Document: NRC Regulatory Guide
Document ID: 82659041-98b0-4721-b25d-c4fb2ea394d0
Document Type: regulatory_guide
Title: An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1635/ML16358A153.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.174
CFR Part: 
CFR Title: 

Content:
nts; Policy Statement.” • Principle 5: The impact of the proposed licensing basis change should be monitored using performance measurement strategies. Each of these principles should be considered in the risk-informed, integrated decisionmaking process, as illustrated in Figure 2. DG-1285, Page 8 Figure 2. Principles of risk-informed integrated decisionmaking The staff’s evaluation approach and acceptance guidelines follow from these principles. In implementing these principles, the staff expects the following: • All safety impacts of the proposed licensing basis changes are evaluated in an integrated manner as part of an overall risk management approach in which the licensee is using risk analysis to improve operational and engineering decisions broadly by identifying and taking advantage of opportunities to reduce risk and not just to eliminate requirements the licensee sees as undesirable. For those cases in which risk increases are proposed, the benefits should be described and should be commensurate with the proposed risk increases. The approach used to identify changes in requirements should be used to identify areas in which requirements should be increased as well as those in which they can be reduced. • The engineering analyses (including traditional and probabilistic analyses) conducted to justify the proposed licensing basis change should (1) be appropriate for the nature and scope of the change, (2) be based on the as-built and as-operated and maintained plant, and (3) reflect operating experience at the plant. The ASME/ANS standard endorsed by RG 1.200 defines as-built, as-operated as a conceptual term that reflects the degree to which the PRA matches the current plant design, plant procedures, and plant performance data, relative to a specific point in time (see Section C.2.3 of this RG for additional information on the relationship between RG 1.174 and the ASME/ANS standard). Acceptability of the engineering analyses is determined by