Document: NRC Regulatory Guide
Document ID: cde52d5a-adf9-49be-9d1f-59449dfca895
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:
cation CC-I When addressing feasibility, RG 1.247, Appendix A, Page A-64 Table A-14. Staff Position on ASME/ANS RA-S-1.4-2021, Technical Requirements for External Flooding PRA Index No. Issue Position Resolution HEPs being assigned a value less than 1.0 when the assigned value should be 1.0. If an HFE that is not feasible is assigned an HEP value less than 1.0, but a feasibility assessment would otherwise demonstrate that the HFE is not feasible, the PRA model may underestimate the risk from that contributor. influencing factors, and the timing considerations in Requirements HR-G1, HR-G4, HR-G6, and HR-G8, INCLUDE the effect of external flooding hazard on the control room and ex-control room human actions. CC-II When addressing feasibility, influencing factors, and the timing considerations in Requirements HR-G1, HR-G4, HR-G6, and HR-G8, INCLUDE the effect of flood impacts external flooding hazard on the control room and ex-control room human actions. XFPR-E7 and XFPR-E8 ------------------------ No objection ---------------------------------- Table 4.3.13.3-7 XFPR-F1 through XFPR-F7 ------------------------ No objection ---------------------------------- Table 4.3.13.3-8 XFPR-G1 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 Clarification COLLECT information via walkdown(s) or, for PRAs performed during pre- operational 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 plant response analysis including consideration of operations; flooding design/licensing basis; design, construction, and performance of flood protection features; hydrology and hydraulics; and manual