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:
stem powered by separate electrical divisions, or they may be two or more separate systems designed to perform the same post-fire safe-shutdown function. In cases where the regulatory requirements for protection (e.g., fire barriers, separation, suppression, detection) of at least one of the redundant trains in a single fire area cannot be met, or where the post-fire safe-shutdown function of the train or system is not the design function, the regulatory requirements for alternative or dedicated shutdown systems apply. In the context of post-fire safe shutdown, the redundant train and the alternative or dedicated shutdown system credited with performing the required functions are also referred to as success paths. 5.1 Post-Fire Safe-Shutdown Performance Goals Licensees should ensure that fire protection features are provided for SSCs important to safe shutdown that are capable of limiting fire damage, so that one success path necessary to achieve and maintain hot-shutdown conditions from either the control room or the emergency control station(s) is free of fire damage. The post-fire safe-shutdown performance goal is that the plant achieves and maintains hot shutdown, as defined by the technical specifications. Section III.L of Appendix R to 10 CFR Part 50 provides the following specific performance goals to achieve the post-fire safe-shutdown goals for alternative or dedicated shutdown capability in accordance with Section III.G.3 of Appendix R: a. The reactivity control function should be capable of achieving and maintaining cold-shutdown reactivity conditions. b. The reactor coolant makeup function should be capable of maintaining the reactor coolant level above the top of the core for boiling-water reactors (BWRs) and within the level indication of the pressurizer for pressurized-water reactors (PWRs). Temporary core uncovery in BWRs when depressurizing and using low-pressure systems for post-fire safe shutdown may be acceptable for plants licensed under 10 CFR