ML011640387
| ML011640387 | |
| Person / Time | |
|---|---|
| Issue date: | 04/13/2001 |
| From: | Thadani A Office of Nuclear Regulatory Research |
| To: | Floyd S Nuclear Energy Institute |
| References | |
| Download: ML011640387 (2) | |
Text
April 13, 2001 Mr. Stephen D. Floyd Senior Director, Regulatory Reform, Nuclear Generation Nuclear Energy Institute 1776 I Street NW Suite 400 Washington, DC 20006
Dear Mr. Floyd:
Thank you for your letter of February 13, 2001, in which you provided an industry perspective on the focus of Option 3. I agree that 10 CFR 50.46 (Emergency Core Cooling Acceptance Criteria) is a prime candidate to be studied under Option 3 for risk-informing. As you know, we commenced a major effort of examining 50.46 in January 2000 and, as we indicated in our latest status report on Option 3, we plan to have recommendations to the Commission on how to proceed with a risk-informed 50.46 in June 2001. In addition, we developing our plans for completing the Option 3 effort and I welcome your input regarding which additional regulations, if any beyond 10 CFR 50.44 and 50.46, from an industry perspective, should be pursued under Option 3.
In regard to 50.46, I also agree that the scope of 50.46 is large. In making risk-informed changes to the technical requirements of 10 CFR 50.46, there is the potential to affect other regulations, and thus, many aspects of plant design and operation. Further, the development of the current 50.46 and LBLOCA has a lengthy history and was the focus of extensive hearings to insure that a robust technical basis existed and the conservatism of the criteria confirmed by extensive experimental programs. Therefore, as we move forward on this effort, in considering risk-informed alternatives, it is essential to proceed in a careful manner to assure that a robust technical basis would be provided with any changes to 50.46. Currently, the staff is evaluating the feasibility of risk-informing the ECCS technical requirements (e.g., 10 CFR 50.46, GDC 35, Appendix K) along with the feasibility of redefining the maximum pipe break size for the LBLOCA design basis accident. As we presented recently to the ACRS (March 16, 2001),
there are a number of technical issues needing resolution. As we look at the feasibility, we are considering the technical issues needing resolution, safety benefits and concerns, and improved efficiency as outlined by the goals in the Agencys Strategic Plan and discussed in our framework for risk-informing 10 CFR Part 50. As discussed with ACRS, we believe that it is feasible to risk-inform many of the technical requirements for all break sizes (e.g., simultaneous LOOP and LOCA, single failure criterion) which would offer substantial unnecessary burden reduction and safety benefits. In parallel, we will continue to complete the feasibility assessment of redefining the LBLOCA and the remaining technical requirements associated with 50.46.
S.D. Floyd 2 We have held several public workshops and meetings on this topic. The information we have received from these meetings, and in your letter, is of great help and is being considered in our study. We will continue to hold public meetings to solicit feedback from the various stakeholders on this important topic. More specifically, we plan to hold at least one more public meeting to help us consider our June recommendations. These recommendations will include both 50.46 and future activities under Option 3 (e.g., additional regulations to be examined for risk-informing). I encourage you and others from the industry (and other stakeholders) to participate in this meeting.
If you have any questions, please do not hesitate to call me or Mary Drouin ((301) 415-6675, email mxd@nrc.gov).
Sincerely,
/S/
Ashok C. Thadani, Director Office of Nuclear Regulatory Research cc: Tony Pietrangelo, NEI Samuel Collins, NRC Thomas King, NRC Distribution: DRAA Chron, PRAB r/f, Drouin, Drouin r/f, Cunningham, Mayfield, Eltawila, King, Thadani, Summerour RES # 2001042 DOCUMENT NAME:g:\mary\response to nei letter (2-13) on lbloca rev 1
OAR in ADAMS? (Y or N) Y ADAMS ACCESSION NO.: TEMPLATE NO. RES-Publicly Available? (Y or N) y DATE OF RELEASE TO PUBLIC SENSITIVE?
N Previously concurred OFFICE PRAB/DRAA PRAB/DRAA DRAA NRR RES NAME *Drouin *Cunningham *King *B. Sheron *Thadani DATE 03/14/01 03/14/01 03/14/01 4/12/01 4/11/01