ML20206A791
| ML20206A791 | |
| Person / Time | |
|---|---|
| Issue date: | 03/31/1987 |
| From: | Morris B NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | |
| Shared Package | |
| ML20206A796 | List: |
| References | |
| RTR-REGGD-1.157, TASK-RE, TASK-RS-701-4 REGGD-01.XXX, REGGD-1.XXX, NUDOCS 8704080173 | |
| Download: ML20206A791 (2) | |
Text
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I l / o g UNITED STATES
,8 g NUCLEAR REGULATORY COMMISSION D j WASHINGTON, D. C. 20555 D
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Division 1 Task RS 701-4 March 1987 REGULATORYGUIDEDISTRIBUTIONLIST(DIVISION 1)
SUBJECT:
REQUEST FOR COMMENTS ON DRAFT REGULATORY GUIDE, "B'iST-ESTIMATE CALCULATIONS OF EMERGENCY CORE COOLING SYSTEM PERFORMANCE" (TASKRS701-4)
The U.S. Nuclear Regulatory Comission (NRC) is proposing to amend the j' requirements of 10 CFR Part 50, " Domestic Licensing of Production and Utilization Facilities." The proposed amendments to 5 50.46 and Appendix K to Part 50 were published in the Federal Register (52 FR 6334) on March 3,1987.
These amendments would allow licensees to use realistic calculations, as opposed to the currently required conservative calculations, to show the acceptability of the ersrgency core cooling system (ECCS) performance. The proposed amendments would also require that the uncertainty of each realistic calculation be determined and that this uncertainty be included in the calculation as a safety factor. The NRC staff has prepared this regulatory guide in draft form to allow the public to participate in the development of guidance on acceptable methods of complying with the proposed amendments.
The final regulatory guide would have three major purposes:
To indicate features of ECCS evaluation codes that are acceptable to produce realistic calculations of ECCS performance.
To indicate models, data, and model evaluation procedures that are acceptable to the NRC staff.
To indicate methods acceptable to the NRC staff for performing uncertainty evaluations.
The NRC staff is considering whether the specific models, data, and model evaluation procedures listed in Appendix A to this draft regulatory guide should be included in the final regulatory guide. These models, data, and model evaluation procedures would be acceptable for realistic calculations required by the proposed rule provided their applicability to the specific use is demonstrated. The public is requested to comment on the following:
- 1. Should the regulatory guide list models, data, and model evaluation procedures that the NRC considers to be acceptable for realistic calculations of ECCS performance?
- 2. Are the models, data, and model evaluation procedures listed in Appendix A to this draft regulatory guide appropriate?
l 8704080173 870331 PDR RECGD 01.XXX R PDR
m-Division 1 Task RS 701-4 March 1987
- 3. Does Appendix B of the draft regulatory guide appropriately discuss the features of best-estimata codes and the estimation of overall calculational uncertainty?
All questions, comments, and supporting data should be directed to:
i Rules and Procedures Branch Division of Rules and Records Office of Administration U. S. Nuclear Regulatory Commission Washington, DC 20555 The public comment period will expire on July 1, 1987. Coments received after that date will be considered if it is practical to do so, but assurance of consideration cannot be given unless coments are received on or before July 1, 1987.
N $w Bill M. Morris, Acting Director Division of Reactor System Safety Office of Nuclear Regulatory Research q l
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