ML25349A093
| ML25349A093 | |
| Person / Time | |
|---|---|
| Issue date: | 12/15/2025 |
| From: | Thomas Scarbrough NRC/NRR/DEX/EMIB |
| To: | |
| References | |
| Download: ML25349A093 (0) | |
Text
ASME OM CODE CASES OM CODE CASES (FOR DIVISION 1)
The following are the latest approved OM Cases as of August 1, 2025.
Cases represent alternatives or additions to the OM Code. A Case can be a method of handling a reply to an inquiry when study indicated that the Code wording needs clarification or when the reply modifies the existing requirements of the Code, or grants permission to use alternative methods.
Cases remain in effect for the applicable editions and addenda until they are annulled.
Applicability Code Case No.
Title Owner of Code Case From Up to and including OMN-1, Rev 2 Alternative Rules for Preservice and Inservice Testing SG - Motor Operated Valves 1995 2006 OMN-2 Thermal Relief Valve N/A Annulled in 2014 OMN-3 Requirements for Safety Significance Categorization of Components Using Risk Insights for Inservice Testing of LWR Power Plants SC Risk Informed Activities 1990 2017 OMN-4 Requirements for Risk Insights for Inservice Testing of Check Valves at LWR Power Plants SC Risk Informed Activities 1996 2022 OMN-5 Testing of Liquid Service Relief Without Insulation N/A Annulled in 2014 OMN-6 Alternate Rules for Digital Instruments SC - Pumps 1990 2005a OMN-7 Alternative Requirements for Pump Testing SC - Pumps 1995 2012 OMN-7, Rev1 Alternative Requirements for Pump Testing SC - Pumps 1995 2022 OMN-8 Alternative Rules for Preservice and Inservice Testing of Power-Operated Valves That Are Used for System Control and Have a Safety Function per OM-10, ISTC-1.1, or ISTA-1100 SC - Valves 1998 2004 OMN-9 Use of a Pump Curve for Testing SC - Pumps 1990 1992 OMN-10 Requirements for Safety Significance Categorization of Snubbers Using Risk Insights and Testing Strategies for Inservice Testing of LWR Power Plants SC Dynamic Restraints 1995 2022 Revised August 1, 2025
OMN-11 Risk-Informed Testing for Motor-Operated Valves SG - Motor Operated Valves 1995 2006 OMN-12 Risk Insights for Pneumatically and Hydraulically Operated Valve Assemblies in Light-Water Reactor Power Plants SC - Valves 1998 2020 OMN-13, Rev 4 Performance Based Requirements for Extending Snubber Inservice Visual Examination Interval at LWR Power Plants SC - Dynamic Restraints 1995 2020 OMN-14 Alternative Rules for Valve Testing Operations and Maintenance, Appendix I: BWR CRD Rupture Disk Exclusion N/A Annulled in 2014 OMN-15, Rev 4 Performance Based Requirements for Extending the Snubber Operational Readiness Testing Interval at LWR Power Plants SC - Dynamic Restraints 1998 2020 OMN-15, Rev 5 Performance Based Requirements for Extending the Snubber Operational Readiness Testing Interval at LWR Power Plants SC - Dynamic Restraints 1998 2022 OMN-16, Rev 2 Use of a Pump Curve for Testing SC - Pumps 1998 2020 OMN-17, Rev 1 Alternative Rules for Testing ASME Class 1 Pressure Relief/ Safety Valves SG - Pressure Relief Devices 1995 2017 OMN-18 Alternative Testing Requirements for Pumps Tested Quarterly Within +/-20%
of Design Flow SC - Pumps 1994 2011a OMN-19 Alternative Upper Limit for the Comprehensive Pump Test SC - Pumps 1994 2009 OMN-20, Rev 1 Inservice Test Frequencies SC - General Requirements All earlier editions and addenda 2015 OMN-21 Alternative Requirements for Adjusting Hydraulic Parameters to Specified Reference Points SC - Pumps 1995 2011a OMN-22 Smooth Running Pumps SC - Pumps 1990 2020 OMN-23 Alternative Rules for Testing Pressure Isolation Valves SC - Valves 2001 2022 OMN-23, Rev 1 Alternative Rules for Testing Pressure Isolation Valves SC - Valves 2001 2022 OMN-24 Alternative Requirements for Testing ASME Class II & III Relief Valves SG - Pressure Relief Devices 2001 2022 OMN-25 Alternative Requirements for Testing Appendix I Pressure Relief Valves SG - Pressure Relief Devices 2001 2022 Revised December 1, 2025
OMN-26 Alternative Risk-Informed and Margin Based Rules for Inservice Testing of Motor Operated Valves SG - Motor Operated Valves 2012 2022 OMN-27 Alternative Requirements for Testing Category A Valves (Non-PIV/ CIV)
SC - Valves 1998 2022 OMN-28 Alternative Valve Position Verification Approach to Satisfy ISTC-3700 for Valves Not Susceptible to Stem-Disk Separation SC - Valves 1998 2022 OMN-29 Pump Condition Monitoring Program SC - Pumps 2004 2022 OMN-30 Alternative Valve Position Verification Approach to Satisfying ISTC-3700 for Valves Susceptible to Stem-Disk Separation SC - Valves 1998 2022 OMN-31 Alternative to Allow Extension of ISTA-3120 Inservice Examination and Test Intervals From 10 Years to 12 Years SC - General Requirements 2001 2022 OMN-32 Alternatives Requirements for Range and Accuracy of Pressure, Flow, and Differential Pressure Instruments Used in Pump Tests SC - Pumps 2001 2022 OMN-32, Rev 1 Alternatives Requirements for Range and Accuracy of Pressure, Flow, and Differential Pressure Instruments Used in Pump Tests SC - Pumps 2001 2022 OMN-33 Alternative Check Valve Exercise Test Frequency SG - Check Valves 1990 2022 OMN-34 Use of Pump Curve Testing SC Pumps 2012 2022 Revised December 1, 2025