operated by UNION CARBIDE CORPORATION for the U.S. ATOMIC ENERGY COMMISSION DESIGN AND OPERATION OF FORCED~-CIRCULATION CORROSION TESTING LOOPS WITH MOLTEN SALT J. L. Crowley W. B. McDonald D. L. Clark DA | Facsimile Price 3 Microfilm Price $ Available from the . Office of Technical Services Department of Commerce Washington 25, D- C. NOTICE This document contains information of a preliminary nature and was prepared primarily for internal use at the Ook Ridge National Laboratory. It is subject to revision or correction and therefore does not represent a final report., The information is not to be abstracted, reprinted or otherwise given public dis- semination without the approval of the ORNL patent branch, Legal and Infor- mation Control Department. OAK RIDGE NATIONAL LABORATORY UNION CARBIDE ORNL- TM- 528 ws\”%_% he LEGAL NOTICE This report was prepared as an account of Government sponsored work. Neither the United Stotes, nor the Commission, nor any person acting on bahalf of the Commission: A. Makes any warranty or representation, expressed or implied, with respect to the accuracy, completeness, or usefulness of the information contained in this report, ot that the use of any information, apparatus, method, or process disclosed in this report may not infringe privately owned rights; or B. Assumes any liabilities with respact to the use of, or for damages resulting from the use of any information, apparatus, method, or process disclosed in this report. As used in the cbove, ‘‘person acting on behalf of the Commission’ includes any employee or confractor of the Commission, or employee of such centractor, to the extent that such employee or contractor of the Commission, or employee of such contractor prepares, disseminates, or provides access to, any information pursuont to his employment or contract with the Commission, or his employment with such contractor, ORNL-TM-528 Contract No. W-7405-eng-26 Reactor Division DESIGN AND OPERATION OF FORCED-CIRCULATION CORROSION TESTING LOOPS WITH MOLTEN SALT J. L. Crowley W. B. McDonald D. L. Clark Date Issued MAY -1 1963 OAK RIDGE NATTONAL LABORATORY Oak Ridge, Tennessee operated by UNION CARBIDE CCORPORATION for the U.5. ATOMIC ENERGY COMMISSION iii CONTENTS Abstract Introduction Description of Test Loop and Auxiliary Equipment Alarm and Automatic-Action Controls Operation and Maintenance of a Test Loop Summary Acknowledgments 15 17 21 21 DESIGN AND OPERATION OF FORCED-CIRCULATION CORROSION TESTING LOCPS WITH MOLTEN SALT J. L. Crowley W. B. McDonald D. L. Clark Abstract Standardized test facilities were developed and oper- ated for investigating the compatibility of structural materials and flowing molten fluoride salts. The standard loop accommodates various combinations of materials, fluids, flow rates, and temperature differentials and permits fabrication of components in sufficient quantity for cost reduction. The test loop consists of a pump, two heated sections, a cooled section, & drain tank, and a frozen- plug-type valve. Automatic controls and equipment were developed to prevent solidification of the salt mixtures (m.p., 800 to 1100°F) in the event of a loss of power. Most test loops are fabricated of 0.5-in.-o0.d., 0.045-in.- wall tubing, and they operate with a temperature differ- ential of up to ZOOOF, a maximum wall temperature in the range 1200 to 1500°F, and a salt flow rate of up to 3 gpm. Twenty-five test loops have been operated for an accumu- lated operating time of 290,000 hr. Individual loops have been operated continuously for more than one year. Introduction Mixtures of molten fluoride salts have been investigated extensively for gpplication in reactor systems as fluid fuels or as heat transfer media. The compatibility of a particular salt mixture with a proposed container alloy is determined, in part, by tests with thermal-convection loops,t and the most promising combinations of salt mixtures and structural material are tThen studied in forced-circulation corrosion test loops. These loops simulate all essential reactor operating con- ditions except radiation.® The test stands and loops have been standard- ized to permit ready replacement and to minimize fabrication costs and installation time. Many mixturss of molten salts have been tested. The basic con- stituents of these have been the fluorides of sodium, lithium, beryllium, zirconium, thorium, ard uranium in various proportiocns that give melting temperatures generally falling in the 800 to 1100°F range.” Viscosity and density vary with each mixture. The viscosity increases with the ount of berylliuvm present and the density ircreszses with the amount of hegvy elements preseunt. 2 typical salt mixture hes & viscosity of 10 centivoise and z specific gravity of 2.4 af iicn’ Tre salt mixtures contalaing beryllium reguaire stringent safety precautions to prevent ex- posure of personnel to this toxic material. To predict accurately corrosion rates for power reactors, the tests must necessarily be of long-term duration. The test stand control system was therefore designed not only to maintain the necessary test corditions for long periods of operation but alsc to provide automatic pretection against sclidificagtion of the salt in the systam. Since melting of the salt imposes severe stresses on the container wall, re- meiving after solidification might cause premature failure of the loop. Degceription of Test Loop and Auxiliary Egulpmen® The test lcop is illustrated in Fig. 1. The loor consists of a pump, two heated sections, a cooled section, a dresin tazk, and a frozen- plug-type valve. Atl wetited parts of the loop are fabricated of the alloy being studied. Loop tubing size is selected to provide the proper cnditions for electrical-resistance heating and to give a pressure drop at design flov that is consistent with the pump capabiliity. A flow the molten-selt circuit and the auxilisry controls for the inert cover gas end utiliities is shown in Fig. 2. A stendard loop supported by its moblile dolly 1s pictured in Fig. 3. This stancard loop was developed from experience gained in rany tests to accommodate the various combinations of materials, fluids, Tlow rates, and temperzoure gradients desired. Such standardization has permitted fabrication of components in quantity for both cost re- duction and ease of gggembly. The interchangeability of the test loops and stands allows the faprication of standby test loop assemblies for guick replacement with s minimum of down time. For most tests, 0.5-in.- 0.d., 0.045-in.-wall tubing has been focund to e suitable. Fig. 1. 1O kva POWER SUPPLY 1600-amp BREAKER 10 kva POWER SUPPLY Molten-Salt Corrosion Testing Loop and Power Supplies. UNCLASSIFIED ORNL-LR-DWG 64740 MAGNETIC GLUTCH & 5HP MOTOR (n\ / SHAFT AND SEAL OIL i S @ \ BAGK FLOW PREVENTER_\ MAGNETIC CLUTGH GONTROL UNIT I ANNULUS QIL BREATHER AND OIL OVERFLOW RETURN FROM SHAFT &7 |2l RETURN FI AN c:” > [ ] OIL. TANK (6 T FLOW ALARM STANDBY OIL PUMP COOLING WATER SUPPLY HELIUM SUPPLY ——<} Uneclassified Photo 34533 FILTER 7Y 1 DRAIN TANK VENT TO OUTSIDE OF BLDG. @ oIL 40% FULL OIL LINE As shown in Fig. 6, the pump has an over- hung vertical shaft with an oil-lubricated face seal above the liquid 10 UNCLASSIFIED ORNL—LR—-DWG 30954 23Y2in. SPARK PLUG PROBE FACE SEAL LIQUID LEVEL INLET IMPELLER VANE DISCHARGE ot in.- Fig. 6. Cross Section of Centrifugal Pump, Mcdel LFB. 11 level in an inert-gas atmosphere. Cooling of the shaft and seal is pro- vided by a flow of oil down through the hollow shaft and out past the seal. The inlet to the pump is located on the side, and the outlet is at the bottom. The performance characterisgtics of the pump for wvarious pump speeds are given in Fig. 4. A pump speed of approximately 3000 rpm ie used for most long-term operation. | The centrifugal pump 1s driven through double V-belts by a variable- speed magnetic clutch and a 5 hp motor. The speed is regulated by an electronic control supplying d-c¢ to the magnetic-clutch unit. In order to decrease the possibility of a flow stoppage as a result of an electronic unit failure, an auxiliary d-c source is supplied for the magnetic clutch, which is preset at the desired speed. This clutch supply circuit is shown schematically in Fig. 7. Relay SR-3 automatically changes over to the auxiliary supply if any perturbation of the normal control occurs. The operation of the pump is then maintained by the auxiliary-clutch supply, while electronic tubes are changed or other repalrs are being made to the normal supply. In the event of the failure of both clutch supplies or a motor failure, steps are taken automatically to provide heat to the entire loop, as will be discussed further in the following section on alarm and automatic-action controls. Since the pump contains the only gas-liguid interface of the system, a sampling device® and level indicators are mounted on the pump bowl flange. The maximum and minimum liquid levels are indicated by a spark- plug-type probe which lights an indicator as the molten salt comes in contact with it. A cross-sectional view of the sampling device is shown in Fig. 8. It consists of a dynamic-seal and ball-plug-valve arrangement through which a dip tube can be inserted into the molten salt and a sample with- drawn without contaminating the inert-gas covering the liquid in the pump bowl. The samples, which are removed periodically for chemical analysis, indicate the type and rate of increase of various corrosion products in the molten salt. In preparation for taking a sample, a seal is established around the periphery of the sample tube, and the inert gas is introduced to purge the volume between this seal and the ball plug valve below. The ball r———————— CONTROL VOLTAGE —— = | NO. 470 CAPACITROL PYROMETER OPENS ON CLUTCH LOW SPEED f 1} Rt OPENS ON 1 I LOOP HIGH SR3-2 SRi-4 TEMPERATURE 4— | 1y cL BYPASS OPEN ON OPERATE — e T CLOSED ON LOW TEMPERATURE 1 CLCSED ON TEST CPEN ON OPERATE- &1 OPENS WHILE CHANGING TRANSFORMER TAP —_| CPENS ON LOOQP HIGH TEMPERATURE -:i t__‘ 2 —TeH (TIME DELAY) HOFE" MAGNETIC AMPLIFIER R2-3 AUXILIARY CONTROLS MAIN RESISTANCE HEATER cmcurrj OPEN ON PREHEAT 52T CLOSED ON OPERATE ” 521 R8-7 s2a T3 MY AR J— Al L/ I MAIN RESISTANCE HEATERS CONTROL CLOSES ON MyM CLUTCH LOW SPEED “t——— [y R 11 SR3-6 CLOSES ON LOOP LOW TEMPERATURE - \LO w 5K SIMPLYTROL n 4 PYROMETER L ra-s METER RELAY—| p CLUTCH AUXILIARY D-C 55 SUPPLY 3 TACHOMETER SPEED AND LOW TEMPERATURE CONTROL OPEN ON LOSS 4 = OF POWER TQO AC, PUMP MCTOR (LF8)—e R5-3 T R & SPEED CONTROL FOR AUXILIARY CLUTCH SUPPLY v ‘71—4;»-— Y Ri-2 -~ 5008 0444 SS— (v) __] 0-100v DC I:—-— —2 Ri-1{ Ri-3 lé‘ T T ] (SR L/ Fig. 7. l—————— NORMAL CLUTCH SUPPLY ————————= PARTIAL CLUTCH SUPPLY CONTROL CIRCUIT —55 Electrical Schematic of 12 - OPENS ON LOSS OF CLUTCH NORMAL SUPPLY CLOSED AT STARTUP OF OPERATION TO ALLOW PICKUP OF R8. R34 T04-0 R y[ OPEN AFTER STARTUP OPEN ON RESET AND PREHEAT CLOSED ON OPERATE SW GBr:r‘ OPEN ON RESET CLOSED ON OPERATE CLOSED ON PREHEAT OPEN ON OPERATE - A SW {6 CR—T SATURABLE REACTOR LFB PUMP -————————————— A-C MOTOR CIRCUIT @ A-C PUMP MOTOR CIRCUIT POTENTIAL MAIN RESISTANCE HEATER POTENTIAL (re) € MAIN RESISTANCE —_— HEATER POTENTIAL TACHOMETER CIRCUIT SUPPLY FOR BLOWER MOTOR O.L. R8-1 BLOWER,/MOTOR CONTROL RE-2 STAR":':-STOP _l SOL. DAMP DAMPER CONTROL —————n 125vDC —ee——— {(BATTERY CIRCUIT} 8-3 ‘ ‘ I | SW IS Oo.L. 80 uf Iy (ma) | \7s} TDt-C SW {3 R9-{ o il - | / T i ®— R6-7 R1O-1 RY0-3 RIO-4 12 "———SUB STA, AND DIESEL CKT. POT,—‘~1 ) N AUTOMATIC OPERATION MAIN SUPPLY COOLER RESISTANCE HEATER RB-6 ¥ (cR) @ COOLER 120v AC COOLER PREHEAT CONTROL CONTACTS POSITION HANDLE £NG | ON | OFF 1 211 X Y A 3 413 X Yo B SELECTOR SWITCH DEVELOPMENT CLUTCH CONTROL CIRCUIT Automgtic Action Relays. UNCLASSIFIED ORNL-LAR-0WG 83067 YARIAC NO. 7 LOOP HEATERS ~-— 440v TO 34/17v 10 KVA TRANSFORMER 0-50v AC 13 UNCLASSIFIED ORNL-LR-DWG 65062 REMOVABLE HEAD ASSEMBLY N SSN..r -;:'////i///é ____ (Y o . g _,y/‘//_‘/,f///// \\\\\\\ix\\\\ % i DI [ 13 DN N 10 Vg in. ? PERMANENT LOOP MOUNTED ASSEMBLY Fig., 8. Cross Section of a Molten-Salt Sampling Device. 1 plug valve 1is then opened, and the dip tube is inserted into the molten -~ salt in the pump. A vacuum is then applied to the dip tube, and the sample is drawn up into the tube. The dip tube is withdrawn, and the ball piuvg valve closed. The number of sampies 1s limited only by the £ mount of molten salt which can be removed without depriming the pump. The fiow of molter salt from the pump is past the drain-tank on, through the first heater section, through a long-radius 180-deg bend, through the second heater seciion, through a coiled cooler, and vack to the pump. The cooler section is a helical coil > mounted in a circular-duct annuius through which ambient air is blown. To provide the necessary preheat temperature for filling the loop and > for protection against solidification of the molten salt in an emergency situation, the cooler coii is provided with electrical heating lugs at both ends and in the center for electrical-resistance heating. The inlet and outlet are kept at the same potential electrically to confine the fiow of current to the cooler coil only. A separate 10-kva saturable core reactor and transformer are connected to the cooler coil for use in preheating or during an emergency alarm condition. The control is set at a predetermined rate of approximately 300 amp and 15 v, and the power is epplied automatically when required. Other auxiliary equipment required for the cperation of the loop inciude a 3000 cfm blowsr, a cooling oil supply, and the necessary util- ities, such as cooling air for the frozen-plug vaive, inert gas, and cooling water. The entire pump, loop, and drain tank assembly is shown in Flg. 3 mounted on & mobile dolly for ease of fabrication, inspection, and instaliation. ne dclly contains one half of the insulated cooler duct and the alir deflector in the center, which forms an annular air passage. 'The back half of the cooler duct is mourted on the permanent stand frame, which also contains the circulating cooling oil system, heater connections, and the pump-drive motor. Mounted over the cooler duct is an insuiated cover 1id that is held in an upright position by a solenoid-held latch during operation of the loop. In the event of an alarm conditiorn which shuts off the blower motor, the latch is released oun the drop 1id and encloses the cooler coil to prevent excessive loss of hesat. ~r 15 All critical loop welding is done by the Heliarc process with inert cover gas and backup purge according to a strict welding specification.” All welds are inspected visually, by dye penetrant, and by x-ray. After welding, the loop is instrumented with Chromel-Alumel thermocouples and heaters. The thermocouples are spot welded to the tubing and covered with shim stock for protection. Both ceramic- and sheath-type heaters are used for heating such auxiliaries as the drain tank, the pump bowl, the heater lugs, and the freeze-plug valve. Standby heaters are mounted on the loop piping for emergency use only in the event of a fallure of the main power supply. After the heaters and thermocouples are attached, the loop is covered with 3 in. of high-temperature insulation. The loop and dolly assembly are tren installed in the facility, and the connections . are made to controls and power supplies. Alarm and Automatic-Action Controls The system thermal inertia is low because of the small~diameter tubing used, and therefore safeguards must be provided to prevent solidi- fication of the salt in the loop. The salt in the cooler coil will become solid in less than 1 min if the flow is stopped and no external heat is applied. An alarm and automatic-action relay system was designed to pro- tect the loop even though there was a failure of the power source or any one piece of operating equipment. The basic ocutline of this system is shown in block form in Fig. 9. Any one of the alarms shown at the.top of Fig. 9, i.e., any condition, which will cause flow stoppage or adverse temperatures, will automatically place the loop in an isothermal or safe condition by performing the actions listed at the bottom of the figure. This results in the entire loop being warmed and in a safe or isothermal condition while the necessary action is taken to restore the equipment to operating condition. To cover the possibiiity of the failure of the main power transformer, the ceramic standby heaters are connected after 2 sec, and they will maintalin isothermal conditions until the main source of power is restored. All relay actions indicated in the block diagram of Fig. 9 are shown schematically in Fig. 7. The battery-powered relay R-8 is de-energized by relasy R-4 to perform the four functions which place the loop on UNCLASSIFIED ORNL-LR~DWG 65068 LOSS OF NORMAL AND AUXILIARY LOSS OF PUMP LOOP LOW LOOP HiGH LOSS OF MAIN POWER CLUTCH SUPPLIES (PUMP STOPS) MOTOR (PUMP STOPS}) TEMPERATURE TEMPERATURE SUPPLY TO HEATER SECTION | INSTANTANEQUS ALARM-ACTION RELAY (NO DELAY IF CONTROL POWER IS AVAILABLE ) TIME-DELAY ALARM-ACTION RELAY (2sec DELAY IF CONTROL POWER NOT AVAILABLE TO ALLOW FOR AUTOMATIC THROWOVER FROM NORMAL TO ALTERNATE FEEDER) ] CONNECTS POWER TO EMER- GENCY HEATERS ON LOOP PIPING AT PRESET RATE SHUTS OFF DROPS LID ON SWITCHES MAIN POWER SUPPLY FROM OPERATE TO CONNECTS POWER TO COOLER COIL BLOWER COOLER BOX PREHEAT CONNECTIONS ON LOOQP AT PRESET RATE Fig. 9. Block Diagram of Automatic Alarm Actions. 91 17 iscothermal operation. To guard against the failure of the power supply to the building which houses the tests or to the bus duct supplying power to the loops, equipment has been designed and installed as shown in block diagram in Fig. 10. Bhould a faillure occur of the normal building feeder, a transfer to an alternate feeder is made automatically within 2 sec. The time-delay relay TD-1 and relay R-3 of Fig. 7 will hold in the battery-powered relay R-8, allowing the transfer to be made without disturbing the operation of the loops. ©Should the bullding electrical power be unavailable for a period longer than z sec; the emergency diesel generator, which started immediately, would begin assuming the load through a sequential timer. Loads would be picked up alternately between motor startup and heater load until the entire facility of 15 loops had power reapplied within 40 sec after the interruption. The 300-kw capacity of the diesel generator is sufficient to operate the loops isothermally until normal building electrical power is again available. Other alarms are available for the protection of the loops that give only an audible or visual signal or both for corrective action to be taken by the operator. These alarms include loss of blower motor, low cooling oil flow, loss of cooler preheat potential, improper position of control switches, improper position of alarm acknowledge switches, and logs of control circuit potential. Operation and Maintenance of a Test Loop The startup of a new corrosion testing loop is preceded by a series of checkouts of equipment. When all the electrical, thermocouple and control circuits are tested satisfactorily and the loop is leaktight, the entire loop is preheated to 1100°F with the pump shaft rotating slowly and the cooling oil circulating. The salt mixture chcsen for the partic- ular test is introduced into the drain tank in a molten state at a slightly higher temperatvre than that of the loop. The drain tank level 4probe indicates when there is sufficient salt to f£ill the loop. Inert gas pressure is admitted to the drain tank and vented from the upper portion of the loop at the pump. NORMAL BUILDING FEEDER 18 ALTERNATE BUILDING FEEDER AUTOMATIC SWITCHING EQUIPMENT DIESEL GENERATOR UNCLASSIFIED ORNL-LR-DWG 65069 AUXILIARY BUILDING FEEDER MANUAL STARTS WHEN POWER FAILS SEQUENTIAL TIMER FOR IN- CREMENTAL APPLICATION OF LOAD | AUTOMATIC SWITCHING SWITCHING EQUIPMENT EQUIPMENT | BUS DUCT SUPPLYING POWER TO EQUIP- MENT AND CONTROLS FOR 15 LOOPS Fig. 10. SUB STATION SUPPLYING 1{{0-kva TRANS~ FORMER POWER FOR {5 LOOPS Block Diagram of Building Electrical Supply. 19 As the salt is slowly forced up into the loop, its path can be traced by the temperature readings of thermocouples placed along the tubing. Level probes in the pump indicate when the loop is full, and this level 1s maintained by manipulation of gas pressure while cooling alr is supplied to the freeze-plug valve. When the temperature of the valve indicates a solid plug, the pressure is released from the drain tank and the pump speed is increased to begin circulation of the molten salt. Power from the main transformer is adjusted to maintain the desired temperature level.. The first load of salt is circulated for a minimum of 2 hr to clean the system and is then dumped into the drain tank and removed. The f:1lling operation is repeated with the supply of salt to be used for the corrosion test. When the test salt is circulating, the differential temperatures are established by shutting off the cooler heat, opening the 1lid on the cooler duct, turning on the blower, closing the 1600-amp heater section breaker (which connects all four heater lugs), and adjusting pump speed, cooling air flow, and main transformer power, as required. When the desired conditions are met, all the controllers, alarm set points, and automatic functioning relays are set for continuous operation. In order to assure, as far as practical, that all emergency equip- ment will function properly when the need arises, a preventive maintenance program is carried out weekly. A check list is completed for each facility which calls for the testing of all important alarms, the throw- over circuit on the auxiliary clutch supply, the cooler drop 1lid, and the clutch brushes; a visual inspection is made of the system. The tests under this program have been operated with maximum wall temperatures of 1200 to 15OOOF, a temperature difference between the maximum wall temperature and the minimum fluid temperature of EOOOF, and flow rates up to 3 gpm. Previously tests were conducted with wall tem- peratures of lSOOOF and higher.® The wall temperatures obtained are limited only by the strength of the container material used. The tem- perature differential obtained is limited by the flow rate and power available. The forced-circulaticn corrosion test facility with eleven test stands showing in the left background is pictured in Fig. 11. The remaining four test stands are on the opposite side of the aisle to the right. Unclassified Photo. 32867 0¢ ' . ' o v ki o T 21 Summary Twenty-five loops have been fabricated with both INOR-8 and Inconel® and have operated under this program for an accumulated total of over 290,000 hr. Twenty of the loops, thirteen of which were fabricated of INOR-8 and seven of Inconel, operated from one to two and a half years before being terminated and examined metallographically. The long-term operation and metallographic examination of these loops was instrumental in the acceptance of INOR-8 as the container material for the Molten Salt Reactor Experiment.l9 The expected corrosion is expected to be less than 1 mils/yr at the design operating temperature of 1225°F. Corrosion specimen weight loss and salt sample data from these loops indicated that the primary corrosion product is chromium and that an essentially constant value was achieved after approximately 5000 hr of operation.l?t Acknowledgments Many persons have made important contributions to the design and operation of these facilities. Acknowledgment is made especially to H. W. Savage under whose direction this program was executed. The suc- cessful operation of these loops was due to a large extent to W. H. Duckworth and the shift operations group under R. Helton, and to many others too numerous to mention. 10. 11. 22 References J. H. DeVan and W. D. Manly, Corrosion Properties of Fused-Fluoride Salt Mixtures, Trans. Am. Nuclear Soc., 1 (1):44 (June 1958). . B. Trauger and J. A. Conlin, Circulating Fused-Salt-Fuel ITrradiation Test Loop, Trans. Am. Nuclear Soc., 2 (L1):173-4 (June 1959). : J. P. Blakely, Molten Seit Compositions, Oak Ridge National Laboratory Report CF-58-6-58 (June 12, 1958). J. J. Keyes and A. I. Krakoviak, High-Frequency Surface Thermal Fatigue Cycling of Inconel at 1400%F, Trans. Am. Nuclear Soc., 2(1):22-4 (June 1959). W. ¥. Boudreau, A. %. Grindell and H. W. Savage, The Development and Operation of Centrifugal Pumps for Liquid Metals and Fused Salts at 1100-150COF, Trans. Am. Nuclear Soc., 2 {1):17-18 (June 1959). W. B. McDonald gnd J. L. Crowley, A Sampling Device for Molten Salt Systems, Oak Ridge National Laboratory Report ORNL-2088 (March 7, 1960). T. R. Housley and P. Patriarca, Procedure Specification PS-2 for D.C. ARC Welding of Inconel Tubing for High Corrosion Applications, ak Ridge National Leboratory. o W. D. Maniy et &l., Metallurgical Problems in Molten Fluoride Systems, Proceedings of the Second United Nations International Conference on the Peaceful Uses of Atomic Energy, Vol. 7, pp. 223-34%, United Nations, Geneva, 1058. J. A. Lane, H. G. MacPherson and F. Maslan, Fiuid Fuel Reactors, p. 596, Addison-Wesley, Reading, Mass., 1958. 5. E. Beail et gl., Molten-Salt Reactor Experiment Preliminary Hazards Report, O=k Ridge Natioral Lavboratory Report Cr-6l-2-46 (Feb. 28, 1961). J. H. DeVan and R. B. Evans III, Corrosion Behavior of Reactor Maverials in Fluorids Salt Mixtures, Oak Ridge National Laboratory Report TM-328 (September 19, 1962 ). O 0= OvJl F o o B 23 DISTRIBUTION MSRP Director's Office 4L3. W. B. McDonald G. M. Adamson LL. H. F. McDuffie L. G. Alexander 45. €. K. MceGlothlan S. E. Beall L6. R. L. Moore M. Bender Lr. J. C. Moyers E. S. Bettis 48. W. R. Osborn F. F. Blankenship 49. P. Patriarca E. G. Bohlmann 50. H. R. Payne D. L. Clark 51. M. Richardson J. A. Conlin 52. R. C. Robertson W. H. Cook 53. H. W. Savage Jd. L. Crowley 54. A. W. Savolainen o. H. DeVan 55. D. Scott R. G. Donnelly 56. J. H. Shaffer J. R. Engel 57. M. J. Skinner C. H. Gabbard 58. G. M. Slaughter R. B. Gallaher 59. A. N. Smith W. R. Grimes 60. P. G. Smith A. G. Grindell 61. I. Spiewak R. H. Guymon 62. J. A. Swartout P. H. Harley 63. A. Taboada P. N. Haubenreich 64. J. R. Tallackson R. Helton 65. R. E. Thoma E. C. Hise 66. D. B. Trauger H. W. Hoffman 67. W. C. Ulrich P. P. Holz 68. C. F. Weaver T. L. Hudson 69. B. H. Webster R. J. Kedl 0. A. M. Weinberg J. J. Keyes, Jr. 71. J. C. White . 5. Kirslis 72. L. V. Wilson A. I. Krakoviak 73.-7h. Cen. Res. Lib. (CRL) J. W. Krewson 75.-76. Doc. Ref. Sec. (DRS). J. A. Lane 77.-89. Lab. Records (LRD) E. M. Lees 90. Lab. Records - RC R. B. Lindauer 91.-105. Div. of Tech. Info. Exten. M. I. Lundin 106. Res. and Dev. Div. (ORO) R. N. Lyon 107,-108. Reactor Div. {(ORO) H. G. MacPherson 109. ORNL Patent Office E. R. Mann External 110.~1X1. D. F. Cope, Reactor Div., AEC, ORO 112. A. W. Larson, Reactor Div., AEC, ORO 113. H. M. Roth, Div. of Res. and Dev., AEC, CRO 114. W. L. Smalley, Reactor Div., AEC, ORO 115. J. W ett, AEC Washlngton