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:
B, Page B-22 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 SPR-B5 The justification for the appropriate capacity based screening level needs to be provided. Neither the action verb for this SR nor that used for SFR-C1 achieves that purpose. Qualification SPECIFY JUSTIFY (e.g. based on the contribution to the risk quantification) an appropriate the set of criteria to be used in support of the screening of SSC failure modes on the basis of fragility. (See SFR- C1.) SPR-B6 The term “with a significant contributor to CDF or LERF” is not defined. How can one determine the significance without performing the calculation? Clarification USE a systematic approach to INCLUDE in the system analysis the effects of those relays or similar devices susceptible to contact chatter whose contact chatter results in the unavailability or spurious actuation of SSCs on the seismic equipment list. with a significant contribution to CDF or LERF. SPR-B7 through SPR-B11 -------------------- No objection -------------------- Notes -------------------- No objection -------------------- Table 5-2.3-4 Introductory text -------------------- No objection -------------------- SPR-C1 through SPR-C6 -------------------- No objection -------------------- Table 5-2.3-5 Introductory text -------------------- No objection -------------------- SPR-D1, SPR-D2 -------------------- No objection -------------------- SPR-D3 Cue availability as well as dependencies are integral part of HRA analyses and maybe affected by seismic events. Clarification For CC I: CALCULATE the HEPs for all HFEs taking into account relevant seismic- related effects on control room and ex- control room post-initiator actions in accordance with