Fuel Building HVAC (HF) Flashcards
Where does essential HVAC system provide negative pressure to during a SIAS?
Fuel building Essential HVAC provides negative pressure below 100’ of Aux Building
What is the Power Generation Design Basis for Fuel Building Normal HVAC ?
Designed to maintain temp for:
-Operability of Fuel Building Equip.
-Provides required ventilation to maintain airborne radioactivity
Does Fuel Building Essential HVAC have a Power Generation Design Basis ?
NO it doesn’t
What is Safety Design Basis for Fuel Building Essential HVAC ?
-Limit potential release radioactive iodine event fuel handling accident or design basis LOCA
-Functions during & after Safe Shutdown Earthquake(SSE)
-Not allow any single failures
How does Fuel Building Supply Air system work during Normal Operation ?
1.)Outside air filtered
2.)Cooled & Heated by AHUs
3.) Supplied throughout fuel building on once through basis
How does Fuel Building Exhaust system work during Normal Operation ?
Exhaust air from various areas of fuel building is exhausted continuously by Exhaust Fans
What happens to Fuel Building system Lineup During a FBEVAS ?
-Normal supply AHUs & Exhaust fans are stopped
-Fuel Building is automatically isolated by isolation dampers on supply & exhaust ducts
-Air is then exhausted through Essential AFUs, while makeup air is drawn into building by Essential AFUs negative pressure
What is Fuel Building Lineup during a SIAS ?
-Essential AFU intake air damper for fuel building will close & Aux. intake damper will open
-Essential AFU will start
-Essential AFU will draw & maintain a negative pressure below 100’ of Aux. Building
-Exhausts air through Aux. Building Essential Pipe Tunnel to Unit, then Atmosphere
During a SIAS what happens to Normal Fuel Building HVAC ?
Normal Exhaust & Supply dampers will remain open ONLY on SIAS
What happens to Normal Supply & exhaust dampers HVAC during a FBEVAS ?
Normal supply & exhaust will close dampers on FBEVAS. They won’t reopen reopen if a SIAS is actuated
What event has priority over Fuel Building HVAC if a SIAS & FBEVAS were to happen at the same time ?
-SIAS has priority and all fuel building intake
-exhaust dampers will close if a SIAS & FBEVAS happen at the same time
How does Non-class 480 Load Center(NG) interface with Fuel Building HVAC(HF) ?
HF AFU heater control receives power from NG
How does HF interface with 480VAC MCC(NH) ?
Normal HF components receiver power from NH
How does HF interface with Control Power(NK) ?
Normal HF system duct heater control circuit receiver power from NK
How does HF system interface with Class 480VAC MCC (PH)?
Powers Essential HF components:
-Essential AFU fans
-Essential AFU Heaters
-Essential AFU dampers(120VAC from MCC D-Panel )
How does HF interface with PK Control Power ?
Safety related dampers in Normal Supply line receives operating power from PK
How does HF system interface with Diesel Generator ?
DGs serve as essential standby power source for HF system
How does HF system interface with Chemical & Volume Control(CH) ?
-RWT & CVCS HUT both vent to Fuel Building Normal HVAC discharge system
-Provides means to monitor Radioactive Vent Discharge
How does HF interface with Domestic Water(DS) ?
DS provides source of water to Fuel Building Normal AHU Air Washer
How does HF interface with Fire Protection ?
-HF is big part of safe plant shutdown during a fire
-HF system has fire dampers
-HF essential AFU have water hookups to deluge fire extinguish nozzles in the charcoal bed
How does HF interface with Aux. Building HVAC ?
-HF provides Essential Exhaust & filtration for Aux. Building below 100’
THIS IS SAFETY RELATED
How does HF interface with Instrument Air(IA) ?
IA provides air to 8 safety related isolation dampers in Norm. Ventilation System
How does HF interface with Freeze Protection(QJ) ?
-During winter water supply to Air Washer is isolated
-Air Washer pump is turned off
-Air Washer Basin is drained
How does HF interface with Radiation Monitoring(SQ)?
-SQ provides monitoring of HF exhaust
-SQ could actuate a FBEVAS
-HF system provides flow signal input to SQ system for signal processing from Radiation Monitoring
What’re the 3 radiation monitors ? What does each Radiation Monitor do ?
RU-31:Monitors Fuel Pool & generates FBEVAS on high Radiation Levels
RU-145:Monitors Fuel Building exhaust & generates FBEVAS
RU-146:High Range monitor monitors exhaust at higher level(Safety Related)
How many supply AHUs have does the normal HVAC have ?
Two 50% capacity supply AHUs
Where does Fuel Building Supply fan draw its air from ?
Draws air from outside through AHU which cools is adiabatically
When will the Heaters turn on down stream of the supply fan ? When will it automatically turn off ?
-Heaters will turn on when temp in Normal Exhaust Plenum drops below 65F
-Heaters automatically turn off during low flow conditions
Where does discharge of Normal Supply AHUs go to after the heaters ?
-Will discharge into a common header & penetrates fuel building
-Inside fuel building ducts split into two, each duct with a CLASS pneumatic isolation damper
What happens when a FBEVAS is generated?
-Fuel Building isolated automatically by closing 8 safety related isolation dampers in Normal Supply & Exhaust ductwork
-Normal Supply AHU & Exhaust fans are stopped
-Two Essential AFU are started
How is air makeup provided to fuel building during a FBEVAS ?
During this mode is drawn into fuel building by negative pressure by Essential Exhaust AHUs
How many Essential AFU are there ? What’re the capacity of the Essential AFUs ?
There are two Essential AFU & they’re both 100% capacity
Where do the Essential AFUs exhaust to ?
Essential AFUs will exhaust to the Fuel Building Normal HVAC exhaust
Where are the Essential Exhaust Trains connected to inside the Aux. Building ?
-They’re connected to ESF equipment rooms , through seismic plenum & tunnel
(HPSI,LPSI,CS, SDCHX Room)
Essential Exhaust systems are only used why ?
Functions only in event during fuel handling accident, LOCA,or required testing
What’re the features for the Essential AFUs Filter Unit Housing?
-Seismic Category
-Service access doors
-Explosion proof light
-Filter test connection
-Pressure gauge connections
-Floor drains
What conditions must be maintained when opening Essential AFUs doors to not affect AFUs operability ?
-Communication maintained with Control Room to close door if necessary
-Doors remain functional & capable of being closed
What’re the heater elements used inside the Essential AFU ? How’re the heater elements controlled
-Preheats Aux.Building or Fuel Building HVAC to ensure humidity <70% to not affect Charcoal Adsorbers
-Moisture Elements & Moisture Switch HI located down stream of Heater
What’re the High Efficiency Pre-Filters used for ?
Filters out large particulate of 85%
What’re the HEPA filters used for ?
Filters out 99.97% of 0.3 micron
What’re the Charcoal Adsorbers used for in the Essential AFU?
Filters our methyliodide from Exhaust air with 99% efficiency
What is the ignition point for the Essential AFUs charcoal Adsorbers ? What is used as fire protection on the Essential AFUs if Charcoal Adsorbers catch fire ?
-625F is ignition point
-Deluge system supplied from fire hose made up by fire department
-Water applied to Charcoal Adsorbers will release adsorbed material
What is used to prevent damage to Fuel Building AFU?
Welding, painting, & use of solvents in fuel building or any zone communicating with AFUs
What is the HEPA filter downstream of the charcoal Adsborber used for ?
Filters out loose charcoal particulate from exhaust air to minimize release radioactive iodine
What is the exhaust fan used for in the Essential AFU?
Draws air through AFU and exhausts it from Fuel Building after FBEVAS, or Aux. Building after SIAS
