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:
ary review organization. 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. D. Design considerations and provisions are made to address VWS voiding and gas intrusion. Gas intrusion or air voids have an extreme negative effect and may cause the VWS pumps to become non-functional and not able to perform their intended function. 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. E. For safety-related mechanical chillers, they are selected and arranged to provide reliability and redundancy to transfer heat. Review emphases are placed on: i. Air cooled mechanical chillers are adequately designed to the outside environmental (dry bulb) conditions. ii. Chiller (condenser, evaporator, and compressor) design margins. iii. Instrumentation and controls such as chiller panel alarms, temperature controls for the returning chilled water, and chiller protection trips (for example, freeze protection) with consideration to automatic starts of standby chillers during normal and abnormal conditions. iv. Potential for oxygen displacement in mechanical equipment rooms due to catastrophic release of refrigerant. Certain refrigerants may require a refrigerant leak detection system. Evaluation against potential effects to MCR occupants is performed by secondary reviewers (Ref. 33). 9.2.7-23 Draft Revision 0 – July 2014 v. Over-cooling the condenser refrigerant (Ref. 17). vi. Determine if a refrigerant purge unit is required for removal of noncondensable gases. This may be a safety-related to nonsafety-related 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.