HF- Fuel Building HVAC

Question 1

What would close the Normal Supply AHU Isolation Dampers and Exhaust Fan Isolation dampers?

Answer 1

FBEVAS

A loss of Instrument Air

Question 2

What provides power to the HF system electric heater control? What powers the control circuits?

Answer 2

NG

NK

Question 3

How much air do the centrifugal fans on the HF Normal supply fans of the AHU deliver?

Answer 3

19,000 cfm

Question 4

What normally powers the HF system fans and pumps?

Answer 4

NH

Question 5

What is the ignition point of the charcoal beds?

Answer 5

625F

Question 6

Why is the Fuel building maintained at a slightly negative pressure with respect to atmosphere?

Answer 6

To ensure that all leakage is into the building

Question 7

Where do the HF Normal Exhaust fans take a suction from?

Answer 7

Exhaust plenums located on the Fuel Building roof

Question 8

How is the air cooled in the HF system during normal operation?

Answer 8

Cooled utilizing evaporative cooling by the air washer which uses Domestic Water

Question 9

What are the automatic functions associated with the Fuel building Normal Supply and Exhaust fans?

Answer 9

In Auto:
They both auto stop on a train ‘A’ or ‘B’ FBEVAS

In manual:

They automatically stop on a Train ‘A’ FBEVAS. If a Train ‘B’ FBEVAS occurs alone the fans will run dead-headed

Question 10

What system serves as the essential standby power source?

Answer 10

DG system

Question 11

What is the flowrate of the two HF Normal Exhaust fans?

Answer 11

21,750 cfm

Question 12

What makes up the Essential AFUs?

Answer 12

Heater, high efficiency air filter, a high efficiency particulate air filter, a charcoal filter, and another high efficiency particulate air filter

Question 13

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?

Answer 13

Hydraulic operated and will fail closed on a loss of power

Question 14

In the normal supply AHU, at what inlet air temperature will a water pump start to supply DS to the spray trees?

Answer 14

> 80 F

Question 15

At what rate do the AFUs discharge downstream of the Normal Exhaust fans?

Answer 15

6000 cfm

Question 16

What is the purpose of the heater in the Fuel building Essential Exhaust Air Filtration Units?

Answer 16

To keep the relative humidity below 70% to ensure maximum absorption by the charcoal filters

Question 17

What signal would automatically stop the Normal Supply and Exhaust fans?

Answer 17

FBEVAS (Fuel Building Essential Ventilation Actuation Signal)

Question 18

Concerning intake dampers HFA(B)-M05 and –M06, what is their purpose?

Answer 18

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

Question 19

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?

Answer 19

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

Question 20

What is the purpose of the Fuel Building HVAC system?

Answer 20

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

Question 21

What system provides air washer makeup?

Answer 21

DS

Question 22

What function does the Instrument Air system serve for the Fuel Building HVAC system? What is the minimum pressure for normal operation?

Answer 22

Provides air supply for the pneumatically operated dampers

air pressure must be a minimum of 35 psig for normal operation

Question 23

What is the purpose of the Essential Exhaust Air Filtration Units and Dampers?

Answer 23

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

Question 24

Describe the automatic functions associated with the Fuel Building/Aux Building Essential Exhaust Air Filtration Units

Answer 24

Will start on either a SIAS (aligns to take a suction on the Aux building lower levels) or a FBEVAS (aligns to take a 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

Question 25

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?

Answer 25

When the exhaust plenum drops below 65F

The heaters will automatically turn off when a low flow condition is present

Question 26

Concerning the Essential Exhaust AFUs and dampers, what is the purpose of the two suction dampers?

Answer 26

Align the AFU to either the Fuel Building on a FBEVAS or the lower levels of the Aux Building on a SIAS

Question 27

Why do the RWT and HUT vent to the Fuel Building HVAC ducting?

Answer 27

Provides a means to monitor radioactive vent discharge