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:
tions that are precursors to leaks and ruptures and to provide plans for additional and more frequent inspections in response to detection of flaws and degradation mechanisms. The plans for additional inspections following detection of a flaw should be targeted toward locations with the same degradation mechanism that may have contributed to the unacceptable flaw development. The nuclear industry has implemented augmented inspection programs to address generic industry- wide piping degradation problems such as IGSCC and FAC. The licensee should identify whether the proposed changes in the ISI program affect previous licensee commitments for augmented inspection programs for piping degradation problems such as IGSCC and FAC. II.2.2 Probabilistic Risk Assessment The quality of the PRA should be compatible with the safety implications of the ISI change being requested and the degree that the justification of the change request depends on the PRA analysis. Guidance relating the acceptable scope, level of detail, and quality of the PRA analysis based on the anticipated change in risk can be found in Regulatory Guide 1.174, in Section 2.2.3, “Quality of PRA Analysis,” and SRP Chapter 19.0, in Section III.2.2.4, “Quality of a PRA for Use in Risk-Informed Regulation.” The PRA performed should realistically reflect the actual design, construction, and operational practices and reflect the impact of previous changes made to the approved requirements. All calculations using the PRA model should be performed correctly and in a manner that is consistent with accepted practices. Limitations and approximations in the PRA and the PRA techniques that can influence the interpretation of the results required to support the ISI application should be clearly described and appropriately addressed. Parameter uncertainty, model uncertainty, and completeness uncertainty should be addressed in accordance with the guidelines of Regulatory Guide 1.174. The programs and procedures