Circ Water Flashcards
Cooling tower pump normal indication
800 amps @ 40-45 psi discharge pressure
Cooling tower pump power supplies
P-39A - F bus
P-39B - G bus
Cooling tower pump start permissives
Condenser inlet waterbox full No standing pump trips Emergency stop button not pushed Lubrication water >8 gpm Waterbox inlet valve closed Pump discharge valve closed
What happens when C/T pump control switch is taken to start
Condenser inlet starts to open
Pump starts when condenser inlet is 33% open
Pump discharge valve starts to open to a preset throttle position (approximately 43%)
What happens when C/T pump control switch is taken to stop
Pump discharge valve starts to close
Pump trips when discharge valve gets to 33% closed
Pump discharge valve fully closes
What happens when C/T pump emergency stop push button is pushed
Immediately trips pump
Pump discharge valve closes fully
Control Room alarm
C/T pump seal and cooling water supply
Normally from filtered service water
Self sealing if filtered service water is lost
C/T pump seal/cooling water alarm
18 gpm
C/T pump trips
Differential current
Bus undervoltage
Ground current
Overcurrent
C/T pump discharge valves MO-5305/5306 functions
Control C/T basin level
Interlocks to open/close on pump start/stop
Won’t auto close if pump is tripped locally from the breaker
Waterbox inlet valves MO-5301/5302 interlock
Open on C/T pump start
Steps to take if waterbox inlet valve leakage is present
Operate the valve to flush the seat
Attempt to seat the valve
Drain the C/T
Dilution water pump power supplies
P-40A - C bus
P-40B - E bus
Dilution water pumps capacity
40,000 gpm
Dilution water pump trips
overcurrent
undervoltage
SIS (load shed)
Interlock associated with radwaste discharge and dilution water pumps
Radwaste discharge CV-1054 won’t open unless a dilution water pump is running
Dilution water pump discharge pressure limitation
Less than 14 psi to prevent flow vibrations
Dilution water pump discharge to mixing basin MO-5311/5312 function
Used during pump starts
Only 1 open at a time
Dilution water pump discharge valves MO-5313/5314 function
Open or close, no throttling
60 second stroke time
Thermal overload has 116 second time delay to allow valve to fully stroke in an overload condition
C/T fill MO-3515/5316
60 second stroke time
Thermal overload has 116 second time delay to allow valve to fully stroke in an overload condition
C/T fan trips
Turbine trip
High vibration
Overload
C/T fan controls
Controls will only start 1 fan on each LCC at a time
Individual - select which fan(s) are started/stopped. Push start/stop button to start/stop selected fans
Master - start/stop all fans
Fans will not automatically trip on a turbine trip if master start sequence is in progress
C/T fan control Init/reset function
Warm reboot that takes < 2 minutes Used to: Clear PPC alarms Lamp test Re-establish communications with the towers
Lose indications of C/T bypass valves and level indication
Will not reposition any components
C/T bypass valves MO-5340/5341 function
Routes C/T pump discharge from over the top to the bottom of the tower
C/T blowdown valves MO-5326A/B function
Lower C/T level by routing water from the C/T to the mixing basin
CR alarm if blowdown flow exceeds 43,000 gpm from either tower
What is the Circ Water System interrelationship with the Pressurizer level control program?
P-40A, Dilution Water Pump, breaker on “C” Bus can provide an alternate source of power to the Pressurizer Heaters. Breaker will trip on Pressurizer low-low level of 36%
