Document: NUREG-0800
Document ID: 2cb61281-91f4-400a-8eda-41e187e51d77
Document Type: srp
Title: AUXILIARY FEEDWATER SYSTEM (PWR)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070570007.pdf
Revision Date: 2023-06
Chapter: 10
Section ID: 10.4.9
CFR Part: 
CFR Title: 

Content:
CFR 50.62 requires that pressurized water reactors have equipment diverse form the reactor protection system to initiate the AFW system under conditions indicative of an ATWS. The AFWS is required to assure adequate removal of heat from the reactor coolant system during an ATWS. 11. 10 CFR 50.63 requires that all light-water-cooled nuclear power plants be able to withstand and recover from a station blackout. RG 1.155 provides guidance for compliance with 10 CFR 50.63. As many safety systems necessary to remove decay heat from the reactor are dependent on AC power, station blackout consequences can be severe. In a station blackout at facilities where no alternate AC power source is provided, the capability to cool the reactor core depends on the availability of systems not reliant upon AC power or on the ability to restore AC power in a timely manner. The AFWS is required for removal of decay heat in the event of a station blackout and must have sufficient capability and capacity to perform the heat removal function for an appropriate duration. To ensure such capability, motive power for motors, pumps, valves, controls and instrumentation for at least one auxiliary feedwater train of adequate capacity for station blackout is verified to be provided that is independent of the normal and emergency AC power systems. Compliance with 10 CFR 50.63 and the positions of RG 1.155 on capability to withstand or cope with a station blackout provides protection against unacceptable offsite radiological consequences should both offsite and onsite emergency AC power systems fail concurrently. III. REVIEW PROCEDURES The reviewer will select material from the procedures described below, as may be appropriate for a particular case. These review procedures are based on the identified SRP acceptance criteria. For deviations from these acceptance criteria, the staff should review the applicant’s evaluation of how the proposed alternatives provide an acceptable method of complying