Aux Building HVAC (HA) Flashcards
What is the normal & essential HVAC used for ?
-Normal HVAC maintains environmental condition for personnel comfort & equipment operability during normal operation
-Essential HVAC serves ESF equipment rooms & safety related Aux Feed Pump Rooms
What’re the functions of the HA system ?
-Maintains slight negative pressure
-control air flow from areas of low airborne radioactivity to progressively higher airborne radioactivity
-Filters the exhaust air prior to discharge atmosphere
What subsystems do the Normal HVAC consist of ?
-Aux. Building Supply Air
-Aux. Building Exhaust Air
-Access Control Area
-Charging Pump Room
-CEDM Recirculation
What rooms have Essential ACUs from Essential HVAC system?
-HPSI Pump Room
-LPSI Pump Room
-CS Pump Room
-EW Pump Room
-Aux. FW Pump Room
-ESF Electrical Penetration Rooms
What is the normal operation of Aux. Building Supply Air system ?
Outside air is filtered, cooled, & heated by AHU which is then supplied to different rooms, the treated air from AHU is supplied to Normal Access ACU
What is normal operation of Aux. Building Exhaust Air system ?
-Within building air flows from potential low radioactivity to higher radioactivity areas
-Continuously exhausted by Normal Exhaust Air Filtration Units
Where is air from the Access Control Room exhausted to ?
It’s exhausted through Aux.Building Normal exhaust Air Filtration Units
What happens to Aux Building Normal HVAC during a LOP & SIAS ?
ESF equipment rooms & safety related Aux Feedwater Pumps are isolated from Aux.Building Normal HVAC
Following a SIAS how is negative pressure maintained below 100’ once isolated from normal HVAC system ?
-Negative pressure maintained by Fuel Building Air Filtration Unite provided
-Air from ESF equip. Room flows through connecting tunnel to fuel building AFU where it’s filtered & released to atmosphere
What is the HA system Fire Damper Configuration ?
What is the capacity of each Normal Supply AHU?
-Rated at 50% capacity(29,200)
What cooling water is sent through the Normal AHU cooling coils ?
Normal chilled water is sent through cooling coils
Where is each AHU heater installed at ? What is it used for ?
What is the common header pneumatically operated isolation damper interlocked with ?
It’s interlocked to open/close when fans are started/stopped
Where are AHU operated from ?
They’re operated from control room & equipped with interlock to ensure number of running AHUs is less than normal exhaust AFUs
Why must there be less or equal running AHU than normal exhaust AFU? How does this mechanism work ?
-This is done to maintain negative pressure
-Mechanism is DP across each Normal Exhaust AFU
What happens when Normal Supply AHU hits low DP setpoint ?
It will secure appropriate Normal Supply AHU
What is the normal operation of Normal Supply AHU & Normal Exhaust AFU ?
-Normally both supply & exhaust fans are running
What happens if you lose a exhaust fan ?
If you lose an exhaust fan, then the opposite train will lose its supply fan(Vice versa between each train)
What happens if you tried starting two supply fans while there is only one exhaust Fan ?
There is an interlock that will trip one of the supply fans to maintain negative pressure in the building
What does a duel duct do for the Access Control Area Normal AHU ?
One duct has hot air from heaters & one duct from cooling coil both enter a mixing box that has dampers to control hot air duct ONLY
When does the Charging Pump Room Normal ACUs turn on & off ?
Starts when pump starts & turns off 5 minutes after pump stops
What cools charging pump normal ACU ?
Normal chilled water goes through cooling coils
How many normal ACUs are in the CEDMCS room ? What is there Capcity ?
Two ACU are in service & each one has 100% capacity
How do the CEDMCS normal ACUs start ?
They’re started by local hand switch near the ACU
What capacity are the Normal Exhaust AFU ?
Two 50% capacity
What’re the major components through the AFU ?
High Efficiency Pre-Filter -Filters large particles
HEPA-99.97% of finer particles
Charcoal Absorber filter- Filters methyliodide/iodine 99% efficient
-HEPA
What is the ignition point of charcoal adbsorption ?
625F fire indicated by temp switch Hi-Hi
What’re the four indicating lights for temp detection system panel locally at each AFU ?
Green-system normal
Yellow-Detection pre alarm 265F temp switch hi alarms in control room
RED- Detection alarm 310F Hi-Hi alarm in control room
White-indicated detector failure
When will ESF Electrical Penetration Room ACUs automatically start ?
-LOP
-SIAS
