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:
Method for Surface Burning Characteristics of Building Materials” (Ref. 94); b. potential heat release of 8,141 kilojoules per kilogram (kJ/kg) (3,500 Btu/pound (lb)) or less when tested under ASTM D3286, “Standard Test Method for Gross Calorific Value of Coal and Coke by the Isoperibol Bomb Calorimeter” (Ref. 95), or NFPA 259, “Standard Test Method for Potential Heat of Building Materials” (Ref. 96). The concept of using a potential heat release limit of 8,141 kJ/kg (3,500 Btu/lb) is like the “limited combustible” concept with its similar limit, as set forth in NFPA 220, “Standard on Types of Building Construction” (Ref. 97); c. floor covering critical radiant flux as determined by testing in accordance with NFPA 253, “Standard Method of Test for Critical Radiant Flux of Floor Covering Systems Using a Radiant Heat Energy Source” (Ref. 98). DG-1359, Page 59 4.1.2 Compartmentalization, Fire Areas, and Zones In accordance with GDC 3 in Appendix A to 10 CFR Part 50, SSCs important to safety must be designed and located to minimize the probability and effect of fires and explosions. The concept of compartmentalization meets GDC 3, in part, by using passive fire barriers to subdivide the plant into separate areas or zones. The primary purpose of these fire areas or zones is to confine the effects of fires to a single compartment or area, thereby minimizing the potential for adverse effects from fires on redundant SSCs important to safety. 4.1.2.1 Fire Areas A fire area is defined as that portion of a building or plant that is separated from other areas by fire barriers, including components of construction such as beams, joists, columns, penetration seals or closures, fire doors, and fire dampers. Fire barriers that define the boundaries of a fire area should have a fire-resistance rating of 3 hours or more and should achieve the following: a. separation of SSCs important to safety from any potential fires in nonsafety-related areas that could