Document: NUREG-0800
Document ID: 4e1d86bd-74a5-4678-8bc0-ffce3ba28ea0
Document Type: srp
Title: RISK-INFORMED INSERVICE TESTING
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0428/ML042880272.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.7
CFR Part: 
CFR Title: 

Content:
d that the impact of the change on individual components can be accommodated, either because there are events in the model that are in direct correspondence with the affected components, or there is a mapping of the impact onto events in the model. Components for which there is no mapping must be addressed with supplementary arguments. Quality: The licensee must show that the PRA has been performed correctly and in a manner that is consistent with accepted practices, and commensurate with the scope and level of detail discussed above. If the approach to ensuring quality includes, in part, a peer review (e.g., an independent peer review, an industry PRA certification, or an industry PRA cross comparison), the staff reviewer should determine that the peer review process has been performed by qualified individuals with knowledge of PRA techniques and practices. Reviewers should use SRP Chapter 19, Appendix A as a guide to perform their own limited review of the PRA. 6. Categorization of Components When risk importance measures are used to group components as low risk significant, additional evaluations, sensitivity studies and other considerations have to be taken into account. Review procedures for component risk categorization are provided in Appendix C of SRP Chapter 19. One of the considerations discussed in Appendix C of SRP Chapter 19 is the issue that importance measures cannot address the integrated impact of the change. This aspect is best addressed during the quantification of the impact of the change (item 7 below). Typically, the PRA derived categorization will only address a subset of the contributions to risk. That is, if the PRA only models internal event initiators at full power operations, results from risk importance calculations will only be applicable for these events. If the PRA results are adopted for other contributors, the reviewer should determine whether the same assumptions that apply for the PRA model are likely to apply under the conditions