OAK RIDGE NATIONAL LABORATORY operated by NUCLEAR DIVISION for the UNION CARBIDE CORPORATION U.S. ATOMIC ENERGY COMMISSION vl ORNL~ TM- 733 (2nd. Revision) COPY NO. - O DATE - September 19, 1966 e Y : Nede 0 N Lkl il - e s /-00; - >0 - MSRE DESIGN AND OPERATIONS REPORT Part VI OPERATING SAFETY LIMITS FOR THE MOLTEN-SALT REACTOR EXPERIMENT S. E, Beall R. H. Guymon RELEASEL FOR ANNOUN CEMENT IX NUCLEAR SCIENCE ABSTRACTS NOTICE This document contains information of a preliminary nature and was prepared primarily for internal use at the Oak Ridge National Laboratory. It is subject to revision or correction and therefore does not represent a final report. Tl DURUAETY HES STV IMIEWLD, NO INVERTIONS GF PATINT INTEREST TO THE A.E.C. AKRE DIS&Q_SE? THEREIN. . c3 e LEGAL NOTICE This report was prepared as an account of Government sponsored work. Nsither the United States, nor the Commission, nor any persen acting on behalf of the Commission: A. Makes any warranty or represantation, expressed or implied, with respect to the accuraey, completeness, or usefulness of the information contained in this report, or that the use of any information, apparotus, method, or proecess disclosed in this report may not infringe privately owned rights; or B. Assumes any ligbilities with respect to the use of, or for damages resulting from the use of any information, epparatus, method, or process disclosed in this report. As used in the above, ‘‘person acting on behalf of the Commission® includes any employee or contractor of the Commission, or employes of such coentractor, to the extent that such employae or contractor of the Commission, or employee of such contractor prepcres, disseminates, or provides access to, any informotion pursuant to his employment or contract with the Commission, or his empleyment with such contractor. _3_ MSRE DESIN AND OPZRATIONS REPORT Part VI OPERATING SAFETY LIMITS TOR THE MOLTEN-SALT REACTOR EXPERIMENT . Beall H. Guymon & bt This document has been prepared at the request of the U. S. Atomic EBrergy Commission to set the limits for various parameters related to the Molten-521t Reactor Experimsnt. Tn some cases the limits report the level at which the reactor will be shut down by automatic monitoring devices. In all cases the reactor operators are obligated to take steps intended to correct a parameter which 1z temporarily outside the specified range indi- atad herein, 1.0 Countainment 1.1 Ieakage from the primary system as indicated by the reactor and drain-tank-cell air activity will not exceed the equivalent of L liters of salt after 120 days of operation at full power, as estimated in the case of the Most Probable Accident.l Offgas activity release will be limited to fission-product concen- trations averaging less than 1.5 x 107% yc/cc in the stack.Z Fission-product release will be monitored by radiation moriteors on the offgas linss and at the stack. 1.2 The cover-gas suprly pressure will be kept at 30 psig or greater and the leak-detector system pressure gbove 50 psig to help pr=- vent excessive exposure to operating personnel, as specified in Chapter 0524 of the AEC Manual.” 1S. E. Beall et al., "MSRE Design and Operations Report, Part V, Reactor Safety Analysis Report, " USAEC Report ORNL TM-T732, Oak Ridge National Iaboratory, August, 196k, ®pased on 3 x 107° uc/cc as permissible concentration at ground level downstream of the stack. An atmespheric dilution of 0.5 x 10° is assumed. Schapter 0524, "Standards for Radiation Protection.™ ~ LEGAL NOVICE _ raport was prepared ag an account of Government spoasored v States, nor the Commission, nor any person acting on behalf of the Co A, Makes any warranty or representation, expressed or implico, w: ari te the aceu- racy, completeness, or usefulness of the information congained {1 tuie coport, on that the use LTTTACEN ke OR NNOUNC EMENT of any information, apparatus, method, or process disclosed in this ceport w2y uot iniringe Bl el & privately owned rights; or B. Agsumes any liabilities with respect to the use of, or for damages resuiting frow the ? - e » ABSTRAF‘TS use of any information, apparatus, method, or process disclosed in this repart. i 1M wiun LEAR =0 TEN CE W As used in the above, ‘‘person acting on behalf of the Cominission’ inclaides any eti- v ployee or contractor of the Commission, or employec of such contractor, to tae eatent thet such employee or contractor of the Commission, ¢r employee of such contractor prepares, disseminates, or provides access to, any information pursuant to his employment or contract with the Commission, or his empleyment with such centractor. 1.0 R2 ou N 2.0 Contaimmert (continued) 1.3 1.4 1.5 1.6 }.....I fl 1.8 The radioactivity iz the reactor cell service lines will be maintained at a level sufficiently low to prevent excessive exposure to personrel, as specified in Chapter 0524 of the AEC Manual. e pres in tlhe reactor an: rair nk ¢ wi main- The essure in tke reactor and drain tank cells will be mai talned below atmospheric rressure during reactor operation. The maximin reactor and draizn-~tank-cell leak rate will noct be aillowed to exceed 1% of the cell volume per day, calculated fior the conditions of the Maximum Credible Accident.® The in-leakage rate will be Jetermined at least once per week. The maximam vapcr-condsnsing system pressure (under nonaccident conditions) will zot exceed 3 psig. During reactor cperation the level of water in the vapor-condensing tank shall be checked at least once a week to insure that it remairs in the range required for proper operatioa (8000 to 9300 gallomns). The building high-bay pressure will be maintained at slightly less than atmospheric pressure {~ 0.1 in. H50) during all oper- ations in which the high bay serves as the secondary contalrment, Tre ventilation syster f and after each charge of by the standard dicctylphthalate test. 1.1C Al] reactor and drain-tank-call shield blocks shall be in placz and gezared by the hold-down devices whenever fuel salt is in the reactor vessel. Tuel System 2.1 The maximum steady-state powar level is 10 Mw (administrative iimit). 2,0 TFuel System (continued) Rl R1 3.0 4,0 2.2 2.3 2.k 2D no Ch 2.7 2.8 2.9 The power level for safety-rod scram trip is 15 Mw or less. The temperature level for safety-rod scram trip is less than 1400°F. Adjustment of the trip between 1300 and 1LO0°F will require administrative approval. The maximum Fuel system cover-gas pressure is 50 psig. The maximum salt fill rate while filling the core is 1.0 £t /min. The maximum.amount'of 23577 which will be added at one time is 120 g. During operation fuel will only be added through the sampler-enricher. The maximum concentration of fissionable material in the fuel salt will not exceed by more than 5% the minimum required for full-power operation at 1200°F with equilibfium xenon and the control rods poisoning 0.6% 8k/k. The fuel salt will be sampled and the concentration measured at least once per week. At no time during critical operation of the reactor will the re- activity anomaly be allowed to exceed 0.5% dk/k. A "reactivity anomaly" is defined as a deviation from the reactivity which Is expected on the basis of measured reactor physics constants and calculated effects of burnup and fission product accumulaticn. A positive period of 1 sec or less will cause a safety~rod scram. Coolant System 3.1 L.1 h.2 L.3 The maximur coolant system cover-gas pressure 1is 50 psig. Control Rods The normal complerent of coxntrol rods is three, of which two are regquired to scram for safety action. The maximum scram time (time from initiation of signal until a rod is on the seat) is 1.3 sec. The rod speed (motor powered) is 0.5 0.05 in./sec. This speed permits maximum reactivity additions in "start" of 0.1% 8k/k per sec and in "run" of 0.05% 8k/k per sec. .0 R1 R1 R1 6.0 7.C Control Rods (continued) L, The scram time of the rods will be checked before each fill with fuel salt. Nueclear Control aand Safety Instrumentation 5.1 All nuclear safety instrumentation will be checked for proper operation before each fiil. 5.2 A minimum of two safety-level channels will be 1n service during reactor operatvio=n. 5.3 A minimum of two reactor-fuel-outlet temperature signals will he in service during rezactor operation. 5.4 A minimum of one Tissicn chamber with count-rate circuit must be in operation diring startup filling operations. 5.5 A minimum ¢f twc pogsitive period safety channels will be in service during reactor operation. Personnel Radiation Monitoring 6.1 Radiation level monitors A minimum of two personnel radiation monitors will be in operation at all times, one in the high-bay area and onhe in the control-roonm area, 6.2 Air monitors A minimum of two air aciivity monltors will be in operation at all times, one in the high-bay area and one in the office— control-room area, Personnel and Procadures 7.1 Perscnzel qualificaticrs The reactor will be operated oaly by gqualified personnel appreoved by the Chisf of Operaticns. It will be operated in conformarcea with documented operating procedures which, in nco instance, dzsiguate authorizstlion to cperate the reactor in excess cf any operating safety limits listed above. 7.0 8.0 .-.T_ Personnel and Procedures (continued) 7.2 The minimum staff requirement for operation during any shift is that at least one supervisor and two technicians will be on duty during reactor coperation. The control room will not be left unattended while fuel is in the reactor vessel. Experimental Limits Experiments will be conducted within the limits specified in this report. Experimental procedures will be approved in advance by the Head of the Operations Department, Oak Ridge National Iaboratory Reactor Division, or his authorized assistant. - ¢ \O Qo= O o o — O 11. 12. 13. 1k, 15. 16. 17. 18. 19. 20. 1. 22. 23, 2L, o5, 26. o7. 28. 29. 30. ORNL-TM-733 Revigion 2 Tnternal Distribution Adamson Affel Beall . Blankenship . Blumberg J. Borkowski B. Briggs . Burger B. Cottrell L HHEQ R SQWOQHE 0T Q y Crowley * . Culler . Engel . Epler . Fraas 9 Gabbard . Gallaher . Grimes . Guymon L R P P H B R H H. Harley N. Haubenreich D. Helt L. Hudson R. Kasten I. Krakoviak B. Lindauer I. Imndin N. Lyon G. MacPherson E. MacPherson C. McCurdy * HEEEER AL I IE DO P e 31. 32. 33. 3k, sk, 55-56. 57-58. 59-61, 62. 63. 6l . McDurfie . McGlothlan . Miller Moore Payne Perry Piper Redford Roller Rosenthal nn Savolainen Scott, Jr. J. Skinner N. Smith Spiewak C. Steffy Tallackson Thoma Trauger Ulrich Webster Weinberg E, Whatley D. Whitman Central Research Library Y-12 Document Reference Section Iaboratory Records Department Iaboratory Records, RC C. E. Iarson S. J. Ditto FEEGEPED FOm SO R W ED S » CEFPREENCEHERY 2O External Distribution 65-79. Division of Technical Information Extension, DTIE 80-81. Reactor Division, AEC, ORO 82. A. Giambusso, AEC, Washington 83-86. H. M. Roth, Division of Research and Development, AEC, CRO 87. W. L. Smalley, Reactor Division, AEC, ORO 88. M. J. Whitman, AEC, Washington