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:
g., small breaks in the primary system or the loss of offsite power). The system is reviewed for whether a single malfunction, a failure of a component, or the loss of a cooling source does not reduce the safety-related functional performance capabilities of the system. The specific areas of review are as follows: 1. The failure of non-essential equipment or components does not affect essential functions of the system. 2 The system is capable of withstanding a single active failure. 3. The system has diverse motive power sources and can meet performance requirements with either of the assigned power sources (e.g., a system with an alternating current (AC) subsystem and a redundant steam direct current (DC) subsystem). 4. The system design precludes fluid flow instabilities (e.g., water hammer) in system inlet piping during normal plant operation or during upset or accident conditions (see SRP Section 10.4.7). 5. System leakage can be detected, collected, and controlled and portions of the system can be isolated for excessive leakage or component malfunctions. 6. There are provisions for operational testing. 7. Instrumentation and control features are provided to verify that the system is operating in an acceptable mode. 8. The system can automatically initiate auxiliary feedwater flow upon a system actuation signal. 9. The system satisfies the recommendations of Regulatory Guide (RG) 1.62 for capability to manually initiate protective action by the AFWS. 10. The system is designed to terminate auxiliary feedwater flow to a depressurized steam generator and to provide feedwater to the intact steam generator automatically. Alternatively, if the intact steam generator is shown to receive the minimum required flow without isolation of the depressurized steam generator and containment design pressure is not exceeded, operator action may be relied upon to isolate the depressurized steam generator. 11. The system possesses sufficient auxiliary feedwater flow capacity to