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’
[HC]
What happens if a pair of CNTMT CEDM Normal ACU fans trips?
What position does the control switch need to be in?
Low Fan D/P sensed automatically starting the other pair of fans after a 120 second time delay
“Normal After Stop” position
[HC]
CNT CEDM Normal ACU fan time delay purpose?
- Allows non-operating fans to come to a stop in case the back draft or suction damper were leaking which could cause the fans to spin backwards
[HC]
What happens to CNT CEDM Normal ACU during a SIAS?
-All operating fans stop,
(Restarted after placed in override)
How is the Containment CEDM Normal ACU affected by a LOP?
The pair of fans that was running prior to the LOP will be started by the load sequencer
What is the purpose of the Containment Reactor Cavity Cooling Fans and how many fans are there?
- air from the lower containment to the reactor cavity
- prevent cement deterioration
- 4 Fans
Where do the Containment Reactor Cavity Cooling Fans take suction from and where are they located?
80’ of containment
How many Containment Reactor Cavity Cooling Fans are normally running? What is the capacity of each fan?
(2/4), one from each pair
(A and C, or B and D)
50%
What system provides power to the Containment Reactor Cavity Cooling Fans?
NH (M19 and M20)
Where is the only location that I could verify the remote position of the Containment Reactor Cavity Cooling Fan damper?
Can only be verified at the MCC supplying power to the damper
[HC]
Rx Cavity Cooling Fans auto feature associated with the CNTMT?
Provided between ‘A’ and ‘B’ and the ‘C’ and ‘D’ fans
Ex. If ‘A’ fan is in AUTO and a low D/P is sensed across the ‘B’ fan, ‘A’ fan will auto start after 60 seconds
[HC]
Pressurizer Normal Cooling Exhaust Fans operation?
Suction/Exhaust?
-2 fans in pressurizer missile shield
-Discharge (Fans: Top)
Suction: Bottom
[HC]
# of Pressurizer Space Exhaust fans running normally?
-1/2
-2nd in AUTO
[CH]
Pressurizer Normal Cooling Exhaust fans Power?
- NH (M71, M72)
- SIAS load shed
[HC]
Pressurizer Normal Cooling Fans auto functions?
B Fan = Low D/P
A Fan = Auto start (60 sec) (if in Auto)
What is the purpose of the Containment Tendon Gallery Supply and Exhaust Fans and where are they located?
Supply and exhaust fans that operate to ventilate the tendon gallery area to ensure a habitable environment prior to personnel access
Located on 100’ level outside containment building
Where do the Containment Tendon Gallery Supply fans get their suction from?
Outside air
What are the power supplies for the Containment Tendon Gallery Supply and Exhaust Fans?
NH
How many exhaust fans are normally operating in the MSSS? How are they controlled?
Both - Each only takes suction on either side of the MSSS (north and south).
Controlled locally
How many AFUs are used in the MSSS Ventilation Supply? What is inside the AFUs?
two, One for each fan
dry filter media
w/a high D/P alarm and an abandoned oil impingement cleaner
What is the auto feature associated with the MSSS Ventilation Supply?
One supply fan is normally operating with the other fan in AUTO
When operating fan trips, and low D/P is sensed across the fan, standby fan will auto start after 60 seconds
[HC] MSSS Ventilation Supply Fans controlled?
Locally - 3-position switch
(STOP/AUTO/START)
[HC]
While doing rounds, you notice that the MSSS Ventilation Supply fan motor is operating, but the blades are not spinning. What happened?
Fans are belt driven; the belt is broken or loose
[HC]
RU-1 Operation?
Location?
AB
Draws a suction from CTMT 95’
Sample Exhausted to CTMT
Describe the RU-1 containment penetration isolation valves. What system powers them? When will they fail closed?
Two installed on each penetration, one inside containment and the other outside
Each valve is class powered and will fail close upon a loss of power (PK), will close on CIAS
Suction line – UV-47 (B train) and UV-46 (A train)
Return line – UV-44 (B train) and UV-45 (A train)
[HC]
How are CNTMT Normal ACU fans paired together?
A and B
C and D
Where do the Containment Pre-Access Filtration AFUs discharge to?
the upper portion of containment
What is the capacity of each Containment CEDM Normal ACU fan?
50%
What happens when the Containment CEDM Normal ACU control switch is turned to the start position?
ACU fans start, intake damper and NC system cooling water supply valve both open
How are the CEDM normal ACU intake dampers physically operated?
motor operated
What is the tech spec associated with the Containment HVAC system?
containment must remain at 117*F or lower
How does the HC system interface with the PPS?
pressure transmitters inside containment generate actuations based on containment pressure
[HC]
7 subsystems?
CEDM ACU
Pre-Access AFU
Normal ACU
Pressurizer Cooling Fan
Rx Cooling Fan
Tendon Gallery
MSSS
