Document: NUREG-0800
Document ID: 2b0752f4-9104-408c-b400-d0ec931a3dbf
Document Type: srp
Title: FIRE PROTECTION PROGRAM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350030.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.5.1
CFR Part: 
CFR Title: 

Content:
h cable trays should also be protected from the effects of a potential exposure fire by providing automatic water suppression in the area where such a fire could occur. In other areas where it may not be possible because of other overriding design features necessary for reasons of nuclear safety to separate redundant safety-related cable systems by 3-hour-rated fire barriers, cable trays should be protected by an automatic water system with open-head deluge or open directional spray nozzles arranged so that adequate water coverage is provided for each cable tray. Such cable trays should also be protected from the effects of a potential exposure fire by providing automatic water suppression in the area where such a fire could occur. The capability to achieve and maintain safe shutdown considering the effects of a fire involving fixed and potential transient combustibles should be evaluated with and without actuation of the automatic suppression system-and should be justified on a suitably defined basis. (3) Electric cable construction should, as a minimum, pass the flame test in the current IEEE Std 383. (This does not imply that cables passing this test will not require fire protection.) (4) Cable raceways should be used only for cables. (5) Miscellaneous storage and-piping for flammable or combustible liquids or gases should not create a potential exposure hazard to safety-related systems. xTrays exceeding 24 inches should be counted as two trays; trays exceeding 48 inches should be counted as three trays, regardless of tray fill. 9.5.1-35 Rev. 2 - July 1981 f. Ventilation (1) The products of combustion and the means by which they will be removed from each fire area should be established during the initial stages of plant design. Consideration should be given to the installation of auto- matic suppression systems as a means of limiting smoke and end heat generation. Smoke and corrosive gases should generally be discharged directly outside to an area that will not