Document: NUREG-0800
Document ID: 2925ed14-c49b-459b-8786-e6bffd2c43c4
Document Type: srp
Title: AUXILIARY FEEDWATER SYSTEM (PWR)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070603.pdf
Revision Date: 2023-06
Chapter: 10
Section ID: 10.4.9
CFR Part: 
CFR Title: 

Content:
rity and capability of the system to transfer heat loads from SSCs important to safety. The safety function of the AFWS is to provide emergency cooling capability for the reactor coolant system in the event of an accident. The periodic testing of the system to comply with GDC 45 provides assurance that the system will be capable of performing its intended function. 7. GDC 46 establishes the requirements for functional testing of cooling water systems. This testing assures the integrity and operability of the cooling water system and its components necessary for the removal of heat loads from SSCs important to safety. The safety function of the AFWS is to provide emergency cooling capability for the reactor coolant system, in the event of an accident, by transferring heat from the reactor coolant system via the steam generators. Compliance with GDC 46 provides assurance that the AFWS will be capable of performing its intended function to remove reactor decay heat following anticipated operational occurrences and design basis accidents. 10.4.9-9 DRAFT Rev. 3 - April 1996 8. 10 CFR 50.63 requires that all light-water-cooled nuclear power plants be able to withstand and recover from a station blackout. Guidance for compliance with 10 CFR 50.63 is provided in Regulatory Guide 1.155. Since many safety systems necessary to remove decay heat from the reactor are dependent on ac power, the consequences of a station blackout can be severe. In the event of a station blackout, where no alternate ac source is provided, the capability to cool the reactor core is dependent on the availability of systems that are not reliant upon ac power from the essential and nonessential buses, 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,