Document: NUREG-0800
Document ID: 8ec28e2c-84e9-408b-afcb-1838fbfe7efc
Document Type: srp
Title: ENGINEERED SAFETY FEATURE VENTILATION SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550041.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.4.5
CFR Part: 
CFR Title: 

Content:
ted accidents. With regard to the ESFVS, the plant design should ensure that electrical contacts and relays in diesel generator rooms are protected from dust, dirt, and grit. For example, contacts and relays must be enclosed in dust-tight cabinets with fully gasketed openings and ventilation louvers must be equipped with filters. In addition, air used for ventilation should be filtered and should be taken from a height of at least 7 meters (20 feet) above ground level. Meeting these requirements provides assurance that a reliable electric power supply will be available for all facility operating modes, including anticipated operational occurrences and postulated accidents. 5. Compliance with GDC 60 requires that provisions be included in the nuclear power unit design to control the release of radioactive materials in gaseous effluents during normal reactor operation, including anticipated operational occurrences. RGs 1.140 and 1.52 present methods acceptable to the Commission staff with regard to design, testing, and maintenance criteria for air filtration and adsorption units of normal ventilation exhaust systems and of engineered safety feature atmosphere cleanup systems used in light-water-cooled nuclear power plants. Atmosphere cleanup systems are included in the design to reduce the quantities of radioactive materials in gaseous effluents released to the environment. 9.4.5-8 Revision 3 - March 2007 Meeting these requirements provides assurance that release of radioactive materials entrained in gaseous effluents will not exceed the limits specified in 10 CFR Part 20 for normal operation and anticipated operational occurrences. 6. Compliance with 10 CFR 50.63 requires a demonstration that the plant has the capability to withstand and recover from a station blackout (i.e., loss of offsite electric power system concurrent with reactor trip and unavailability of the onsite emergency ac electric power system). A station blackout analysis covering a minimum acceptable