CT-Condensate Transfer Flashcards
What is the purpose of the CT system?
Provides an initial fill for the condensate and feedwater system
Serves as a reservoir to supply or receive condensate as required by the Main condenser hotwell control system
Provides a source of makeup water to the steam generators and various safety related surge tanks
provides make-up to the polishing demins in the secondary chemical control system
The CT system provides provisions for what safety related functions?
Providing Aux Feedwater pumps for S/G makeup
During LOP, provides emergency makeup to:
EW surge tanks, EC Expansion Tanks, and DG Cooling Water Surge tanks
Makeup to the spent fuel pool
What is the normal source of makeup water to the CST?
Demineralized
Water
Why do we establish a nitrogen blanket on the CST?
To prevent the absorption of oxygen by the condensate
What powers the Condensate Transfer pump motors?
PH (A for ‘A’ pump, B for ‘B’ pump)
What assures that CT safety related equipment is not degraded by freezing? What methods of freeze protection are there?
Freeze Protection System (QJ)/Heat Tracing
heat trace, insulation, operational and administrative procedures
How much of the CST is specifically designated to supply the plant for shutdown and cooling system emergency makeup?
330,000 gallons
Why is there a connection to the Fuel Pool Cooling and Cleanup system (PC)?
PC system receives water from the CST as an alternate source of makeup
Where is the CST located?
Yard plant north of the MSSS building
What is the purpose of the CST?
To store water for polishing demins and makeup water to the condenser
Provides a water source for Aux Feedwater and a backup source for safety systems such as DG cooling, EW, EC, and Spent fuel pool
What is the nominal capacity of the CST?
550,000 gallons
Why is there additional volume above the maximum normal operating level in the CST?
To accommodate insurges due to secondary system thermal expansion
What is the backup makeup water source for the CST?
Liquid Radwaste
What nitrogen pressure is maintained in the CST? How is pressure managed?
3.5 in H2O (0.13 psig)
auto pressure control system
What is the purpose of the CST’s two relief valves (Breather valves)?
Overpressure protection and vacuum breaker
When would the two CT pumps auto start?
Upon a receipt of a number of PPS ESFAS signals:
LOP, SIAS, CREFAS, CRVIAS
What is the purpose of the CT pump mini-flow recirculation and where do these lines, with flow orifices, return water to in the CST?
To prevent pump overheating when operating at shutoff head
Above the 330, 000 gallon level
Where are the non-essential AFP suction valves located?
CST pump house room
How far open do the suction valves need to be for the ‘N’ AFP start permissive? For seismic considerations, what is their normal status?
80%
closed
Where are the non-class AFN suction valves operated from and where do they both receive power from?
Control Room
PHA
What is the purpose of the CST loop seal?
To protect the CST against nitrogen loss, but also prevents excessive tank pressure or vacuum in the event of a failure of the tank breather valves (Relief valves)
What major components does the CT system consist of?
Condensate storage tank
two condensate transfer pumps
piping, valves, instrumentation, controls and annunciators
When does the CT system maintain proper condensate inventory in the secondary system?
during start-up, shutdown, hot standby, cooldown and normal power
What is the normal source of make-up water to the CST?
DW
What does the GA (service gas) system do for the Condensate Transfer system?
N2 blanket on the CST (condensate storage tank) to prevent oxygen absorption by the condensate
Where do the CT (condensate transfer) system drains lead to?
OW, north condenser sump
How does the Condensate transfer system interface with the CD (condensate) system?
The CD system receives makeup and initial fill from the CT system and returns excess condensate inventory.
Level control makeup valves and a reject valve in the CD system regulate the level in the hotwell.
How does FLEX interface with the CT (condensate transfer) system?
CST (condensate storage tank) provides an alternate connection to the AF pump suctions via a FLEX tie-in. So should the normal AF suctions become unusable, you could still get CST water to the AF pumps via FLEX connections.
What systems can the condensate storage tank provide water to as a backup source?
diesel generator cooling
essential cooling water
essential chilled water
spent fuel pool
Do the condensate transfer pumps share a suction and discharge pipe or are they separate and redundant?
separate and redundant
What situation would cause the CST breather relief valves to lift?
failed open N2 regulator
What situation would cause the CST breather relief valves to break vacuum?
rapid drop in tank level during hotwell make-up
What is the tech spec low CST level?
29.5’
What regulates level in the CST?
pneumatic level controller and a level control valve
What regulates pressure in the CST?
a pneumatic controller and a pressure control valve
What could happen to the CST if a vacuum is drawn in the tank?
It could collapse
What will happen if the CST is overfilled?
It will blow out the loop seal and spill on the ground
Where do the CT pumps receive power from?
CTA-P01 – PHA
CTB-P01 – PHB
When conductivity is high in the condenser hotwells, and the interlock to close LV-75 is in bypass mode, what other interlock is also bypassed?
the signal to close LV-75 on Main Feed Pump low suction pressure
What is the motive force, normally, of water flow from the CST to the condenser hotwells? What provides the motive force for draw off back to the CST?
D/P since the hotwells are at a vacuum
(can also be done by gravity feed)
draw off line is downstream of the condensate pumps, which provides the motive force
How often do the CT pumps normally run?
only when the emergency loads require make up
