CD- Condensate Flashcards
What is the purpose of the Main condenser?
Condenses and collects turbine exhaust steam and various equipment drains
Collects and stores condensate in the hotwell, acting as a reservoir for use in the S/G
What connects the Condenser shell to the LP turbine?
Dogbone seal
What is the purpose of the Dogbone seal?
Prevents air leakage into the condenser while allowing movement between the turbine casings and condenser sections
The dogbone seals have a trough around the seal that is normally dry. When would it be filled and what fills it?
Filled with Condensate Service Header during a Degraded Vacuum event
What is the purpose of the water sealed Condenser Equalization Duct and where is it located?
Located above A and B shell false bottoms
Allows pressure between the sections to equalize if an abnormal pressure/temperature differential develops
(the water seal will “blow out”, thus equalizing pressure, if the temperature in any section exceeds that in the adjoining section by 30F)
How is each section of the condenser protected from overpressure?
Rupture discs set at 5 psig on its associated LP turbine hood
Why have the main condenser tubes had plastic lath installed? How many tube bundles are in each section of the condenser sections?
To prevent vibration failure of the tubes
4
Why do the tube lengths vary in the three condensers?
To compensate in part for the progressively higher CW temperatures since it flows through them in series
(higher temps means higher pressure per condenser section)
What is the purpose of the Condenser Waterboxes?
Provide the supply and return headers to the condenser tubes
provide air removal piping
Where are the air off-take pipes installed and how far do they extend?
At the center of each tube bundle to remove air and non-condensable gases
Extend the tube bundle length
How can the condenser Reheater Tray (inner bottom) level affect ‘A’ AFP operability after a LOOP?
After an MSIS, level can back up and potentially back up the steam line drains and cause the pump to be inoperable
Why are the hotwells equipped with spargers? When would they be used? Is this a normally performed evolution?
Could be used to admit AS directly into the condensate located in the hotwells
Can be done during startup to heat the water for cleanup purposes
This operation is not normally performed
Where are the Longitudinal divider plates installed? Purpose of the plates?
These plates ensure condensate formed around a given set of tube bundles will flow to the associated hotwell half
This feature allows continued operation if a tube leak occurs in one CW flowpath
The corresponding hotwell half can be isolated and pumped out to the Circ Water System by one of the condensate pumps to minimize further secondary system chemical contamination
What is the purpose of the Condensate detention time in the CD system? What is the total distance traveled by the condensate from the inner bottom sump to the hotwell outlet to the CD pumps?
Aids condensate reheating and sampling
a full condenser shell length
Why is there a salinity detection bay provided near each main condenser waterbox?
To detect CW leakage between the tubes and tube sheet
How much condensate storage volume is provided by the condenser hotwell?
100,000 gallons
What is the condensate storage volume of the condenser hotwell based on?
4 minutes of operation at “valves wide open”
What CST level would cause the two Hotwell Makeup valves to auto shut?
30’
How do the condenser Hotwell Automatic Makeup valves respond to a loss of IA?
Fail closed
Where are the condenser Hotwell Automatic Makeup valves located?
140’ Turbine Building
Where are the condenser hotwell manual make up valves located?
100’ Turbine Building
The single draw-off automatic control valve will open based on the higher of two levels of what condenser hotwells?
1C or 2C
How does the main condenser hotwell draw-off auto control valve react to a loss of IA?
Fails closed
What are the interlocks associated with the main condenser hotwell draw-off control valve?
It will automatically close when either SG feedwater pump suction pressure is low or any condenser hotwell cation conductivity is high
If the main condenser hotwell draw-off control valve closes due to high conductivity, how can I operate it?
By placing the key-locked bypass switch to the bypass position at the local panel
(no main control room control)
Concerning bypassing the main condenser hotwell draw-off control valve, what else can I use the key-locked bypass switch position for?
To drain the hotwells to the CST
How are the CD pump suction and recirculation valves interlocked? How many suction and recirculation valves does each CD pump have?
When the suction valve goes closed, the corresponding recirculation valve goes closed
A and C both have 1
B has 2