USER OFFICE REVIEWER: D. ROSS PAGE: 16 PROPOSED NEW DATA IS BEING CONSIDERED AS PARTIAL BASIS FOR MODIFICATION OF PRESENT ECCS RULE (10 CFR 50.46 AND APPENDIX K). *** NRR IMPACT OF RESULTS *** NEW DATA CONFIRMS MARGINS ALLOTTED IN PRESENT ECCS RULE ARE CONSERVATIVE. (1.E., INCREASE PEAK KW/FT, ETC.). IF ACCEPTED FOR USE IN LOCA LICENSING CALCULATIONS, VENDORS COULD USE ADDITIONAL MARGIN IN DESIGN. *** NRR COMMENTS AND REMARKS *** INITIATE RULEMAKING TO MODIFY APPENDIX K. THE COMMISSION APPROVED THE PROPOSED ACTION PLAN TO MODIFY APPENDIX K (SECY 78-26). NRR AND RES ARE PREPARING A REQUEST TO SD TO APPENDIX K (ECCS EVALUATION MODELS). THESE STUDIES PROVIDE INFORMATION NECESSARY TO ASSESS THE DEGREE OF CONSERVATISM OF THE DECAY HEAT ASSUMPTIONS IN 10 CFR 50 SCHED. RESP. DATE: 09/01/77 BIL NO: 77-008 DATE ISSUED: 01/31/77 BIL TITLE: DECAY HEAT DATA APPLICABLE TO LOCA EVALUATION RES UNIT RES. TECHNICAL LEAR RECENT CALCULATIONS AND EXPERIMENTS WERE PERFORMED TO DETERMINE A BEST ESTIMATE OF THE VALUE OF THE RESIDUAL (DECAY) HEAT THE SUBJECT RIL ANNOUNCED THE AVAILABILITY OF THE SIMMER-1 CODE. THE SIMMER-1 CODE IS RECOGNIZED BY NRR AS AN IMPORTANT FIRST STEP *** NRR : IMPACT OF RESULTS *** THERE IS NO IMPACT SINCE RESULTS USING THE SIMMER-1 CODE ARE NOT SUFFICIENTLY SUBSTANTIATED TO BE USED DIRECTLY IN THE LICENSING *** NRR : COMMENTS AND REMARKS *** NRR VIEWS THE SIMMER PROGRAM AS AN IMPORTANT LONG TERM EFFORT TO DESCRIBE THERMAL AND MECHANICAL CORE DISRUPTION ACCIDENT 1. 2. TO SAUL LEVINE, RES FROM B. RUSCHE, NRR, "LMFBR SAFETY RESEARCH PROGRAM PLAN", 3/15/77. (CC. TO C. KELBER). TO L. S. RUBENSTEIN FROM R. P. DENISE, "DEGREE OF SUPPORT FOR RESEARCH PROGRAMS FOR ADVANCED REACTORS", 1/6/77 TO E. G. CASE FROM R. P. DENISE, "NRR COMMENTS TO ACRS ON ARSR PROGRAM", 7/15/77. TO SAUL LEVINE, RES, FROM E. CASE, HRR, "RES INFORMATION ON THE UNDERSTANDING OF CDA ENERGETICS IN LMFBR'S". RIL TITLE: SIMMER CODE FOR ANAL OF CORE DISRUPT ACCIDENTS IN LMFBR'S SPONSORING OFFICE(S): NRR THE SIMMER CODE FOR ANALYSIS OF HYPOTHETICAL CORE DISRUPTIVE ACCIDENTS IN LMFBR'S RES COMMENTS THE SIMMER CODE IS DESIGNED TO PREDICT THE MOTION OF FAST REACTOR CORES DURING POTENTIAL CORE DISRUPTIVE ACCIDENTS. A TRIAL RIL IIILE CRITIQUE OF BOARD-HALL MOD FOR THERM DETON IN U02-NA SYS SPONSORING OFFICE(S): NRR RES UNIT RES TECHNICAL LEAD A CRITIQUE OF THE BOARD-HALL MODEL FOR THERMAL DETONATIONS IN THE U02-NA SYSTEM RES COMMENTS THIS CRITIQUE OF THE BOARD-HALL THEORY FOR THERMAL EXPLOSIONS IN A URANIUM OXIDE-SODIUM SYSTEM REINFORCED THE BELIEF THAT SUCH OFFICE: NRR IMPACT STATEMENT SCHED. RESP. DATE: 09/09/77 ACTUAL RESP. DATE: 09/09/77 *** NRR APPLICATION TO THE REGULATORY PROCESS *** USER OFFICE REVIEWER: H. GAMMILL ESTIMATES OF THERMAL DETONATION ENERGIES ARE DIRECTLY RELEVANT IN LICENSING DECISIONS RELATED TO CONTAINMENT REQUIREMENTS FOR *** NRR IMPACT OF RESULTS *** ISSUES, SHOULD CONTINUE. IDENTIFIED PERCEPTIONS AND NEED FOR EXPERIMENTS. THE RESULTS OF THE CRITIQUE ARE MINIMAL IN THIS ON-GOING TECHNOLOGICAL EXPLORATION, EXCEPT AS NOTED ABOVE IN REINFORCING THE SUCH WORK, INDEPENDENT ASSESSMENTS OF IDENTIFIED AND POTENTIAL SIGNIFICANT SAFETY *** NRR : COMMENTS AND REMARKS *** THE INITIAL EFFORT OF AN EXPERIMENTAL AND ANALYTICAL EVALUATION OF THE BOARD AND HALL MODEL OF THERMAL EXPLOSIONS WAS UNDERTAKEN |