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:
modification of the RI-ISI program resulting from changes in plant design features, plant procedures, equipment performance, examination results, and individual plant and industry failure information. Inspection scope and examination methods for the RI-ISI program should provide an acceptable level of quality and safety as stipulated in 10 CFR 50.55a(a)(3)(i). Inspection strategies should ensure that failure mechanisms of concern have been addressed and that there is a sufficiently high probability of detecting damage before structural integrity is impacted. Safety significance of piping segments should be taken into account in defining the inspection scope for the RI-ISI program. Degradation mechanisms, postulated failure modes, and configuration of piping structural elements should be incorporated in the definition of the inspection scope and inspection locations. For piping segments that are included in the existing plant FAC or IGSCC (Category B-G) inspection programs, the inspection locations should be the same as in the existing programs. For segments not in these programs, inspection locations should be mainly based on specific degradation mechanism and industry as well as plant-specific cracking experience. Determination of inspection locations for segments with no known degradation mechanism but high failure consequence should be based on sensitized weld locations, stress concentration, geometric discontinuities, and terminal ends. Plant- specific pipe cracking experience should be considered in selecting inspection locations. To be acceptable, alternative examination methods should be specified to ensure structural integrity in cases where examination methods cannot be applied due to limitations, such as inaccessibility or radiation exposure hazards. System pressure tests and visual examination of ASME piping structural elements should continue to be performed regardless of whether the segments contain locations that have been classified as safety