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:
tive to the effectiveness of past inspections of the piping and the flaws that have been observed should be described. II.2 Element 2: Engineering Analysis After the proposed changes to the licensee's ISI program have been defined, the licensee should conduct an engineering analysis of the proposed changes using a combination of traditional 3.9.8-8 engineering analysis with supporting insights from a PRA. Regulatory Guides 1.174 and 1.178 provide guidance for the performance of this evaluation. II.2.1 Traditional Analysis The traditional engineering analyses conducted should assess whether the impact of the proposed ISI changes (individually and cumulatively) is consistent with the principles that defense in depth and adequate safety margins are maintained. The primary regulations governing ISI of piping are 10 CFR 50.55a and Appendix A to 10 CFR Part 50. The intent of these regulations is to maintain the structural integrity of piping in a nuclear power plant. The regulations reference other codes and requirements that define the elements of a defense- in-depth philosophy to ensure the structural integrity of piping. For each of the regulations and licensing bases relevant to the ISI of piping, the licensee should ensure that the proposed changes to the ISI program do not deviate from the regulations and licensing bases. ASME B&PVC Section XI is referenced in 10 CFR 50.55a for the detailed requirements regarding piping ISI. The objective of the ISI requirements of the ASME Code has been to identify conditions, such as flaw indications, that are precursors to leaks and ruptures in pressure boundaries that may impact plant safety. The licensee should verify that the proposed changes to the ISI program meet or exceed the intent of ASME B&PVC Section XI to identify conditions 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