- provide cooling water to the condensers of the main steam turbines
- for each unit a flow of 535,000 gpm to the main steam turbine condensers
- provides water for auxiliary cooling equipment
- for each unit a flow of 26,000 gpm to the Raw Cooling Water System
- provides an efficient means of rejecting waste heat from the power generation cycle into the ambient surroundings
- used to dilute and disperse:
- the low-level radioactive liquid wastes (monitor tank pump discharge & cask decontamination tank pump discharge)
- steam generator blowdown
- monitor tank pump discharge
- cask decontamination tank pump discharge
- Open
- water bypasses the cooling tower lift pumps and is returned to the reservoir through the diffuser pond and the discharge diffusers
- Helper
- water is pumped into the cooling towers by the lift pumps, passes through the cooling towers where part of the waste heat is liberated directly to the atmosphere, and then is returned to the reservoir through Gate structure 1, the diffuser pond, and the discharge diffusers
- Closed
- water is pumped through the cooling towers where all the waste heat is liberated directly to the atmosphere and then is returned to the intake channel through a discharge control structure (Gate 2) located in the return channel
- CCW Pump Start Interlocks
- CCW pump enabled - 5 of 6 condenser waterboxes sets having fully open inlet and outlet valves.
- Each of the other two CCW pumps must be either
- Running, or
- Have its associated discharge valve < 5% open
- Have a start signal with the discharge valve > 5% open. This interlock is bypassed by the local "D" test-stop switch.
- CCW Pump Trip Signals
- Pump discharge valve < 5% open and closing
- Electrical fault on board (50, 51, 83),( 81 under frequency for motors- internals removed reference 1, 2-45N763-3)
- Exciter/motor fault (20 sec TD after breaker closes)
- Abnormal power factor (56) (after TDPU).
- Motor not able to reach synchronous speed (71FX)
- S.C.R. or S.R. fuses open (53EX)
- Loss of 120 VAC control power
- Loss of excitation (41) (after TDPU)
- Loss of 250 VDC (when 120 VAC is available)
- "A" switch in main control room
- "B" switch in intake board room
- "D" switch - Test switch local station on base of motor
- "E" switch at discharge gate
- HS-27-12 switch in the intake valve area
- There are 6 identical 1750 hp pumps, each having a capacity of 187,000 gpm at 30.0 TDH
- Each is an electric, motor-driven, vertical, mixed flow type pumping unit with synchronous motor with static exciter
- Flows
- CCWS will provide a flow of 530,000 gpm to the main turbine condenser waterboxes
- CCWS will provide 26,000 gpm to the raw cooling water system
- CCW Pump Motors
- Synchronous Motor
- 1750 HP
- 3 Phase
- 6600-V
- 60 HZ
- 120 Amperes
- 30 Poles
- Power Factor 1.0
- Rating
- Continuous
- Temp. Rise 80°F
- Insulation is grade "B"
- Heater for Motor is 6KW fed off 480-V water supply board & MCC A, No. 2 unit off B
- Control Power: 250V DC
- Power Supply
- 1A fed off 6.9-kV unit board 1A
- 1B fed off 6.9-kV unit board 1B
- 1C fed off 6.9-kV unit board 1D
- Exciter Power for Synchronous Motor - fed off each CCWP motor supply through a transformer located at motor on pump deck, then rectified to 125-V DC in exciter control cabinet in pumping station electrical equipment room (3 exciter control cabinets/unit.)
- Rating
- Excitation 125-V DC
- Field current 114 amperes
- Ambient Temp. 40°C
- Control Locations
- Local pushbutton at motor TEST-RESET-SAFE-STOP
- Each motor and butterfly valve has a control switch - combination switch on the CCW control panel in electrical equipment room at the pumping station. A total of six switches for six pumps and valves for units 1 and 2. Also at each switch is a set of motor lights (green and red) and a set of lights for the butterfly valves (green and red). Positions for each switch: STOP-START-PULL TO CLOSE valve.
- In the unit 1 (Unit 2 on other end of board) control room on panel M-15 is a control switch for each CCWP motor and discharge valve; a combination switch with discharge valve lights (green and red) and motor lights (green-white-red) above the control switch which has positions STOP-CLOSE-START OPEN-PULL TO CLOSE VALVE.
- CCW Pump Start Interlocks
- CCW pump enabled - 5 of 6 condenser waterboxes sets having fully open inlet and outlet valves.
- Each of the other two CCW pumps must be either
- Running, or
- Have its associated discharge valve < 5% open
- Have a start signal with the discharge valve > 5% open. This interlock is bypassed by the local "D" test-stop switch.
- Operating Characteristics
- Normal starts and stops from MCR and local switches act through the pump discharge valves to START and STOP the pump motor, with the final pump motor START/STOP signal coming from valve limits < or > 5% open. This ensures a lower starting current on the pump motor, protects against dead-heading and prevents short-circuiting backflow through an idle pump.
- The pump may be started from any of 5 switches:
- "A" switch in main control room
- "B" switch in intake board room
- "D" switch - Test switch local station on base of motor
- "E" switch at discharge gate
- HS-27-12 switch in the intake valve area
- All switches except the "D" test-switch act through the valve control - the "D" switch bypasses the valve limit interlocks both on starting and stopping the pump motor.
- CCW Pump Trip Signals
- Pump discharge valve < 5% open and closing
- Electrical fault on board (50, 51, 83),( 81 under frequency for motors- internals removed reference 1, 2-45N763-3)
- Exciter/motor fault (20 sec TD after breaker closes)
- Abnormal power factor (56) (after TDPU).
- Motor not able to reach synchronous speed (71FX)
- S.C.R. or S.R. fuses open (53EX)
- Loss of 120 VAC control power
- Loss of excitation (41) (after TDPU)
- Loss of 250 VDC (when 120 VAC is available)
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