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:
riteria for determining the acceptability of a correlation model. Clarification INCLUDE information relevant to justifying the modeling of fragility dependency correlation of SSCs and its basis (e.g., similarity of component construction and location, and response spectra at the locations) to support SPR- B4. DG-1362, Appendix B, Page B-13 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 Table 5-2.2-3 Introductory text -------------------- No objection -------------------- SFR-B1, through SFR-B3 -------------------- No objection -------------------- SFR-B4 The action verb ESTIMATE implies using judgement or qualitative measures which are inconsistent with the intent of the SR. The action verb CALCULATE involves a mathematical process whereas the action verb ESTIMATE does not necessarily involve a calculation (e.g., quantification of a probability or frequency) and can be derived qualitatively. Qualification If median-centered response analysis is performed, CALCULATE ESTIMATE the median response (i.e., structural loads and floor response spectra) and ESTIMATE the variability in the response. SFR-B5 -------------------- No objection -------------------- SFR-B6 In the 2009 revision (SFR-C2), part of the SR asked one to ACCOUNT for the entire spectrum of input ground motion levels displayed in the seismic hazard curves. This sentence is removed in the code case. However, this sentence also ensures the quality of the results of the probabilities response analysis. Qualification If probabilistic response analysis is performed to calculate structural loads and floor response spectra, ENSURE that the number of simulations done (e.g., Monte Carlo simulation or Latin Hypercube Sampling) is