Auxilairy Feedwater(CA) Flashcards
What is the purpose of the Auxiliary Feedwater System?
- The Auxiliary Feedwater System provides a nuclear safety related source of emergency feedwater to the steam generators to maintain secondary side level, at times when the normal feedwater system is not available:
A. Removes Primary Coolant stored energy
B. Removes residual core energy
C. Prevents over-pressurization of the primary coolant system
D. Prevents primary coolant expansion(boiling) that could lead to fuel damage - Required to operate until the NC temperature is lowered to the point a which the Residual Heat Removal System(ND) may be operated(Mode 4 less than 350F)
- May be used as normal feedwater when less than 3% power
What is the system designator for the Auxiliary Feedwater System?
CA
What is the mission time for the Auxiliary Feedwater System?
7.5 days
What is the design/capacity of the Auxiliary Feedwater Motor Driven Pumps?
- 2 AC motor driven pumps per unit
- 100% capacity, each pump can supply all of the Auxiliary Feedwater requirements of 2 Steam Generators
- 490 gpm design flow
- Horizontally mounted, centrifugal pump
What is the power supply to the Motor Driven Auxiliary Feedwater Pumps?
ETA / ETB
Which Steam Generators are each Motor Driven Auxiliary Feedwater Pump aligned to?
A Pump - A and B Steam Generators
B Pump - C and D Steam Generators
What is the design/purpose of the Turbine Driven Auxiliary Feedwater Pump?
- There is one turbine driven pump per unit
- Capable of supply 100% of the Auxiliary Feedwater requirements
- Normally aligned to all four Steam Generators
- Design flow rate of 550 gpm
Where is the steam to the Turbine Driven Auxiliary Feedwater Pumps supplied from?
- Steam is supplied from the ‘B’ and ‘C’ Steam Generators, with one steam line supplying 100% of the requirements:
A. SA-2 from the ‘B’ Steam Generator
B. SA-5 from the ‘C’ Steam Generator - Steam can be supplied from the Auxiliary Steam system for testing
What is the normal position of the Auxiliary Feedwater Pump Suction Valves, and how are they maintained?
- The suction valves for all three pumps are open with power removed.
- The breakers are padlocked open to ensure they are not closed inadvertently
When will overspeed trip signals be generated for the Turbine Driven Auxiliary Feedwater Pump?
- Electrical Trip at 115% speed
2. Mechanical Trip at 125% speed
What is the correct way to trip the Turbine Driven Auxiliary Feedwater Pump?
Depress the manual trip lever locally at the CAPT
How is the Trip Throttle Valve Linkage reset for the CAPT?
The operator has to pull the trip linkage towards the Trip Throttle Valve.
What is the design/purpose of the Auxiliary Feedwater Discharge Flow Control Valves?
- Pneumatically operated, fail open valves
2. Following a CA Auto Start the FCVs will open to their travel stops
What is the number one preferred source of water for the Auxiliary Feedwater Pumps?
The Auxiliary Feedwater Condensate Storage Tank(CACST) - 42,500 gallons
What is the number two preferred source of water for the Auxiliary Feedwater Pumps?
The Upper Surge Tank(UST) - 85,000 gallonsd
What is the number three preferred source of water for the Auxiliary Feedwater Pumps?
The Condenser Hotwell - 161,000 gallons
Why is the Hotwell Isolation Valve to the Auxiliary Feedwater System, CA-2, normally maintained in open with power removed?
This ensures that a spurious closure of CA-2, CA-4(UST), and CA-6(CACST) such as might be caused by a fire doesn’t cause a loss of all Condensate to CA.
What is the number four preferred source of water for the Auxiliary Feedwater Pumps?
The assured source, and the number four preferred source, is Nuclear Service Water(RN)
What is the number five preferred source of water for the Auxiliary Feedwater Pumps?
The “sabotage proof” source, and the number five preferred source of water is Condenser Circulating Water(RC).
What conditions will cause Nuclear Service Water to automatically align to the Auxiliary Feedwater System?
- Each train has three suction pressure switches
- All three channels have a 5 second time delay to prevent actuation on the pressure drop following a normal system start
- 2/3 channels sensing low pressure will align the RN valves to the CA suction FOLLOWING AN AUTOMATIC INITIATION
What conditions will cause Condenser Circulating Water to automatically align to the Auxiliary Feedwater System?
- Each train has three suction pressure switches
- All three channels have a 5 second time delay to prevent actuation on the normal pressure drop following a system start
- 2/3 channels sensing low pressure will align the RC valves to the CA suction REGARDLESS OF WHETHER IT’S AUTO INITIATION SIGNAL OR A MANUAL INITIATION.
Where does recirculation flow from all of the Auxiliary Feedwater Pumps go?
The Upper Surge Tank(UST)
What are the automatic start signals for the Motor Driven Auxiliary Feedwater Pump?
- Safety Injection - Train Related
- Blackout - Train Related
- Steam Generator Narrow Range Lo-Lo Level - 2/4 channels Lo-Lo on 1/4 Steam Generators
- Loss of both normal Feedwater Pumps - 2/3 low FWPT control oil pressure starts both Motor Driven CA Pumps
- AMSAC - ATWS Mitigation System Actuation Circuit
A. Loss of CF Feed Path
B. Both CFPTs Tripped
What is the setpoint for the Unit 1 and Unit 2 Steam Generator LO-LO Level Motor Driven CA Pump automatic start?
Unit 1 - 11%
Unit 2 - 37%
