Document: NRC Regulatory Guide
Document ID: 7d480029-59df-44fe-9db8-c1c86566dac9
Document Type: regulatory_guide
Title: Operation and Maintenance Code Case Acceptability, ASME OM Code (Rev. 5)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2219/ML22196A063.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.192
CFR Part: 
CFR Title: 

Content:
the approval of the annulled Code Case. Applicants or licensees should not begin to implement such annulled OM Code Cases before the rulemaking. Notwithstanding these requirements, the Commission may impose new or revised OM Code requirements, including implementation schedules, which it determines are consistent with the Backfit Rule (10 CFR 50.109, “Backfitting”). ASME may revise an OM Code Case, for example, to incorporate user experience. The licensee or applicant cannot apply the older or superseded version of the OM Code Case for the first time. If an applicant or a licensee applied a Code Case before it was listed as superseded, the applicant or the licensee may continue to use the Code Case until the applicant or licensee updates its Construction Code of Record (an applicant would update its application) or until the licensee’s 120-month IST update interval expires, after which the continued use of the OM Code Case is prohibited unless the NRC grants approval under 10 CFR 50.55a(z). If an OM Code Case is incorporated by reference into 10 CFR 50.55a and later ASME issues a revised version because experience has shown that the design analysis, construction method, examination method, or testing method is inadequate, the NRC will amend 10 CFR 50.55a and the relevant RG to remove the approval of the superseded OM Code Case. Applicants and licensees should not begin to implement such superseded OM Code Cases in advance of the rulemaking. RG 1.193, “ASME Code Cases Not Approved for Use,” lists the OM Code Cases that the NRC determined to be unacceptable. With regard to the use of any OM Code Case, the user is responsible for ensuring that the provisions of the OM Code Case do not conflict with regulatory requirements or licensee commitments. DG-1407, Page 6 C. REGULATORY POSITION RG 1.192, Revision 5, supersedes Revision 4. For Revision 5 of RG 1.192, the NRC reviewed the OM Code Cases listed in an applicability index on the ASME C&S Connect website.