Document: NRC Regulatory Guide
Document ID: 96ecfd93-e64a-4f35-93fe-d3b95daac61d
Document Type: regulatory_guide
Title: Monitoring the Effectiveness of Maintenance at Nuclear Power Plants + HISTORY –HISTORY 06/2018 – DG-1336 , Proposed Revision 4 09/2011 – DG-1278 , Proposed Revision 3 08/1996 – DG-1051 , Proposed Revision 2 06/1994 – DG-1031, Proposed Revision 1 11/1992 – DG-1020, Proposed Revision 0 (Rev. 4)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1812/ML18129A080.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.160
CFR Part: 
CFR Title: 

Content:
ting an NRC requirement. However, licensees and applicants may consider and use the information in the secondary reference, if appropriately justified, consistent with current regulatory practice, and consistent with applicable NRC requirements. DG-1336, Page 12 C. STAFF REGULATORY GUIDANCE 1. NUMARC 93-01 The NRC staff endorses the use of Revision 4F to NUMARC 93-01 as an acceptable method for complying with the provisions of 10 CFR 50.65, subject to the following exceptions and clarifications. General Clarification This revision of NUMARC 93-01 references the rule in Section 10 CFR 50.65 that was published in 1999. As described in Section B “Discussion,” subsection “Development of the Maintenance Rule (10 CFR 50.65), of this DG, the Maintenance Rule was amended several times after 1999 to, among other things, clarify that holders combined licenses issued under part 52 must comply with the requirements in 10 CFR 50.65. It is noted that this revision of NUMARC 93-01 does not discuss the later added aspects of the rule. Licensee should consult the current version of 10 CFR 50.65 when following Rev. 4F of NUMARC 93-01. Maintenance-Preventable Function Failures as an Indicator of Reliability NUMARC 93-01 states that performance criteria for SSCs of high safety significance should be established to ensure that reliability and availability assumptions used in the plant-specific safety analysis are maintained or adjusted. NUMARC 93-01 further allows the use of maintenance-preventable functional failures (MPFFs) as an indicator of reliability. The Maintenance Rule requires that the performance of SSCs be monitored commensurate with safety; however, the Maintenance Rule does not require that the assumptions in the safety analysis be validated. Licensees who choose to use their safety analyses as described in NUMARC 93-01 must be able to demonstrate how the number of MPFFs allowed per evaluation period is consistent with the assumptions in the risk analysis. For