Containment Ventilation Flashcards
What are the Phase “A” trips for Ctmnt Ventilation?
- Containment Purge Valves Close
- Instrument Rm Purge Valves Close
- Containment Pressure Relief Valves Close
- Containment Upper Vent Fans
- Instrument Rm Fans
What trips on a Phase “B” signal for Ctmnt Ventilation?
- Ctmt Lower Vent Fans
- CRDM Fans
- Pressurizer Enclosure Fans
- Reactor Cavity Fans
What trips on a CVI signal for Ctmnt Ventilation?
- Containment Purge Fans and Valves
- Instrument Room Fans and Valves
- Containment Pressure Relief Fan and Valves
What does the CVI Train A isolate/trip?
Inside Ctmnt valves plus Trips Instrument Rm Purge Supply Fan
What does the CVI Train B isolate/trip?
Outside Ctmnt valves plus trips all other fans
What Ctmnt Ventilation trips on a Load Conservation?
- Containment Pressure Relief Fan
- Ctmt Upper Vent Fans
- Instrument Room Fans
- Pzr Enclosure Fan
- Hot Sleeve Fans
- Rx Cavity Fans
What normally running Ctmnt Ventilation does NOT trip on a Load Conservation?
- CLVs (need for containment pressure)
- CRDM fans (needed for Nat Circ cooldown)
What happens with Ctmnt Ventilation when a 1 psi in lower ctmnt signal is received?
- CEQ fan Cooling Valves Open
- U1 CEQ Fan starts on 283 sec time delay
(Fan suction valves open on fan start) - U2 CEQ Fan starts on 2 min time delay
(Fan suction valves open on fan start)
How will Containment Pressure Relief Damper, VDC-207 fail on a loss of ctrl air?
open
What starts/opens on a 1 psi in Ctmnt signal?
CEQ fans start and suction valves open on the start
What do you use to reduce pressure in ctmnt if > 0.3 psi?
Containment Pressure Relief Fan (Normal)
CPS/CPX would be abnormal
What will give you a Containment Vent Isolation?
- High Rad in Upper or Lower Ctmnt
- Manual Phase A
- Manual Phase B
- Manual or Auto SI
What Ctmnt Ventilation will trip on a charcoal filter fire?
- Inst Room Purge Exhaust Fan
- CPR Fan
(Both will restart once temp is < 400°F)
What is your CEQ fan trying to maintain while its running?
< 4% Hydrogen atmosphere in Ctmnt
What are the places where the CEQ fans take a suction?
- SG enclosures
- Pzr Enclosure
- CLV fan rooms
- IR
- Upper Cntmt Dome
- Lower Ctmnt general area
When Phase A ctmnt isolation signal is reset, what will automatically realign?
Containment Upper Vent Units (CUVs) will automatically restart
Where does the CEQ fan exhaust to?
Lower Vent Unit Fan Area
During normal plant operation, control air to Containment Pressure Relief Inlet Volume Damper, VDC-207, is lost due to a small leak at the air valve.
How is Containment Pressure Relief System operation affected?
(ASSUME the leak does NOT effect any other component or system)
The system can be operated at full flow as the damper fails open
If a small instrument air leak inside Containment causes a slow rise in Containment pressure, what should be done to reduce Containment pressure?
The Containment should be vented using the Containment Pressure Relief system.
Which Ctmnt Vent Fan has the only electric heater that is outside ctmnt?
Intrument Room Purge Supply Fan
Following a Design Basis Loss of Coolant Accident, portions of the Containment Ventilation System are used to:
Ensure that in case of a LOCA, any hydrogen formation does not accumulate in isolated pockets in excess of 4% by volume
Following a Design Basis Loss of Coolant Accident (DB LOCA), portions of the Containment Ventilation System are used to …
aid in the reduction of containment pressure after blowdown
What is the flowpath for the containment purge supply fans?
Outside air is drawn in through an intake hood on the roof of the Auxiliary building.
The air flows through a roughing filter, medium efficiency filter, steam heating coil, and the supply fan.
The supply fan discharges the air through a backdraft damper to the common supply header which directs the air to the upper and lower compartments.
What is the flowpath for the containment purge exhaust fans?
Two exhaust fans draw air from the upper and lower containment volumes through inside and outside containment isolation valves.
The air flows** through a HEPA filter to the fan suction and is discharged through a backdraft damper to the plant vent.**
