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:
shutdown capability and the prevention of radiological release, can be integrated in the planning and design phase, a new DG-1359, Page 81 reactor plant should have minimal reliance on operator manual actions and alternative or dedicated shutdown systems (protection for fires in the main control room will require alternative shutdown capability). 5.3.1.4 Fire Modeling When one of the redundant safe-shutdown trains in a fire area is maintained free of fire damage by one of the specified means in Regulatory Position 5.3.1.1, then fire modeling may be used to demonstrate that components important to safe shutdown, including SSCs that are not part of the success path, are protected from fire damage. The use of fire modeling should be in accordance with the licensee’s FPP and license condition. Regulatory Position 1.8.7 of this guide provides information on fire modeling. When fire modeling is used to demonstrate that components important to safe shutdown are protected from fire damage, the analysis should consider in situ and transient fire sources in the area and all targets that involve components important to safe shutdown. The fire models should be used within the bounds of their capability. By considering expected room configurations (e.g., doors open or closed), the fire modeling analysis should show that the largest expected fire will not affect the components important to safe shutdown. In addition, the area being analyzed should include effective automatic suppression in the fire area, a significant margin between the expected fire and the damage threshold of the target, or other features to provide an adequate safety margin and defense in depth. 5.3.1.5 Examples of Safe-Shutdown Success Path Components and Components Important to Safe Shutdown General examples of components that should be considered part of the safe-shutdown success path and components that are important to safe shutdown are listed below. Appendix H to NEI 00-01, Revision 4, provides