Condensate and Feedwater Flashcards
Starting interlocks of the A MFP (Motor driven)
- One CD/CDBP running
- Good oil pressure
- FW002A open (discharge valve)
- CB005A open (suction valve)
- FW027A open (Manual recirc isolation)
P2A MD MFP trips: (7)
- Electrical (OC, Grnd OC, Diff OC, UV)
- High lube oil temperature (175F)
- Low lube oil pressure (10#)
- P-14
- SI
- Low suction pressure (282#)
- No CD/CBP running
2B/2C turbine driven MFP starting interlocks:
- FW027B/C manual recirc open
- FW012B/C Recirc AOV open
- Turbine reset/latched
- HP and LP stops open
2B/2C Turbine driven MFP trips (7)
- Overspeed (5720 rpm)
- Low exhaust vacuum (14” Hg bypassed on startup)
- Low lube oil pressure (10#)
- P-14
- SI
- Both HP and LP stops closed
- Manual
SU feed pump has _____ starting interlocks, which are ______. SU feed pump will trip on _______.
No
None
1. Electrical (OC, Grnd OC, UV)
2. Low lube oil pressure (<5#)
SU feed pump is normally used at what power level?
<15%
To reset FWI from P-4:
Reset FWI 2/2 pushbuttons in “Yellow” on MCB
Reset FWI auxiliary relays 2/2 pushbuttons
Cycle RTBs to reset P4
To reset FWI from P-14
Restore all SG levels to normal
To reset FWI from SI
Reset SI to clear input
Cycle RTBs to momentarily clear P4 seal in
Reset FWI 2/2 pushbuttons in ‘yellow’ on MCB
Reset FWI auxiliary relays
CD152 is the _______ valve and begins to ______ and is full closed when ______.
AE/GS condenser bypass valve/ condensate recirc to condenser
Modulate closed >2100 gpm and
is full closed >7130 gpm based on highest flow reading
What is purpose of the FW heaters?
Improve efficiency and limit thermal stresses of SG
Where is the condensate collected in the heater directed?
Back to the condensate system via HDT or back to the condenser.
How is fine control of SG level maintained at all power levels?
Feed reg bypass valves at low power and FRVs >20% power.
CD/CDBP trips: (4)
- Phase overcurrent
- Ground overcurrent
- Lube oil pressure <4.0 psig
- Bus UV
CD/CDBP start interlocks
Sufficient lube oil pressure on both CD and CDBPs, 6 psig.
When does FWI occur?
RX trip with low Tave (564F)
Hi-HI SG level P-14
SI
What portions of CD/FW are safety related?
MFW check valves to SGs and FW035s to SGs
What major components exhaust to the main condenser?
TDMFWP turbines, main turbines (LP) and Steam dumps
How is vacuum in the main condenser maintained?
Condensing action of the steam
-and-
Air ejectors to remove air and non condensibles
Why is condenser level selection swapped from one side to the other when power is changed?
Lowest side is always selected to ensure adequate NPSH for the CD pumps. At low power the pump recircs raise the west side level. At high power the heater inputs raise the east side level.
CD-210A/B are the ________ valves and receive an open signal when______.
Condensate pump common discharge valves
Downstream pressure reaches 35 psig (CDBP low suction pressure)
CD157A/B are the _______ valves and work with _____ to maintain a total flow of ______. They also automatically open when ______.
GS condenser bypass valves
CD152 recirc to condenser
7130 gpm
Low FW pump NPSH signal
CB113A/B/C/D are the ____ valves and auto open when CDBP discharge flow rate drops to less than ____.
CDBP recirc valves
1700 gpm, full open at 839 gpm
Standby CDBP recirc valve kept _____ to prevent _____.
Closed
Flow through idle pump back to condenser
How is adequate oil pressure indicated in the MCR for a CD/CB pump?
White “OIL PRESS UP” light lit above AO pump H/S
What will auto start a CD/CB aux oil pump on the STBY CD/CB pump?
Low FP NPSH or low lube oil pressure (< 5 psig)
What interlock must be met to allow a manual or auto start of a CD/CB pump?
Adequate oil pressure – 6 psig
What conditions must be met to allow an auto start of a CD/CB pump?
Selected to STBY, C/S in NAT, Low NPSH present, and adequate oil pressure
If bus 143 is de-energized, what CD/CB pumps are affected?
1A and 1C pumps CB recirc valves will fail open, 1CD152 will fail open, and no power to the 1A/1C CD/CB pp aux oil pumps.
What will automatically trip a CD/CB pump?
Phase A/C or Ground OC, UV on Bus, or Low oil pressure on CD or CB pumps
How is condensate flow through the air ejectors controlled?
Minimum flow is established by CD152. As flow increases, a hinged baffle plate in each condenser allows more flow to bypass
If low NPSH is sensed, what happens to CD152 and CD157A/B?
CD152 closes, CD157A/B open
Hi‑2 level on any _1 LP heater causes the associated LP heater string to auto‑isolate after a time delay.
Bypass _____
Inlet _______
Outlet______
Opens
Shuts
Shuts when inlet 95% shut
How many trains of 1st stage low pressure heaters are there per Unit?
How many heaters in a single train of 2nd stage LP heaters?
3
2
The ____ will auto start, if enabled, on the loss of a ____.
_______ Starts at Time Zero.
Also at Time Zero, the Motor Driven Feed Pump gets a start signal and will start __________.
At ____ seconds, the ______ swaps to Auto, normally in Manual at 25%, and starts throttling to restore / maintain SG levels.
The recirc valve for the tripped TDFP _____.
The recirc valve for the running TDFP will go to_____ if an Alternate Action occurs.
MDFP (A); TDFP
Lube oil pump
when LO pressure is adequate
At 5 seconds; FW016 slim swaps to auto
Closes
manual if an alternate action occurs
The auto start function of the MDFWP will be automatically defeated at _______% steam flow, but will auto re-enable above _____% steam flow.
58
58
Steam supplies for TD MFWPs
MS ____MS & RHS _____ RHS _______
MS 0-25%
MS and RHS 25-45%
RHS>45%
How is the Motor Driven Feed pump kept warm for fast start any time?
Warm up line to the HDT through FW032
At 45% power on Unit 1, how far open is the LP governor for the 1B FW Pump?
Fully; HP governor is throttling closed as LP pressure rises
Emergency DC oil pump for TD MFWPs is for ______ only.
Coastdown
FW12A/B/C are the ______ and in modulate mode will ______ and will also ______.
MFWP recirc valves to condenser
Throttle open on low pump flow
-and-
auto open on P-4 signal
FRVs (FW510) auto _____ on a ____signal. FRBVs (FW510A) auto _____ on _____ signal.
Close
FWI
Close
FWI
FRBV fail ____ on loss of ______ or ______.
Close
IA or DC bus 111/112
FW009s feedwater isolation valve ______ to open and ____ to close.
Auto close on ______.
FWIVs – hydraulic to Open and N2 to Close
Valves fail “as is” on loss of power
Auto CLOSE on: 1. SI 2. P-4 with Lo Tave 3. P-14
What will automatically open a main feed pump recirc valve in Modulate? Three items including flow rates.
P-4, < 4050 gpm flow from _B or _C or < 8800 gpm flow from _A, and MFP trip
What type of valve is the HP (_7) Heater bypass valve?
MOV
What will automatically close a Feedwater Regulating Valve?
SI, P-14- P-4 with Lo Tave (564F), and Loss of IA
What does the white light near a FWIV C/S indicate when lit?
Hydraulic pump is running
P-14 is the ______
Setpoint and Coincidence_____
Function______
SG Hi-2 level
2/4 NR >88.0% (80.8% U2) on 1/4 SGs
1. Actuates FW isolation
2. Trips Main FW pumps
3. Closes FW002s
4. Trips main turbine
What are the inputs to the FW Low NPSH alarm?
FW pressure and temperature, and FW discharge flow
What functions does the Steam Flow/Feed Flow Mismatch circuit perform?
Bistable and alarm only; no RPS functions
FW Low suction pressure setpoint is ______ and also causes _____.
282# and also causes a MCR alarm
The following components are actuated on a MFWP low NPSH signal:
CD pp recirc CD152 closes
GS bypasses CD 157A/B opens
Starts S/B CD/CB pp and aux oil pumps
Water hammer prevention signal U2 only setpoints and automatic actions
Low SG pressure <600#
low SGWL <5% NR 2/3 45 second time delay
Isolates all potential flow paths to SG
FW043 (FW9 bypass)
FW039 (bypass around FRV/FBRV)
FW009 but only if FRV or FBRV not closed
FW 035 FRV/FBRV bypass, only low pressure w/CS in auto
ODD number valves
Purge permissive only used on U2. inputs_____ and _____.
2/3 on 3 locations >255F
required flow rate and time
What specific plant events/circumstances are mitigated by FWI?
High S/G level or excessive cooldown rate
What additional action(s) occur(s) on SI or P-14 initiated FWI that do/does not occur on a P-4/Low Tave initiated FWI?
Main Feed pumps do not trip
What will auto open the Exhaust Hood Sprays?
Turbine Speed > 600 rpm and LP turbine inlet pressure < 18 psig
Dissolved O2 _______
pH – _______
PAA – ________
Ammonium Chloride _______
Dissolved O2 – Hydrazine
pH – MPA (Methoxypropylamine)
PAA – Remove iron
Ammonium Chloride – Balance Na/Cl ratio in SGs
Glandwater Injection:
From CB common discharge for
Main condenser Block Valve Lantern Rings (i.e. FW/MSR drains)
Main FW pump seals, HD pump seals, CD/CB pump seals
MS Valve Lantern Rings (_MS005s, Steam Dump Iso Vlvs)
Main Condenser Vacuum Breaker loop seal fill lines
Drains cascade to the ______ or cascade/drain to the ___.
cascade to the main condenser
or cascade/drain to the HDT
Why do the steam dump downstream isolation valves have gland water injection?
Prevent condenser air inleakage
What affect does a loss of IA have on the CD/CB and FW systems?
All FW control AO valves, including FRVs and FRBVs, F.C. isolating feed to SGs. All recircs F.O. and all LP Htr String bypasses F.C. _FW016 F.A.I. (MDFP discharge AOV)
CST level must be ______ in modes _______.
If not verify operability of ___ and restore in ____ days.
> =60%, modes 1-3
Backup water supply within 4 hours and restore within 7 days
Basis for 60% CST level
LCO The specified level assures the required useable volume
of approximately 212,000 gallons is met. This volume is
sufficient to maintain the RCS in MODE 3 at normal operating
pressure and temperature for 2 hours, followed by a cooldown
to RHR entry conditions at 50F/hour, followed by a period
not longer than one-hour to allow warmup of the RHR pumps
prior to placing the RHR system into service in shutdown
cooling mode.
3.7.3 – Secondary Specific Activity;_____uCi/gm Dose Equiv I-131; MODES 1-4
<=0.1 uci/gm
Why delay a FWI signal until Tave is < 564F on a Rx trip (P-4)?
To prevent damage to FW heater reliefs due to the thermal-hydraulic transient that would occur if FWI occurred immediately after P-4.
CB025 FW heater string bypass valve is a(n) _________ and its control switch must be _______ to make up seal in contacts.
AOV
Held in open until valve is open
On high level in a _5 or _6 heater, the affected string is _______ bypassed and then isolated in same manner as the first stage LP heater string isolation
Manually
Heater drain tank pumps inject water into condensate and feedwater system between what two components?
5A/B DC and 5A/B
The _HD046 valves heater drain isolations to second stage heater train, will only open if ________.
…….if the associated second stage LP heater string is in service (based on inlet/outlet valve positions).
SU FW pump capacity ratings
2000 HP
5300 GPM
recirc modulates 2000-2500 GPM and disch pressure 2500#
MDFP Auto Start Feature________ and sequence: ______
The MDFP will auto start on the loss of a TDFP
1) Ovation sends a signal to start Lube Oil Pump and 1A FW Pp at time zero.
2) When Lube Oil Pressure interlock (pressure up) is met, 1A FW Pp will actually start.
3) At 5 seconds the _FW016 controller shifts to Auto (Normally in Manual at 25%), and will then throttle to maintain required flow
4) The recirc valve for the tripped TDFP will auto close.
5) The recirc valve for the running TDFP will go to manual, if an Alternate Action occurs.
6) As the unit is coming down in power, before a Turbine Driven Feed Pump is secured, ensure the Auto Start feature for the Motor Driven Feed Pump is Disabled.
7) The Auto Start Function will automatically be Blocked at < 58% Steam Flow, if it is allowed to automatically block it will automatically enable at 58% steam flow as the unit is ramped up.
MDFP trips: (9)
- Phase A/C Overcurrent
- Neutral Ground Overcurrent
- High Differential Current
- Bus _56 Undervoltage
- SI or P-14
- Low oil pressure - 10 psig
- High oil temperature - 175F
- Low suction pressure – 282 psig
- All CD/CB pump breakers OPEN
Backup bearing oil pump auto starts at _______ bearing pressure and the emergency oil pump starts at ______.
13#
10#
Whenever MFWIV accumulator nitrogen pressure _______ the valve is inoperable.
<1900#
Water Hammer Prevention System (Unit 2 only)
Actuates at ________ or _________ with ___ second time delay.
The following valves close; _____, _____, _____, and _______.
<600# SG pressure 2/3 or low SG level (<5% NR 2/3 with 45 sec time delay)
FW043s
FW039s
FW009s (if associated FRV or FRBV is not closed)
FW035s (only low pressure, with CS in auto)
Heater string isolation valves are operated from MCR at panel _____.
PM03J
For Unit 2 only, the 2FW039 valves are closed between ___ and ___ percent reactor power.
20-80%
If the difference between NPSH available and required is reduced to the setpoint _______, the FW pump NPSH Low Alarm bistable is actuated.
If the difference is reduced further______, an additional bistable actuates which results in the following auto actuations:
120 psig
100 psig
a) GS condenser bypass valves (_CD157A/B) fully open.
(1) Lowers CD system headloss, thus raising flow/head supplied by CD system.
b) _CD152 (CD pump recirc.) shuts.
(1) Maximizes flow to FW pumps rather than route it to condenser.
c) Start signal to standby CD/CB’s aux oil pump
d) Start standby CD/CB pump set selected.
(1) Maximize flow/head supplied by CD system.
FW009 opening interlocks for Unit 2
> 255F 2/3 on 3/3 locations for 8 minutes, then
130-220 gpm for the next 8 minutes
Must have 1310 gpm (600,000 lbm/hr) to open valve after purge permissive.
