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:
nd (2) stated that they had an equivalent program or will implement one. Subsequently, utilities docketed commitments to maintain their selected target reliability values (i.e., maintain the emergency diesel generator target reliability of 0.95 or 0.975). Those values could be used as a goal or as a performance criterion for emergency diesel generator reliability under the Maintenance Rule. Emergency diesel generator unavailability values were also assumed in plant-specific individual plant examination analyses. These values should be compared to the plant-specific emergency diesel generator unavailability data regularly monitored and reported as industrywide plant performance information. These values could also be used as the basis for a goal or performance criterion under the Maintenance Rule. In addition, in accordance with 10 CFR 50.65(a)(3), licensees must periodically balance the unavailability and reliability of the emergency diesel generators. Use of Other Methods Licensees may use methods other than those provided in NUMARC 93-01 to meet the requirements of the Maintenance Rule. The NRC will inspect the implementation of these methods on a plant-specific basis. 2. Probabilistic Risk Assessments Use of Probabilistic Risk Assessments NUMARC 93-01 contains multiple references to the use and application of a PRA or a probabilistic safety assessment (PSA) in a licensee’s implementation of the Maintenance Rule. The NRC staff endorses the use and application of these risk analyses as described in NUMARC 93-01. Like other types of engineering analyses used to support the regulatory process, risk analyses must be sound and technically defensible. Sound and technically defensible risk analyses help increase confidence in and the consistency of decision making. When a PRA is used in a licensee’s implementation of the Maintenance Rule, the acceptability of the base PRA should be sufficient to provide the needed confidence in the results being used in the decision.