Containment Air Coolers Flashcards
LCO 3.6.4 “Containment Pressure” requirements
Containment pressure shall be <= 1 psig in modes 1 & 2, and <= 1.5 psig in modes 3 & 4
LCO 3.6.4 “Containment Pressure” applicability
Modes 1-4
LCO 3.6.4 “Containment Pressure” required actions if containment pressure not within limit
Restore containment pressure to within limit within 1 hour
LCO 3.6.5 “Containment Air Temperature” requirements
Containment average air temperature shall be <=140 F
LCO 3.6.5 “Containment Air Temperature” applicability
Modes 1-4
LCO 3.6.6 “Containment Cooling Systems” requirements
2 containment cooling trains shall be operable
LCO 3.6.6 “Containment Cooling Systems” applicability
Modes 1-3
LCO 3.6.6 “Containment Cooling Systems” required actions if less than 100% of the required post accident containment cooling capability is not available
IMMEDIATELY enter LCO 3.0.3
What makes up left train of containment cooling?
- 2 spray pumps P-54B/C
- CV-3001, Containment Spray Header Isolation
- VHX-4
What makes up right train of containment cooling?
- 1 spray pump P-54A
- CV-3002, Containment Spray Header Isolation
- VHX-1, 2, and 3
- 2 Service Water Pumps P-7A/C
What is the normal lineup of the CACs?
4 CAC’s operating with all 8 fans running and all critical service water inlet/outlet valves open
Where does the condensate from the CAC coils drain to?
- Drains go to the containment sump sized for 20 gpm
- Flapper sized for 150 gpm in the event of a service water leak
What is the function of the blow out panel on the CACs?
Ruptures at 1 psig in the event of steam/water coming from the CAC suction source (steam generator shed)
What happens to the CAC System on SIS?
- All of the ‘B’ fans stop
- All high capacity service water outlet valves open
- VHX-4 service water inlet closes
Why does the VHX-4 service water inlet go closed on SIS instead of the outlet?
If the outlet were closed, SW would be in the coils with no flow. On an extreme heatup of containment, the expansion of the water in the coils due to the temperature rise could cause the coil to rupture.
What is the cooling water supply for the CACs?
‘B’ Critical Service Water header
What are the power supplies for the CAC 75 HP ‘A’ fans?
VHX-1/2/3 - LCC-12
VHX-4 - LCC-11
What are the power supplies for the CAC 30 HP ‘B’ fans?
VHX-1/2/3 - MCC-3
VHX-4 - MCC-4
Why do the 30 HP ‘B’ fans trip on SIS?
They are not big enough to handle the more dense air from a DBA
When are the Pressurizer Shed Fans required?
Required when the plant is hot. Started during the 250 pound checklist
What causes “Containment Recirc Fans Trip” alarm?
Any fan breaker open with its control switch in the after start position
What causes “Containment Air Cooler VHX-1/2/3/4 Dry Pan Hi Level” alarm?
6” of water in the dry pan
What causes “Containment Air Cooler Serv Water Leak” alarm?
300 gpm difference between SW into and out of containment. Isolate 1 CAC at a time to find and isolate the leak
Why do VHX-1/2/3 ‘A’ fans need to be running to be considered operable?
CHP and SIS don’t start them unless there is a loss of offsite power
What is the maximum indicated flow rate on the PPC CAC SW leak detector?
7500 gpm. Anything greater than 7500 gpm will still indicate 7500 gpm
How should SW be valved into the CACs and why?
-Open CAC SW outlets
-Open SW to and from containment
-Open CAC SW inlets
Done in this order to minimize water hammer or transients
What conditions warrant starting a 3rd Service Water Pump?
- Either critical service water header < 50 psig
- Local service water pump discharge pressure < 53 psig
- Loss of temperature control on any SW cooled component due to low flow
What conditions warrant stopping a 3rd Service Water Pump?
- Both critical service water headers > 70 psig
- Local service water pump discharge pressure > 73 psig
