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:
uld include a review of air-operated component failure positions to verify that they are correct for assuring performance of required safety functions. This issue is described in Generic Letter 88-14, “Instrument Air Supply System Problems Affecting Safety- Related Equipment.” 3. The reviewer verifies that the design has features to meet the generic recommendations of NUREG-0611 and NUREG-0635. For additional short term recommendation No. 2 regarding AFW pump endurance tests, a 48 hour test is acceptable rather than the 72 hour test specified in the NUREGs. The reviewer coordinates with the I&C reviewer to assure that the instrumentation and control system aspects of these recommendations are met by the system design. 4. The reviewer verifies that an AFWS reliability evaluation has been performed in accordance with 10 CFR 50.34(f)(1)(ii) as clarified in item II.E.1.1 of NUREG-0737. The reliability analysis is reviewed to determine the potential for AFW system failure under various loss of main feedwater transients. The AFWS unreliability is determined based on analysis using methods and data presented in NUREG-0611 and NUREG-0635. As an alternative to determining AFWS unreliability using the methods of NUREG-0611 and NUREG-0635, AFWS unreliability may be established through probabilistic risk assessment methods accepted by the staff [e.g., NUREG/CR 2300 and NUREG/CR 2815]. The acceptance criteria of 10-4 to 10-5 per demand (exclusive of station blackout scenarios) must be met regardless of the method selected. 5. The reviewer coordinates with the organizations responsible for power distribution and controls to assure that the AFWS has sufficient capability, capacity, and independence from essential and nonessential ac power to provide adequate decay heat removal for withstanding or coping with, as applicable, and recovering from, a station blackout in accordance with 10 CFR 50.63 and RG 1.155, Positions C.3.2.2, C.3.3.2, and C.3.3.4. 10.4.9-14 Revision 3 - March