Document: NUREG-0800
Document ID: e32f0820-4e33-476e-aa36-4ca8c2c64af0
Document Type: srp
Title: Use of Probabilistic Risk Assessment in Plant-Specific, Risk-Informed Decisionmaking:
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0119/ML011940192.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.0
CFR Part: 
CFR Title: 

Content:
different SSC groups at different times, reviewers should also assess the basis for the licensee's grouping criteria, keeping in mind the potential common cause failures. Monitoring should be applied to SSCs in a manner commensurate with their importance to safety as determined by the engineering evaluation that supports the LB change. This monitoring should be contingent on the reliability/availability allocated to SSCs in the risk model (or on performance of operators, where appropriate) used to support the proposed change in regulation. As such, reviewers should ensure that the chosen performance criteria are consistent with the level of performance allocated in the risk analysis. When monitoring that is already being performed as part of the Maintenance Rule implementation or as part of other plant programs is also proposed for the current application, reviewers should ensure that the monitoring proposed is sufficient for the SSCs affected by the risk-informed application, and the performance criteria chosen are appropriate for the application in question. As part of the evaluation of the licensee's monitoring program, reviewers should assess the proposed provisions for cause determination, trending of degradation and failures, and corrective actions. The program should be structured such that feedback of information and corrective actions is accomplished in a timely manner, and degradation in SSC performance is detected and corrected before plant safety can be compromised. In cases where monitoring detects degradation, there should be provisions for a trending and corrective action program, or for the SSCs to be refurbished, replaced, or tested/inspected more often (or a combination of these initiatives). The preferred initiative should be selected on the SRP 19-27 111.3 Element 3: basis of determination regarding the cause of the degradation (whether it is generic, age-related, etc.). Reviewers should evaluate if the information gathered during monitoring