Containment Ventilation System(VV) Flashcards

1
Q

What is the purpose of the Containment Ventilation System?

A

The Containment Ventilation System ventilates and cools the lower and upper containment areas, control rod drive mechanism area, and the incore instrumentation room including the pipe chase and the digital rod position indication(DRPI)panels.

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2
Q

What is the purpose of the Lower Containment Ventilation Units?

A

The LCVUs maintain the lower containment air temperature:

  1. 100F - 120F during Mode 1
  2. 60F - 120F during Modes 2, 3, and 4
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3
Q

How many Lower Containment Ventilation Units are there, and where do they take a suction from and discharge to?

A
  1. There are 4 Lower Containment Ventilation Units
  2. The LCVUs take a suction from the air around the air handling unit and air from the discharge of the CRDM fans
  3. The LCVUs discharge to the supply header distribution duct
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4
Q

How many speeds do the Lower Containment Ventilation Units have?

A

They have two speeds - slow and fast

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5
Q

What system provides cooling water flow to the Lower Containment Ventilation Units?

A
  1. Normal supply - Containment Chilled Water(YV)

2. Backup supply - Nuclear Service Water(RN)

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6
Q

Where does the condensation from the Lower Containment Ventilation Units drain to?

A

The condensate is collected and sent to the Ventilation Unit Condensate Drain Tank(VUCDT)

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7
Q

How does the Thermostatic Flow Control Valve operate in the NORMAL MODE?

A

The thermostatic flow control valve located on the cooling water outlet of the LCVU will modulate to control temperature at 100F

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8
Q

How does the Thermostatic Flow Control Valve operate in the MAX COOL MODE?

A

The thermostatic flow control valve fails open to allow full cooling flow through the LCVU.

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9
Q

What is the normal mode of operation for the Thermostatic Flow Control Valves for the Lower Containment Ventilation Units, and why?

A
  1. The normal mode of operation is MAX COOL
  2. This prevents tripping YV Chillers after the CRDMs are de-energized due to fluctuations, and it also prevents open reliefs on the YV piping.
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10
Q

What will cause the cooling water bypass valve on the Lower Containment Ventilation Units to fail open?

A
  1. LCVU is selected to High Speed

2. Containment pressure reaches 0.5psig

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11
Q

How does the Thermostatic Flow Control Valve operate if the bypass valve is failed open, in the NORM mode?

A

The thermostatic flow control valve will continue to modulate to control for 100F

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12
Q

What is the purpose of the Pipe Tunnel Booster Fans?

A
  1. Circulate air outside the crane wall
  2. Low and High Speed
  3. No cooling coils
  4. They draw air from the ā€˜Dā€™ LCVU discharge prior to the supply header and discharge to the pipe tunnel and DRPU cabinet area
  5. Normally one in service running at the same speed as the Lower Containment Ventilation Units
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13
Q

What is the purpose of the Upper Containment Ventilation System?

A

The Upper Containment Ventilation System maintains upper containment air temperature:

  1. 75-100F in Mode 1
  2. 60-100F in Modes 2, 3, and 4
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14
Q

How many Upper Containment Ventilation Units are there, and where are they located?

A
  1. There are 4 Upper Containment Ventilation Units

2. The UCVUs are located on top of the Steam Generator enclosures

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15
Q

Where do the Upper Containment Ventilation Units draw a suction from and discharge to?

A

The Upper Containment Ventilation Units draw air from and discharge to the upper containment air volume

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16
Q

How many Upper Containment Return Air Fans are there, and what is there flowpath?

A
  1. There are four Return Air Fans

2. They draw a suction from the containment dome and discharge to the suction of the upper containment ventilation units

17
Q

What system provides the cooling water for the Upper Containment Ventilation Units?

A
  1. Normal - Containment Chilled Water(YV)

2. Backup - Nuclear Service Water(RN)

18
Q

Where is the condensate from the Upper Containment Ventilation Units directed?

A

The condensate from the Upper Containment Ventilation Units is collected and directed to the Ventilation Unit Condensate Drain Tank(VUCDT).

19
Q

How many speeds do the Upper Containment Ventilation Units have?

A

One speed

20
Q

What is the interlock between the Upper Containment Ventilation Units and their associated Return Air Fan?

A

When the RAF control switch is in AUTO the associated RAF will start when the Upper Containment Ventilation Fan is started.

21
Q

What temperature do the Upper Containment Ventilation Units maintain?

A

90F

Lower Containment Ventilation Units maintain 100F

22
Q

How does the Thermostatic Flow Control Valve for the Upper Containment Ventilation Units operate in the NORM MODE?

A

The thermostatic flow control valve located on the cooling water outlet of the UCVU will modulate to control temperature at 90F

23
Q

How does the Thermostatic Flow Control Valve for the Upper Containment Ventilation Units operate in the MAX COOL MODE?

A

The thermostatic flow control valve fails open to allow full cooling flow through the UCVU.

24
Q

What is the purpose of the Control Rod Drive Mechanism Ventilation System?

A

The four fans of the CRDM Ventilation system draw air from the Control Rod Drive Enclosure and discharge air to the inlet of the Lower Containment Ventilation Units.

25
Q

What system supplies cooling water to the CRDM Ventilation Fans?

A

There are no cooling coils associated with the CRDM Fans

26
Q

What is unique about the dampers that the CRDM Fans discharge to?

A

The dampers that the CRDM Fans discharge to are interlocked with the LCVUs. When the LCVU is off the associated damper is closed to prevent air being sent to an off service LCVU.

27
Q

When are two Control Rod Drive Fans required to be in service?

A

Two CRDM Fans are required to be in service whenever NC temperature reaches 350F OR the CRDMs are energized.

28
Q

What is the purpose of the Incore Instrumentation Room Ventilation System?

A
  1. Two single speed IIRVUs
  2. Normal cooling is YV, and backup is RN
  3. Condensate is directed to the VUCDT
  4. Normally temperature is maintained at 90F
  5. Designed to maintain max temperature less than or equal to 100F
29
Q

How does is cooling water controlled for the Incore Instrument Room Ventilation Units?

A
  1. NORM - valve modulates for 90F

2. MAX COOL - valve fails open for maximum cooling flow

30
Q

What is the purpose of the Containment Auxiliary Charcoal Filter Units?

A

The CACFUs are used during outages to reduce the level of radioactivity in the lower containment

31
Q

When is the filter media for the Containment Auxiliary Charcoal Filter Units installed?

A

The filter media is not installed during normal operations to prevent clogging the sump screens however the carbon stays installed.

32
Q

What is unique about the power supply to the Containment Auxiliary Filter Units?

A

The CACFUs are the only component in the Containment Ventilation System that IS NOT powered from blackout power MCCs.

33
Q

What are the power supplies to the Lower Containment Ventilation Units?

A

A - MXQ
B - MXP
C - MXO
D - MXR

34
Q

What is the power supply to the Pipe Tunnel Booster Fans?

A

A - MXO

B - MXP

35
Q

What is the power supply to the Upper Containment Ventilation Units?

A

A - MXQ
B - MXP
C - MXO
D - MXR

36
Q

What is the power supply to the Return Air Fans?

A

A - MXQ
B - MXP
C - MXO
D - MXR

37
Q

What is the power supply to the CRDM Fans?

A

A - MXO
B - MXP
C - MXQ
D - MXR

38
Q

What is the power supply to the Incore Instrument Room Ventilation Units?

A

A - MXQ

B - MXR