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:
4.3.13.2-1 RG 1.247, Appendix A, Page A-61 Table A-14. Staff Position on ASME/ANS RA-S-1.4-2021, Technical Requirements for External Flooding PRA Index No. Issue Position Resolution HLR-XFFR-A through HLR-XFFR-F ------------------------ No objection ---------------------------------- Table 4.3.13.2-2 XFFR-A1 through XFFR-A5 ------------------------ No objection ---------------------------------- Table 4.3.13.2-3 RG 1.247, Appendix A, Page A-62 Table A-14. Staff Position on ASME/ANS RA-S-1.4-2021, Technical Requirements for External Flooding PRA Index No. Issue Position Resolution XFFR-B1 A walkdown should be performed for post- operational plants as part of an investigation. However, a physical walkdown of a plant in the pre-operational phase of development may not always be possible. Performing an investigation that involves something less than a walkdown for post-operational plant may result in a mischaracterization the plant's as-built design in the PRA. Clarification COLLECT information via walkdown(s) or, for PRAs performed during the preoperational phase, investigation(s) about either the as-built, as-operated or as-designed, as-intended-to- operate, as applicable, plant and site characteristics relevant to the fragility evaluation, such as establishing or confirming the location and characteristics of flood protection features, penetrations/seals, and drainage features. XFFR-B2 A walkdown should be performed for post- operational plants as part of an investigation. However, a physical walkdown of a plant in the pre-operational phase of development may not always be possible. Performing an investigation that involves something less than a walkdown for post-operational plant may result in a mischaracterization the plant's as-built design in the PRA. Clarification For operating reactors, ASSESS the condition (e.g., SSC degradation) and configuration of SSCs observed during the walkdowns or, for PRAs performed during the preoperational phase, investigation(s).