HA- Aux. building HVAC Flashcards
What maintains the lower levels of the Aux Building under a slight negative pressure after a SIAS?
Fuel Building/Aux Building Exhaust Essential AFUs
How does HA and EW interact?
EW provides start/stop signals to HA ACUs when the EW pump is started/stopped
HA ACUs provide cooling and ventilation in the rooms in which EW system pumps are located
What is the fan rated for in the HA Normal Exhaust Air Filtration unit? Where does it exhaust to?
30,000 cfm
plant vent
What is the purpose of the HA Outside Air Normal Supply AHU interlock?
To ensure that the number of running AHUs are equal to or less than the number of running exhaust normal AFUs, which will maintain the Aux Building at a slightly negative pressure
How long after the supply valves go closed will the Aux Feedwater Pump AHUs auto stop?
5 minutes
What happens with the ESF Electrical Penetration Room ACUs when a SIAS or LOP is generated?
ACUs will auto start and have to be manually secured at their MCC after the SIAS or LOP are secured
How is HA affected by a loss of Instrument Air?
Normal AHUs discharge dampers fail close, causing the AHU fans to be dead-headed (Room temps will start to elevate due to no supply air)
Exhaust Normal AFU dampers on the suction side fail closed, causing the AFUs to run with a closed suction path that will cause the associated AHU to trip on low DP across the AFU
Access Control area AHU continues to run, taking suction on the HA supply header and may result in contamination of the 140’ spaces supplied by this AHU.
Hot air to the mixing boxes is stopped, causing the discharge to be in full cooling mode
WC flow to the charging pump room ACUs fails open
What does RU-9 monitor? (100’ East End)
Exhaust flow from the 100’ level and below, which helps us to detect leakage associated with various systems
If any of the Essential ACUs lose an individual room cooler, it will make that rooms equipment inoperable. How long do I have to restore it?
72 hours
What does RU-8 monitor? (140’ East Pen)
The Exhaust duct for radiation before the air is treated in the normal exhaust AFUs
Which Units have had its ‘A’ HA Outside Air Normal Supply AHU OIC replaced with filter media? Which AHUs still have the oil impingement cleaners?
Unit 1 and 2 ‘A’ units have filter media
all others have OIC
What is the capacity of the CEDMCS Room Normal ACUs and what do they cool?
Two 100% capacity redundant ACUs
circulate air in the CEDM cabinet and MG Set rooms
When do the Charging Pump Room Normal ACUs start and stop?
On a receipt of a pump running signal
When the signal clears, a time delay actuates and maintains the ACU running for 5 minutes
When would I ever connect the water deluge system in the aux building HVAC system?
Excessive temperature levels to prevent reaching the ignition point of activated charcoal of 625F
Concerning the Access Control Area Ventilation system, what is meant by a dual duct AHU?
It takes suction from a single supply duct and distributes air to two distribution ducts
What happens when water is applied to activated carbon filters?
Will cause all adsorbed materials to be released
What could be an adverse effect of air flow imbalances?
Fire dampers not being able to close in response to an actuation
How is HA affected by a loss of Class 125 VDC?
HA system pump room supply and exhaust isolation dampers
-Isolation dampers that isolate below 100’ level of the Aux Building will fail closed
How does the HA system interface with WC?
cooling water to the normal HA AHUs, access control ACU, CEDMCS room ACUs and charging pump room ACUs
What provides the necessary heating for the hot duct in the Access Control Area Ventilation system?
Electric heating coil located in parallel with the cooling coil within the AHU
If a high temperature for AFP ‘A’ is due to a steam leak, what actions must be taken?
AFP ‘A’ room must be isolated from Room B within 1 hour to prevent degradation of both trains of aux feed due to high temperature
When does the steam driven Aux feedwater pump AHU auto start? When will it stop?
when either of the two steam supply valves go open
5 minutes after both steam supply valves are closed
Areas below what level in the Aux Building are isolated from the normal HVAC system on a receipt of a SIAS?
100’