FHA Flashcards
What valve modulates to maintain Aux building at a negative pressure?
F021
Is the F021 on the inlet or the outlet?
inlet
How does the F021 respond to DP change in the Aux building?
DP goes down - less negative: valve closes
DP goes up - more negative: valve opens
F021 is on the inlet
what must be running to start supply fans?
exhaust fans
when will STBY fan auto start?
Loss of operating fan sensed by fan low DP
What happens if exhaust fan trips?
supply fans trip
what are the FHA fan coil units and what are the trips?
C002: trips on F003/F004 < full open, smoke detector, manual reset
C005: trips on F003/F004 < full open, inlet duct high temp, auto reset
C007: no trips
What is the supply fans’ suction source?
outside air
what happens when SBGT initiates?
All fans stop and dampers close
what happens if running exhaust fan trips and STBY fan fails to start?
Supply fan will trip
Which pool has the reheater coil?
spent fuel pool
what’s the purpose of the reheater coil?
Aid in mixing and absorption of fission product gases as well as minimizes fog forming on pool surface during refuel
what initiates Standby Gas?
- 41.6” Rx water level
1. 23 psig drywell pressure
30 mr/hr in fuel pool sweep
3.6 mr/hr FHA exhaust
Which DP transmitter is used for maintaining negative pressure in the Aux building?
Higher of the 2 (closest to zero)?
What will trip the exhaust fans (both sets)?
F003/F004 < full open