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:
ate the ability of the plant to safely shut down for a fire in any given area. Regulatory Position 5.1 of this guide identifies the safe-shutdown performance goals. The licensee should demonstrate the ability of the selected systems to accomplish these performance goals. Analysts assess fire damage to safe-shutdown equipment or fires with the potential to result in the release of radioactive materials to the environment on the basis of a single fire, including an exposure fire. An exposure fire is a fire in a given area that involves either in situ or transient combustibles and has the DG-1359, Page 20 potential to affect SSCs important to safety or the release of radioactive materials located in or adjacent to that same area. The effects of such a fire (e.g., smoke, heat, or ignition) can adversely affect those SSCs important to safety or the ability to prevent release of radioactive materials. Thus, a fire involving one safe-shutdown success path may constitute an exposure fire for the redundant success path located in the same area, and a fire involving combustibles not in either redundant success path may constitute an exposure fire for both redundant success paths located in the same area. The analysis should identify the safe-shutdown components and circuits for each fire area and demonstrate that the plant meets the guidelines in Regulatory Position 5.3 or that it provides an alternative or dedicated shutdown, in accordance with Regulatory Position 5.4 of this guide. For each plant, the combinations of systems that provide the shutdown functions may be unique for each area; however, the shutdown functions provided should ensure that the plant achieves its safe-shutdown performance objectives. The licensee should also develop and implement procedures necessary to implement safe shutdown as appropriate (see Regulatory Position 5.5 of this guide). 1.4 Fire Test Reports and Fire Data The licensee should evaluate fire reports and data (e.g., fire barrier testing