Refueling Water System(FW) Flashcards
What is the purpose of the Refueling Water System?
- Provide a source of borated water to be used during refueling, a LOCA, or as makeup to the Spent Fuel Pool
- Remove impurities from the Refueling Cavity and Transfer Canal during refueling operations, and cleanup of the Refueling Water Storage Tank(FWST) following refueling.
- Provide a means of transferring water between the refueling cavity and the FWST
- Provides borated water requirements and miscellaneous flow paths:
A. Borated water for filling and makeup to the Cold Leg Accumulators from the FWST
B. NI pump’s minimum flow returns to the FWST
C. NS pump’s recirculation test line returns to the FWST
What is the design/purpose of the Refueling Water Storage Tank(FWST)?
- 395,000 gallon tank(TS min 377,537)
- Has a 14 foot concrete wall that acts as a missile shield
- Heaters maintain the tank at greater than or equal to 70F
- Primary suction source for all ECCS pumps
- Suction source for containment spray(NS)
What is the minimum required temperature of the FWST and why?
- 70F
2. Any colder and the boron will start to come out of solution
What is the design/purpose of the Missile Wall Sump?
- Collection point for rainwater or a puncture of the FWST
- The sump is manually pumped down IAW the alarm response procedure to the YV sump
- Pump automatically stops:
A. When level decreases to setpoint
B. When FWST puncture alarm received(12” from bottom of the Missile Wall)
What is the purpose of the Refueling Water Pump?
- Designed to transfer all of the water from the Cavity and the Transfer Canal to the FWST in 24 hours
- Controlled from the Control Room
- Can be used to recirculate the FWST and cleanup the FWST using the KF filters
What is the purpose of the Refueling Water System Recirculation Pumps?
- Recirculate the discharge piping
- Will trip if the FW-33A or FW-49B(suction valves from the FWST) close.
- Two pumps per FWST
- Recirculates the discharge piping once every 2.5 hours
How will a Safety Injection Signal affect the Refueling Water System?
- FW-1A and FW-32B(FW pump suction valves from the FWST) close
- FW-33A and FW-49B(FWST suction valves to the header/recirculation pumps) close ->this will trip the recirculation pumps
How many Refueling Cavity Drain Valves are there and what is their purpose?
- There are 6 drains, normally locked open at during operation
- The Refueling Cavity Drains allow water from Containment Spray to flow back to Lower Containment
- Visually inspected by AOs to verify not obstructed
What is the purpose of the Reactor Vessel Flange Seal?
- 5 piece hard rubber seal
2. Installed prior to filling the refueling cavity to prevent water from flowing past the flange into lower containment
What is the normal position of the Fuel Transfer Canal Isolation Valve(KF-122) during operation and why?
- Normally KF-122 is locked open
- KF-122 is locked open because it provides the suction source for the Standby Makeup Pump
- Must be closed prior to removing the blind flange
How many turns is it to operate the Fuel Transfer Canal Isolation Valve(KF-122), and why is it important to not operate the handwheel beyond that point?
- 110 turns
2. Operating the valve handwheel beyond that point could damage the valve seat
What are the power supplies to the valves in the Refueling Water System?
EMXA
EMXB
EMXI
What is the preferred source of the filling the deep end of the Refueling Cavity and why?
FW is preferred over ND due to surface and airborne contamination concerns
Why do we control the upper limit of FWST temperature to a maximum of 100F?
Prevents reaching higher containment pressures during a LOCA
What is the system designator for the Refueling Water System?
FW
