Document: NUREG-0800
Document ID: 010ad62f-cd7b-4f06-9f81-a781faf5701b
Document Type: srp
Title: ENGINEERED SAFETY FEATURE VENTILATION SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070560.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.4.5
CFR Part: 
CFR Title: 

Content:
accident in one part of a multiple-unit facility will not propagate to unaffected units. Therefore, the ESFVS for each unit should be designed to accommodate accident conditions. At the same time, the operating environment of equipment associated with unaffected units must be maintained within specified limits. Meeting these requirements provides assurance that a failure will not affect additional units of a multiple-unit facility.55 4. Compliance with GDC 17 requires that onsite and offsite electrical power be provided to permit functioning of structures, systems, and components important to safety. Each electric power system must provide sufficient capacity to ensure that specified fuel DRAFT Rev. 3 - April 1996 9.4.5-8 design limits and design conditions of the reactor coolant pressure boundary are not exceeded as a result of anticipated operational occurrences. In addition, core cooling, containment integrity, and other vital functions must be maintained in the event of postulated 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.56 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. Regulatory Guides 1.140 and 1.52 present methods acceptable to the