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:
e been addressed and there is a sufficiently high probability of detecting damage before structural integrity is impacted. The process by which the safety significance of piping segments is taken into account in defining the scope of the inspection program is reviewed. The inspection scope, examination methods, and methods of evaluation of examination results are reviewed with the objective of establishing whether the RI-ISI inspection program provides an acceptable level of quality and safety. The criteria for selecting areas and volumes of safety significant piping structural elements for inspection are reviewed to ensure that the applicable degradation mechanisms are addressed. The methods by which the degradation mechanisms, postulated failure modes, and configuration of piping structural elements are incorporated in the inspection scope and inspection locations are reviewed. The manner in which significant stress concentration, geometric discontinuities, and generic as well as plant-specific pipe cracking experience is considered in selecting inspection locations is reviewed. Alternative methods to ensure structural integrity in cases in which examination methods cannot be applied because of limitations, such as inaccessibility or radiation exposure hazards, are reviewed. In the context of the RI-ISI program, the sampling strategy is defined by the selection of structural elements that are proposed by the licensee for inclusion in the inspection. The reviewer will determine whether the criteria for the expansion of the sample size are acceptable and that sequential sampling is based on ISI findings and other evidence of structural degradation. Inspection methods and acceptance standards used in the implementation of the RI-ISI program are reviewed. Inspection methods selected by the licensee should address the degradation mechanisms, pipe sizes, and materials of concern. The manner in which the degradation mechanism is taken into consideration in determining