ML23285A270
| ML23285A270 | |
| Person / Time | |
|---|---|
| Issue date: | 10/25/2023 |
| From: | Andrea Veil NRC/NRR/DORL/LPL4 |
| To: | Mauer A Nuclear Energy Institute |
| References | |
| Download: ML23285A270 (1) | |
Text
October 25, 2023 Mr. Andrew N. Mauer Senior Director, Regulatory Affairs Nuclear Energy Institute 1201 F Street, NW, Suite 1100 Washington, DC 20004
SUBJECT:
U.S. NUCLEAR REGULATORY COMMISSIONS RESPONSE TO NUCLEAR ENERGY INSTITUTES LETTER DATED APRIL 19, 2023, REGARDING FEEDBACK ON THE RISK-INFORMED PROCESS FOR EVALUATIONS
Dear Mr. Mauer:
I appreciate the feedback that you provided in your letter submitted to the U.S. Nuclear Regulatory Commission (NRC), on April 19, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23163A048), on the risk-informed process for evaluations (RIPE). The purpose of this letter is to provide you with the NRC staffs preliminary assessment of Nuclear Energy Institutes (NEIs) feedback, consistent with the information that was discussed during the October 5, 2023, public meeting on this topic (ML23264A801).
In your letter dated April 19, 2023, you offered two recommendations, as listed below, based on NRCs temporary staff guidance (TSG) DORL-2021-01, Revision 2, Risk-Informed Process for Evaluations (ML22088A136) and your interpretation of Regulatory Guide (RG) 1.174, Revision 3, An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis (ML17317A256):
NEI Recommendation 1:
The risk criteria in section 2 of NRCs TSG-DORL-2021-01 should be revised as follows:
The issue contributes less than 5 x 10-7 /year to core damage frequency (CDF).
The issue contributes less than 5 x 10-8 /year to large early release frequency (LERF).
NEI also conveyed that Recommendation 1 would also require revisions to sections 3.2, 3.3.3, 4.1.2, and 4.3.3 of the TSG.
NEI Recommendation 2:
The risk thresholds should not be pass/fail criteria.
During the October public meeting, the NRC staff conveyed its preliminary assessment that NEIs Recommendation 1 is reasonable because the proposed risk acceptance criteria are indicative of a very small change in risk per RG 1.174, and applications submitted under RIPE will be reviewed by NRC staff in accordance with the principles of risk-informed decision making in RG 1.174. The NRC staff noted that NEIs proposed risk acceptance criteria are similar to the risk acceptance criteria for Notices of Enforcement Discretion per NRC Enforcement Manual, Appendix F, Notices of Enforcement Discretion, (ML19193A023) and are smaller than the risk thresholds for normal work controls in NRC-endorsed industry guidance, Nuclear Management and Resources Council (NUMARC) 93-01, Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, Revision 4F (ML18120A069).
During the public meeting, the NRC staff conveyed its preliminary assessment that NEIs Recommendation 2, to allow more flexibility in the risk criteria for RIPE, is not recommended because it could result in added complexity and delays that do not align with the goals of RIPE.
However, after further consideration, NRC staff agrees that the criteria need not be pass/fail.
The NRC staff will consider for review, on a case-by-case basis, applications with minor deviations from the RIPE acceptance criteria. Where the risk acceptance criteria are slightly exceeded, a licensee may request a RIPE review, supported by an explanation as to why the minor deviation is acceptable, such as an explanation of how the analysis provided is overly conservative. The NRC staff noted that the additional flexibility in the risk acceptance criteria could potentially affect the review timeline and/or required NRC staff review resources, as approved by management. The NRC staff also reinforced the benefits of licensees requesting pre-application meetings before submitting RIPE applications.
During the discussion portion of the public meeting, NEI conveyed its plans to (1) revise its technical document, NEI 21-01, Industry Guidance to Support Implementation of NRCs Risk-Informed Process for Evaluations, reflecting the recommended risk acceptance criteria, considering the NRC staffs preliminary assessment and (2) submit its RIPE guidance document, as a publicly available document to the NRC. The NRC staff plans to review the NEI RIPE guidance document, considering the feedback received from the October 5th public meeting, send a letter to NEI with the NRC staffs final assessment of the NEI guidance document, and proceed with updating TSG-DORL-2021-01, accordingly.
If you have any questions regarding this matter, please contact Siva Lingam at 301-415-1564 or by email to Siva.Lingam@nrc.gov.
Sincerely, Andrea D. Veil, Director Office of Nuclear Reactor Regulation Andrea D.
Veil Digitally signed by Andrea D. Veil Date: 2023.10.25 17:01:30 -04'00'
- by email OFFICE NRR/DORL/LPL4/PM*
NRR/DORL/LPL4/LA*
NRR/DRA/APOB/BC (A)* NRR/DORL/LPL4/BC*
NAME SLingam (WOrders for)
PBlechman RRodriguez JDixon-Herrity DATE 10/16/2023 10/16/2023 10/16/2023 10/16/2023 OFFICE NRR/DRA/D*
NRR/DORL/D*
NRR/FO NAME MFranovich (MKhanna for) BPham (VCusumano for) AVeil DATE 10/17/2023 10/20/2023 10/252023