LOT 202.13 Feedwater Flashcards
- LOT 202.13 Feedwater*
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What supplies steam to the deaerator?
Aux Steam
Used During S/U
Switch on CP008
- *Main Steam**
- Used < 25% and during load rejection*
Extraction Steam
8th stage of HP turbine (25% - 100%)
Supplied from 2 of 6 crossunder piping
- LOT 202.13 Feedwater*
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What will auto start the SUFW pump?
- Auto Start:*
- *Trip of SGFPT**
- Start Permissives:*
- *SUFW Lube Oil Pressure > 5 psig**
Suction Pressure > 180 psig
Suction Valve (FW-0517) Open
NPSH Pressure > 80 psid
No Trip Signals
- *No FW Isolation Signal**
- P-14 or SI ONLY*
Hand Switches not in Stop/PTL
On Pump Start:
- Releases discharge non-return valve (DOES NOT OPEN DISCHARGE MOV)
- Recirc valve starts to modulate (3300 gpm - 7000 gpm)
- Secures aux seal cooling pumps
Note:
By procedure, a SUFW will have it’s discharge MOV already open
- LOT 202.13 Feedwater*
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What will auto close the SGFPT recirc valve?
SGFP Trip
SGFPT Low Lube Oil Trip
Modulates to maintain 5625 gpm normally
- Goes full open at 4000 gpm
- LOT 202.13 Feedwater*
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What is required to reset a FW isolation?
- P-14:*
- *Reset SI/P-14 (CP006) w/ P-4 False**
- *Reset FW Cont & Bypass Valves (CP006)**
- *FW Isolation Switches to “Open” (CP006)**
- Allows control of PBVs, FWIVs, and FWIBs*
SI:
Reset SI (CP001)
Reset SI/P-14 (CP006) w/ P-4 False
Reset FW Cont & Bypass Valves (CP006)
FW Isolation Switches to “Open” (CP006)
Allows control of PBVs, FWIVs, and FWIBs
- P-4 w/ Tavg Low (574 ˚F) [2/4]:*
- *Reset Low Tavg (CP006)**
- Resets all valves except MFRVs*
- *FW Isolation Switches to “Open” (CP006)**
- Allows control of PBVs, FWIVs, and FWIBs*
- *P-4 must be False to operate MFRVs**
- LOT 202.13 Feedwater*
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What cools the DA Vent Condenser?
Condensate
- Steam condensed and sent to DA waterbox
- Non-Condensables sent to CARS discharge header → Unit Vent (Monitored release path)
- LOT 202.13 Feedwater*
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What provides overpressure protection for the Deaerator?
- *7 Reliefs**
- Set at 235 psig*
Relieves to atmosphere.
- LOT 202.13 Feedwater*
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Where does the DA High Level Dumps and the DA belly drains discharge water to?
- High Level Dumps:*
- *Condenser 13**
DA Belly Drains:
Storage Tank #1: Condenser 11
Storage Tank #2: Condenser 13
- LOT 202.13 Feedwater*
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What will trip a SUFW pump?
SUFW Lube Oil Pressure < 5 psig
- *FW Isolation**
- SI OR P-14 ONLY*
NPSH < 80 psid
- *Undervoltage**
- 1H Standby Bus*
Phase Differential
Overcurrent
On SUFW Trip:
- Discharge MOV / Non-Return close (Signal sent for 160 sec)
- Recirc Valve Closes (Signal sent for 5 sec)
- Aux cooling pumps start
- LOT 202.13 Feedwater*
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What causes a Feedwater Isolation Signal?
- P-4 True:*
- *Tave - Low (574 ˚F) [2/4]**
- No Permissives:*
- *SI**
- *P-14**
- S/G Level - High (87.5%) [2/4 on 1/4]*
P-4 True: Rx Trip [2/2] AND Bypass Bkrs [2/2] open
- Note:*
- Closes FWIVs, bypasses, FRVs, Low FRVs, and PBVs
- Trips MFP turbines, SUFW, and the Turbine. (SI AND P-14 ONLY)
- Does NOT trip the FW Booster pumps
- LOT 202.13 Feedwater*
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How does the Deaerater MS Supply valves (PV-7174 / PV-7174A) behave during a large load rejection?
Opens and Pegs DA Pressure to preloss pressure for 6.3 mins
Open Permissives:
NO P-4
NO SI
NO P-14
- Maintains FWBP NPSH
- Minimizes flashing
- Note:*
- DA Pressure compared to Auctioneered High FWBP Temp (PSat) (Modulates Valves)
- DA Pressure / Rate compared to crossover piping pressure (Detects loss of load)
- LOT 202.13 Feedwater*
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What is the motive force for opening/shutting the FWIVs?
Hydraulic open / Pneumatic (N2) closed
- FWIVs fail closed on loss of hydraulics/power.
- Will NOT close on loss of N2 pressure
- LOT 202.13 Feedwater*
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Where does the mini flow from the FWBP and MFPs go?
DAST #1
- LOT 202.13 Feedwater*
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What will auto start/trip a FWBP?
- Auto Start:*
- *Trip of running pump**
Start Permissives:
Lube Oil Pressure > 8 psig
DAST Level > 6%
Oil Pressure ≥ 11 psig
Local switch not in stop
Trip:
Lube Oil Pressure < 8 psig
DAST Level < 6%
UV on switchgear
Overcurrent
Breaker Closing:
- Opens Discharge MOV (Locks in open signal for 3 min)
- Recirc valve will modulate (8000 gpm)
Start permissives being met will be indicated by blue light on 13.8 kV switchgear
- Does not indicate whether MCR switch is in Stop/PTL
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Note:
By procedure a standby FWBP will have it’s discharge MOV already open
- LOT 202.13 Feedwater*
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What powers the FW Booster pumps / SUFW pump?
- FW Booster Pumps:*
- *1F / 1G / 1J Aux Bus**
- SUFW Pump:*
- *1H Standby Bus**
FW Booster Pumps: (50% capacity) [CP008]
- < 40%: 1 Running / 1 Stby / 1 PTL
- > 40%: 2 Running / 1 Stby
SUFW: [CP006]
- Can provide 20%
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Note:
SGFPTs provide 40% each. (Can operate with 2 SGFPTs and SUFW pump)
- LOT 202.13 Feedwater*
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What are the open permissives for the FWIVs?
SGNR Level > 5%
SG Pressure > 685 psig
- FWIVs fail closed on loss of hydraulics/power. (Will not close on loss of N2 pressure)
- Hydraulic open / N2 closed
- FW Isolation Energizes Train A/B solenoids, which secure the hydraulic pumps and dump hydraulic fluid (Manual switches [2 / SG] located on CP006)
- Open permissives being met allows de-energizing Train A/B solenoids.
Note:
Same concept for FWIBs and Preheater Bypass Valves (PBVs) except solenoids de-energize to dump hydraulics and energize to allow opening.
- LOT 202.13 Feedwater*
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What supplies the FWBP shaft seals?
Condensate Polisher Outlet
Leakoff collected in Condensate Return Tank → Seal Leakoff tank → Condenser 12.
- Note:*
- SGFPT seals also supplied by Condensate polisher outlet
- Cold return goes to Seal leakoff tank
- Hot return goes to DA.
- LOT 202.13 Feedwater*
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What are the open permissives for the SGFP discharge MOVs?
- Open Permissive:*
- *SGFPT Latched**
- NO AUTO OPEN SIGNALS
- Valve auto closes on trip of SGFPT
- LOT 202.13 Feedwater*
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What cools the FWBP lube oil cooler?
CL-ACW
Also cools the SUFW pump seal water and lube oil.
Note:
FWBP Seal water cooled by condensate polisher outlet.
- LOT 202.13 Feedwater*
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What Deaerator Storage Tank level setpoints will cause automatic /operator actions?
- High 2 (89%/90%):*
- *DA Inlet MOVs Close (CD-574/CD-575)**
Extraction Steam Block / Non-Return valves Close
FW HTR 11A/B Drain to DA Valves Close
- 86%:*
- *High Level Dump Valves Open (FW-7175/7175A)**
- 30%:*
- *POP09 requires Rx Trip**
- 6%:*
- *FWBPs Trip**
Normal Level is 70%
Note:
Meter on CP008 and ICS will stop indicating at 30%
- LOT 202.13 Feedwater*
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At what power levels are the Low Power FRVs and Main FRVs used?
- Low Power FRVs:*
- *< 15%**
- Fail closed on Loss of Air/Power*
- Main FRVs:*
- *≥ 15%**
- Fail closed on Loss of Air ONLY*
- Controlled from CP006
- *
Note:
2 safety related solenoids for FW Isolation signal
- LOT 202.13 Feedwater*
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What connects the SUFW Seal Aux Cooling Pump motor to the pump?
Magnetic Coupler
Occasionally, the pump will lose magnetic coupling and stop pumping. Stopping and restarting the motor usually restores proper coupling.
- LOT 202.13 Feedwater*
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How is DA level control achieved?
- Manual:*
- *Used when < 5% Feed Flow**
- Single Element:*
- *Used 5% - 20% Feed Flow**
- *DAST Level ONLY**
- Average of DST #1/#2 Level compared to LK-7406 setpoint (CP008)*
- Three Element:*
- *Used > 20% Feed Flow**
- *DAST Level**
- Average of DST #1/#2 Level compared to LK-7406 setpoint (CP008)*
- *Feed Flow compared to Condensate Flow**
- Sum of all 4 feed flows*
Controls CD-7406A (Low Flow) [<40%] and CD-7406 (High Flow) [≥ 40%] (Switch at 40% is automatic)
- LOT 202.13 Feedwater*
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What is the functions of the Deaerator / DA Storage Tanks?
- *Reduce O2 and condensable gases**
- < 2 ppb O2*
- 5 min retention time in DASTs*
Preheat FW
NPSH for FW Booster Pumps
