Document: NUREG-0800
Document ID: b1bccb14-17b6-422b-93ee-6d4f00b6512b
Document Type: srp
Title: CHILLED WATER SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1510/ML15103A559.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.2.7
CFR Part: 
CFR Title: 

Content:
terface. F. CWS 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 CWS 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 CWS does not preclude essential functions. The review identifies these non-seismic category components or piping and ensures appropriate provision of isolation capabilities in failure. B. Essential CWS portions are protected from the effects of floods, hurricanes, tornadoes, and internally- or externally-generated missiles. Flood protection and missile protection criteria are evaluated in detail under the SRP sections for SAR Chapter 3. The reviewer uses the procedures in these SRP sections to ensure that the analyses presented are valid. A statement to the effect that the system is located in a seismically qualified Category I structure tornado-, missile-, and flood-protected or that system components are located in individual cubicles or rooms that withstand both flooding and missiles is acceptable. The location and design of the system, structures, and pump rooms (cubicles) are reviewed for whether the degree of protection is adequate. 8. The SAR descriptive information, P&IDs, CWS drawings, and failure-modes and effects analyses are reviewed by the primary review organization for whether essential portions of the system