Document: NRC Regulatory Guide
Document ID: 6f84e3bf-9ff3-49fb-a16a-0de3b89e6bc6
Document Type: regulatory_guide
Title: An Approach for Plant-Specific Risk-Informed Decisionmaking for Inservice Inspection of Piping (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2103/ML21036A105.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.178
CFR Part: 
CFR Title: 

Content:
ry methodologies and of numerous plant-specific relief requests for inservice inspection (ISI) programs, the NRC staff issued Revision 1 of this RG in 2003. In addition, the NRC staff has periodically reviewed this RG and is now issuing this updated version. This revision incorporates the updated guidance on defense in depth and conforms to the latest RG program guidance. The NRC has not approved the RI-ISI processes described in EPRI TR-112657 and WCAP-14572 for generic use. When licensees intend to use an RI-ISI process not approved for generic use, the NRC staff anticipates that the licensees will incorporate changes to their ISI programs by requesting NRC approval of alternative inspection programs that meet the criteria of 10 CFR 50.55a(z)(1) and provide an acceptable level of quality and safety. As always, licensees should identify how the chosen approach, methods, data, and criteria are appropriate for the decisions they need to make. Licensees may use ASME Code Cases approved by the NRC as an alternative to compliance with ASME BPV Code provisions that the NRC has incorporated by reference into 10 CFR 50.55a. In 2014, the NRC approved ASME Code Case N-716-1 as an alternative RI-ISI process in RG 1.147. ASME Code Case N-716-1 indicates that a licensee may use the Code Case without requesting NRC approval unless the licensee holds a combined operating license issued after January 1, 2012. When a licensee intends to use Code Case N-716-1 for new reactors, the NRC staff will review operating experience to confirm the adequate use of the Code Case in the development of plant-specific RI-ISI programs. However, the status of ASME BPV Code and Code Cases continues to change, and the NRC staff updates 10 CFR 50.55a and RG 1.147 periodically. Accordingly, licensees should refer to the latest revision of 10 CFR 50.55a and RG 1.147 to identify the provisions of ASME BPV Code and Code Cases on ISI that the NRC has approved. This guide’s principal focus is on the use of