Document: NRC Regulatory Guide
Document ID: 1bd47be4-b79c-4108-b744-3e7d400266e8
Document Type: regulatory_guide
Title: ASME Code Cases Approved for Use Without Conditions (Rev. 0)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2509/ML25091A013.pdf
Revision Date: 2025-09
Chapter: 
Section ID: RG-1.262
CFR Part: 
CFR Title: 

Content:
G 1.262, Page 5 ASME may revise a code case, for example, to incorporate user experience. The licensee or applicant may not apply the older or superseded version of the code case unless it was applied before it was superseded. If an applicant or a licensee applied a code case before it was listed as superseded, it may continue to use the code case until it updates its Construction Code of Record for Section III (an applicant would update its application) or until the licensee’s ISI/IST code of record interval expires for Section XI and the OM Code, after which the NRC prohibits the continued use of the code case unless the agency approves its use under 10 CFR 50.55a(z) or under 10 CFR 50.12. If the NRC incorporates a code case by reference into 10 CFR 50.55a and if ASME later issues a revised version of the code case because experience has shown that the design analysis, construction method, examination method, or testing method is inadequate, the NRC would amend 10 CFR 50.55a and the relevant RG to remove its approval of the superseded code case. Applicants and licensees should not begin to implement such superseded code cases in advance of the rulemaking. With regard to the use of any code case, the user is responsible for ensuring that the provisions of the code case do not conflict with licensee commitments or other regulatory requirements. RG 1.262, Page 6 C. REGULATORY POSITION The NRC reviewed the ASME BPV Code, Section III and Section XI, code cases listed in Supplements 3 through 6 to the 2021 Edition, and Supplements 0 through 3 to the 2023 Edition and the OM code cases listed in the applicability index on the ASME C&S Connect website. The NRC also reviewed select code cases from Supplements 5 and 6 of the 2023 ASME BPV Code. The following three tables list the code cases addressed by this RG: (1) Table 1, “Acceptable Section III Code Cases,” contains Section III code cases that are acceptable for use by applicants and licensees for Section III