N21 - Feedwater Flashcards
When is manual control used?
< 100 rpm
When will the controller auto swap from speed auto to manual? (going down)
< 300 rpm
Speed sensor fail hydraulic servo slave failure
both stop valves not full open
turbine trip
When is it preferred to swap from speed auto to feed auto?
2100 rpm
When will it auto swap from feed auto back to speed auto?
Speed signal exceeds the HSS limit (High speed stop)
speed below LSS limit
Signal “bad quality”
signal processing circuit fail (slave module)
When is emergency manual activated?
when digital control senses Hydraulic servo slave module is not in communication with the multi-functional processor
What is a risk of emergency manual mode?
OVERSPEED because there is no feedback to INFI-90
What’s the power supply for the RFPT speed control?
1Y99
Where does the RFPT turbine exhaust to?
HP condenser
What power levels is Start-up level control used for?
0-20%
What Rx power can you go to with the loss of HP feedwater heater string?
95%
What should vacuum be maintained at when the turbine is in operation? (vacuum in the RFPT lube oil tank)
> .5” wc or write a CR
How many low pressure steam poppets are there?
7
How many high pressure steam poppets are there?
1
Which poppets are used during start up? (low or high pressure poppets)
High pressure
At what reactor pressure, should you put in a feed pump?
400 psig
what’s the purpose of the feedwater system? (3)
- provides high pressure makeup water to make up for steam produced in the reactor during all modes of operation.
- preheats the water to 420 deg F
- Provides recirc flow path from common header back to hotwell. Also for heater drain clean-up
What does the HPU control?
Governor
What percent are the reactor feed pumps brought online?
< 8% they windmill off condensate booster pump
8% one pump
Approx 50-65% (no higher than 65), 2 pumps
What must min/flow valve be in, to start be in to start feed pumps?
cascade
What’s the purpose of the vacuum trip?
Protect the RFPT casing (backpressure)
How does the min/flow valve operate? (for feed pumps)
Works off percentage of pump speed
What must be running to “windmill” RFP using condensate booster pumps?
Oil pump
What does nitrogen accumulator do for RFP HPU?
Smooth out pressure pulsations from pump piston, and provide a surge volume to maintain pressure constant
What’s the function of the kidney loop?
takes suction from reservoir and recircs it through filter and heat exchanger
What’s the purpose of long cycle cleanup? (flow path)
Goes through condensate pumps, through CFFF, condensate booster pumps, LP heaters, Rx feed pumps, HP heaters, back to the condenser to remove stagnant, low purity water
What’s the purpose of short cycle clean up? (flow path)
Flow through condensate pumps, through CFFF, back to condenser through min-flow valve.
Where does the back-up (EOP) pump get its power from?
“F” bus
How does the pump suction valve (F029A/B) react to low lube oil pressure?
Auto closes @ <4 psig, resets @ 7 psig
Will an HPU trip directly trip a RFPT?
NO
When will Emergency DC oil pump auto start?
50 psig
Where do the RFPs receive sealing water from?
Condensate booster pumps
Where are the reactor feed pump suction valves operated from?
P175
Where are the 2 places the RFPT can get its steam from, and when is each place used?
Equalizing header @ start-up
2nd stage MSR (outlet) at power
What are the RFPT trips?
- SSCCORED How Many Bearings (3)
S - suction love pressure <= 157 psig (15sec A, 45sec B)
S- suction low flow 90% 5 min (admin manual trip) <80% 30 sec TD Auto trip
C- HP control oil press low <=75 psig
C- HPU header <= 1400# AND BOTH pump discharge <= 1500# (5 sec TD)
O- Overspeed mechanical or electrical >= 6100 rpm
R- RPV Level 9, 58” (1 sec TD)
E- Exhaust vacuum low <= 16” Hg vacuum
D- Deviation in Governor position/demand 20%
How - High discharge pressure >= 1580 psig
Many - Manual
Bearings - Thrust bearing wear detector high >= 40#
Turbine oil <= 4#
Pump oil <= 4#
What are the HPU trips?
Standby pump starts at 1500 psig
> 11” from top of tank LO-LO in reservoir
< 65 deg F temp in reservior
What is the power supply to the lube oil pumps?
A - 13BD1
B - 12BE6
When does the standby lube oil pump auto start?
< 222 psig
What is power limited to with one feed pump?
How long?
How many times per year?
then what must be done?
80%?????
3 hours
4 times per year
Reduce to 78.5% power