Auxiliary Feedwater System Flashcards
(28 cards)
What is the Basis for the amount of AF that is reserved for use in the plant during emergency situation?
Provides sufficient reserve of feed water to permit the plant to operate in mode 3 for 8 hours followed by an orderly plant cool down rate not to exceed 75F/HR to the point where shutdown cooling may be placed in operation (RCS temp 350F)
What is the capacity of the CST and RMWT?
CST 550,000
RMWT 480,000
How is HA affected by a high water level in either AF pump room?
Aux building AHU dampers isolate the rooms
How is ‘N’ AFP self lubricating?
Uses dipper rings to throw oil onto the bearings
What provides cooling water for AFP lube oil coolers?
Pump first stage discharge
Where is AF ‘N’ powered from?
Control power?
PBA-S03
Control power - has 2 sources PKA-D21 and ‘A’ battery charger
Why does the AF ‘N’ have 2 class powered suction valves?
Provide class and seismic protection boundary for CST inventory, separating it from the non-seismic piping to AF ‘N’ downstream isolation valves. (CTA-HV-4 & CTA-HV-111)
Where are the AF ‘N’ class power valves located and what is there designation?
CST pump house (CTA-HV-4 & -1)
What is the interlock associated with AF ‘N’ and its suction valve? What is the purpose?
If either valve (CTA-HV-4 & -1) is less than 80% open then the pump will not start and will trip if running
Purpose is to provide protection from a low suction pressure condition, which could damage the pump
Where are all the non-seismic penetrations located on the CST?
Above the safety storage volume of 330,000 gallons or 29.5 feet
What is the difference between AF ‘N’ and ‘B’ even though they are similar pumps?
‘B’ designed to meet seismic requirements
‘B’ equipped with a larger horsepower motor (125% larger)
‘B’ equipped with auto start feature from the ESFAS load sequencer module of the BOP ESFAS that will start under certain conditions
What happens when the AF ‘B’ ‘A’ start?
Essential air cooling unit auto starts
What is the purpose of the AF ‘A’ worm drive gearbox?
Coupled to an oil pump and the turbine governor actuator and driven off the turbine
What provides cooling water to the AF ‘A’ lube oil cooler?
First stage of the AFP
What is the minimum speed of AF ‘A’ pump to provide adequate lube and cooling?
1000rpm
How do we maintain the cleanliness of the AF ‘A’ governor control system?
Renewable cartridge filter that has a built in dirt alarm that will auto bypass the filter when it becomes clogged
How does the AF ‘A’ respond to AFAS?
SGA-UV-134A and -138A open first to bring the turbine up to speed in a slow and controlled manner
30 seconds later SGA-UV-134 and 138 open to allow maximum steam flow to the turbine and as the turbine approaches nominal speed, governor begins to throttle governor control valve to 3600 rpm
Why is there a large condensate pot installed in the Aux Building?
To allow constant draining of moisture that accumulates in the steam supply line
Without it moisture could accumulate in the steam supply line and greatly increase the chance of turbine overspeed during startup
Where can I trip AFA-HV54 electrically?
What is AFA-HV54?
Board 6 in the control room
‘A’ remote shutdown panel
local control panel
It is the steam supply valve to the ‘A’ AF turbine AFA-k01
What is a trip of AFA-HV-54?
Mechanical overspeed device
What is the purpose of the AF regulating and isolation valves?
Provides means to regulate and isolate flow, respectively to the steam generators from the essential AF pumps
What powers the regulating and isolation valves associated AF ‘A’?
PKA and PKC
What is pressure locking in regards to double disk gate valves?
When a valve is closed and water gets trapped and thermal expansion locks the valve
How do we prevent pressure locking?
Each ‘A train isolation babes bonnet area is connected to a relief valve that relieves to the CST, normally via ‘A’ AFP mini-flow line
‘B’ has an equalizing valve on the bonnet and discharges to the side of these valves
