HC- Containment HVAC Flashcards
[HC]
Purpose? (3)
- Maintains CNTMT temp for equipment operation
- Maintains CNTMT airborne activity within acceptable limits for personnel access
- Cools Main Steam and Feedwater pipe penetrations by supplying o/s air and exhausts from MSSS
[HC]
CNTMT Normal ACU’s Purpose?
Flowpath?
- Recirculate and cool CNTMT air
- Fans take suction on CB 120’
discharge to CB 100’ & 80’ elevations
[HC]
Which cooling water cools CNTMT Normal ACUs 3 cooling coils?
What regulates flow?
What isolates cooling water?
-[NC]
-Flow regulating valve from ACU Fan outlet temp.
-[NC] isolated when ACU stops
[HC]
CNTMT Normal ACU fans Location?
Power Supply?
CT 120’
PG
(PGA = A/C PGB= B/D)
[HC]
When closes/opens CNTMT Normal ACU dampers?
ACU fan start/stop
[HC]
CNTMT Normal ACU heaters are in series with what components?
Purpose?
Normal Status?
-C&D fans (one fan per ACU)
-Maintain CNTMT temperature during prolonged shutdown periods
- Down Powered
[HC]
CNTMT Normal ACU heaters have what kind of interlock?
Low Air Flow Interlock
- if air flow is too low to remove the heat generated by the heating elements, will trip heater.
[HC]
During normal operations, CNTMT Normal ACU has one fan running while the paired fan is secured in each duct.
What will happen if an operating fan trips?
What position does the switch need to be in place for this to happen?
- Low fan D/P is sensed, automatically starting the other fan after a 60 second delay
- ‘Normal After Stop’ position
[HC]
CNTMT Normal ACU fan 60 second time delay purpose?
Allows non-operating fans to stop if the back draft or suction damper were leaking, cause the fans to spin backwards
[HC]
What happens to the CNTMT Normal ACU fans upon a SIAS?
All operating fans stop,
can be restarted after they are in override
How are the Containment Normal ACU fans affected by a LOP?
If the fan was running prior to the LOP, the load sequencer will start the fan
[HC]
Containment Pre-Access AFUs are operated when?
Location?
-To support personnel access to CNTMT during power operation and before an outage
-CB 140’
[HC]
Containment Pre-Access AFU capacity?
50%
[HC]
CNTMT Pre-Access AFUs components (4) and functions?
High Efficiency Bank
- removes large radioactive airborne particulates
- protects first HEPA from excessive loading
1st HEPA Filter
- removes smaller particles
Charcoal filter
- remove fission product gases (mainly Iodine)
2nd HEPA filter
- remove charcoal fine particles
[HC]
Power for CNMT Pre-Access AFU fans?
NG
[HC]
CNTMT CEDM Normal ACUs purpose?
Components?
Location?
Keeps CEDM temperatures within limits
CEDM Normal ACUs (2) consist of:
two fans
cooling coils
ducting
dampers
CNTMT 157’
[HC]
What cools CNTMT CEDM Normal ACU cooling coils?What starts/stops it?
[NC] Nuclear Cooling Water
starts/stops automatically w/ associated fan
[HC]
How many CNTMT CEDM Normal ACUs are operating?
Can 1 fan cool the CEDMs properly?
- 1 of 2 w/ both fans running
- yes
[HC]
Why are CNTMT CEDM Normal ACU fan’s backdraft dampers installed on the discharge side?
Prevent a short circuit air flow during a 1 fan operation
[HC]
CNTMT CEDM Normal ACU fans power?
Location?
PG
- PGA = A/C
- PGB = B/D
CNT 157’