Document: NRC Regulatory Guide
Document ID: bbd6ed7f-058c-4bd2-8849-f708d0179bbf
Document Type: regulatory_guide
Title: Flexible Mitigation Strategies for Beyond-Design-Basis Events + HISTORY - HISTORY 11/2015 – DG-1301 , Proposed Revision 0
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1316/ML13168A031.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.226
CFR Part: 
CFR Title: 

Content:
ime periods in which the equipment and connection points may be unavailable for any reason, with the duration of the acceptable time period being based on the ability of the licensee to accomplish the intended function of the equipment by other means. When a licensee is unable to accomplish the intended function of the equipment by other means, unavailability durations are limited to periods comparable to those allowed by Technical Specifications for safety-related SSCs with similar functions. (See, e.g., the completion times allowed for restoration of turbine-driven auxiliary feedwater trains in limiting condition for operation 3.7.5, “Auxiliary Feedwater (AFW) System,” of NUREG-1431, “Standard Technical Specifications – Westinghouse Plants,” Rev. 4.0, Volume 1, “Specifications,” which range from 24 hours to 7 days. [Ref. 24]) When a licensee is able to accomplish the intended function of the equipment by other means (i.e., the equipment is spare equipment beyond the minimum necessary to accomplish the intended function), unavailability of the equipment is limited to 90 days based on a normal plant work cycle of 12 weeks in order to avoid displacing maintenance actions for other safety- significant equipment or SSCs. DG-1301, Page 13 When a licensee is able to accomplish the intended function of the equipment by other means, but that means is not protected from all possible effects of natural phenomena, unavailability of the equipment is limited to 45 days based on a short-cycle work period of 6 weeks in order to avoid displacing maintenance actions for other safety-significant equipment or SSCs. Similar controls are applied to connection points for the equipment to installed SSCs. Staff Position: Section 11.5.3 of NEI 12-06, Rev. 1A provides an acceptable method for controlling unavailability of the equipment in order to satisfy that element of reasonable protection. 4. Equipment Maintenance 10 CFR 50.155(c)(3) requires that the equipment relied on