Condensate Flashcards
What provides makeup to the Condensate system?
CST
Where are the valves for the CD system makeup?
Manual- 100’ TB (HCV-154,155)
Automatic- 140’ TB (LV-81, 82)
What is used to fill the CD mini-flow recirc lines prior to first CD pump start?
DW
What are the expansion joints?
Also known as dogbone seals. Prevent air leakage into the condenser while allowing movement between turbine casings and condenser sections.
What all drains into the main condenser?
- FW pump seal leakoff
- GS unloading valve (pv-27)
- 6 of the SBCS control valves
- LPFW htr drains
- Turbine casing
- HP/LP stop valves
- Above/below seat drains
- Feed Pump turbine exhaust
If the CD system isn’t available what can supply the CD service header?
DW (DWN-HV-275)
What do the Condenser Equalization Ducts do?
They are located above the A and B false bottoms; they allow 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 30 degrees F.
What is the normal operating level of the hotwell?
41-43 inches
What cause a CD pump to trip?
- Hotwell level 30 inches
- Low mini flow after 45 seconds. (3600 gpm set-point, normal 4500)
- “B” CD pump will trip if one of its two suction are not full open. (normally both are full open)
Where does blowdown and drawoff go from the CD system?
Blowdown- CW (For cleanup/level control)
Drawoff- CST (Level control)
What would cause the hotwell drawoff valve to automatically close?
- High cation conductivity
- Low MFP suction pressure (245 psig)
Explain the override available with the hotwell drawoff valve?
On the 140’ of the TB, in the southwest corner. You can override the high cation conductivity to open the hotwell drawoff valve. There is a key switch.
When will the Condensate system makeup valves automatically close?
When CST level goes below 30 feet. This is to prevent feeding a leak and draining the CST below our Tech spec level of 29.5 feet.
Where is each condensate pump powered from?
PO1A- NBN-SO1
PO1B- NBN-SO1
PO1C- NBN-SO2
Explain the CD pumps?
Three six-stage Vertical centrifugal pumps 50 percent capacity Raise pressure from vacuum to around 440 pound on a common discharge header
Talk about the interlocks within the CD demin inlet, bypass, outlet valves.
The inlet valve (HV-191) must be full open to give the outlet valve (HV-199) an open permissive.
The inlet and outlet valves must be open to give the bypass valve a modulate permissive.
The bypass valve (PDV-195) will modulate with a differential pressure lower then 55 psid. Greater then 55 psid the bypass valve will be full open.
How do the CD pump recirc valves fail on a loss of IA?
Fail open
What are the tube lengths for each condenser?
A- 45.5’
B- 50’
C- 55.25’
What provides cooling for the CD pump LO?
TCW
What does seal water do for the CD pump?
Lubricates and cools the pump seal. It is supplied from the CD service header.
How does the Condensate cross-tie pressure control valve (PV-208) fail on a loss of IA?
Fails closed
Explain how makeup is provided to the condenser?
By vacuum drag through the LV-81/82 valves automatically from the CST.
How does the Hotwell drawoff valve fail on a loss of IA?
Fails closed on a loss of IA
Which condenser section has the best vacuum the worst? Why?
A-Best
C- Worst
Because CW runs in series through the condenser so as it gets to the ‘C’ section it is warmer and at a higher pressure therefore less vacuum.
How does the demin bypass valve fail on a loss of air?
Fails open
When would you need to change or clean the CD pump suction strainers?
7” H2O differential pressure
How does the condensate service header pressure control valve fail on a loss of air?
Fails closed.
Where is the condensate service header pressure controller?
100’ turbine building near SE side of condenser
Where is DWN-V275, alternate supply to the condensate service header?
100’ turbine building on south side near the demin shack
Where are the controllers for the hotwell level and drawoff controllers?
Control Room
Where are the long path recirc valves?
- HV-46 is accessed from the 100 TB up the stairs above the hydrazine addition area.
- VA-31 is underneath the MFP platform on the ‘B’ side.
Why do we have hood spray?
Cool-down exhaust hoods during startup
How is the condenser filled during initial fill, after an outage?
The head from the CST is enough to drive the water into the condenser thru the manual isolation valves.
At full power, what position is the CD mini-flow valves in?
Fully closed
Explain how the upper and lower bearings on a CD pump are lubricated?
Upper- Oil
Lower- Grease
Explain starting the first condensate pump and filling the CD/FW systems?
- Fill hotwell by gravity feed from CST (HCV-154/155)
- Fill recirc piping with DW via portable hose
- Vent suction/discharge piping
- Check CD pump seal leakoff/TC cooling for LO sat
- Once first CD pump is running on recirc the rest of the CD/FW system can be filled and vented.
- Be cautious not to exceed the makeup rate
- Now to fill the system we use the running pumps discharge bypass valve. (opened a couple turns to slowly fill/ vent the system)
- When the system is filled/vented it is placed on long path recirc
Explain the flowpath for long path recirc.
- CD Pumps to Demins to LPFW htrs bypass MFP’s to HPFW htrs to HV-46/VA-31 back to the condenser
Explain the position of the pump bypass valves when on long path recirc.
One of the valves will be open 25% and the other will be closed.
Explain a controlled shutdown of the CD/FW system going into an outage?
Power is reduced to 50%; the first MFP is secured.
After that the first CD pump is secured. Around 2-3% power the 2nd MFP is secured and then another CD pump will be secured. The last CD pump will run on long path recirc.
When taking a LPFW Heater out of service; what do we monitor and what do we take out of service first?
- Monitor MFWP suction pressure
- Take extraction steam out first
- Remove condensate second
What do we need to do big picture if Condenser vacuum is degrading slowly?
- MT load reduced
- Reactor power reduced (Rods/Boron)
- If vacuum can’t be maintained trip the turbine
- Load now to SBCS (1007/1008)
If we are using the SBCS via 1007/1008 to control load; what is a caution for us?
HW level could decrease quicker then normal makeup capabilities. AO may have to manually makeup at HCV-154/155.
At what condenser pressure is the SBCS valves 1001-1006 unavailable?
5.5” HgA
On a loss of vacuum, what does the AO in the field check?
CD expansion joints, CW system, Air removal pumps, Gland seal
How much of a condenser tube leak can the CD demins handle?
1 gpm of CW in system leakage