Document: NRC Regulatory Guide
Document ID: 22ccfd5e-c5d8-4615-a02c-32369aa9f533
Document Type: regulatory_guide
Title: Acceptability of Probabilistic Risk Assessment Results for Risk-Informed Activities (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1930/ML19308B636.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.200
CFR Part: 
CFR Title: 

Content:
y. For those flood and fire sources that do not significantly contribute to seismic core damage frequency and/or seismic large early release frequency, estimate ESTIMATE the seismic fragilities. Table 5-2.2-7 Introductory text -------------------- No objection -------------------- SFR-F1 -------------------- No objection -------------------- SFR-F2 Related Table 5-2.2-6 that provides supporting requirements associated with calculation of seismic-fragility parameters use distinct action verbs ESTIMATE and CALCULATE, respectively, for Capability Category I and Capability Category II. However, the related supporting requirement SFR-F2, item (i) associated with documentation of fragility parameter values only Clarification Regarding list item (i) in SFR-F2: (i) estimation or calculation of fragility parameter values for each SSC modeled (median capacity, logarithmic standard deviation reflecting the randomness in median capacity, and logarithmic standard deviation representing the uncertainty in median capacity), and DG-1362, Appendix B, Page B-19 Table B-1. Staff Position on ASME/ANS RA-S Case 1, “Case for ASME/ANS RA-Sb-2013 Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment of Nuclear Power Plant Applications,” Technical and Peer Review Requirements of a Level 1, Seismic PRA for the At-Power Operating Mode Index No Issue Position Resolution uses the word “estimation,” but not “calculation.” Therefore, the documentation supporting requirement item (i) is partly inconsistent with other related supporting requirements. SFR-F3 -------------------- No objection -------------------- Section 5-2.3 Introductory text, Issue 1 The seismic PRA depends on both the capability and completeness of the internal events at-power PRA. Clarification It is assumed: • Relative to the systems-analysis requirements contained herein, the seismic PRA analysis team possesses a full-scope internal events, at-power Level 1 and Level 2 LERF PRA,