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:
nts 1/2023E N-888-2 Similar and Dissimilar Metal Welding Using Ambient Temperature SMAW or Machine GTAW Temper Bead Technique 3/2023E N-892-1 Alternative Requirement for Form OAR-1, Owner’s Activity Report, or Inservice Inspection Summary Report Completion Time 0/2023E N-894 Repair of Class 1, 2, and 3 Austenitic Stainless Steel with Thermal Fatigue Cracking 3/2023E N-922 Alternative Requirements for Application of Structural Factors to Secondary Stresses for Analytical Evaluation of Flaws in Piping in Accordance with IWB-3644, IWC-3644, and IWD-3644 4/2021E N-923 Mechanical Piping Joints 4/2021E N-932 Alternative Requirements for Acceptance of Containment Base Metal Corrosion or Erosion 1/2023E N-939 Alternative Requirements for Use of Mandatory Appendix XI for Repair/Replacement Activities for Aboveground Class 3 Polyethylene Piping 6/2023E RG 1.262, Page 9 3. Acceptable OM Code Cases The NRC determined that the OM code case listed in table 3 is acceptable for use by licensees in their IST programs. The OM Code editions to which the use of the specified code case is applicable are provided in the third column of table 3. To assist users, new or newly revised code cases are shaded in grey to distinguish them from those listed in previous versions of this guide. Users should be aware that a code case approved in this RG may be a more recent version of a code case previously approved in RG 1.192. Licensees are required to follow 10 CFR 50.55a(b)(6) when applying ASME OM code cases. The NRC will update this table in the future as additional code cases are determined to be appropriate for this RG. Table 3. Acceptable OM Code Cases CODE CASE NUMBER TITLE APPLICABILITY OMN-23, Revision 1 Alternative Rules for Testing Pressure Isolation Valves 2001 to 2022 Editions RG 1.262, Page 10 D. IMPLEMENTATION The purpose of this section is to provide information to applicants and licensees regarding the NRC staff’s plans for using this RG. This RG lists the ASME BPV Code,