Document: NRC Regulatory Guide
Document ID: 8e45dce1-e1e7-4415-b1dd-7e2a610e545b
Document Type: regulatory_guide
Title: Fire Protection for Nuclear Power Plants (Rev. 4)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2023/ML20231A835.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.189
CFR Part: 
CFR Title: 

Content:
licensing basis (i.e., 10 CFR Part 50, Appendix R, Section III.G.1.b, or applicable BTP), fire damage must be limited so that at least one success path can be repaired or made operable within 72 hours using onsite capability or within the time period required to achieve a safe-shutdown condition, if less than 72 hours. For alternative or dedicated shutdown, equipment or systems that are the means to achieve and maintain cold-shutdown conditions may be damaged by fire. If fire damage does occur to alternative or dedicated shutdown equipment and systems, the damage should be limited so that the systems can be made operable and cold shutdown achieved within 72 hours (or less time, if required) using only onsite power. Systems and components used for safe shutdown after 72 hours (or less time, if required) may be powered from offsite power only. Repairs made to ensure cold-shutdown capability (e.g., the replacement of fuses and cabling) are permitted. Selected equipment replacement is also allowed, if practicable. Procedures should be prepared for repairing damaged equipment (see Regulatory Position 5.5.3 of this guide), and dedicated replacement equipment should be stored on site and controlled. Repairs should be of sufficient quality to ensure safe operation until the normal equipment is restored to an operating condition. Repairs not permitted include the use of clip leads in control panels (i.e., hard-wired terminal lugs should be used) and the use of jumper cables other than those fastened with terminal lugs. When repairs are necessary in the fire area, the licensee should demonstrate that sufficient time is available to allow the area to be reentered, that expected fire and fire suppressant damage will not prevent the repairs from taking place, and that the repair procedures will not adversely affect operating systems. 5.3 Fire Protection of Safe-Shutdown Capabilities The post-fire safe-shutdown analysis should ensure that one success path remains free of fire