Document: NUREG-0800
Document ID: 7916b088-fb90-4163-84fe-027bd315bcc5
Document Type: srp
Title: REVIEW OF RISK INFORMATION USED TO SUPPORT PERMANENT PLANT-
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0717/ML071700658.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.2
CFR Part: 
CFR Title: 

Content:
endix provides review guidance for the likely elements of a PRA that may affect or be affected by proposed changes to the LB. Reviewers should choose the relevant parts of this appendix, guided by the application-specific SRP sections (where available) and by the cause-effect relationship described in Subsection III.2.2.1 of this SRP section. For additional background on the PRA review, the reader is referred to the bibliography provided in Section A.11 of this appendix. A.1 Initiating Event Analysis a. Areas of Review Whether or not a PRA includes a particular initiating event depends on the scope of the PRA, the frequency of the given event, the plant systems or other features available to mitigate the event, and the consequences of the event if unmitigated. Proposed plant changes could affect the frequency of initiating events, the probability of mitigating event initiators, and in some cases, event consequences. In addition, plant changes could potentially introduce new initiating events or increase the importance of events that were previously screened out. b. Review Guidance and Procedures For risk-informed applications, reviewers should determine whether the licensee followed a systematic approach to determine whether initiating events and anticipated plant response are affected by the proposed changes. Reviewers should also determine whether the licensee’s process includes provisions to evaluate whether the proposed changes can (i) increase the 19.2-42 June 2007 frequency of an initiator already included in the PRA, (ii) increase the frequency of initiators that were initially screened out in the PRA, (iii) introduce new initiating events, or (iv) affect the grouping of initiating events. These considerations are discussed in more detail in the following paragraphs. Applications that change the frequency of an initiator or the ability of the plant to respond to event initiators are relatively easy to model in the risk analysis if the initiators are already