Document: NUREG-0800
Document ID: 05a851a6-07ff-41b4-8528-a032ba433e04
Document Type: srp
Title: FIRE PROTECTION PROGRAM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0327/ML032740044.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.5.1
CFR Part: 
CFR Title: 

Content:
re adequately separated such that one success path of safe shutdown capability will be available post-fire. Fire barriers or automatic suppression, or both, may be used to protect redundant systems or components necessary for safe shutdown. In addition to identifying the protection provided for redundant safe shutdown systems, the analysis must also include an evaluation of associated circuits and the potential impacts these circuits might have on the safe shutdown capability. Associated circuits are those circuits within a fire area that may be subject to fire damage that can affect or prevent post-fire safe shutdown capability. Associated circuits of concern are defined as those cables (safety-related, non-safety-related Class 1E and non-Class 1E) that do not meet fire separation requirements and have 1) a common power source with the safe shutdown equipment, 2) a connection to circuits for equipment whose spurious operation could adversely affect safe shutdown, or 3) a common enclosure with safe shutdown circuits. The analysis must demonstrate that potentially disabling conditions caused by associated circuits are prevented or otherwise mitigated and the potentially impacted safe shutdown equipment will function as designed. The safe shutdown analysis should describe the methodology necessary to accomplish safe shutdown, including mitigation of spurious operations or other faulted conditions related to associated circuits. Manual actions may not be credited in lieu of providing the required separation of redundant systems or associated circuits located in the same fire area unless alternate, dedicated, or backup shutdown capability is provided. The analysis should also demonstrate that plant areas where operator actions are necessary are accessible and habitable under fire/post-fire conditions, and without traversing the affected fire area. Procedures should also be described for those actions necessary to repair those safe shutdown systems and components