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:
The evaluation should include a determination of whether the potential failure of each segment is best characterized as a demand failure while responding to a plant transient or an operational failure which causes a plant transient. When data analysis is utilized to develop a quantitative estimate, the data should be appropriate and complete. When elicitation of expert opinion is used in conjunction with, or in lieu of probabilistic fracture mechanics or data analysis, a systematic procedure should be developed for conducting such elicitation and a suitable team of experts should be selected and trained. When categorization based on the degradation mechanism is used, the justification for the relationship between the degradation mechanism and the assigned category should be appropriate and complete. The assessment of piping failure potential should take into account uncertainties. These uncertainties include, but are not limited to, design versus fabrication differences, variation in material properties and strength, the effect of various degradation and aging mechanisms, variation in steady-state and transient loads, availability and accuracy of plant operating history, availability of inspection and maintenance program data, and capabilities of analytical methods and models to predict realistic results. The methodology, process, and rationale used to determine the failure potential of piping segments should be reviewed and approved by the plant expert panel as part of its deliberations during the final classification of the safety significance of each segment. This process should be justified, documented, and included in the submittal. When computer codes are used to develop quantitative estimates, the techniques should be verified and validated against established industry codes. II.2.2.5 Consequences of Failure The impact on risk that is due to piping pressure boundary failure should consider both direct and indirect effects. Consideration of direct effects