Document: NUREG-0800
Document ID: 5cdeed4a-6cd5-4840-90c0-5159fbf2c9f0
Document Type: srp
Title: CHILLED WATER
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1409/ML14093A350.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.2.7
CFR Part: 
CFR Title: 

Content:
d interface. RTNSS B: applies for nonsafety-related functions in the post-72 hour period. RTNSS C: applies for nonsafety-related defense-in-depth functions in order to meet NRC safety goal guidelines. Nonsafety-related nonrisk-significant: applies to refrigerant leak detection systems. F. VWS pumps are adequately designed related to net positive suction head required (NPSHr) and are evaluated against NPSH available (NPSHa) under normal and accident conditions. Potential VWS pump vortexing conditions are also evaluated. RTNSS B: applies for nonsafety-related functions in the post-72 hour period. RTNSS C: applies for nonsafety-related defense-in-depth functions in order to meet NRC safety goal guidelines. For RTNSS B and C replaces paragraph 6.K with the following: VWS pumps are adequately designed related to net positive suction head required (NPSHr) and are evaluated against NPSH available (NPSH) under post-72 hours periods and defense-in-depth functions. Potential VWS pump vortexing conditions are also evaluated. 7. The reviewer verifies whether the system is designed to maintain system functions as required in such adverse environmental phenomena as earthquakes, tornadoes, tsunami, hurricanes, and floods. The reviewer evaluates the system using engineering judgment and the results of failure-modes and -effects analyses to determine the following: 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 non-seismic Category I structures that house, support, or are close to essential portions of the VWS does not preclude essential functions. The review identifies these non-seismic category components or piping and ensures appropriate provision of isolation capabilities in failure. RTNSS B: applies. RTNSS B SSCs are considered risk-significant RTNSS B SSCs do not need to operate during accident conditions, but in the post-72 hour period. RTNSS B SSCs should