Fuel Building HVAC (HF)

Question 1

Where does essential HVAC system provide negative pressure to during a SIAS?

Answer 1

Fuel building Essential HVAC provides negative pressure below 100’ of Aux Building

Question 2

What is the Power Generation Design Basis for Fuel Building Normal HVAC ?

Answer 2

Designed to maintain temp for:
-Operability of Fuel Building Equip.
-Provides required ventilation to maintain airborne radioactivity

Question 3

Does Fuel Building Essential HVAC have a Power Generation Design Basis ?

Answer 3

NO it doesn’t

Question 4

What is Safety Design Basis for Fuel Building Essential HVAC ?

Answer 4

-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

Question 5

How does Fuel Building Supply Air system work during Normal Operation ?

Answer 5

1.)Outside air filtered
2.)Cooled & Heated by AHUs
3.) Supplied throughout fuel building on once through basis

Question 6

How does Fuel Building Exhaust system work during Normal Operation ?

Answer 6

Exhaust air from various areas of fuel building is exhausted continuously by Exhaust Fans

Question 7

What happens to Fuel Building system Lineup During a FBEVAS ?

Answer 7

-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

Question 8

What is Fuel Building Lineup during a SIAS ?

Answer 8

-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

Question 9

During a SIAS what happens to Normal Fuel Building HVAC ?

Answer 9

Normal Exhaust & Supply dampers will remain open ONLY on SIAS

Question 10

What happens to Normal Supply & exhaust dampers HVAC during a FBEVAS ?

Answer 10

Normal supply & exhaust will close dampers on FBEVAS. They won’t reopen reopen if a SIAS is actuated

Question 11

What event has priority over Fuel Building HVAC if a SIAS & FBEVAS were to happen at the same time ?

Answer 11

-SIAS has priority and all fuel building intake
-exhaust dampers will close if a SIAS & FBEVAS happen at the same time

Question 12

How does Non-class 480 Load Center(NG) interface with Fuel Building HVAC(HF) ?

Answer 12

HF AFU heater control receives power from NG

Question 13

How does HF interface with 480VAC MCC(NH) ?

Answer 13

Normal HF components receiver power from NH

Question 14

How does HF interface with Control Power(NK) ?

Answer 14

Normal HF system duct heater control circuit receiver power from NK

Question 15

How does HF system interface with Class 480VAC MCC (PH)?

Answer 15

Powers Essential HF components:
-Essential AFU fans
-Essential AFU Heaters
-Essential AFU dampers(120VAC from MCC D-Panel )

Question 16

How does HF interface with PK Control Power ?

Answer 16

Safety related dampers in Normal Supply line receives operating power from PK

Question 17

How does HF system interface with Diesel Generator ?

Answer 17

DGs serve as essential standby power source for HF system

Question 18

How does HF system interface with Chemical & Volume Control(CH) ?

Answer 18

-RWT & CVCS HUT both vent to Fuel Building Normal HVAC discharge system
-Provides means to monitor Radioactive Vent Discharge

Question 19

How does HF interface with Domestic Water(DS) ?

Answer 19

DS provides source of water to Fuel Building Normal AHU Air Washer

Question 20

How does HF interface with Fire Protection ?

Answer 20

-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

Question 21

How does HF interface with Aux. Building HVAC ?

Answer 21

-HF provides Essential Exhaust & filtration for Aux. Building below 100’
THIS IS SAFETY RELATED

Question 22

How does HF interface with Instrument Air(IA) ?

Answer 22

IA provides air to 8 safety related isolation dampers in Norm. Ventilation System

Question 23

How does HF interface with Freeze Protection(QJ) ?

Answer 23

-During winter water supply to Air Washer is isolated
-Air Washer pump is turned off
-Air Washer Basin is drained

Question 24

How does HF interface with Radiation Monitoring(SQ)?

Answer 24

-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

Question 25

What’re the 3 radiation monitors ? What does each Radiation Monitor do ?

Answer 25

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)

Question 26

How many supply AHUs have does the normal HVAC have ?

Answer 26

Two 50% capacity supply AHUs

Question 27

Where does Fuel Building Supply fan draw its air from ?

Answer 27

Draws air from outside through AHU which cools is adiabatically

Question 28

When will the Heaters turn on down stream of the supply fan ? When will it automatically turn off ?

Answer 28

-Heaters will turn on when temp in Normal Exhaust Plenum drops below 65F -Heaters automatically turn off during low flow conditions

Question 29

Where does discharge of Normal Supply AHUs go to after the heaters ?

Answer 29

-Will discharge into a common header & penetrates fuel building -Inside fuel building ducts split into two, each duct with a CLASS pneumatic isolation damper

Question 30

What happens when a FBEVAS is generated?

Answer 30

-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

Question 31

How is air makeup provided to fuel building during a FBEVAS ?

Answer 31

During this mode is drawn into fuel building by negative pressure by Essential Exhaust AHUs

Question 32

How many Essential AFU are there ? What’re the capacity of the Essential AFUs ?

Answer 32

There are two Essential AFU & they’re both 100% capacity

Question 33

Where do the Essential AFUs exhaust to ?

Answer 33

Essential AFUs will exhaust to the Fuel Building Normal HVAC exhaust

Question 34

Where are the Essential Exhaust Trains connected to inside the Aux. Building ?

Answer 34

-They’re connected to ESF equipment rooms , through seismic plenum & tunnel (HPSI,LPSI,CS, SDCHX Room)

Question 35

Essential Exhaust systems are only used why ?

Answer 35

Functions only in event during fuel handling accident, LOCA,or required testing

Question 36

What’re the features for the Essential AFUs Filter Unit Housing?

Answer 36

-Seismic Category -Service access doors -Explosion proof light -Filter test connection -Pressure gauge connections -Floor drains

Question 37

What conditions must be maintained when opening Essential AFUs doors to not affect AFUs operability ?

Answer 37

-Communication maintained with Control Room to close door if necessary -Doors remain functional & capable of being closed

Question 38

What’re the heater elements used inside the Essential AFU ? How’re the heater elements controlled

Answer 38

-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

Question 39

What’re the High Efficiency Pre-Filters used for ?

Answer 39

Filters out large particulate of 85%

Question 40

What’re the HEPA filters used for ?

Answer 40

Filters out 99.97% of 0.3 micron

Question 41

What’re the Charcoal Adsorbers used for in the Essential AFU?

Answer 41

Filters our methyliodide from Exhaust air with 99% efficiency

Question 42

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 ?

Answer 42

-625F is ignition point -Deluge system supplied from fire hose made up by fire department -Water applied to Charcoal Adsorbers will release adsorbed material

Question 43

What is used to prevent damage to Fuel Building AFU?

Answer 43

Welding, painting, & use of solvents in fuel building or any zone communicating with AFUs

Question 44

What is the HEPA filter downstream of the charcoal Adsborber used for ?

Answer 44

Filters out loose charcoal particulate from exhaust air to minimize release radioactive iodine

Question 45

What is the exhaust fan used for in the Essential AFU?

Answer 45

Draws air through AFU and exhausts it from Fuel Building after FBEVAS, or Aux. Building after SIAS