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:
SR review is then provided for each HLR. The SRs define the minimum requirements necessary to meet each CC. Some of the SR action statements apply to only one CC, while others cover both CCs. When an action statement spans both categories, it applies equally to each CC. A PRA is considered to have met an HLR if the PRA meets all the applicable SRs under that HLR. The peer review team should determine that an SR is not met when a preponderance of evidence demonstrates that the minimum requirements in an SR at a particular CC are not met. The peer review should identify any issues that impact the acceptability of the PRA and document these problems in an F&O. The F&Os specify the PRA element and SR of concern and RG 1.247, Page 59 describe the level of compliance with that SR in the PRA. The level of significance of each F&O should be characterized as one of the following: • finding—an issue or discrepancy that is necessary to address to ensure the technical adequacy of the PRA, the capability of the PRA, or the robustness of the PRA update process; • suggestion—an observation considered desirable to maintain maximum flexibility for applications and consistency with industry practices; • best practice—an observation of practices that utilities throughout the industry would want to emulate; and • unreviewed analysis method—an observation regarding the use of methods that are new or beyond the expected expertise of the review team. A finding F&O should be written for an SR assessed at CC-I when the SR is being assessed against CC-II. The product of a peer review is a written report documenting the details, findings, observations, conditions, and results of the review. The peer review team should document the results of the review following the guidance in Section 9 of NEI 20-09, Revision 1. A follow-on peer review is performed after the initial peer review of the PRA has already been conducted and at least the F&Os classified as “findings” from the