig. 12.B8. PERIOCD ENDING DECEMBER 16, 1952 production of weak joints. Samples held at the brazing temperature for 20 min seem to produce stronger joints. Figure 12.9 is a photomicrograph of the room-temperature fracture of a joint held at the brazing temperature for 5 minutes. Some Nicrobraz can be seen in this photograph, but no brittle fracture is evident. Although the specimen that was held for 20 min at the brazing temperature broke near the brazed joint, no evidence of Nicrobraz alloy conld be found upon metallo- graphic sectioning. The greater alloying of the braze and the base metal is a result of the increased diffusion occurring at this longer time. The increase in tensile strength of the second bar probably results from this alloying. The average of four room-tempera - ture tensile tests on joints brazed at short times was 38,300 psi. A joint brazed for 20 min at the brazing temperature fractured at 81,700 psi. Type 316 Stainless Steel Brazed with 16.5% Cr-10.0% Si-2.5% Mn-71.0% Ni After 100 hr at 1500°F in Sodium. Etched with aqua regia. 150X. 1169 ANP PROJECT QUARTERLY PROGRESS REPORT ’ 2 ‘ Y ! oo A\ N ¢ j : ’ A ; - : } ‘ v - J { ¥ R < - ¥ ';‘ . ' e } "}_ # < ! “ { s X ’ : ' [ * e ’ . . . # / } /‘, { . - € \\ . . . e -.#) \ . ‘, ‘r ‘ K;r"{ j 7 ! /e : ] V fl’ ¢ / ‘\ P .. J LAl - ! e N L : : ; » § { ' R 3 N\ Y ’ ’ . Fig. 12.9. Brazing time, 5 min. The average tensile strength of four Inconel bars that were heat -treated similarly was 87,300 psi. This seems to indicate that if time is allowed for sufficient diffusion to occur, joint efficiencies of over 90% can be obtained. However, a more thorough investigation of the effect of brazing time on room-temperature strengths is being conducted at present, The tensile strengths of Nicrobrazed Inconel joints tested at 1500°F were much more consistent, The average tensile strength of joints brazed at short times was 24,400 psi, whereas the sample brazed for 20 min fractured at 24,700 psi. Several test bars failed in the parent metal at a point definitely not in the diffusion zone of the brazed joint. The average elevated-temperature tensile strength of four Inconel test bars that were heat treated at the brazing temperature for 5 min was 23,700 psi. These data indicate that the Nicrobrazed Inconel joints at 1500°F are often as strong 170 Etched with aqua regia. | UNCLASSIFIED y Y.7835 v i - ey . i . / ' k * P L 3 L 3 - 1 . § - § \’v {—. 2 : ¥ W / \ ' * /‘i -’ » i A 1 P F, - Joe VEET e | : "\ {4 R - i f < . L~ -~ , * 7 : 2 . \"/’ ’ 3 o i i - f : i W . ¥ * v N v i e ’ ™ * ¢ -t é‘ \ ! £ ot i < # . \ i L g “ . 3 ‘ - . iy ..t ¢ ayy it - j / ¥ ! / { ' - t h N ] Sy . « . e -~ Room-Temperature Fracture of a Nicrobrazed Inconel Test Bar. 200X. as the Inconel base metal, The dif- fusion of the braze metal while the specimen 1s at the testing temperature undoubtedly has some effect upon the Joint strength at this temperature, Butt-brazed Inconel test bars brazed with the 60% Pd-40% Ni alloy were tested at room and elevated temperatures. The average room- temperature tensile strength of these brazed joints was 87,600 psi, whereas those tested at 1500°F averaged 21,000 psi. Check bars of Inconel heat treated for 5 min at 2300°F were also tested so that the strengths of samples subjected to the brazing cycle could be determined. The joint efficiency at room temperature was found to be 100%, whereas at 1500°F the value was 93%. Extremely deleterious effects of the high-temperature heat treatment involved in Ni-Pd brazing were not evident in short-time tensile tests on Inconel. Inconel 0.252-1n.-dia tensile bars heat treated for 5 min at the Nicrobrazing temperature of 2100°F had an average room-temperature strength of 87,300 psi and an average 1500°F strength of 23,200 psi. Test bars heat treated for 5 min at the Ni-Pd brazing temperatures of 2300°F fractured at an average room-tempera- ture strength of 84,500 psi and at an average 1500°F scrength of 22,600 psi. Thus, the larger grained Inconel has a tensile strength at room temperature of only 3.2% less than the finer grained Inconel; at 1500°F the dif- ference 1is only 2.6%. Since all tensile bars 1n the experiments were machined from the same Inconel rod, there is indication that heat treat- ment was the influencing factor, Melting Point of 60% Pd-40% Ni Alloy. Although the 60% Pd-40% Ni brazing alloy has many very desirable properties, 1its high melting point might exclude 1ts use in many appli- cations., In an attempt to lower 1its melting point by alloying, beryllium additions of from 0.25 to 4% were made. A 1% beryllium alloy was found to have a melting point slightly below 2200°F, but recent tests indicate that its flowability properties are very poor. In further attempts to obtain a lower melting point alloy without impairment of the corrosion resistance and physical properties of the basic alloy, additioms of Al will be made to the Pd-Ni alloy. CERAMICS RESEARCH J. M. Warde, Metallurgy Division Development of Cermets for Reactor Components, The Cr-Al,0, cermet fabrication studies have resulted imn successful disks 1 in. in diameter and 20 mils thick. Several sandwich disks were also made that contained a thain layer of U0, mixed with Cr-Al,0;. A die 1is now being made to permit pressing of annular rings of a fuel- bearing material. In-reactor tests of these cermets are now being con- templated. ' ‘ PERIOD ENDING DFCEMBER 10, 1952 A 7ZrC-Fe cermet was fabricated as a possible material for pump parts, seals, and bearing materials. This cermet, along with Kennametal 151-a, is being tested for corrosion resis- tance in fluorides, Na, and Pb. These materials appear to be very promising. Corrosion data and photomicrographs will be included in the next report. Attempts to hot press SiC-81 mix- tures have not yet been successful. A vacuum induction furnace is nearly built that will be used to study sintering of this and other cermets. Ceramic Coatings for an Aircraft Type of Radiator. A satisfactory dipping technique was developed for the application of NBS ceramic coatlng A-418 to provide oxidation resistance at elevated temperatures to parts fabricated from nickel for an aircraft type of radiator. The first composi- tion of this coating was described previously.(?’ The radiator parts -will be coated as soon as they are available. Ceramic Coatings for Shielding Metals. Work was commenced on the development of a coating contalning a minimum of 10% by weight of boron that could be flame-sprayed onto metal surfaces for use in reactor shielding. A lead-borate enamel was developed’ that could be successfully applied in a 20-mil coating to No. 20 gage stain- less steel by flame-spraying. The batch composition of this enamel 1s as follows: B,0, 35. 0% PHO 62.5% ZnO 2. 5% Further work 1s in progress in an attempt to coat a mild steel plate 5 ft by 5 fv by 7/8 in. for use in a shielding experiment. : Uniformity of Beryllium Oxide Blocks (.. M. Doney and J. M, Warde, Metallurgy Division). A study of the physical structure of the BeO blocks (1) 1952, T. N. McVay, ANP Quar. Prog. Rep. June 10, OBRNL-1227, p. 152. : 171 ANP PROJECT QUARTERLY PROGRESS REPORT to be used in the ABE was made to aid in the interpretation of BeO-NzakK compatibility test data, These blocks, fabricated by the Norton Co., were made by hot-pressing BeO powder. They are hexagonal blocks 2 1/8 in. on a side, 3 11/16 in. in diameter across center of faces, and 6 in. long. They are fabricated with a center hole running axially through the block; the diameter of the hole (depending on the position of the block 1n the reactor core) is 1/2, 1 1/8, or 1 3/4 inches. A visual examination was made of about 30 blocks of the type having a 1/2-in.-dia hole. These blaocks had been sawed in two on a - plane perpendicular to the long axis. It was observed that in all cases the core of the blocks had a different physical structure than did the outer portion of the same blocks. In order to study this core structure, .six blocks that had not been sawed were soaked 1n fuchsin dye for 12 hours. The dye 1s most absorbed in the more porous areas in the block, and Fig. 12.10, a photograph of one of the dyed specimens, shows the typical soft core structure noted in all ‘the dyed specimens. Samples taken from the inside and outside surfaces of these blocks showed density variations from 2.80 to 2.83 at the outside, which decreased to 2.26 to 2.43 at the inside. The apparent porosity of the dense portion of the block i1s practi- TABLE 12. 5. compared with values up to 23.3% for the soft core. Table 12.5 gives results of density, apparent porosity, and water absorption measure- ments for specimens cut from various portions of the block, Blocks that have a 1 1/8-in.-dia central hole are being split longi- tudinally so that the two halves can be placed around a cooling pipe. With the blocks split, a large amount of inner surface will be expoesed to the coolant material. This inner surface is low-density material that 1is particularly susceptible to NaK cor- rosion. To determine the extent of the low density region, a random sample of these blocks was soaked in cally zero, 7912 Fig. 12.10. bye-treated Bel Block Showing Porous (Central Section. DENSITY, POROSITY, AND WATER ABSORPTION MEASUREMENTS OF VARIOUS SECTIONS OF THE Be0 BLOCK T wer weronn, v | oy weionn, 5 | L T RBSORPTION, T SUSPENDED | | ppmecry | FOROSITY, SQURCE (&) (8) ¥ - D (¥ - D)/D WEIGHT, &* ¥F - 3e» (g/cms) (¥ - D)W - 8) (%) (g) {%) Quier edge I 1.3612 1.3609 0 0,881 0.4802 2.83 0 Outer edge 1.8459 1.8458 0 1.187 0.6589 2.80 0 OQuter edge 2.0859 2.0860 0 1.350 0.7359 2.83 Q Core 1.3957 1.2789 0.-1168 9.13 0.845 0.5497 2.33 21.25 Core 1.3555 1.2661 0.08%4 7.06 0.835 0.5205 2.43 17.18 Core 1.1778 1.0630 0.1098—L 10. 28 0.707 0.4708 2.27 23.32 *Weight suspended in water, **Equivalent te volume. .| 172 fuchsin dye for 12 hr, and specimens were cut from selected localities in the block. Figure 12.11 shows the density and per cent porosity placed on the block in the location from which the sample was taken. The dark shaded areas on the right of the block indicate the porous portions shown up by the penetration of the dye. Five samples of blocks with a 1 3/4-1in.-dia central hole were soaked in dye and were also found to have a porous central core, _ : A general observation was made regarding the prevalence of cracks in all the blocks examined. All the blocks have at least one crack, and some blocks contain several cracks. In some cases these cracks are visible at the surface of the block, but in the majority of the blocks the cracks are confined to the interioer portion. These cracks are quite narrow and Fig. 12.11. size ARE BeO Block. "heating, PERIOD ENDING DECEMBER 10, 1952 contribute only slightly to the po- rosity. The presence of one of these cracks may be observed in Fig. 12.11. The porous condition developed 1in the hot-pressed BeO blocks i1is a defect caused by fabrication. A probable cause of the defect is that the hot- pressed die had too tight a fit on the top and bottom punches around the central pin, which would cause binding and therefore uneven pressure appli- cation. A further factor is faulty filling of the die, which would cause bridging of the powder around the pin. Other factors such as too short time of applicdation of pressure, too short time of holding at pressing tempera- ture, uneven temperature distribution in the BeO powder because of too rapid cooling of the die to room temperature without extracting the core pin, etc., could also have af- fected the final density. PHOTD 5 5675 ¥ pensity and Per Cent Porosity at various Locations in z Full- 173 ANDP PROJECT QUARTERLY PROGRESS REPORT 13. BEAT TRANSFER AND PHYSICAL PROPERTIES RESEARCH H. F. Poppendiek, Reactor Experimental Engineering Division The thermal conductivity of the flnoride mixture NaF-BeF, (57-43 mole %) was experimentally determined to be 2.4 Btu/hr-ft-°F over a temperature range of 452 to 586°C. This result 1s comparable with the thermal con- ductivities previously obtained for some of the other fluoride mixtures. Two new thermal conductivity devices have been developed and successfully tested with ordinary liqguids. The enthalpies and heat capacities of fuel mixture NaF-KF-ZrF,-UF, (4.8-50.1-41.3-3.8 mole %) have been obtained. The heat capacity can be represented by ¢ = 0,28 + 0.015 cal/cm*°C over theptemperature range 540 to 900°C. The viscosities and densities of the fluoride mixtures NaF-ZrF, (50-50 mole %) and NaF-ZrF,-UF, (50-25-25 mole %) have been measured with the modi fied Brookfield viscometer. The viscosity of the first mixture ranged from 15 cp at 610°C to 5 cp at 1030°C. The viscosity of the second mixture ranged from 20 cp at 650°C to 11 cp at 880°C. These results are compared with the viscosity measurements previously determined for some of the other fluoride mixtures. Development of the capillary viscometer is con- tinuing. The vapor pressure of NaZrF, in- creases from 8 mm Hg at 800°C to 30 mm Hg at 900°C; this behavior is similar te that previously reported for the NaF-ZrF,-UF, (50-46-4 mole %) mixture. FExperimental values of the vapor pressure of BeF, measured at BMI agreed with values calculated at ORNL.. Preliminary experimental heat transfer coefficients have been pbtained for the case of turbulently flowing NaF-KF-LiF mixture in a long tube. It appears that heat transfer with this mixture can probably be described by the usual forced-convection 174 expressions characterizing ordinary fluids, as was found to be the case for molten sodium hydroxide. Several thermal analyses pertaining to the reflector-moderated reactor have been conducted. One study was made concerning the heat generation within the reflector and shell of the reactor. Another analysis consisted of preparing design charts for cooling- hole distributions in reactor re- flectors. An attempt to minimize the weight and volume of air radiators has been initiated. A pyrex thermal convection harp has been designed and constructed for an experimental inquiry into harp convection velocities. The experi- mental data are to be used to check the validity of analytical methods used to predict the circulation velocities. An investigation has been initiated in an attempt to derive a heat-momentum transfer analogy for the annulus 1in much the same way as it has been derived for the pipe system. An experiment has been designed that will make possible an experimental study of the heat transfer charac- teristics of a simple, fuel-circulating system; a long pipe will be used in which the flowing fluid is heated internally by an electric current. The experimental results will be compared with the previously obtained theoretical results. THERMAL CONDUCTIVITY OF LIQUIDS W. D. Powers R. M. Burnett S. J. Claihbhorne W. B. Harrison Reactor Experimental Engineering Division A thermal conductivity device similar to the one described previ- ously(!) was used to study the fluoride Ll e L. F. Basel and M. Tobias, ANP Quar. Prog. Rep. Dec. 10, 1950, ORNL-91%, p. 196. mixture NaF-BeF, (57-43 mole %). The results of three independent sets of measurements are given in Table 13.1.: Figure 13.1 shows a plot of the thermal conductivities of several fluoride salt mixtures as a function of uranium concentration. It appears that the thermal conductivities of these somewhat similar fluoride mixtures decrease as the uranium weight percentages increase. A new thermal conductivity device for studying both liguids and solids has been developed that consists of an electric heater, a thermal con- ductivity cell, a heat meter, and a water cooler. Calculations reveal that thermal conductivities can be measured to within +10% of their true PERIOD ENDING DECEMBER 10, 1952 TABLE 13.1. THERMAL CONDUCTIVITY OF NaF-BeF, THERMAL AVERAGE TEMPERATURE CONDUCTIVITY TEMPERATURE RANGE (Btu/hr+ ft- °F) (°c) (°c) 2.3 528 470 to 586 2.5 527 47] to 584 2.4 526 452 ta 500 values. Thermal conductivity measure- ments of water, obtained with the heat-meter thermal conductivity device, agree with literature values to within 6.5%. _ _ A transient method for determining the thermal conductivity of liquids DWG. 47410 30 FLuome-:1 1 ‘ MIXTURE NO. MIXTURE COMPOSITION 12 : 5s | 2 NaF-KF-UF, (46.5-26.0-275 mole %) __| ' 39 12 NaF -KF-LiF (11.5-42.0-465 mole %) m o' 14 NaF -KF~LiF -UF, (109-435-44.5-11 mole %) * a0 30 NaF-ZrF, -UF, (50-46-4 mole %) _ ] g : 2 35 NoF-BeF, (57-43 male %) a kS & = 1.5 : > ey 5 30 2 0 =z D o . aj "0 \ < ; . u'_‘ . L €I L \ \\ 2 0.5 e frorean 0 : ) 10 20 20 40 50 60 70 80 90 ' URANIUM CONCENTRATION (wt %) ‘ Fig. 13.1. Thermal Conductivity of Fluoride Mixtures as a Function of Uranium Conecentration. 175 ANP PROJECT QUARTERLY PROGRESS REPORT has been developed. A thin-walled metal tube with a small diameter is immersed in the liguid being studied, and the tube i1s suddenly heated by a direct current of electricity. The transient temperature rise of the tube 1sa function of the heat capacity of the tube and the thermal conduc- tivity, heat capacity, and density of the liquid. The early part of the temperature-time function is completely controlled by the conduction mechanism. Analyses of the solutions of the transient conduction equations per- taining to the system described(?’ show that liquid thermal conductivities may be determined from the experi- mental temperature-time measurements. This transient apparatus has been used to check the thermal conductivity of water and glvcerine at room tempera- ture; the results agree to within +10% of the values reportedin the lit- erature. In addition to the continued study of fluoride salt mixtures, it 1is planned to measure the thermal con- ductivity of molten sodium hydroxide by oneor more of the methods discussed above. HEAT CAPACITY OF LIQUIDS W. D. Powers G. C. Blalock Reactor Experimental Engineering Division The enthalpy and the heat capacity of the fuel mixture NaF-KF-ZrF,-UF, (4.8-50.1-41.3-3.8 mole %) have been determined by Bunsen i1ce calorimeters for the temperature range of 540 to 900°C and are given by the equations: H, (liquid) - Hyo. (solid) = .15 + 0,287 , c, 0.28 + 0.015 where H is in cal/g, T in °C, and c, in cal/g-°C. The fuel mixture NaF-ZrF,-UF, (50-46-4 mole %) and the (2)W. B. Harrison, Transient Methods for Determining Thermal Conductivity of Liquids, ORNL CF-52-11-113 (Nov. 1, 1952). i 176 eutectic mixture of NaCH and LiOH are currently being studied. VISCOSITIES OF FLUCRIDE MIXTURES Measurements with the Brookfield Viscometer (R. F. Redmond, T. N. Jones, Reactor Experimental Engineering Division). The viscosities of the fluoride salt mixtures NaF-ZrF, (50-50 mole %) and NaF-ZrF, -UF, (50-25-25 mole %) have been measured with a Brookfield viscometer contained in an inert atmosphere. These results are plotted in Fig, 13.2, together with the viscosities of several other fluoride mixtures. The zirconium- bearing salts have much higher vis- cosities than NaF-KF-LiF (11.5-42.0- 46.5 mole %) and NaF-KF-LiF-UF, (10.9-43.5-44.5-1.1 mole %)}; the beryllium-bearing fluoride mixture NaF-BeF, (57.0-43.0 mole %) is also characterized by higher viscosities. In general, it appears that an increase in uranium content yields an increase in the viscosity. Capillary Viscometer (F. A. Knox, N. V. Smith, F. Kertesz, Materials Chemistry Division). The capillary viscometer previously described(3+*) has been used to study fused fluorides over the temperature range of 600 to 800°C. All the materials studied 1in this apparatus were purified by the hydrogenation-hydrofluoerination procedure. The apparatusin its present form does not sufficiently protect the mixtures from exposure to air, and modifications are being made to the equipment to improve the gquality of the inert atmosphere maintained over the melt. Bloom, Harrap, and Heymann (%) determined values for the viscosity of various chloride mixtures by using (3)J. M. Cisar, F. A. Knox, F. Kertesz, R. F. Redmond, and T. N. Jones, ANP Quar. Prog. Rep. June 10, 1952, OBRNL-1294, p. 146. 4 F. A, Knox, N. V. Smith, and F, Kertesz, ANP Quar. Prog. Rep. Sept. 10, 1952, ORNL-1375, p. 145, (S)H. Proc. Roy. Soec. Bloom, B. S. Harrap, S. E. Heymann, (London) 194A, 237 (1948). PERIOD ENDING DECEMBER 10, 1952 e DWG. 17411 30 20 10 6 \\‘ ‘\ ?\\\ ’gnt-; ~ \:‘\/14 \'\\ \ 2 /::A ‘.\\ . - 0 =2 4 12 '\\\ > ~ ~ % SN0 > ‘\\ 1.._._ o S 2 9 > "~ — __NaOH L ~%“"----\_ = ~ - 3 ‘.‘-.M\ S & : — < o8 I FLUORIDE - il MIXTURE NO. MIXTURE COMPOSITION 0.6 12 NGF -KF~LiF (11.5-42.0-465 mole %) — 14 NaF - KF~LiF - UF, (109-435-44.5-1.1 mole %) 0.4 27 NaF- ZrF, -UF, (46~50-4 mole %) 31 NaF-ZrF, (50-50 mole %) - 33 NaF-ZrF, -UF, (50-25-25 mole %) 35 NaF ~BeF, (57-43 mole %) 0.2 ‘ ‘ . 800 900 1000 1100 1200 1300 1400 1500 TEMPERATURE (°K) Fig. 13.2. Vviscosily of SeveralfFIuoride Mixtures as a Function of Temper- ature. ~ 177 ANP PROJECT QUARTERLY PROGRESS REPORT glass capillaries in apparatus of this type. The use of glass capillaries with fluorides, even at temperatures below 650°C, proved impossible, how- ever, because the innmer surfaces of the capillaries were attacked to such an extent that the original brations could not be reproduced. The use of small nickel capillaries (about 0.08-mm bore) tended to cause plugging by the mixtures being studied. Larger capillaries (2.4-mm bore) minimized this difficulty, but they were impractical for studying low- viscosity liquids. With the large capillaries, Reynold’s numbers below 300 were obtained, and the viscosities measured —- based on calibrations with glycerol solutions at room tempera- ture - are probably reliable as preliminary estimates. The viscosities of the several fluoride mixtures thus determined are in gualitative agree- ment with those presented in Fig. 13.2. cali- DENSITY OF FLUDRIDE MIXTURES R. F. Redmond T. N. Jones Reactor Experimental Engineering Division Preliminary density measurements have been made for the fluoride mixtures NaF-ZrF, (50-50 mole %) and NaF-ZrF,-UF, (50-25-25 mole %), and the values are tabulated in Table 13.2. TABLE 13.2. DENSITIES OF T®¥d FLUORIDE MIXTURES AT VARIOUS TEMPERATURES TEMPERATURE DENSITY FLUORIDE MIXTURE . 3 (°C) (g/cm”) NaF-ZrF, 592 3.35 (5050 mole %) 690 3.28 762 3.21 862 3.14 NaF-ZrF,-UF, 682 4.13 (50-25-25 mole %) 156 4,0% 820 3.94 178 VAPOR PRESSUREL OF MOLTEN FLUCRIDES H. E. Moore Materials Chemistry Division The vapor pressure of ZrF, above the pure compound NaF-ZrF, (50-50 mole %) is of interest because this substance will serve as the fuel carrier introduced initially in the ARE. Vapor-pressure data for this salt were obtained in the temperature range of 795 to 994°C by the method originally described by Rodebush and Dixon, (%) which has been discussed in previous reports.(’*8) The values obtained, given in Table 13.3, are best represented by the equation -7213 m_ff—-+ 7.635 , log P = where P is in mm Hg and T 1s in °K, The heat of vaporization is 33 kcal/ mole, and the boiling point, calcu- lated from the equation, is 1244°C, The vapor pressure of the NaF-ZrF, (NaZrFs) i1s very similar to that of the mixture containing 46 mole % ZrF,, 50 mole % NaF, and 4 mole % ur,, reported previously.(%) This, of course, 1s not surprising, since substitution of 8 mole % of NaUF, for NaZrF, should not greatly influence the equilibrium pressure of ZrF,. Verification of results obtained by this method has been attempted during the past quarter by using other procedures applicable to fused salts at high temperatures. Agreement among the various methods has, in general, been encouraging. Values for the vapor pressure of ZrF, (36 mm Hg at 768°C and 96 mm Hg at 806°C) were obtained by using a diaphragm apparatus similar to that used for vapor pressure (G)W. H. Rodebush and A. L. Dixen, Phys. Rewn, 26, 851 (1925), R. E. . Moore and C. J. Barton, ANP Quar, Prog. Rep. Sept. 10, 1951, ORNL-1154, p. 136. (B)H. E. Moore and C. J. Barton, ANP Quar, Prog. Rep., Dec, 10, 1951, OONL-1170, p. 126, (9)H. E. Moore and C. J. Barton, ANP Quar. Prog. Rep. Sept. 10, 1952, ORNL-1375, p. 147. TABLE 13.3. VAPOR PRESSURE OF NaZrF, TEMPERATURE OBSERVED PRESSURE (°c) (mm Hg) 795 8 803 8 807 : 8 835 13 835 14 854 - 16 858 18 868 20 886 28 887 27 923 39 846 47 948 50 964 64 967 63 994 a0 measurements of UF,.('%) These data are in fair agreement with the values (39 and 94 mm Hg) obtained by the Rodebush method. (%) In addition, tentative values for this compound, 29 mm Hg at 751°C and 56 mm Hg at 786°C, obtained by using a capillary “bridge’’ apparatus, (11+12) gpree fairly well with the values of 26 and 59mm Hg obtained by using the Rodebush me thod. ' : In the past quarter, ‘vapor-pressure data obtained by applying a trans- piration method to beryllium fluoride were reported by Battelle Memorial Institute, ¢*3) A comparison of the data from Battelle with values calcu- lated from the equation reported by this Laboratory('*) is (ID)K. 0, Johnson, The Vapor Pressure of firaniun Tetrafluoride, Y-42 (Oct. 20, 1947). : (11)C. G. Maier, Yapor Pressures of the Common Metallic Chlorides and a Static Method for High Temperatures, U.S, Burean of Mines, TP-360. (12)D. W. Kuhn, A. D. BRyon, and A. A. Palko, The VYapor Pressures of Zirconiuw Tetrachloride and Hafniua Tetrachloride, Y-552 (Jan. 17, 1950). (3¢ A, Sense, M. J. Snyder, and J. ¥. Clegg, Prog. Rep. Sept. 1952, BMI-772, p. 46, ; R. E. Moore, ANP Quar. Prog. Rep. June 10, 1952, ORNL-1294, p. 150, ' given 1n PERIOD ENDING DECEMBER 10, 1952 Table 13.4. The two sets of values are probably in agreement, within the experimental errors of both methods. TABLE 13.4., COMPARISON OF VAPOR PRESSURE OF BeF, BY DIFFERENT METHODS VAPOR PRESSURE TEMPERATURE (mm Hg) {(°C) - BMI Data ORNL Data 778 1.25 2.1 849 7.25 8.8 918 23.5 24 969 51.0 47 CONVECTIVE HEAT TRANSFER 1IN FLUGRIDE MIXTURE NaF-KF-LiF H. W. Hoffman J. Lones Reactor Experimental Engineering Division The construction and instrumentation of the experimental system for the determination of convective heat transfer coefficients for the fluoride mixture NaF-KF-LiF (11.5-42.0-46.5 mole %) have been completed. This system is a modification of the ‘one used for obtaining heat transfer coefficients in a tube with molten sodium hydroxide in turbulent flow. (1% All system components, with the exception of the test section, have been constructed of Inconel; A nickel tubing was used for the test section. Swagelok connections and “0’" ring flanges have replaced the all-welded construction of the sodium hydroxide system. The heat loss calibration and five heat transfer runs with NaF-KF-LaiF were made. These runs covered a Reynold’s modulus range of 2000 to 6000. Figure 13.3 presents the data for NaF-KF-LiF compared with data for air that were obtained by various (IS)H. W. Hoffman and J. Lones, ANP Quar. Prog. Rep. Sept. 10, 1952, ORNL-1375, p. 148. 179 ANP PROJECT QUARTERLY PROGRESS REPORT Q.01 pemmmmmmmmemmn o GRAETZ (FROM DREXEL AND McADAMS); £/0 = 39; AIR | o |.OWDERMILK, HUMBLE AND DESMON; £/0 =60, AIR — e ool ’ -~~COLBURN; £/0 AS INDICATED; OILS | & THIS lNVESflGAflON L/D =200, NaF ~KF- UF(EUTECflC) | Llwmqifllgi UNGLASSIFIED DWG 17412 ?(FULLY DEVELOPED T** TURBULENT F%OW)‘*j MML;ML,@, ,,,,,,,,,,, ______ _____ i i ’ i { oo b 102 2 5 Re Fig. 13.3. J-Factor vs. Reynolds Modulus for NaF-¥F-L1iF, Air, and Other Fiuids. investigators. {16+ 17.18) The heat transfer coefficients are correlated in this figure by the j factor (the product of the Stanton modulus, h/c¢ G, and the two-thirds power of the Prandtl modulus) as a function of the Reynold’s modulus. It is to be noted that the transition from laminar flow to fully developed turbulent flow occurs over a region extending from Re = 3000 to Re = 10,000. The preliminary data of the current investigation fall near the air datain this transition region. Further work is to be done at higher fluid temperatures to extend the data into the region of fully developed turbulence. The experiments with the NaF-KF-ILaF mixture were prematurely terminated because of the failure of the nickel test section. '“Ring’ cracks caused (16)R, E. Drexel and W. H. McAdams, Nat. Adv. Comm. Aero., Wartime Report ARR4AF28. (IT)W. H. Lowdermilk, L. V. Humble, and L. G, Desmon, KHeasurements of Average Heat Transfer and Friction Coefficients for Subsonic Flow of Air in Smooth Tubes at High Surfece and Fluid Tempera- tures, NACA-102 (1951), (la)A. P. Colburn, Engineering Bulletin Purdue University, Vol. 26, No. 1 (Jan. 19, 1942). 180 a portion of the test section (5 1/4 in. long and located approximately at the center of the test section) to fall out. The failure was not caused by corrosion but appears to be due to metal fatigue resulting from the high temperatures to which the nickel section was subjected. A new test section of Incomnel (L/D = 137) 1s being fabricated. Although the length-to-diameter ratio for this tube is less than that for the nickel tube, 1t 1s still sufficient to ensure that the entrance length will be exceeded within the confines of the test section.(!?) ANALYSIS OF SPECIFIC REACTOR HEAT TRANSFER PROBLEMS W. S. Farmer Reactor Experimental Engineering Division Heat Generation in the Reactor Reflector. 1In order to arrive at an estimate of the heat generation to be (19)11 W, Hoffman and J. Lones, ANP Quar. Rep. Sept., 106, 1952, ORNL-1375, p. 148. Prog. expected in the reflector and shell of the reflector-moderated reactor (cf., “General Design Studies,’ sec. 3), several radiation source problems were analyzed. The largest source of heat in the reflector results from the absorption of gamma rays generated in the fuel coolant as a result of prompt fission and decayof the fission products. The magnitude of this source of heat generation was deter- mined by using three methods of calculation based on isotropic source distribution and exponential attenu- ation. In the first calculation, the gamma -ray source was assumed to be distributed uniformly in a spherical annuilus, and the same absorption coefficient was assigned to both the reflector and fuel coolant. 1In the second method, the source was distrib- uted uniformly in an infinite slab of thickness equal to the annulus, and the true absorption coefficients of the fuel coolant, shell, and reflector were used in evaluating the heat generation from gamma-ray absorp- tion at any point in the reflector. The resulting heat generation was corrected for geometry by a plane-to- sphere transformation, The third, and probably the best, approximation to the true heat generation in the reflector was obtained by solving for the current of radiation from the surface of the fuel cooclant by using a spherical annulus geometry. Thisg cirrent was then assumed to enter the face of a composite slab made up of the shell and reflector that surround the fuel coolant. The resulting heat generation was then transformed from a slab geometry to a spherical geometry. A secondary source of heat gener- ation in the reactor reflector and shell arises from the absorption of gamma rays generated by neutron capture in the reflector and shell. 1In order to evaluate this source of heat gener- ation, a general solution was deter- mined for the case of a nonuniform source of radiation in a slab geometry PERIOD ENDING DECEMBER 10, 1952 in which the mneutron flux could be approximated by a power series or exponential expression,( In order to simplify the com- putation of the maximum temperature rise in the reflector resulting from heat generation, general design charts that give this temperature rise for various values of heat generation, coolant-hole diameter, thermal con- ductivity, and coeolant-hole spacing were prepared for several pertinent materials. (?1) : Analysis of Fluid-to-Air Radiators. The design of the air radiator for transferring the heat generated in the reactor coolant to the air propulsion stream flowing through the turbojet engines has been analyzed in an effort to minimize air radiator welght and size. An analysis of the radiator volume, weight, and pressure drop was made for fixed conditions of power output, mass velocity per frontal area, and thermal conditions for a design in which plane-plate, finned radiators of stainless steel and nickel are used. In arriving at a solution, the heat transfer coeffi- cients for the radiator were deter- mined on the basis of laminar flow through flat ducts, since the Reynold’s number for flow through the radiation over the pertinent range of conditions was less than 2000, Multiple calcu- lations were made for a range of values of tube diameter, fin thickness, fin spacing, and tube pitch. On the basis of this evaluation, the optimum radiator design appears to be that with tube diameters between 1/8 and 1/4 in., 20 to 30 fins per inch, a fin thickness of 0.010 in., and a patch of three times the tube diameter. A review of the literature covering the thecoretical and experimental work (20)W. S. Farmer, Heat Generagtion in ¢ Slab for o Non«Uniform Source of Radiation, ORNL CF-52-9-202 (Sepr. 4, 1952). ' (21} . . . , W. 85, Farmer, Cooling Hole Distribution for Rz;tc)tor Reflectors, ORNL CF-52-9-201 (Sept. 3, 1952), : 181 ANP PROJECT QUARTERLY PROGRESS REPORT on air radiations and simulated flat- duct systems is being made. A solution is sought that will suitably correlate the nonisothermal heat transfer results of air radiator tests being conducted by the ANP Division, NATURAL CONVECTION IN CONFINED SPACES AND THERMAL LOOP SYSTEMS D. C, Hamilton F. E. Lynch L. D. Palmer Reactor Experimental Engineering Division Temperature profiles have been measured in the flatnflate natural- convection apparatus(??) over the practical range of variables attainable with the present equipment. The data will be presented in a forthcoming ORNL report and will be analyzed in relation to the theory previously developed. An example of a typical experimental temperature profile is given in Fig., 13.4. The annulus, natural-convection apparatus is ready to be operated, (22)0. C. Hamilton asd F, E. Lynch, ANP Quar. Prog. Rep. June 10, 1952, ORNL-129%4%, p. 158, UNCLASSIFIED DWG. 1743 1.0 -~ m—fl——u——w 0-8 _— - e . oo e —— CONDUCTION CURVE — —_ {NO CONVEfiHON) T 06 e e e — e — ,. *gi)fii . WITH CONVECTION~__ 0.4 TEMPERATURE FUNCTION, & Q.2 0 — e e LEFT CENTERILINE RIGHT walLL WALL Fig. 13. 4. Typical Temperature Pro- file with Natural Convection. 182 except for construction of the two thermocouple assemblies. After the flat-plate data have been analyzed, the annulus experiments will be stacrted. The test section shown in Fig., 13.5 was described in detail previously. (?3) The test section has been assembled and installed in a 20-in,-ID can, and the can will he sealed and maintained at a slight vacuum to prevent mercury vapor from leeking into the room during operation. In the pyrex model of a thermal harp, shown in Fig. 13.6, the tube has an inside diameter of 16 mm and the over-all height of the apparatus is 30 inches. The temperature differ- ential between the hot and cold legs is provided by running hot and cold water through the condenser tubes. The natural-convection velocity of the water in the inner tube is measured by observing the motion of small particles. The data now being obtained with this apparatus will provide a means of checking the validity of analytical methods of predicting harp velocities. TURBULENT CONVECTION IN ANNULIZ W, B. Harrison J. 0. Bradfute Reactor Experimental Engineering Division Relatively little satisfactory information on turbulent-flow, forced- convection, heat transfer in anrulus systems 1s available in the litera- ture. (2%) However, a significant number of momentum transfer studies have been reported, (257 and investi- gation has been initiated in an attempt to derive a heat-momentum transfer analogy for the annulus in muech the (23)p. C. Hamilton and F. E. Lynch, ANP Caar. Prog. Rep. Sept. 10, 1952, ORNL- 1375, p. 149. (24)H. C. Claiborne, A Review of the Literature on Heut Transfer in Annuli and Noncircular Ducts for Ordinary Fluids and Liquid Metals, ORNL CF-52-8-166, 25]H. C. Claiborne, Critical Review of the Literature on Pressure Drop in Noncircular Ducts and Annuli, OBNL-1248 {(May 6, 1952). PERIOD ENDING DECEMBER 10, 1952 ; UNCLASSIFIED 5 J DWG_ 17414 UPPER ELEGTRODE = CENTER THERMOGOUF’LE ASSEMBLY 77 ' = I!fi“‘% ——WALL THERMOCOUPLE ASSEMBLY Y (8%in. LONG) 5 II | i i i i B . i 3 i 4 K ; i ; 'l i il b i i f 2 ik - i N ] COOLANT QUT COOLANT QUT ——— TEST SECTION ASSEMBLY (%-in. 1.D., O187-in. WALL , 16 %g-in. LONG, INSIDE "SURFACE ELECTRICALLY INSULATED WITH ENAMEL) ~_ | ~~— COOLANT JACKET (1%g-in. 1.D., 0.125-in. WALL , 1535 -in. LONG) e b r i COOLANT N fFig. 13.5. Test Section Detail of Annulus Natural-Convection Apparatus. 183 ANP PROJECT QUARTERLY PROGRESS REPORT - UNCL ASSIFIED 5 e R = o ey S L TR hE SR P Pyrex Thermal Convection Loop. 13- 69 Fig. 184 same way as it has been done for the pipe system. The velocity profiles, as well as the eddy diffusivity profiles obtained from radial shear stress and velocity gradient data, are required in such an analysis. Thus, the first step in such a study must be the development of a generalized velocity profile for the annulus. Several possible ways of generalizing experimental annulus velocity data are currently being tried; the experi- mental data of Knudsen and Katz, (?%) Mikrjukov, (?27) and Rothfus, Monrad, and Senecal, (%) are being utilized in this study. : CIRCULATING-FUEL HEAT TRANSFER H. F. Poppendiek G. Winn Reactor Experimental Engineering Division Mathematical studies of circulating- fuel heat transfer in long pipes have (26)J. G. Knudsen and D. L. Katz, Proceedings of the Midwestern Conference on Fluid Dynamices, First Conference, Moy 12-13, 1950, p., 175. {27)V. Mikrjukov, J. Tech. Phys. (U.8.5.R.) 4, 961 (1937). S (2B)H. R. ‘Rothfus, C. C. Monrad, and B, E. Senecal, Ind. Eng. Chea. 42, 2511 (1950}, PERIODfENDING DECEMBER 10, 1952 been previously presented. (?2:30) 4 modest experimental study has been initiated in an attempt to compare the theoretical and experimental behavior of this volume heat source system. A sulfuric acid solution: is to be circulated in a closed loop by means of aglass pump. An a-c electric current is to be passed through the acid flowing in a long plastic pipe (1/4 in. in inside diameter and 2-ft long) located in the flow system. The current flow will yield a volume heat source within the acid. Acid flow rates, pipe wall temperatures, and mixed-mean acid temperatures into and out of the test section will be measured. Test section and heat exchanger heat balances will also be made. The temperature differences 1in this system will lie within the range necessary to yield only minor changes in electrical resistivity of the acid, so an almost uniform volume heat source exists in the system., It is proposed to study both laminar and turbulent flow regimes. (ZQ)H. F, Poppendiek and L. D. Palmer, Forced Convection Heat Transfer in o Pipe System with Volume Heat Sources Within. the Fluids, Y-F30-3 (Nov. 20, 1951}, (SO)H. F, Poppendiek and L. D. Palmer, Forced Convection Heat Transfer in Pipes with Volume Heat)Sources Within the Fluids, OBNL-1395 (Dec. 2, 1952). 185 ANP PROJECT QUARTERLY PROGRESS REPORT 14. D. S. Billington, RADIATION DAMAGE Solid State Division A, J. Miller, ANP Division Radiation-damage studies of ma- terials exposed in the ORNL graphite reactor, the LITR, and the 86-in. cyclotron have continued. A sample of a zirconium-bearing fused fluoride fuel has been irradiated with a high flux 1n the MTR, but examination of the irradiated capsule and its con- tents has, not yet been made. A sodium- filled loop was operated in the LITR at about 1200°F, but it was shut down after seven days because of a flow stoppage. Additional irradiations of fuel have been carried out in the LITR at ARE fission rates for extended periods of time. High power dissipations, in the range that would occur in an air- craft reactor, were achieved for long periods of time in fuels by using 22- Mev protons from the cyclotron, and there was some indication, but no positive evidence, of radiation damage or radiation-induced corrosion. In-reactor cantilever creep measure- ments on Inconel in an air atmosphere were continued in both the graphite reactor and the LITR. From these more recent measurements, 1t appears that the radiation has only a small effect on the creep strength. Examination of some of the older test rigs showed that the decrease in creep strength previously reported could possibly have been due todefective extensometer devices. Apparatus is being con- structed for creep measurements 7in the MTR. These radiation damage studies are described in the following. Additional information is contained in the Solid State Division Quarterly Progress Report for the Period Ending November 10, 1952. 186 TIRRADIATION OF FUSED MATERIALS G. W. Keilholtz D, F. Weeks J. G. Morgan M. T. Robinson H. E. Robertson D. D, Davies C. C. Webster A. Richt P. R, Klein W, J. Sturm M. J. Feldman Solid State Division R. J. Jones R. L. Knight Electromagnetic Research Division B, W. Kinyon OBNL Engineering Division The installation in the MTR of the testing facility for fused salts was completed, The guide tube extends from a 1 3/8-in, hole in a beryllium “A’ piece through a specially designed flange in the north-tank access hole. In the first run, a l-in. column of salt was contained in a 0,1-1in,-1ID Inconel capsule. The capsule tempera- ture was maintained at 1500°F by means of a controlled flow of cooling air. The flux at the capsule position was determined by means ofcobalt wire with the MTR operating at 19 and at 25 megawatts. The estimated thermal flux for the first capsule run at 30 mega- watts was 2,1 x 104, The capsule contained a fuel with the composition NaF-ZrF -UF, (50.0- 46.2-3.8 mole %). It was maintained at 1500°F for 116 hr at full flux, and there was an estimated power dissipation of 1900 watts/cm® in the fused salt, This approaches the power density expected 1in an aircraft reactor, Examinations of the irradiated capsule and the salt are now being made, In addition, two capsules containing the fuel have been irradiated in the LITR at 140 watts/cm® for 565 hr, and two more have been placed in the LITR for 1000-hr tests. Examinations of the irradiated materials are now being made. ‘ Preparations are nearing com- pletion for melting-point checks and fission-fragment-activity determi- nations on all specimens of reactor- irradiated fuel. Equipment has been constructed for rocking a capsule so that the fuel will cycle through a thermal gradient; this equipment will be used when a horizontal beam hole in the LITR is available for the experi- ments. : Inconel capsules containing fuels NaF-KF-Z¢F -UF, (4.8-50.1-41.3-3.8 moele %) and NaPV-ZrF, -UF, (46-50-4 mole %) were bombarded with 22-Mev protons from the 86-in. cyclotron. Power densities of several thousand watts per cubic centimeter of irradi- ated fuel were used for periods up to 92 hours, In evaluating the effects of theirradiation, only metallographic examinations of the Inconel could be considered reliable, since the irradi- ated volume of the capsule containing the fuel was large enough to cause a threefold dilution of dissolved Inconel components., For each experi- ment, listed in Table 14.1, there was PERIOD ENDING DECEMBER 10, 1952 a furnace-heated control that showed 0.5-m11 paits. Tt can be seen that there is some indication of attack on the Inconel at the higher power densities, : ' IN-REACTOR CIRCULATING LOOPS 0. Sisman R. M. Carroll W. W, Parkinson C. D. Bauman J. B. Trice C. Ellis A, S. Olson W, E. Brundage M. T. Morgan F. M. Blacksher Solid State Division An Inconel loop containing sodium was operated in the LITR at a tempera- ture in the region of 1200°F for seven days. The loop was shut down and re- moved because of a flow stoppage; the reason for the stoppage is now being determined. A prototype pump for use in an MTR fluoride loop 1s being constructed. Fabrication of other portions of the loop is being delayed until information about the MIR capsule tests i1s obtained and further evaluwation can be made of the experiment planned. | TABLE 14.1. CYCLOTRON IRRADIATIONS OF FUELS FUEL TRRADIATION POWER DISSIPATION INCONEL PITS ‘ " TIME (hr) (watts/cm®) (mil) NaF-KF-ZrF ,-UF, 3 2400 0.5 4.5 2300 0.5 7 4100 1.5 8 1150 0.5 NaF-ZrF,-UF, 5.6 2800 0.5 10.6 2200 0.5 14.3 2000 0.5 15. 4 2900 0.5 46. 4 3300 2.0 92 1700 0.5 187 ANP PROJECT QUARTERLY PROGRESS REPORT CREEP UNDER JTRRADIATION W, W, Davis J., C, Wilson J. C, Zukas Solid State Division Additional cantilever creep tests on Inconel with the standard ARE 2-hr, 1700°F anneal were carried out at 1500°F in air atmospheres in the graphite reactor and the LITR. As shown in Figs., 14.1 and 14.2, there are only small differences between the bench and in-reactor tests, The upward deflection after 400 hr in the curve for the 3000-psi test in the ORNL graphite reactor is probably due to faulty operation of the temperature controller. The results are to be checked by postirradiation measure- ments of the creep deflections on a remotely controlled profilometer. Postirradiation measurements were made on specimens annealed at 1650°F and irradiated in the graphite reactor at 1500°F., Their creep curves were shown in a previous report¢?!) as curve A, 1500 psi, and curve C, 2000 psa, The profilometer measurements indicated that the large extensions which were measured were in error and that the actual extensions were not much greater than those occurring in the bench tests. Several tests reported last quarter as being 1n progress were negated by faulty microformers, The design for the bellows-loaded tensile crecep test in the MIR is near- ing completion, and most of the com- ponents have been fabricated partly assembled for test. (l)J. C. Wilson, J. C, Zukas, and W, W, Davis, ANP Quar. Prog. Rep. June 10, 1952, ORNL-1294, p. 164, and SSD-A-499 DWG.1TO3T7A 006 |- A-—BENCH TEST O—HOLE HB-3 LITR. FAST FLUX, > 10'? 3 ® —HOLE 15 ORNL GRAPHITE REACTOR. FAST FLUX, 4 x10'° & ANNEALED 2hr AT 1700°F M&——A—’M & l... - B\ 0.02 Cr__{}fl——-—-Cf”ff"‘p==55£::‘;~—“JD 441’——““-4‘ 0 200 400 600 TIME (hr) Fig. 14.1. Cantilever Creep Tests om Inconel in Air at 1300°F and 1500 psi. 188 PERIOD ENDING DECEMBER 10, 1952 S 55 D-A-500 OWG. 170 38A 014 A\ —BENCH TEST _ / 042 |- O ——HOLE HB-3 LITR.FAST FLUX,>10'? ® —HOLE 15 ORNL GRAPHITE REACTOR. FAST FLUX, 4 x! O‘IO 0.10 ANNEALED 2hr AT 1700°F = _ &/AA 5(106 _ {r?QZ//”’ > ul : 7 0.04 e J‘% : & | 0.02 N e 0 . 200 400 600 TIME (hr) Fig. 14.2. Cantilever Creep Tests on Inconel in Air at 1500%‘ and 3000 psi. 189 ANP PROJECT QUARTERLY PROGRESS REPOCRT 15. ANALYTICAL STUDIES OF REACTOR MATERIALS C. D. Susano Analytical Chemistry Division C. R. Baldock Stable Isotope Research and Production Division J. M. Warde Metallurgy Division An empirical volumetric method for the determination of zirconium 1n reactor fuels has been developed. The method 1s based on the measurement of the basicity produced by the reaction between zirconium hydroxide and excess potassium fluoride. An 1indirect volumetric method for the determina- tion of zirconium, which depends on precipitating zirconium as the slightly soluble benzoate or m-nitrobenzoate and subsequently determining the organic acid by titration, proved unsatisfactory because of the variable composition of the precipitate. At- tempts to determine zirconium by titrating zirconium m-nitrobenzoate in nonaqueous media with perchloric acid were not successful. The use of mandelic acid as a precipitant for zirconium in the presence of a large excess of uranium was shown to be superior to phenylarsonic acid, m-nitrobenzoic acid, and cainnamic acid. The stability of the chromium complex with diphenylcarbazide was increased by development of the complex in 0.2 N perchloric acid. The separa- tion of traces of aluminum 1n reactor fuels by means of anionic-exchange resins was studied; preliminary results indicate that this technique is feasi- ble. A bibliography of recent litera- ture on bromine trifluoride as a reagent for the determination of oxygen in metallic oxides has been started. An improved apparatus for the determi- nation of trace amounts of water in solids was designed and fabricated for measuring the electrical conductivity of anhydrous hydrogen fluoride to determine 1ts water concentration. 190 In addition to the chemical analy- ses, various compounds of 1nterest were examined by spectrographic or petrographic techniques. The useful- ness of the spectrograph has been enhanced by the construction of a source that is good for temperatures approaching 2850°C. The petrographic studies have led to the classification of many complex compounds that are not found 1n the literature. The work of the ANP Analytical Laboratory service group consisted chiefly of analyses of beryllium- and zirconium-bearing fluoride mixtures. A review of the methods used and a summary of the services performed are included. CHEMICAL ANALYSIS OF REACTOR FUELS J. C. White J. E. Lee, Jr. C. M. Bovyd W. J. Boss C. K. Talbott Analytical Chemistry Division The research and developmental work on methods for the analysis of reactor fuels and their components has been of a diversified nature during thais quarter. The primary interest has been in the development of a volumetric method for the determination of zir- conium. Other problems that have been studied include: the colorimetric determination of chromium; the de- termination of oxygen 1n metallic oxides; the separation and determina- tion of traces of aluminum 1n reactor fuels; the determination of water 1in components of reactor fuels; the design of apparatus that will permit the measurement of the conductivity of liquid hydrofluoric acid so that 1its water content can be determined; the 1dentification of the products that are produced by the reaction of - NaK and components of the fuels; the adaptation of a method for the de- termination of Be0 in NaK; and the adaptation of a method for the de- termination of UOQ, in UF,. A discus- sion of these problems 1s included in the following paragraphs. Zirconium. An empirical volumetric method for the determination of zir- conium has been developed. The method 15 based on the measurement of the basicity produced by the reaction between zirconium hydroxide and excess potassium fluoride, which was discussed in a previous report.(!) TFree acid in the starting solution in excess of 0.5 N produced results approximately 2% high. This interference can be overcome by dilution; a practical limitation must be 1imposed, however, because of the difficulty encountered in determining the end point. The use of acid media other than sulfuric acid was also explored. Only perchlorate systems were definitely unsatisfactory because of excessive hydrolysis at high acidity. Another approach to the development of a volumetric method for zirconium was to precipitate the hydroxide from a mineral acid solution with excess ammonium hydroxide, centrifuge, wash, and dissolve in standard acid; the excess of standard acid was determined by titration. This method 1s satis- factory in an academic sense, but 1is hardly practical because of the copious washing required to free the hydrous oxide from basic salts and excess precipitant. j The guantitative precipitation of zirconium by benzoic acid and nitro- benzoic acids has been reported.¢2?:3) {1) R. Rowan, Jr., J. C. White, C. M. Boyd, W. J. Ross, and C, K. Talbott, ANP Quar. Prog. Rep. Sept. 10, 1952, ORNL-1375, p. 159. (E)C. Lakshman Rao, M. Venkataramaniah, and Bh. S5, V. RAaghava Rao, J. Sci, (India) 108, No. 7, 152-4 (1951}, M. Venkataramaniah and Bh. S. V. Raghava Rao, Z. anal. Chem. 133, 24B-31 (1651). Ind., Resecoarch PERTOD ENDING DECEMBER 10, 1952 The reported method was used as a basis for formulating a volumetric method in which the precipitate 1is dissolved in dilute acid, and the liberated organic acid 1is extracted with ethyl ether and determined by titration in methyl alcohol-benzene solution with sodium methylate by using thymol blue as the indicator. However, a precipitate of varying composition is formed, and attempts to establish an empirical relationship were unsuccessful. Further study of the reported gravimetric methods showed low results in all cases, the extent being de- pendent upon the mnature of the medium of precipitation. For example, 1in a sulfate system, no precipitate 18 formed with benzoic acid because of the strength of the zirconium sulfate complex in solutions that are more acid than pH 3 to 4. A slight pre- cipitate was noted when m-nitrobenzoic acid was used as the precipitant. Nitric or hydrochloric acid solutions are recommended for this procedure. An attempt was made to titrate zirconium m-nitrobenzoate with per- chloric acid in ethylene glycol~ isopropyl alcohol solutien. Zirconium 1s not sufficiently basic in this medium, however, to give a distinct break in the potentiometric titration made by using a glass electrode as the indicator electrode and a calomel electrode as the reference electrode. Since mandelic acid gives a pre- cipitate of definite composition with zirconium, this reagent will be studied for application to volumetric procedures. ' The effect of large excesses of uranium on the gravimetric determina- tion of zircomium was studied briefly in an attempt to select the precipitant least affected. Four reagents, phenyl- arsonic acid, mandelic acad, m-nitro- benzoic acid, and cinnamic acid, were tested on solutions of zirconium containing a fivefold excess of uranium. . The number of determinations 191 ANP PROJECT QUARTERLY PROGRESS REPORT made was i1nsufficient to permit a statistical study; however, the re- sults clearly 1i1ndicated that the mandelic acid method was superior 1in the presence of uranium. Phenylarsonic acid gave slightly high results; m-nitrobenzoic acid, slightly low results. Cipnamic acid 1s unsatis- factory for this purpose; the average of three determinations in the uranium- containing solution was 15% lower than the amount taken. chromium. The chromium-diphenyl- carbazide complex 1s usually developed in 0.2 N H,S0,, a medium said to produce maximum stability of the complex, Thirty minutes is considered the maximum period before serious fading occurs. The use of 0.2 N perchloric acid solution increases the period of color stability to nearly 60 min, regardless of the oxidant used. Acid concentrations greater than 0.2 N are harmful; for example, 0.6 N prevents color formation en- tirely. Aluminum. The determination of traces of aluminum can be accomplished by means of “aluminon’*) reagent; however, complete separation from a number of interfering cations 1is necessary. JIn order to apply this method to reactor fuels, aluminum must be separated from zirconium and 1iron. A chemical separation based om con- trolled-acidity precipitation with *“oxidine” was unsuccessful. Separation by 10on exchange 1s currently being studied. One procedure is to retain the zirconium and uranium as sulfate complexes on an anionic exchanger that passes aluminum. An alternate pro- cedure 1s to retain both aluminum and zirconium as fluoride complexes and separate them by elution, as reported by Freund and Miner. (%) Results on (¢)C. J. BRodden (Editor-in-Chief), Analytical Chemistry of the Manhattan Project, p. 387, McGraw-Hili, New York (1950). (S)H. Freund and F, J. Miner, Determination of Aluminum in Zirconium Utilizing Ton Exchange Separation, paper presented at Northwest Regional Meeting of American Chemical Society, June 20-21, 1952, Oregon State College, Corvallis, Oregon. 192 these tests are inconclusive, but promising. Oxygen. The preparation of a bibliography of recent literature on bromine trifluoride has been started in connection with the design and fabrication of experimental equipment for work with this reagent. Of special interest are the physical data, the inorganic oxide fluorimations, and the material corrosion information. Water. Developmental work on the me thod for determining traces of water in solids 1n a finely divided state was completed with the successful testing of an apparatus that has re- duced the blank {(that is, before addition of the samples) to approxi- mately 15 mg of water., This method has been reported in more detail 1in previous reports(?!? and a formal report will be i1ssued in the near future. The concentration of water 1in anhydrous hydrogen fluoride can be conveniently determined by measuring 1ts electrical conductivity. A pro- cedure(®’) has been developed and used for determining the water content of the HF used as a cover gas in fuel preparation. The two cylinders tested thus far showed 0.5 and 0.35 wt % water. DETERMINATION OF BERYLLIUM IN NaK J. C. White J. E. Lee, Jr. C. M. Bovyd W. J. Ross C. K. Talbott Analytical Chemistry Division A method for the determination of beryllium in NaK has been adapted for evaluating the compatibility of DBeQ, as a moderator, with NaK. Beryllium is determined, 1n both the soluble and insoluble phases following dis- solution of the NaK, by colorimetric measurement of the complex formed with p-nitrobenzenecazo-orcinal.(7) This (6) . . B (7f. A. Westbrook, private communication. C. J. BRoddes, op. cit., P. 354, method can be utilized to determine 0.2 ug per milliliter of solution. A method was developed for this dis- solution in which NaK was submerged in a high-boiling-point inert hydrocarbon (2,2,5-trimethylheptane) and reacted slowly by drop-wise addition of methyl alcohol. This procedure provides a rapid and safe method for dissolving alkali metal eutectics. SPECTROGRAPHIC ANALYSIS C. R. Baldock Stable Isotope Research and Production Davision For some time it has been recognized that an extremely high-temperature ion-source oven was needed for the investigation of such refractory materials as the oxides and other compounds of uranium. A direct-heating type of oven has been constructed that makes possible heating of materials to a temperature that approaches the melting point of tantalum (2850°C). The oven 1s small, contains no thermal insulating material, and 1s thereby free of the need for troublesome outgassing. The heater i1s mounted on a subassembly that i1is easily attached to and removed from the i1on source; thus, 1t 1s easy to change samples. Because of the favorable sample loca- tion, considerable improvement 1in the ion-generating efficiency has been ob- tained, compared with that of previous equipment. Quite satisfactory analy- ses can be performed with much less than 1 mg of sample. | Uranium Oxides. Three oxides of uranium, UO,, UOQ,, and U,0,, have been i1nvestigated 1in considerable detail. The presence of these materi- als as 1mpurities in aircraft fuels or in other uranium compounds can now be detected with high precision. : Nickel Fluoride. In an effort to explain the existence of some non- stoichiometric compounds of nickel and fluorine, several tests were made on NiF, material. The prepared NiF, was PERIOD ENDING DECEMBER 10, 1952 carried to charge exhaustion 1n an older socurce oven that reached a tem- perature of 750°C. The residue of this test was subsequently examined at 1100°C 1in the new type of oven heater, and i1t proved to be nickel oxide (NiO). Evidence from this subsequent test proved that above 1100°C the NiO dissociates by thermal decomposition to nickel and oxygen. It was of interest that the oxygen came off as O,. : : PETROGRAPHIC EXAMINATION OF FLUORIDES G, D. White, Metallurgy Division T. N. McVay, Consultant Routine petrographic examinations of some 600 samples of fluoride mix- tures were made in comnection with fuel investigations. The products of the ZrQ, -HF reaction and the NaF-ZrOF, reaction have been examined in some detail. | Zr0,-HF. A petrographic analysis was made of the products of the reac- tion between Zr(Q, and 48% HF, reacted at room temperature; two phases were observed. Chemical analysis gave compositions that were approximately those of hydrates of ZrF,. The first of these phases 1s uniaxial, which indicates that it is either tetragonal or hexagenal. The index of refraction parallel to the ¢ axis is 1.504, ‘and parallel to the other axes 1s 1.528. The second phase 1s biaxial negative, which indicates that it 1s either triclinic, monoclinic, or orthorhombic. The crystals are tabular and have a fibrous structure; cleavage is good. The birefringence is low; the maximum interference color 1s a first-order red. The refractive indexes range from 1.42 to 1.47 and thus indicate a variation in the water content of the material. ' : NaF-ZrOF,. Sodium fluoride was reacted with zirconium oxyfluoride which had been prepared in the labora- tory. Well-developed, but small, 193 ANP PROJECT QUARTERLY PROGRESS REPORT ZrO, crystals were formed, and there was some NazZrF, in the 2Na¥F.ZrOF, mixture. There was also a very small amount of another phase, probably NaF, that had a low index of refraction. These products would be expected to form if the following reaction took place: 2(2NaF'ZrOF2)"““"> NayZrF, + Zr0, + NaF. The ZrO, crystals, together with what is thought to be Na,ZrF,, were formed in the NaF-ZrOF, mixture. This would be expected from the following reaction: 2{NaF.ZrOF,) —> Na,ZrFg t Zr0, . OPTICAL PROPERTIES OF SOME FLUORIDE COMPOUNDS T. N. McVay Consultant, Metallurgy Division The compounds examined were pre- pared by V. Coleman of the Materials Chemistry Division. The x-ray pattern of the Na,UF, was analyzed by B. S. Borie, Jr., of the Metallurgy Division. Na ,UFg. The Na,UF, had the fol- lowing properties: hexagonal; uniaxial negative; color, green; O = 1,495 * 0.003; birefringence about (.005. K;UF,. The crystal system of K;UF, was not determined, but the material is orthorhombic, monoclinic, or tri- clinic, with the following properties: biaxial negative; 2V about 70 deg; color, light blue; refractive index of about 1.414, with low birefringence; pleochroic, Z = light blue, X = color- less, Na ,Zr¥,. The crystal system of Na,ZrF, was not determined, but the material 1s either tetragonal or hexagonal, with the following proper- ties: wniaxial negative; O = 1,386 0.003; colorless; birefringence low, not greater than 0.005. 2ZrF,-UF,;. The crystal system of 272rF,.UF,; was not determined, but the material 1s orthorhembic, monoclinic, or triclinic, with the following properties: biaxial; 2V about 90 deg; color, deep orange-red; refractive 194 index of about 1.576, fringence. with low bire- CHEMICAL ANALYSES FOR UG, IN UF, J. C. White J. E. Lee, Jr. C. M. Boyd W. J. Ross C. K. Talbott Analytical Chemistry Division The * ammonium oxalate insolubles” procedure(®? for the determination of U0, in UF, was applied successfully to the determination of UO, in UF,. The trifluoride is more resistant than the tetrafluoride to complexing with oxalate 1on and requires a reflux period of about 8 hr for a 1- to 2-g sample. It is postuvlated that the mechanism of the reaction involves the slow oxidatian of UF, to UF, and its subsequent complex formation with oxalate 1on. SERVICE CHEMICAL ANALYSES H. P. House I.. J. Brady J. R. Lund Analytical Chemistry Division In order to determine zirconium 1in the corrosion test samples to which titanium had been added either as the metal or the hydride, 1t was necessary to use mandelic acid as the precipi- tating agent, since titanium 1s pre- cipitated along with zirconium when phenylarsonic acid is employed. Recent spectrographic analysis of the zirconium oxide residues from ignition of the phenylarsonic acid precipitates has shown that varying amounts of arsenic remain with the zirconium. If conditions for complete volatilization of the arsenic durang ignition cannot be established, the mandelic acid method will be used to replace the present method for de- termining zirconiuim. In order to study the reactions that take place when NaK 1s introduced into molten zirconium fuel, a pro- cedure that i1ncluded measuring the hydrogen evolved during dissolution (E)Ibid. » P. 81, of the sample im acid was employed. It was hoped that this method would give an accurate measure of the UF, formed during the reaction with NaK. However, the results indicate that other compounds or possibly metals are formed that evolve hydrogen, since more hydrogen than can be attributed to the formation of UF, is often evolved. The isolation and subsequent determination of UF; in samples of this type have not been accomplished, and further work will be necessary to develop an adequate method. There was an increase 1n the number of samples of beryllium-sodium~uranium fluoride eutectic analyzed during this period. Requests for the estimation of the concentration of the major constituents of the eutectic made necessary the adaptation of methods for determining uranium and berylliium. Since the uranium concentration was relatively high (15 to 25%) and beryl- lium caused no interference, the use of the Jones reductor with a final oxidation titration with ceric sulfate proved adequate for determining this element. An estimate of the beryllium content was made by precipitating the uranium and beryllium together with ammonium hydroxide, igniting the pre- cipitates to the oxides, and subtract- ing the weight of the uranium oxide, as previously determined by titration, from the weight of the combined oxides. The weight of beryllium oxide is thus obtained by difference. A separation step, which includes re- duction of uranium with zinc amalgam and precipitation with cupferron, serves to remove the uranium prior to precipitation of the beryllium with ammonia; the ignited beryllium oxide is then free from contamination with uranium. This method of analysis has been employed recently for samples_of beryllium eutectic. One series of samples of lead was tested for minor impurities by apply- ing colorimetric methods after removal of the lead by electrolytic deposition. PERIOD ENDING DECEMBER 106, 1952 Samples of alkali hydroxides de- rived from corrosion tests were ana- lyzed for iron, chromium, and nickel. The range of comncentraticn of impuri- ties in these samples was great enough to require the use of colorimetric and gravimetric methods. Since the material was not homogeneous and could not be ground to fine particle size, the entire sample was dissolved to ensure that the aliquot tested was representative of the batch. A few purified alkali hydroxide samples were tested for carbonate impurity by reacting the carbon dioxide evolved with standard barium hydroxide solution. The excess barium hydroxide was then titrated with standard hydro- chloric acuid. A number of Sodlum samples was analyzed for the General Electric Company. Each sample was tested for sodium monoxide content, and selected samples of the series were analyzed for minor 1impurities. A greater diversity of miscellaneous samples was tested during the quarter, but further description of the samples or details of the methods will not be attempted in this report. Of the total of 905 samples ana- lyzed during the quarter, 617 were submitted by the Reactor Chemistry group, 167 by the ANP Experimental Engineering group, 68 by the ANP Critical Experiments group, 34 by the General Electric Company, 17 by the Flectromagnetic Research group, and 2 by the Ceramic laboratory. The backlog of samples was reduced during the period by approximately 50%, as indicated in the summary, Table 15.1. TABLE 15.1. BACKLOG SUMMARY Samples on hand, 8-10-52 211 Number of samples received 80 2 Total number of samples 1013 Number of samples reported 905 Backlog as of 11-10-52 108 195 SUMMARY AND The list of reports that has been issued by the Project during the last quarter includes 14 formal reports and 46 informal documents {(not including internal documents) on all phases of - ANP research at ORNL (sec. 16). A directoryof the research projects INTRODUCT ION of the ANP Division of ORNL 1is given in section 17. Also included are the Laboratory’s subcontracts to its ANP Project, as well as the research projects being performed by ORNL for the ANP programs of other organi- zations. | 16. LIST OF REPORTS ISSUED REPORT NO. TITLE OF REPORT AUTHOR(S) DATE ISSUED I. Experimental Epgineering and Design Y-F17-19 Performance and Endurance of a Nicrobrazed G. D. Whitman 8-11-52 Stainless Steel Sodium-To-Air Radiator Core Element ORNL.-1215 Heat Transfer and Pressure Loss in Tube G. H. Cohen 8-12-52 Bundles for High Performance Heat Exchengers A. P. Fraas and Fuel Elements M. E. LaVerne Y-F17-24 Model DA ARE Centrifugal Pump H. W. Savage 8-29-52 Y-F17-25 Dynamic Test of Compatibility of BeO with L. A. Mann 9.2-52 NaK Under Temperature Cycling Y-F15-11 Investigation of the Fluid Flow Pattern in a R. E. Ball 9-4-52 Model of the “Fireball” BReactor ORNL - 1287 Preliminary Investigation of a Circulating- R. W, Schroeder {(to be issued) Fuel Reactor System ' ORNL~ 1330 Heat Exchanger Design Charts A. P. Fraas (to be issued) Y-F17-28 Valve and Pump Packings for High Tempera- H. R. Johnson 9-15-52 ature Fluoride Mixtures CF.52-11-156 Report of ARE Design Review Committee T, E. Cole 11-19-52. Y-918 Potential Lubricants to Meet Extreme Temper- E. P. Carter - 16-29-52" ature, Pressure and Radiation Demands IY¥. BReactor Physics Y-F10-111 Some Solutions of Age Equatibn R. Osborn 11-17+52 Y-F10-112 The Temperature Dependence of a Cross Section R. Osborn 11.17-52 Exhibiting a Resonance ' : Y-B4-58 Literature Survey of Danger Coefficient Data E. P. Carter 7-11-52 _ I1I. Shielding CF-52-5-1 Neutron and Gamma Dose Distribution Beyond C. E. Clifford 8-14-52 Part 2 Shield, Parc 2 ' CF-52-T-71 Gamma Ray Spectral Measurements with the F. €. Maienschein 8-8-52 Divided Shield Mockup, Part 11 CF-52-7-83 Gamma Measurements on the GE Reactor Ducts C. E, Clifford 8§~16-52 C. L. Storrs, Jr. : 199 ANP PROJECT QUARTERLY PROGRESS REPORT CF-52-8-120 Y-F30-8 CF-52-9-99 CF-52-9-145 CF-52-9-161 CF-52-11-143 ORNL-1217 ORNL- 1438 CF-52-8-38 CF-52-10-9 CF-52-11-124 Y-889 CF-52-8-163 CF-52-8-212 CF-52-9-201 CF-52-9-202 CF-52-11-72 CF-52-11-103 CF-52~11-104 CF-52-11-105 CF-52-11-106 CF-52-11-113 ORNL-1342 ORNL.-1395 200 Aircraft Shield Analysis Radiation Through the Control Rod Pene- trations of the ABE Shield Neutron to Gamma Ray Ratio Experiments Biological Experimentation in Support of ANP Project The Development of Lead-Impregnated Moulding and Modeling Materials for Shielding of Penetrating Radiations Basic Shielding Research Neutron Transmission Through Air Filled Ducts Determination of the Power of the Bulk Shielding Reactor, Gamma-Ray Spectral Measurements with the Divided Shield Mockup, Part ITI1 Summary of Lid Tank Neutron Dosimeter Measurements in Pure Water Gamma Ray Spectral Measurements with the Divided Shield Mockup, Part IV > .. Wilson L. Walker fi. L. F, Enlund J. L. Meem J. Furth E. P. Blizard E. P. Blizard . E. Clifford Johnson . Meem & . Maienschein V. Blosser s IV. Heat Transfer and Physical Properties Research Selected Physical Properties of Mercury in the Temperature Range 100 to 1000°C. A Literature Search Measurement of the Thermal Conductivity of Flinak Physical Property Charts for Some Reactor Fuels, Coolants, and Miscellaneous Materials Cooling Hole Distribution for Reactor Reflectors HHeat Generation in a Slab for a Non-Uniform Scurce of Radiation Measurement cf the Thermal Conductivity of Fluoride Mixture No. 33 Heat Capacity of Fused Salt Mixture No. 21 Heat Capacity of LiOH Density Measurements of Fuel Salts No. 31 an Viscosity Measurements of Fuel Salts No. 31 and 33 Transient Methods for Determining Thermal Conductivity of Liquids Enthalpies and Heat Capacities of Stainless Steel (316) and Zirconium Forced Convection Heat Transfer in Pipes with Volume Heat Sources F. L. S. Sachs Cooper J. Caliborne ANP Physical Properties Group, BEEDivision W, W, i = 0P A7 F = S. Farmer S. Farmer Gy Claiborne Powers Powers Redmond Jones Redmond Jones W Zm =2W T O Harrison F. Redmond Lones . Maienschein 8-20-52 9-.25-52 9-18-52 9-24-52 9-26-52 11-19-52 11-11-52 (to be issued) 8-8-52 10-1-52 11-17-52 T-10-52 8-26-52 8-28-52 9-3-52 9-4-52 11-11-52 11-15-52 11-15-52 11-15-52 11-15-52 11-1-52 {to be issued) F. Poppendiek (to be issued) D. Palmer CF-52-11-85 ORNL-1433 ORNL-1372 CF-52-10-187 MM-19¢ 1) CF-52-8-151 CF-52-9-5 CF-52-9-59 CF-52.9-125 CF-52-11-7 CF-52-11-12 CF-52-11-13 CF-52-11-116 CF-52-11-146 ORNL-1354 Y-F33-3 MM-48¢ 1) Y-F26-44 ORNL-1375 ORNL- 1407 PERIOD V. Radiation Damage Effect of Irradiation on BeQO Preliminary Title List for Blbllography on Hadiation Effects in Solid Materials Neutron Spectra from Fluoral Activation Xenon Problem - ARE VI. Metallurgy and Ceramics Metallographlc Examination of Nicrobrazed Stainless Steel Sodium-Air (No. 2) Heat Exchanger Fpllow1ng Failure During Test Unusual Diffusion and Corrosion Phenomena Observed in Liquid Metal and Molten Caustic Corrosion Tests Memorandum on Reflector-Moderator Matrix Subsurface Void Formation in Metals During High Temperature Corrosion Tests Cermet Program Fabrication of Spherical Particles Structure of Norton’s Hot Pressed Beryllium Oxide Blocks : Fuel Element Program Mass Transfer in Dynamic Lead-Inconel Systems Structure of the BeO Block w1th the 1-1/8 1n. Central Hole A Compilation of Data on Crucibles Used in Calcining, Sintering, etc. VI1I. Miscellaneous The Solid Phases of Alkali and Uranium Fluoride Systems Meteorology and Cllmabology in the 7500 Area ANP Information Meeting of November 25, 1952 : Aircraft Nuclear Propulsion Project Quarterly Progress Eort for Period Ending September 10, Aircraft Reactor Experiment anards Summary Report (I)Nu-her assigned by ANP Réporta Dffice. ENDING DECEMBER 10, G. W. Keilholtz R. . Cleland J. B, Trice W, A, Brooksfiank E. E. Hoffman A. deS. Brasunas J. B. Johnson G. D. White A. deS. Brasunas J. R. Johnson . S. Bomar . Inouye v 13 L. M. Doney J. M. Warde J. V. Cathcart L. M. Doney M., Schwartz A. G. H. Anderson U. 8. Weathef Bureau W. B. Cottrell ¥. B. Cottreil J. H. Buck W, B. Cottrell 1952 11-13-52 11-14-52 {to be issusd) 10-22-52 8-18-52 8-29-59 9-2-52 9-5-52 9-23-52 11-1-52 11-1-52 11-3-52 11-24-52 11-17-52 (to be issued) 10-1-52 10-52 11-15-52 11-5-52 11-24-52 201 ANP PROJECT QUARTERLY PROGRESS REPORT I' A, 202 17. REACTOR AND COMPONENT DESIGN Aircraft Reactor Design 1. Do W B Reflector-Moderated Reactor Studies Fluid-Fuel Flow Studies Gamma Heating of the Moderator Nuclear Ramjet Design Studies Design Consultants ARE Reactor Design . SO 1 O .Core and Pressure Shell Fluid Circuit Design Pressure and Flow Instrumentation Structural Analysis Thermodynamic and Hydrodynamic Analysis Remote-Handling Fquipment Shielding and Off-Gas System Electrical Power Circuits ARE Control Studies 1. 2. 3. High-Temperature Fission Chamber Control System Design Control Studies on Simulator ARE Building Facility 1. Internal Design ARE Installation and Operation 1. 2. 3. 4. Instrumentation Coordination Installation and Design Expeditors Control Equipment Reactor Physics 1. 2. 3. 4. 5. Analysis of Critical Experiments Fermi-Age and Boltzmann Equation on Computing Machines Kinetics of Circulating-Fuel Reactors Computation Techniques for ARE-Type Reactors Computation Techniques for Reflector-Moderated Reactors Critical Experiments 1. 2. ABE Critical Assembly Reflector-Moderated Beactor Critical Assembly 9704-1 9704-1 9704-1 9704-1 9704-1 9201-3 62061-3 9201-3 9201-3 9201-3 9204-1 9201-3 9201-3 1000 4500 4500 4500 1000 7503 7503 7503 7503 9704-1 2068 9704-1 9704-1 9704-1 9213 9213 DIRECTORY OF ACTIVE ANP RESEARCH PROJECTS AT ORNL Fraas, lLaVerne Bussard Abernathy Fox, Longyear Fraas, Stumpf Wislicenus, JHU Haines, Wyld, BMI Chambers, Hemphill Cristy, Jackson, Fckerd, Scott Hluchan, Affel, Williams Maxwell, Walker Lubarsky, Green- street Hutto Enlund Walker Hanauer Epler, Bates, Ruble, reen, Mann Stone, Oakes, Mann Browning Hluchan, Affel Wischhusen, Watts Perrin, West Mann Mills Edmouson, Coveyou Prohammer, Frgen Bengston Frgen Callihan, Zimmerman, Williams, Scott, Keen (Same as above) i. IX. A, PERIOD ENDING DECEMBER 10, 1952 Seal and Pump Development 1. Mechanical Pumps for High-Temperature Fluids 2. High-Temperature Seals for Rotary” Shafts 3. Rocking-Channel Sealless Pump 4. Seals for NaOH Systems Valve Development 1. Valves for High-Temperature Fluid Systems Heat Exchanger and Radiator Development 1. High-Temperature Fluid-to-Air Heat Exchange Test : : 2. Fluoride-to-Liquid Metal Heat Exchange Test 3. Heat Exchanger Fabrication 4. Boeing Turbojet with Na Radiator’ 5. Radiator and Heat Exchanger Design Studies Instrumentation 1. Pressure-Measuring Devices for High-Temperature Fluid Systems ' : 2. Flow-Measuring Devices for High-Temperature Fluid Systems 3., Liquid-Level Indicator and Control for High- Temperature Fluids High-Temperature Strain Gage 5. High-Temperature Calibration Gage SHIELDING RESEARCH Cross-Section Measurements 1. Neutron Velocity Selector 2. Analysis for He in Irradiated Be 3. Total Cross Sections of N** and 0'® (GE) 4. Elastic-Scattering Differential Cross Section of N'* and 016 (GE) 5. Total Cross Sections of Li%, Li7, Be®, B!?, Bl2’ C12 . 6. Fission Cross Sections 7. Cross Sections of Be, C, W, Cu 8. Inelastic-Scattering Energy Levels 9. FEffective Removal Cross Sections Shielding Measurements 1. Divided-Shield Mockup Tests (GE) 9201-3 9201-3 BMI - BMI - 9201-3 9201-3 £ 9201-3 9201-3 - %201-3 9201-3 9201-3 9201-3 9201-3 BLH Cornell ~Aero. Lab. 4500 3005 3026 5500 3500 3500 5500 3001 5500 3001 3010 McDonald, Cobb, Whitman, Huntley, Grindell McDonald, Tunnel, Ward, Smith, Msason Dayton Simmons, Allen Tunnell, Ward, MeDonald Whitman, -Fraas, Salmon, LLaVerne Salmon, Fraas, ‘Longyear Fraas Fraas, Crocker (GE), Potter (GE) ‘ Fraas, Bailey, (Tulane Univ.) Peterson, Southern, Taylor Engberg McDonald, Smith Taylor, Southern Trumme 1 Southern Pawlicki, Smith, ‘Thur low Parker Willard, Bair, Johnson Johnson, Bair, Willard, Fowler Johnson, Willard, Bair : Lawphere, Willard Clifford, Flynn, Blosser Willard, Bair, Kington Blizard, Flynn, and crew Meem and crew 203 ANP II1. 204 PROJECT QUARTERLY PROGRESS REPORT Bulk Shielding Reactor Power Calibration Bulk Shielding Reactor Operation Heat Belease per Fission Air Duct Tests - Large Mockups (GE) Thermal Shield Measurements (DuPont) Streaming of Neutrons Through Metals Air-Scattering Experiments O @~ O LN b N Primate Exposures to Radiation (School Aviation Medicine, ORNL, Wright Field, Convair) Shielding Theory and Caleculations 1. Survey BReport on Shielding 2. Shielding Section for Reactor Technology 3. Correlation of Bulk Shielding Facility and Lid Tank Data 4, Calculations on Air-Scattering Experiments in Bulk Shielding Facility 5. Divided-Shield Theory and Design Air Duct Theory (GE) 7. Shielding Section for Reactor Handbook 8. Consultation on Radiation Hazards (GE) 9. Shielding Consultant Shielding Instruments Gamma Scintillation Spectrometer Neutron Dosimeter Development Proton Recoil Spectrometer for Neutrons He? Counter for Neutrons LiT Crystals for Neutrons NN s WO RO Neutron Spectroscopy with Photographic Plates MATERIALS RESEARCH Ligquid Fuel Chemistry 1. Phase Equilibrium Studies of Fluorides 2. Preparation of Standard Fuel Samples 3. Special Methods of Fuel Purification 4. Complex Fluorides of Structural Metals 5. Thermodynamic Stability and Electrochemical Properties of Fuel Mixtures 6. Hydrolysis and Oxidation of Fuel Mixtures 7. Stability of Slurries of UO3; in NaOH 8. Phase Fquilibria Among Silicates, Borates, etc. 9, Fuel Mixtures Containing Hydrides 10. Chemical Literature Searches 11. Solution of Metals in Their Halides 3010 3010 3010 3001 3001 3001 3010 3010 4500 4500 4500 4500 NDA 3001 4500 2001 Cornell Univ. 3010 3016 3010 3010 3010 3006 9733-3 9733-3 9733-3 9733-3 9733-3 9733-3 BMI MHI 9704-1 4500 Johnson, McCammon Leslie Meem Flynn and crew Flynn and crew Flynn and crew Hungerford, Blizard Meem and Crew Blizard Blizard Blizard Blizard, Simon, Charpie Goldstein Simon, Clifford Blizard, Hungerford, Simon, Ritchie, Meen, Lansing, Cochran, Maienschein, Burnette Morgan Bethe Maienschein Blosser, Hurst, Glass Cochran, Henry Cochran Maienschein, Schenck Johnson, Haydon Barton, Bratcher, Traber, Snell Nessle, Forgan Grimes, Blankenship, Nessle, Blood Overholser, Sturm Overholser, Topol Blankenship, Metcalf Patterson Crooks Banus Lee Bredig, Johnson, Bronstein 12. 13. 14. 15. 16. 17. 18. 19. PERIOD Preparation and Properties of Complex luorides of Structural Elements Reactions of Fluorides and Metal Oxides Prgparation, Phase Behavior, and Reaction of U 3 : Preparation of Specimens for Radiation Damage Phase Behavior of Fuels with Added Reducing Agents NaK-Fuel Reaction Tests Free Energy of Fluorides _ Ligquid Fuel Chemistry Consultants B. Liguid-Moderator Chemistry Preparatton and Evalwation of Pure Hydroxides Electrochemical Behavior of Metal Oxides in Molten Hydroxides Moderator Systems Containing Hydrides Hydroxide-Metal Systems C. Corrosion by Ligquid Metals 9. 10. 11. 12. 13, Static Corrosion Tests in Liquid Metals and their Alloys Dynamic Corrosion Research in Convection Loops Effect of Crystal Orientation on Corrosion Effect of Carbides on Liquid Metal Corrosion Mass Transfer in Molten Metals Diffusion of Molten Media into Soiid Metals Structure of Liquid Pb and Bi Alloys, Mixtures, and Combustion of Liquid Sodium Protective Coating§ for Corrosion Resistance Mass Transfer and Corrosion Inhibitor Studies Handling of Liquid Metal Samples Compatibility of BeO and NaK Compatibility of Materials at High Temperatures D. Corrosion by Fluorides 1. 2, Static Corrosion of Metals and Alleys in Fluoride Salts Static Corrosion Tests in Fluoride Salts Fluoride Corrosion in Small-Scale Dynamic Systems Dynamic Corrosion Tests of Fluoride Salts Reactioq of Metals with Fluorides and Contaminants E%uilibr@a Between Electropositive and ransition Metals in Halide Melts: Corrosion by Fluorides in Stand Pipes ENDING DECEMBEB 10, 1952 9733-3 9733-3 9733-3 8733-2 9733-2 9201-3 $9201-3 9733-3 1 9733-2 4500 2000 9201-3 2000 2000 2000 9201-3 2000 2000 2000 2000 9201-3 9201-3 9201-3 2000 2000 9766 9766 2000 6201-3 9733-3 3550 9766 Overholser, Sturm Blankenship, Heoffman Coleman, Hoffman, Kelly, Barton Boody | Overholser, Redman, Blankenship, Hoffman, Kelly : Mann, Cisar Mann, Petersen Gibb, Tufts College Hill, Duke Univ. Weekes, Texas ASM Carter Overholser, Ketchen Bolomey, Cuneo Banus Bredig, Johnson, Bronstein Vreeland, Hoffwman Adamson Smith, Cathcart, Bridges Vreeland, Hof fman Cathcart, Adamson Smith, Cathcart Smi th Smith, Hall Vreeland Adamson Ke tchen Mann, Cisar Bomar, Vreeland Vreeland, Day, Hof fman Kertesz, Buttram Smith, Meadows, Croft Kertesz, Buttram, Croft, Smith, Meadows, Vreeland, Nicholson, Hoffman, Trotter Adamson, Beber Overholser, Redman, Powers, Sturm Bredig, Johnson, Bronstein Kevrtegz, Buttram, Croft 205 ANP PROJECT QUARTERLY PROGRESS REPORT G. 206 Corrosion by Hydroxides 1. 2, 3. 4, 5. Static Corrosion of Metals and Alloys in Hydroxides Mass Transfer in Mclten Hydroxides Physical Chemistry of the Hydroxide Corrosion Phenomenon Static and Dynamic Corrosion by Hydroxides Static Corrosion by Hydroxides Physical Properties of Materials e W B2 W oo~ 3 oLn e e x e s Density of Liquids Viscosity of Liquids Thermal Conductivity of Seolids Thermal Conductivity of Liguids Specific Heat of Solids and Liquids Viscosity of Fluoride Fuel Mixtures Vapor Pressure of Fluoride Fuels Vapor Pressure of BeF, Density of BeO Blocks Evaluation of Materials for High Thermal Conductivity Suitable for Radiator Fin Heat Transfer 1. 6. Heat Transfer Coefficients of Fluoride and Hydroxide Systems Heat and Momentum Transfer in Convection Loop Free Convection in Liquid Fuel Elements Heat Transfer in Circulating-Fuel Systems Forced Convection in Annuli Radiator Analysis Fluoride Handling 5. 6. Fuel Production Design of Special Fluoride Handling Equipment Small-Scale Handling of High-Temperature Liquids Preparation (Experimental) of NaZrF Preparation of Enriched Fuel for Radiation Studies Fluoride Sampling Techniques Liguid Metal Handling 1. 2. 3. Sampling Techniques NaK Distillation Fquipment NaK Handling Dynamic Liguid Loops 1, 2. Operation of Convection Loops Operation of Figure-Eight Loops 2000 2000 2000 9766 BM1 9204-1 9201-4 8204-1 9204-1 9201-4 9766 9733-2 BMI 9766 2000 5204-1 9204-1 9204-1 9204-1 920]1-4 9204-1 9201-3 9733-3 9733-2 9733-2 9733-3 9201-3 9201-3 9201-3 9201-3 9201-3 9201-3 Vreeland, Day, Hof fman Vreeland, Smith, Cathcart Cathcart, Smith Kertesz, Croft, Buttram, Smith Jaffee, Craighead Jones, Redmond Jones, Redmond Powers, Burnett Claiborne, Powers, Burnett Powers, Blalock Kertesz, Knox Barton, Moore Patterson, Clegg Doney Bomar, Slaughter, Oliver Hoffman, lLones Hamilton, Palwmer, Lynch, Poppendiek Hamilton, Lyrnch Poppendiek, Winn, Palmer Bradfute, Harrison, Poppendiek Farmer Nessle, Eorgan Grimes, Blankenship, Nessle Blood, Thoma, Weinberger Blankenship and crew Baody, Blankenship Mann, Blakely Mann, Blakely Mann, Cisar Mann Adamsan Coughlen 3. 4, 5. PERIOD ENDING DECEMBER 10, UOQ,«NaOH Slurry Loop Operation of Thermal Convection Loops Fluid Circuit Mockups K. Materials Analysis and'lnspection Me thods 1. N O o =1 . e 10. 11. 12, 13. 14, 15. 16. 17. 18. 19. Determlnatlon of Metalliec Corroqlon Products in Proposed Reactor Fuels Analysis of Beactor Fuels Determination of Reduced Species in Reactor Fuels Following Reaction with NaK Determination of Oxides in Reactor Fuels Determination of Water in Hydrogen Fluoride Determination of Efficiency of Removal of NaK by Distillation from ARE High-Temperature Mass Spectrometry X-Ray Study of Complex Fluorides Petrographic Examination of Fuels Chemical Methods of Fluid Handling Metallographic Examination Identification of Compounds in Solidified Fuels Preparation of Tested Specimens for Examination Tdentification of Corrosion Products from Dynamlc Loops Assembly and Interpretation of Corrosion Data from Dynamic Loop Tests Determination of Combined Oxygen in Fluoride Mixtures Metallurgical anmlnab1on of Englneerlng Parts Analyses of Na and NaK for Na,0 Ydentification of Corrosion Products L. Radiation Damage 1. Liquid Compound Irradiation in LITR Liguid Compound Irradiations in Cyclotron Liquid Compound Irradiations 1in MTR Ligquid Metal Corrosion in ORNL Graphite Reactor loops Stress Corrosion and Creep in LITR Liquid Metal Loops Creep of Metals in OBNL Graphite Reactor and LITR Thermal! Conductivity of Metals in ORNL Graphite Reactor and LITR Neutron Spectrum of LITR Radiation~-Damage Consultants BMIY 2000 9201-3 9733-4 9733-4 9733-4 9733-4 9733-4 9201-3 9735 3550 9766 9201-3 2000 9733-2 9733-2 9733.3 2000 9733-3 9201-3 9201-3 9201-3 2000 3005 9201-3 NRTS 3001 3005 3001 3025 3001 3005 3005 1952 Simons Cathcart, Bridges, Smith Mann White, Talbott White, Ross White, Talbott White, Lee Whive, Talbott White, lLee Baldock Agron McVay, White Mann, Blakely Gray, Krouse, Roeche Barton, Hoffman Kelly Meadows, Didlake Hof fman, Blankenship, Smith, Borie, Dyer Adamson, Blankenship, Smith, Vreeland, Blakely Vhite, Lee Adamson, Vreeland, Gray , Mann Dyer, Borie Keilholtz, Morgans Webster, Kinyon, Davies, Feldman, Bobinseon : Sturm, Jones, Binder Keilholtz, ¥lein, Morgan, Bacht, Robertson Sisman, Bauman, Carroll, Brundage, Blacksher, Parkinson, Ellis, Dlsen, James, Mor gan Sisman, etc., (as above) Wilson, Zukas, Davis Cohen, Templeton Sisman, Trice Ruark, JHU, Smith, Cornell Univ. 207 ANP PROJECT QUARTERLY PROGRESS REPORT 208 Strength of Materials 1, 2, 3. Creep Tests in Fluoride Fuels Creep and Stress-Rupture Tests of Metals in Vacuum and in Fluid Media High-Temperature Cyclic Tensile Tests Tube Burst Tests Tube Burst Tests Relaxation Tests of Reactor Materials Creep Tests of Reactor Materials (GF) Fvaluation Testing for Other Development Groups Designing and Evaluating New Testing Methods Fatigue Testing of Reactor Materials Metals Fabrication Methods SY O B WM -3 10. 11. 12, 13. 14. 15. New 1. 2. 3. Welding Techniques for ARE Parts Brazing Techniques for ARE Parts Mol ybdenum Welding Research Molybdenum Welding Besearch Resistance Welding for Mo and Clad Metals Welds in the Presence of Various Corrosion Media Nondestructive Testing of Tube-to-Header Welds Basic Evaluation of Weld-Metal Deposits in Thick Plates Evaluation of the Cone-Arc Welding Technique Development of High-Temperature Brazing Alloys Evaluation of the High-Temperature Brazing Alloys Brazing of Testing Components for Evaluatioen Application of Resistance-Welding Methods to ANP Materials Welding Comsultant Fabrication Procedures for Nickel and Its Alloys Metals Development Me and Cb Alloy Studies Heat Treatment of Metals Alloy Development of New Container Materials Solid Fuel Element Fabrication 1. 2. 3. Solid Fuel Element Fabrication Diffusion-Corrosion in Solid Fuel Flements Determination of the Engineering Properties of Solid Fuel Elements Electroforming Fuel-Tube-to-Header Configurations Electroplating Mo and Cb Carbonyl Plating of Mo and Cb 9201-3 2000 2000 9201-3 2000 2000 2000 2000 2000 2000 2000 2000 BMI MIT RPI 2000 2000 2000 20600 Wall- Colmonoy 2000 2000 2000 International 2000 2000 2000 2000 2000 2000 Gerity Mich. Gerity Mich. 2000 Adamson Oliver, Douglas, Weaver Oliver, Woods Adamson Oliver, Woods, Weaver Oliver, Woods, Weaver Olivexr, Woods, Weaver Oliver, Woods, Reber Oliver, Beber Oliver, Reber Slaughter Housley, Slaughter Parke Wulff Nippes, Savage Vreeland, Slaughter Slaughter Slaughter, Gray Slaughter Peaslee Slaughter Slaughter, Petersen, Fraas Slaughter Patriarca Nickel Company Incuye Coobs Bomar, Inouye Bomar, Coobs Bomar, Coobs Bomar, Coobs, Woods, Oliver, Douglas Graaf Graaf Bomar PERIOD ENDING DECEMBER 10, 1952 7. Fuel Spherical Particle Production {P&W) 8. 1Inspection Methods for Fuel Elements 2600 Bomar, Levy 9. Carbonyl Plating Commonwealth Eng. Corp. 1¢. Production of High-Temperature Screens Gfigifiy Graaf - ich. Q. Ceramics and Metals Ceramics 1. Metal Cladding for BeO Gerity Graaf ‘Mich, 2. Control Rod Development 2000 Bomar, Coobs 3. Hot Pressing of Be#ring Materials 2000 Bomar, Coobs 4., High-Temperature Firing of Uranium Oxide to Produce Selective Powder Sizes 2000 Bomar, Coobs 5. Development of Cermets for Reactor Components 9766 J%hnfon, Shevlin, : _ aylor 6, Ceramic Coatings for ANP Radiator: 9766 White, Griffin 7. Ceramic Valve Parts for Liguid Metals and oSy Shevlin, Johnson, Fluorides Taylor 8. Production of Control Rod Samples :(GE) for ~ : Testing 2000 Bomar, Coobs 9. Ceramic Reflector 9766 Johnson, White 10, Ceramic Coatings for Shielding 9766 Yhite, Shevlin OSU 11. High-Temperature Ceramic Coatings H?tpoint, : - Inc. 1Vv. TECHNICAL ADMINISTRATION OF AIRCRAFT NUCLEAR PROPULSION PROJECTY AT OAK RIDGE PROJECT DIRECTOR * Dual Capacity. NATIONAL LABORATORY R. C. Briant* ASSOCIATE DIRECTOR FOR ARE J. H. Buck* ASSISTANT DIRECTOR FOR COORDINATION A. J. Miller* Administrative Assistant L. M. Cook Project Editor W. B. Cottrell PROJECT DIRECTORY SECTION - NUMBER STAFF ASSISTANT FOR PHYSICS W. K. Ergen* Shielding Research E. P. Blizard 11 AB,C,D Reactor Physics W. K. Ergen* 1 E Critical Experiments A. D. Callihan I G Nuclear Measurements A. H. Snell I1 A STAFF ASSISTANT FOR RADIATION DAMAGE A. J. Miller* Radiation Damage D. §. Billington I11 L STAFF ASSISTANT FOR GENEBAL DESIGN A. P. Fraas* General Design A. P. Fraas* I A STAFF ASSISTANT FOR ARE J. H. Buck* ABE Operations E. S. Bettis 1 C,D,E ARE Design R. W. Schroeder 1 B,D Experimental Engineering. H. W. Savage I §r§,}.§: IfI C,D, 209 STAFF ASSISTANT FOR ENGINEERING RESEARCH Heat Transfer and Physical Properties Ceramics STAFF ASSISTANT FOR METALLURGY Metallurgy STAFF ASSISTANT FOR CHEMISTRY Chemistry Chemical Analyses *Dual Capacity. 210 n== == - o®® ST Em oD Briant* Poppendick Warde Manly* Manly* Grimes* Grimes* Susano I11 111 11 III III F,G c,D,E,J,K,M,N,0,P,Q AB,D,E,F . HK K *i