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:
of the reactor to the cut-in conditions for low pressure residual heat removal. Compliance with GDC 19 and BTP RSB 5-1 ensures the availability of adequate instrumentation and controls to perform the required safety function under all anticipated conditions. 5. GDC 34 and 44 establish the requirements to assure the capability to transfer heat from the reactor to a heat sink under normal and accident conditions with sufficient redundancy and isolation capability to ensure the safety function can be accomplished including in the event of a single failure of a active component with or without a coincident loss of offsite power. The capability to transfer heat loads during normal and accident conditions is necessary to ensure that the integrity of the fuel, the reactor pressure boundary, and containment are maintained. The AFWS functions to transfer the heat from the reactor coolant system via the steam generators. Suitable redundancy provides additional assurance that the system will be capable of performing the safety function 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. In support of these criteria, the AFWS should have a low unreliability to reduce 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. 6. 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 safety function of the AFWS is to provide emergency cooling capability for the reactor coolant system in the