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:
orm the EOP mitigating function and is not “used” for that purpose. Accordingly, it’s not scoped into the Maintenance rule under 50.65(b)(2)(i). However, for uses different than described above, where FSG equipment is relied upon to mitigate the design basis accidents or design basis events addressed by the EOPs, the equipment would scope in under 50.65(b)(2)(i).1 SSCs Considered under 10 CFR 50.65(a)(1) Licensees have asked whether the NRC would consider a large number of SSCs monitored under 10 CFR 50.65(a)(1) to be an indicator of poor maintenance performance. The NRC staff’s view is that the number of SSCs monitored under 10 CFR 50.65(a)(1) will not be used as an indicator of licensee performance under the Reactor Oversight Process. The staff recognizes that the number of SSCs monitored under 10 CFR 50.65(a)(1) can vary greatly because of factors that have nothing to do with the quality of the licensee’s maintenance activities. For example, two identical plants with equally effective maintenance programs could have different numbers of SSCs monitored under 10 CFR 50.65(a)(1) because of differences in the way system boundaries are defined (e.g., a system with three trains may be defined as one system at one plant while the same system may be defined as three separate systems at an identical plant) or because of differences in the way performance criteria are defined at the two plants (e.g., a licensee that takes a very conservative approach to monitoring against the performance criteria would have more SSCs in the 10 CFR 50.65(a)(1) category). The NRC staff also cautioned licensee managers that they should not view the number of SSCs in the 10 CFR 50.65(a)(1) category as an indicator of performance because that attitude might inhibit the licensees’ staff from monitoring an SSC under 10 CFR 50.65(a)(1) when a performance criterion has been exceeded or a repetitive MPFF has occurred. If there is some doubt about whether a particular SSC should be