Document: NUREG-0800
Document ID: b07c8dd1-23f6-41f1-a3ba-aa378f9ea59a
Document Type: srp
Title: RISK-INFORMED INSERVICE INSPECTION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0325/ML032510135.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.8
CFR Part: 
CFR Title: 

Content:
Systems The scope of piping systems included in the RI-ISI program is reviewed in accordance with the acceptance criteria in Section II.2.2.1. III.2.2.2 Piping Segments Criteria and procedures used to establish piping segments within the piping systems are reviewed to determine whether consequences of failure, degradation mechanisms, and segment boundaries are properly considered for defining piping segments in accordance with the acceptance criteria given in Section II.2.2.3 of this SRP section. III.2.2.3 Evaluating Pipe Failures with PRA Acceptable approaches for evaluating pipe failures with PRA are provided in Section II.2.2.3. The approach used is reviewed to verify whether the sequence of events from new initiators is appropriately developed if piping segment failure introduces new initiating events. If the pipe segment failure yields the same consequences as some other initiator already included in the PRA, the 3.9.8-17 reviewer verifies that the risk from the original initiating event is appropriately represented in the ISI analysis. If pipe failures are characterized by a set of PRA basic events used as surrogates representing the equivalent impact of the pipe failure, the basic events are reviewed to ensure that the surrogate is an adequate representation of the pipe segment failure and that the resulting risk insights are reflected in the ISI analysis. If surrogate basic events cannot be found, the analysis used to characterize the new failure events using the PRA models or results and extract representative risk insights is reviewed. III.2.2.4 Piping Failure Potential The processes and documentation used to identify the degradation mechanisms is reviewed to verify that they are sufficient and were systematically applied. The identified degradation mechanisms are reviewed to determine that the results are an appropriate characterization and were developed at a level of detail consistent with the use of the information to support the change request. These