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:
smic and quality group classifications, and the P&IDs indicate any points of change in piping quality group classification. The review for seismic design is performed by the SEBECGB and the review for seismic and quality group classification is 53 performed by the EMEB as indicated in Subsection I of this SRP section. 54 d. Design provisions have been made that permit appropriate inservice inspection and functional testing of system components important to safety. It is acceptable if the SAR information delineates a testing and inspection program if the system drawings show the necessary recirculation loops around pumps or isolation valves as may be required by this program. e. Design provisions have been made that ensure detection and mitigation of steam binding of the AFWS pumps due to back-leakage from the main feedwater system (MFWS) through isolation valves between the AFWS and the MFWS (Reference 21).55 2. The reviewer verifies that the system safety function will be maintained as required, in the event of adverse environmental phenomena, breaks or cracks in fluid system piping outside containment, system component failures, loss of an onsite motive power source, or loss of offsite power. The reviewer uses engineering judgment and the results of failure modes and effects analyses to determine that: a. The failure of portions of the system or of other systems not designed to seismic Category I standards and located close to essential portions of the system, or of nonseismic Category I structures that house, support, or are close to essential portions of the AFWS, will not preclude operation of the essential portions of the AFWS. Reference to SAR sections describing site features and the general arrangement and layout drawings will be necessary, as well as the SAR tabulation of seismic design classifications for structures and systems. b. The essential portions of the AFWS are protected from the effects of floods, hurricanes, tornadoes, and internally or