Document: NRC Regulatory Guide
Document ID: 80776ca5-a83d-4667-9a94-0bffa1befa91
Document Type: regulatory_guide
Title: Fire Protection Guidelines for Nuclear Power Plants (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1221/ML12216A013.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.120
CFR Part: 
CFR Title: 

Content:
provide fire detection, annunciation, confinement, and suppression for the plant. The staff should also be responsible for fire prevention activities, maintenance of fire protection systems, training, and manual firefighting activities. It is the combination of all these that provides the needed defense-in-depth protection of the public health and safety. Some of the major conclusions that emerged from the Browns Ferry fire investigations warrant emphasis and are discussed below. 1. Defense in Depth Nuclear power plants use the concept of defense in depth to achieve the requ'ired high degree of safety by using echelons of safety systems. This concept is also applicable to fire safety in nuclear power plants. With respect to the fire protection program, the defense-in-depth princi- ple is aimed at achieving an adequate balance in: a. Preventing fires from starting; b. Detecting fires quickly, suppressing those fires that occur, putting them out quickly, and limiting their damage; and c. Designing plant safety systems so that a fire that starts in spite of the fire preven- tion program and burns for a considerable time in spite of fire protection activities will not prevent essential plant safety functions from being performed. No one of these echelons can be perfect or complete by itself. Strengthening any one can compensate in some measure for weaknesses, known or unknown, in the others. The primary objective of the fire protection program is to minimize both the probability and consequences of postulated fires. In spite of steps taken to reduce the probability of fire, fires are expected to occur. Therefore, means are needed to detect and suppress fires with particular emphasis on providing passive and active fire protection of appropriate capability and adequate capacity for the systems necessary to achieve and maintain safe plant shutdown with or without offsite power. For other safety-related systems, the fire protection should ensure that a fire will not cause