Components cooling water system

Component cooling water system Spent fuel pool cooling and cleanup system Residual heat removal system Essential service water system... 

Component cooling water system X 2 charging pumps, 4 high head injection pumps, 2... 

PROBABILITY OF CORE MELT DUE TO COMPONENT COOLING WATER SYSTEM FAILURES... 

The SSWS cools the Component Cooling Water System (CCWS) through the Component Cooling Water Heat Exchangers and rejects the heat to the ultimate heat sink during normal, transient, and accident conditions. The CCWS in turn provides cooling water to those safety-related components necessary to achieve a safe reactor shutdown, as well as to various non-safety reactor auxiliary components. 

The component cooling water system (CCWS) provides a continuous supply of cooling water to plant components which handle potentially radioactive fluids. In doing so, it forms an intermediate barrier between these potentially radioactive systems and the service water system, thereby reducing the possibility of discharging radioactivity to the environment. Component cooling water is supplied to NSSS as required by the following operations ... 

The seal is cooled through two independent and redundant seal cooling systems the seal injection system and the component cooling water system (CCWS). 

The plant model includes eight different safety systems that are mostly four-redundant. The safety systems are divided into two separate subsystems Reactor Protection System (RPS) and Diverse Protection System (DPS), which are implemented on different automation hardware. The RPS safety systems are automatic depressurisation system (ADS), component cooling water system (CCW), emergency core cooling system (ECC), service water system (SWS) and residual heat removal system (RHR). The DPS safety systems are emergency feed water system (EFW), and main feed water system (MFW). In addition, the AC power system belongs to both RPS and DPS. The model describes the operation logic of the safety systems, the hardware equipment used to implement each system, and the associated failure modes for each piece of equipment. 

The component cooling water system supply temperature to the normal residual heat removal system heat exchangers is based on maximum normal ambient wet bulb temperature as defined in Table 2-1 of Reference 6.1. The maximum normal ambient temperature is assumed for shutdown cooling ... 

The component cooling water system is a closed loop cooling system that transfers heat from various plant components to the service water system during normal phases of operation. It removes heat from various components needed for plant operation and removes core decay heat and sensible heat for normal reactor shutdown and cooldown. 

The following design requirements for the component cooling water system support safe operation of the plant during normal operations ... 

The component cooling water system can transfer heat from plant components as required, to support normal power operation. 

The component cooling water system can remove, in conjimction with the normal residual heat removal system, both residual and sensible heat ftom the core and the reactor coolant system and reduce the temperature of the reactor coolant system during the second phase of cool down. 

The component cooling water system also has the capability to provide the additional defence in depth during and following fault conditions ... 

The component cooling water system is designed for normal operation in accordance with the following criteria (see Section 9.2.2.1.2. lof Reference 6.1) ... 

The component cooling water system provides sufficient surge capacity to accept approximately 11.4 m /hr leakage into or out of the system for 30 minutes before any operator action is required. 

The first phase of plant cool down is accomplished by transferring heat from the reactor coolant system via the steam generators to the main steam systems (see Section 6.6.6). The component cooling water system, in conjunction with the normal residual heat removal system (see Section... 

As a defence in depth, the component cooling water system is capable of providing decay heat removal to the service water system during certain fault sequence scenarios, (see Chapter 19 of Reference 6.1)... 

The fire protection system also has the following capabihty to provide the additional defence in depth support during and following fault conditions it can deliver an alternative supply of cooling water to the normal residual heat removal system after a loss of normal component cooling water system function. 

Connections are provided between the fire protection system and the normal residual heat removal system. A permanent eonneetion is provided to allow the fire protection system to fiimish water to cool a normal residual heat removal system pump and heat exehanger following a fire that disables the normal component cooling water system cooling function (see Table 9.5.1-4 of Reference 6.1). 

It has the capability of transferring heat from the component cooling water system to the atmosphere. 

Component cooling water system radiation monitor. Radioactive material in the component cooling water system indicates leakage. The monitor initiates an alarm in the main control room. 

Component cooling water system radiation monitor ... 

Simplification of supporting systems, such as the component cooling water system (CCWS), the essential service water system (ESWS) and the emergency AC power system. These are designed as non-safety grade systems, possible by use of the stand-alone direct heat removal system (SDHS). 

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