Document: NRC Regulatory Guide
Document ID: 47b09be1-4bf8-45f9-a099-7fed871c09bd
Document Type: regulatory_guide
Title: Plant-Specific, Risk-Informed Decisionmaking: Inservice Testing (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2114/ML21140A055.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.175
CFR Part: 
CFR Title: 

Content:
dance on risk metrics for plants licensed under 10 CFR Part 52. f. Increases in CDF and LERF resulting from proposed licensing basis changes should be limited to small increments. The decision process should track and consider the cumulative effect of such changes, whether they result in an increase or a decrease, if available, in risk. For purposes of this guide, a proposed licensing basis change that meets the acceptance guidelines discussed in Section C.2.4 of RG 1.174 is considered to meet the intent of the policy statement. RG 1.175, Page 20 g. The licensee should evaluate the acceptability of the proposed licensing basis changes in an integrated fashion that ensures that all principles are met. h. Data, methods, and assessment criteria used to support regulatory decisionmaking should be well documented and available for public review. These expectations apply to both probabilistic and deterministic engineering considerations, which are addressed in more detail in this section and in RG 1.174. Licensees are expected to review commitments related to outage planning and control to verify that they are appropriately reflected in the licensee’s component grouping. This should include components necessary to maintain adequate defense-in-depth as well as components that might be operated as a result of contingency plans developed to support the outage. Licensees are also expected to review licensing basis documentation to ensure that the deterministic engineering-related factors mentioned above are adequately modeled or otherwise addressed in the PRA analysis. When making final programmatic decisions, choices should be made based on all the available information. There may be cases where information is incomplete or where conflicts appear to exist between the deterministic engineering data and the PRA-generated information. The licensee should use well-reasoned judgment to resolve the issues in the best manner possible, including due consideration to the safety of