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:
e NRC endorsed OM Code Cases through this guide for the first time in June 2003. Beginning with the 2009 Edition, ASME changed the title of the OM Code to “Operation and Maintenance of Nuclear Power Plants.” ASME periodically publishes a new edition of the OM Code. The latest editions and addenda of the OM Code that the NRC has approved for use are referenced in 10 CFR 50.55a(a)(1)(iv). ASME also periodically publishes OM Code Cases, which provide alternatives to existing OM Code requirements that ASME developed and approved. This RG identifies the OM Code Cases that the NRC has determined to be acceptable alternatives to applicable parts of the OM Code. Applicants or licensees may use these OM Code Cases without requesting authorization from the NRC, provided that they are used with any identified limitations or modifications. Under 10 CFR 50.55a(z), a licensee or applicant may request authorization to use OM Code Cases that the NRC has not yet endorsed. That section permits the use of alternatives to the OM Code requirements referenced in 10 CFR 50.55a, provided that the proposed alternatives result in an acceptable level of quality and safety and their use is authorized by the Director of the Office of Nuclear Reactor Regulation. The OM Code is incorporated by reference into 10 CFR 50.55a. The regulation at 10 CFR 50.55a(b)(6) states the requirements governing the use of OM Code Cases. Because of continuing change in the status of OM Code Cases, the NRC staff plans periodic updates to 10 CFR 50.55a and to this guide to accommodate new OM Code Cases and any revisions of existing OM Code Cases. OM Code Cases DG-1407, Page 5 that the NRC approves provide an acceptable voluntary alternative to the mandatory OM Code provisions. When an applicant or licensee initially implements an OM Code Case, 10 CFR 50.55a requires implementation of the most recent version of that Code Case as listed in Tables 1 and 2. If an applicant or licensee implements an OM Code Case and a