CP-Containment Purge

Question 1

What is the purpose of the containment purge system?

Answer 1

Purges the Containment atm to the Plant Vent Stack while introducing filtered and treated air from outside.

Question 2

What is the refueling purge subsystem used for?

Answer 2

Ventilation air for personnel comfort during refueling operations and maintenance.
Hi flowrrate (30,000 cfm supply 33,000 cfm exhaust)
Keep airborne rad below permit levels

Question 3

What is the Power-Access Purge subsystem used for?

Answer 3

Vent air to allow Containment access for limited periods during power operation.
Low flowrates (2000 cfm supply 2200 cfm exhaust)
Keep airborne rad below permit limits for short-term occupancy while at power.

Question 4

What is an alternative use for the Power-Access Purge?

Answer 4

Lower pressure in the Containment by periodically venting a portion of the Containment air to the Plant Vent Stack.

Question 5

What components does the refueling purge subsystem consist of?

Answer 5

• Containment Refueling Purge Normal Air Handling Unit (AHU), CPN-A01
• Two Containment Refueling Purge Normal Exhaust Fans, CPN-J01A/B
• Ductwork, Fan Discharge Dampers, and Containment Isolation Valves

Question 6

What is the flow path of the normal AHU in the Containment Refueling Purge subsystem?

Answer 6

Provides filtered and conditioned air > Discharge Dampers > Containment
Isolation Valves, CPA-UV-2A and CPB-UV-3A > Containment

Question 7

Where do the Exhaust Fans draw air from and discharge air to in the Containment Refueling Purge subsystem?

Answer 7

Draw air from the Containment atmosphere > Containment
Isolation Valves, CPA-UV-2B and CPB-UV-3B > Discharge Dampers > Plant Vent Stack > atmosphere.

Question 8

What is the purpose of the containment refueling purge normal AHU?

Answer 8

Filters and conditions outside
air supplied to Containment during refueling operations to provide an environment for safe access of
personnel.

Question 9

What components are in the Containment Refueling Purge Normal AHU?

Answer 9

• Oil Impingement Air Filter (OIC)
• Cooling Coil (C/CH)
• Heating Element (H/E)
• Fans

Question 10

What is the flow path inside the Containment Refueling Purge Normal AHU?

Answer 10

The two Fans, CPN-A01A & CPN-A01B, draw OSA > Oil Impingement Air Filter > Cooling Coil > Heating Element

Question 11

What is the purpose of the oil impingement air filter?

Answer 11

It is in “dust mode” removes fine particles from outside air during a dust storm.
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Question 12

What is the purpose of the cooling coil?

Answer 12

Coil supplied with Normal Chilled water (WC) from a 3-way valve to maintain fan discharge temp of 70°F

Question 13

What is the purpose of the fans in the Containment refueling purge normal ahu?

Answer 13

Two 50% capacity vane axial Fans, CPN-A01A & CPN-A01B
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Each fan has a dedicated discharge damper that is interlocked to open on start and close on stop of fan.

Question 14

How to dampers fail if there is a loss of air or control power to the solenoid op valve controlling air supply?

Answer 14

Damper fails closed.
If the damper fails closed it will trip the fan associated with it.

Question 15

What is the interlock with the containment isolation valves and the containment refueling purge normal ahu fans?

Answer 15

The Containment Isolation Valves must be open for the AHU Fans to start.

Question 16

Where are the containment refueling purge normal ahu fans operated?

Answer 16

A hand switch in the control room taken to “refueling purge” position as long a CIV are open.

Question 17

What is the power supply for the Containment Refueling Purge Normal AHU heating element?

Answer 17

NG- 480 Load Center

Question 18

What is the purpose of the Containment Refueling Purge Normal Exhaust Fans?

Answer 18

Exhaust air from the Containment
to Plant Vent Stack to atmosphere
Also keep negative pressure
inside Containment.

Question 19

What is the design of the Containment Refueling Purge Exhaust Fans?

Answer 19

50% capacity vane axial fans.
Both run during operation of the
Refueling Purge subsystem.
Capacity is larger than the
Containment Refueling Purge Normal AHU Fans to maintain negative pressure inside Containment.
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Question 20

Describe the normal operation of the Containment Refueling Purge subsystem.

Answer 20

Only operated in MODES 5, 6, and Defueled.
* The Equipment Hatch is open: Normal AHU OFF, Exhaust fans ON, Air from containment exhausted to atm (we open breaker to AHU to acheive)
* Only the Personnel Hatch (PAL Doors) are open: Normal AHU ON, Exhaust fans ON

Question 21

What are the components of the Power-Access Purge subsystem?

Answer 21

• Power-Access Purge Normal Air Handling Unit (AHU), CPN-A02
• Power-Access Purge Normal Exhaust Air Filtration Unit (AFU), CPN-J02
• Ductwork, Fan Discharge Dampers, and Containment Isolation Valves

Question 22

What is the purpose of the Vent Mode in the power-access purge subsystem?

Answer 22

o Used to depressurize the Containment Building prior to operation of Power-Access Purge.
o Used to maintain Containment pressure within the Tech Specs