HF- Fuel Building HVAC Flashcards
What is the purpose of the Fuel Building HVAC system?
To provide required environment for personnel occupancy and equipment operation during normal plant operation
Responsible for controlling the release of airborne reactivity to the surrounding area from the Fuel building in the event of a fuel handling accident
Fuel Building Essential Ventilation also controls release of airborne radioactivity to the surrounding area from below 100’ level of the Aux Building following a LOCA
What signal would automatically stop the Normal Supply and Exhaust fans?
FBEVAS (Fuel Building Essential Ventilation Actuation Signal)
What would close the Normal Supply AHU Isolation Dampers and Exhaust Fan Isolation dampers?
FBEVAS
A loss of Instrument Air
What is the purpose of the Essential Exhaust Air Filtration Units and Dampers?
Upon a fuel handling accident or SIAS, two 100% capacity AFUs will treat the exhausted air form either the Fuel Building or Auxiliary Building <100’ level prior to discharging it to the environment
Concerning the Essential Exhaust AFUs and dampers, what is the purpose of the two suction dampers?
Align the AFU to either the Fuel Building on a FBEVAS or the lower levels of the Aux Building on a SIAS
What makes up the Essential AFUs?
Heater
high efficiency particulate air filter
upstream high efficiency air filter
a charcoal filter
downstream high efficiency particulate air filter
Concerning the Essential AFU dampers that take suction from the Fuel Building and Aux Building, how are they operated and what is their fail position upon a loss of power?
Hydraulic operated and will fail closed on a loss of power
What is the purpose of the heater in the Fuel building Essential Exhaust Air Filtration Units?
To keep the relative humidity below 70% to ensure maximum absorption by the charcoal filters
Why do the RWT and HUT vent to the Fuel Building HVAC ducting?
Provides a means to monitor radioactive vent discharge
What system provides air washer water makeup?
DS
What system serves as the essential standby power source?
DG system
What function does the Instrument Air system serve for the Fuel Building HVAC system? What is the minimum pressure for normal operation?
Provides air supply for the pneumatically operated dampers
air pressure must be a minimum of 35 psig for normal operation
What provides power to the HF system electric heater control? What powers the control circuits?
NG
NK
What normally powers the HF system fans and pumps?
NH
How is the air cooled in the HF system during normal operation?
Cooled utilizing evaporative cooling by the air washer which uses Domestic Water
Why is the Fuel building maintained at a slightly negative pressure with respect to atmosphere?
To ensure that all leakage is into the building
In the normal supply AHU, at what inlet air temperature will a water pump start to supply DS to the spray trees?
> 80 F
How much air do the centrifugal fans on the HF Normal supply fans of the AHU deliver?
19,000 cfm
The air that leaves the HF normal AHU is sent through an electric heater. When will that heater turn on automatically? When will they turn off?
Turn on = the exhaust plenum < 65F
Turn off = automatically turn off when a low flow condition is present
What is the flowrate of the two HF Normal Exhaust fans?
21,750 cfm
Where do the HF Normal Exhaust fans take a suction from?
Exhaust plenums located on the Fuel Building roof
What are the automatic functions associated with the Fuel building Normal Supply and Exhaust fans?
In Auto:
both auto stop on a train ‘A’ or ‘B’ FBEVAS
In Manual:
-auto stop on a Train ‘A’ FBEVAS.
-If a Train ‘B’ FBEVAS occurs alone, the exhaust fans will run dead-headed
How do the Fuel building and Aux Building Essential Exhaust AFUs function to filter the air from either location? What is the purpose of the heaters?
Electric heaters keep humidity below 70% to maximize absorption in the charcoal
Flow goes through high efficiency filter bank to remove dust
Further filtration accomplished by first of two HEPA filters, then to the charcoal which will remove Iodine from the air
Second HEPA removes charcoal particles from the air
At what rate do the AFUs discharge downstream of the Normal Exhaust fans?
6000 cfm
Describe the automatic functions associated with the Fuel Building/Aux Building Essential Exhaust Air Filtration Units
Will start on either a SIAS (aligns to take suction on the Aux building lower than 100’) or a FBEVAS (aligns to take suction on the Fuel Building)
A SIAS takes precedent if both signals are present at the same time and will align to take suction on the Aux Building
What is the ignition point of the charcoal beds?
625F
Concerning intake dampers HFA(B)-M05 and –M06, what is their purpose?
HFA(B)-M05 aligns suction of respective Essential AFU to the Fuel Building
HFA(B)-M06 aligns suction of respective Essential AFU to the lower levels of the Aux building
