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:
that demonstrates that these changes do not impede the successful implementation of the other SSCs. These uses of non-safety-related SSCs should be evaluated against all other 10 CFR 50.65(b) scoping criteria. o The following two items apply when EOP steps are added that direct operators to FSGs for additional defense-in-depth measures. If these are met, then the non-safety-related equipment in the FSGs is not considered “used” in the EOPs: o Differentiate the non-safety-related equipment in the FSGs from the equipment providing EOP mitigation function in the Maintenance Rule scoping evaluation or EOP change process documentation. o Equipment already scoped into the Maintenance Rule under the “used in plant EOPs” criteria should not be removed from the Maintenance Rule scope based solely on the addition of non-safety-related equipment in the FSGs as a defense-in-depth measure. DG-1336, Page 10 The above language applies to the use of nonsafety related equipment implemented through the use of FSGs as an additional level of defense-in-depth in a design basis accident, and as a means to address a beyond design basis accident as described in EA 12-049. Section 8.2.1.3 defines “Mitigate or Mitigating” as “actions or steps taken to lessen the severity or the adverse consequences of the event/symptom that necessitated entry into the EOP.” While it is true that utilizing the FSG could lessen the severity or the adverse consequences of the initiating event or symptom that led into the EOPs, the FSGs are not required to mitigate the within-design-basis accidents addressed by the EOPs; the FSGs are not essential to or relied upon for the successful mitigation. Therefore, FSG equipment used to address a beyond-design-basis event condition is not required to perform 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,