Condensate Transfer and Storage & Aux Feedwater Flashcards
(107 cards)
What is design basis for Condensate Transfer & Storage system ?
-Initial fill for Condensate & FW system
-Help maintains level in Condenser hot wells
-Provide water for CD Demins for resin regeneration
-Backup water to Spent Fuel Pool
-Emergency makeup for EW,EW, & DG Jacket Water Surge Tanks
Why is the CST Tank reinforced with concrete ?
-Needs to meet seismic category 1 requirements to be functional during safe shutdown
-Protects against tornado borne missiles
What is 300,000 gallons of water dedicated to inside the CST Tank ?
-To use Aux. FW system and provide FW to maintain plant in hot standby for 8 hours
-Allows controlled plant cooldown at max rate of 75F/hr to shutdown cooling is initiated
What is the other 220,000 gallons dedicated for inside the CST Tank ?
-Dedicated to 3 days of normal makeup to Condensate & FW systems
-Used by Secondary Chemistry Control system without replenishment from DW
How are the penetrations into the CST Tank arranged ?
-Essential operations is everything below the 300,000 gallons
-Non-Essential has penetration above the 300,000gallons
What is the normal makeup to the CST ? How is it done ?
-DW is normal makeup and is normally done automatically based on CST lvl
-Makeup line has a bypass line that can be used when level control balance is isolated
What is the backup makeup water to the CST ? Why is this makeup water supply not normally used ?
-Recycled Monitor Tanks is backup makeup source to CST
-Not normally used because it can potentially be contaminated
What cover gas is used for the CST Tank ? How is regulated ?
-Nitrogen gas is used
-Regulated to 3.5 psig by a PCV
-Bypass line can be used when PCV is isolated
What’re the two breather valve used for?
-One breather valve is used pass nitrogen from atmosphere from failed open nitrogen supply line
-Other breather valve allows air into CST to prevent vacuum during Main Condenser Hotwell Makeup
What is the purpose for Tank Overflow & Loop Seal line ?
-Loop seal prevents nitrogen from leaking out
-Overflow is directed to north condenser sump
Why should the CST inventory not be <40F & >120F ?
-<40F precludes thermal shock to SGs
->120F is upper limit of design calculations
What is the primary supply line for the FLEX SG Makeup Pump ?
Pump draws from CST Drain Line
Where is the valve located that is used to align the FLEX SG Makeup Pumps used for ?
The valve to align is located in CST Drain Pit
What conditions must the CST Drain out be maintained in ?
CST Drain pit must be maintained locked by Operations & Security departments
What’re pre-requisites to placing CST in Normal Operation ?
-DW available
-LP Nitrogen is available
Where do the Condensate Transfer Pumps supply makeup water to ?
-DG Jacket Water Storage Tanks
-EC Surge Tanks
-EW Surge Tanks
-Spent Fuel Pool
Is there expected to be leakage from the Condensate Transfer Pumps ?
-Some leakage is expected both during operation & while secured
-Leakage will fall to pump skid and directed to floor drain
Where do the Condensate Transfer Pump recirc. lines discharge to ?
Recirc. lines will discharge back into CST from associated Train Aux FW Pump Recirc. Lines
Where are the Condensate Transfer Pumps powered from ?
Powered from class 480MCC (PH)
What ESFAS signals auto start the Condensate Transfer Pumps ?
-LOP (Train Specific)
-SIAS
-CREFAS
-CRVIAS
What do the CST Suction Isolation Valves to the ‘N’ Aux FW Pump do ?
Provides isolation for CST & Seismic break between Seismic Category 1 & Seismic Category 2 rated supply line
What conditions are the CST Suction Isolation Valves usually in ?
They’re normally closed
How are both of the CST Suction Isolation Valves interlocked with ‘N’ Aux Fw Pump ?
Provides low suction pressure protection
What position must the CST Suction Isolation Valves be in to start and run the pump ?
-Both valves must be >80% open
-If one valve drops below 80% open it will trip the ‘N ‘ Aux FW Pump