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:
c Document Room (PDR) at 11555 Rockville Pike, Rockville, MD. For problems with ADAMS, contact the PDR staff at (301) 415-4737 or (800) 397-4209; fax (301) 415-3548; or e mail pdr.resource@nrc.gov. 12 Copies of American Nuclear Society (ANS) standards may be purchased from the ANS Web site (http://www.new.ans.org/store/), or by writing to: American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526; telephone (800) 323-3044. DG-1359, Appendix B, Page B-1 APPENDIX B TESTING AND QUALIFICATION OF ELECTRICAL RACEWAY FIRE BARRIER SYSTEMS B-1. Fire Endurance Test Acceptance Criteria for Electrical Raceway and Component Fire Barrier Systems for Separating Safe-Shutdown Functions within the Same Fire Area The fire endurance qualification test for fire barrier materials applied directly to a raceway or component is considered to be successful if all three of the following conditions are met: a. The average unexposed side temperature of the fire barrier system, as measured on the exterior surface of the raceway or component, does not exceed 139 degrees Celsius (C) (250 degrees Fahrenheit (F)) above its initial temperature. National Fire Protection Association (NFPA) 251, “Standard Methods of Test of Fire Endurance of Building Construction and Materials,” (Ref. B-1) and American Society for Testing and Materials (ASTM) E119, “Standard Test Methods for Fire Tests of Building Construction and Materials,” allow this temperature to be determined by averaging thermocouple temperature readings. For the purposes of this criterion, the licensee may use thermocouple averaging if similar series of thermocouples (e.g., cable tray side rail) are averaged together to determine temperature performance of the raceway fire barrier system. In addition, conditions of acceptance are placed on the temperatures measured by a single thermocouple. If any single thermocouple exceeds 30 percent of the maximum allowable temperature rise (i.e., 139 ºC + 42 ºC = 181 ºC (250