Document: NUREG-0800
Document ID: ac43f632-9db1-4857-9f56-bfba45965456
Document Type: srp
Title: * These are modifications to a plant’s design, operations, or other activities that require NRC approval. These modifica
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0232/ML023250195.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19
CFR Part: 
CFR Title: 

Content:
that revisits the assumptions or screening criteria used to support the initial omission. III.2.2.4 Quality of a PRA for Use in Risk-Informed Regulation The baseline risk profile is used to model the plant's licensing basis and operating practices that are important to safe operation. As such, the profile may provide insights into areas in which existing requirements can be relaxed without unacceptable safety consequences. It is therefore essential that the PRA adequately represent the risk profile. To complement this requirement, it is necessary to identify those elements of the plant that are responsible for reducing the risk to acceptable levels and to adequately address those elements in the licensee's programmatic activities. Therefore, the following criteria should be satisfied in risk-informed regulation. • A reasonable assurance exists with regard to the adequacy of the PRA. That is, the PRA model properly reflects the actual design, construction, operating practices, and operating experience of the plant and its owner. This should include plant changes arising from the licensee's voluntary actions, regulatory requirements, or previous changes made to the LB. • The results and conclusions are "robust" and, where appropriate, the licensee has conducted an analysis of uncertainties and sensitivities to show this robustness. • Key performance elements are appropriately classified, and performance is backed up by licensee actions. PRA results are dependent on plant activities. They reflect not only inherent device characteristics, but also numerous programmatic activities, such as IST, ISI, quality assurance, or maintenance. Use of a PRA to justify relaxation of a requirement should therefore imply a commitment to the important programmatic activities that are needed to maintain performance at the PRA-credited levels that served as the basis for the proposed relaxation. III.2.2.4.1 Review of the PRA Quality Required for an Application The submittal must