Document: NRC Regulatory Guide
Document ID: 8a2332d3-66ca-40af-84e1-507db8b26559
Document Type: regulatory_guide
Title: TRIAL - Acceptability of Probabilistic Risk Assessment Results for Non-Light Water Reactor Risk-Informed Activities
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2123/ML21235A008.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.247
CFR Part: 
CFR Title: 

Content:
nd appropriate for the plant. CC-II CALCULATE contact chatter seismic fragilities using plant- specific data or JUSTIFY the applicability and use of generic fragility data for relays and other similar devices that affect risk-significant SSCs and are identified in the Systems Analysis. RG 1.247, Appendix A, Page A-44 Table A-11. Staff Position on ASME/ANS RA-S-1.4-2021, Technical Requirements for Seismic PRA Index No. Issue Position Resolution reasonably reflect the as-designed or as-to- be-built plant. If such assumptions cannot be shown to be bounding for the range of anticipated sites, the results may not appropriately reflect the expected plant response. SFR-E5 The applicability of generic data to a given SSC should be justified. This is because of the potential for SSCs in NLWR designs that may not correspond to established SSC categories and/or may not be in common SSC locations in the plant. When estimating fragilities for PRAs developed for the pre- operational phase, demonstrating that generic or conservative assumptions are bounding for the range of anticipated sites helps ensure that these fragilities can reasonably reflect the as-designed or as-to- be-built plant. If such assumptions cannot be shown to be bounding for the range of anticipated sites, the results may not appropriately reflect the expected Clarification CC-I ESTIMATE seismic fragilities for credible seismic-induced flood sources (see Requirement SFR-D6) and seismic-induced fire ignition sources (see Requirement SFR-D7) and JUSTIFY the use of generic fragility data or conservative assumptions as being applicable and appropriate for the plant. CC-II CALCULATE seismic fragilities using plant-specific data or JUSTIFY the applicability and use of generic fragility data for credible seismic-induced flood sources (see Requirement SFR-D6) and seismic-induced fire ignition sources (see Requirement SFR-D7) that are risk-significant contributors. RG 1.247, Appendix A, Page A-45 Table A-11. Staff