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:
on in the event of system or component failures. The capability to isolate components, subsystems, or piping if required provides assurance that the AFWS will accomplish the safety function of reactor coolant system heat removal by ensuring delivery of feedwater from functional supplies to functional steam generators. For these criteria, the AFWS should have low unreliability in reducing the core damage frequency due to loss of reactor coolant system heat removal capability. Compliance with the design criteria provides assurance that heat removal will be accomplished and reactor coolant system and fuel integrity will be maintained. 8. GDC 45 establishes the requirements for periodic inspection of cooling water systems to ensure the integrity and capability of the system to transfer heat loads from SSCs important to safety. The AFWS safety function is to provide emergency cooling capability for the reactor coolant system in the event of an accident. The periodic testing of the system for compliance with GDC 45 assures system capability to perform its intended function. 9. 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 AFWS safety function 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. GDC 46 assures AFWS provides assurance that the AFWS 10.4.9-10 Revision 3 - March 2007 will be capable of performing its intended function to remove reactor decay heat following anticipated operational occurrences and design basis accidents. 10. 10 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