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:
abilities 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 continue to perform their 9.2.7-24 Draft Revision 0 – July 2014 required RTNSS functions, assuming a single failure of a component to perform its intended RTNSS function in the post-72 hour period. RTNSS C: applies. RTNSS C SSCs do not need to operate during accident conditions, but are relied upon in order to meet NRC safety goals guidelines. For RTNSS B and C replace paragraph 7.A. with the following: The failure of portions of the system or of other systems not designed to seismic Category I standards and located close to important portions of the system or of non-seismic Category I structures that house, support, or are close to important portions of the VWS should not preclude its ability to support required actions in the post-72 hours period or defense-in-depth functions. The review identifies these non-seismic category components or piping and ensures appropriate provision of isolation capabilities in failure. Reference to SAR Chapter 2, describing site features and the general arrangement and layout drawings, is necessary, as well as the SAR tabulation of seismic design classifications for structures and systems. Essential VWS 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