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:
REVIEW RESPONSIBILITIES Primary - Organization responsible for the review of cooling water systems Secondary -- Organization responsible for the review of chemical control Organization responsible for chemical effect on control room occupants I. AREAS OF REVIEW The chilled water system (VWS) provides a closed loop of cooling water for room ventilation equipment and components of the emergency core cooling system (ECCS). In addition, the VWS may also provide cooling to non-safety related components (non-essential) such as miscellaneous pumps and ventilation equipment. Typically the safety-related VWS supplies chilled water via the chilled water pumps to “essential” (used for safety features) loads for temperature control and room cooling in the main control room 9.2.7-2 Draft Revision 0 – July 2014 (MCR), Class 1E electrical rooms, safeguard building, auxiliary feedwater room (pressurized water reactors only), fuel building, ECCS rooms, reactor core isolation cooling room (RCIC) (boiling water reactors only), or control complex. Chillers function to cool water (usually to near 44 °F to °46 F) utilizing refrigerant with phase changes between liquid and gas. Chillers normally consists of a cooler, condenser, compressor, motor (and associated drives), guide vanes, oil support system, hot gas bypass line, instrumentation and controls, and refrigerant. A chiller compressor can be either scroll, screw or centrifugal. Each of these compressor types have limitations on heat-removal capability. Cooling for the chiller condenser is either water-cooled, for example by the reactor auxiliary cooling water system, or air cooled. The review of the VWS encompasses components required for safe shutdown during normal operations, anticipated operational occurrences, and accident conditions and for prevention or mitigation of the consequences of accidents. The VWS may perform cooling water functions to nonsafety-related risk-significant and nonsafety-related nonrisk-significant