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
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CFR Title: 

Content:
ch separate redundant components and are protected against the effects of internal and external missiles. 5. The applicant has met the requirements of GDC 5 with respect to sharing of SSCs. Acceptance is based on the failure of any component including a pipe break and single active failure not preventing the safe shutdown and cool down of either unit (together or singularly). 6. The applicant has met the requirements of GDC 19 as related to the design capability of system instrumentation and controls for prompt hot shutdown of the reactor and potential capability for subsequent cold shutdown. The AFWS design meets the requirement of BTP 5-4 which requires the capability to bring primary plant temperature to the RHR cut- in point following four hours at hot standby from the control room using only safety grade equipment and assuming any single active failure. 7. The applicant has met the requirements of GDC 34 and 44 because the AFWS design has the capability to transfer heat loads, including decay heat from the reactor, during normal operating and accident conditions assuming any single active failure. The system has suitable redundancy such that it can withstand a pipe break and single active failure and still perform its safety function. The system design also has sufficient diversity such that it meets the requirements of BTP 10-1. In addition to meeting these GDC, the applicant has also met the generic recommendations identified in NUREG-0611 and NUREG-0635 and has performed a reliability analysis in accordance with 10 CFR 50.34(f)(1)(ii) as clarified in NUREG-0737, item II.E.1.1. The results of the reliability analyses were acceptable since it was shown that the AFWS has an unreliability in the range of 10-4 to 10-5 per demand. 8. The system pumps, valves, heat exchangers and piping, to the extent practicable, are designed and located to facilitate periodic inspection as required by GDC 45 by providing adequate accessibility to conduct the required