RQ-C-4934, Compressed Air

Question 1

How do the MSIV dump valves fail?
- loss of 250 VDC
- loss of air

Answer 1

• Closed (250 VDC)
• Open (Air)

Question 2

The Unit 1 Control Air Compressor has been removed from service for maintenance. Which one of the following can not be used to supply the Unit 1 Control Air header loads.

A) Unit 1 Plant Air Compressor
B) Unit 2 Plant Air Compressor
C) Backup Plant Air Compressor
D) Unit 2 Control Air Compressor

Answer 2

D) Unit 2 Control Air Compressor

Question 3

The following conditions exist:
Both Units are at 100% power.
Unit 1 Plant Air Compressor is removed from service for maintenance.
Unit 2 Plant Air Compressor trips and will not restart.
Both Units Control Air Compressors and the Back-Up Air Compressor are in normal standby alignment.
Assuming no Operator action, which of the following are true regarding UNIT 1 Control Air?

A) The U1 CAC will automatically start at 90 PSIG on the CA Wet Receiver and will only supply Unit 1 CA loads.
B) The BAC PAC will start at 95 PSIG on PA header pressure to supply Unit 1 CA Loads.
C) The U1 CAC will automatically start at 90 PSIG on the PA Header to supply Unit 1 CA loads.
D) The U2 CAC will automatically start at 90 PSIG on the CA Wet Receiver to supply both U1 and U2 CA Loads.

Answer 3

A) The U1 CAC will automatically start at 90 PSIG on the CA Wet Receiver and will only supply Unit 1 CA loads.

Question 4

Which of the following describes the correct flowpath of air for the Control Air System during normal operation?

A) Control Air Compressor, air dryer prefilters, plant air receiver.
B) Control Air Compressor, air dryer prefilters, wet air receiver.
C) Plant Air Compressor, plant air receiver, air dryer prefilters.
D) Plant Air Compressor, wet air receiver, air dryer prefilters.

Answer 4

C) Plant Air Compressor, plant air receiver, air dryer prefilters.

Question 5

At what pressures will the following automatic actions occur?

Standby PAC starts at __________ PSIG,
the Ring Header Isolation valves close at __________ PSIG,
and the CAC starts at __________ PSIG.

A) 95, 85, 90
B) 90, 95, 85
C) 97, 85, 90
D) 85, 95, 90

Answer 5

C) 97, 85, 90

Question 6

Following a loss of control air, the NESW RCP Motor Air Cooler containment isolation valves will be…?

A) Fully closed
B) Throttled to ≈ 50% preset position
C) Open due to the presence of local air receivers
D) Latched open and will only close on a valid containment isolation signal

Answer 6

A) Fully closed

Question 7

An AEO reports a large air leak on the PA header south of 1-PRV-11 – U1 Ring Header Isolation valve and north of 2-PRV-21 – U2 Ring Header Isolation valve. The Unit 1 PAC is running with the U2 PAC in STBY.

Which of the following conditions exists: (assume no equip fails and no operator action)

A) The U2 PAC starts and even though the ring header isolation valves close, both units’ control air headers continue to be supplied by the PACs.
B) The U2 PAC starts, both units’ CACs start and the ring header isolation valves close. The control air headers are supplied from their respective CACs.
C) The ring header isolation valves will close, but will NOT isolate the unit control air systems from the leak and both reactors must be manually tripped.
D) The U1 ring header isolation valves close isolating the leak so that the U1 PAC continues to supply U1 control air. The U2 PAC starts and supplies U2 control air.

Answer 7

B) The U2 PAC starts, both units’ CACs start and the ring header isolation valves close. The control air headers are supplied from their respective CACs.

Question 8

U1 is in OHP-4022-064-002 – Loss of Control Air Recovery. While performing actions, 1-WCR-920 – NESW to 1-HV-CUV-1 Tr ‘A’ Containment Isolation valve fails closed and cannot be reopened.

Which of the following actions should the operator take?

A) Stop ventilation unit 1-HV-CUV-1
B) Stop ALL upper containment ventilation units ONLY.
C) Stop ALL upper and lower containment ventilation units.
D) Locally open 1-WCR-912 – 1-WCR-920 Bypass Valve.

Answer 8

A) Stop ventilation unit 1-HV-CUV-1

Question 9

U2 has entered 2-OHP-4022-064-001 – Control Air Malfunction, based upon a 100 PSIG control Air Pressure alarm. The BOP has verified that CA Header pressure on 2-XPI-100 is less than 100 PSIG and lowering.
Which of the following pressures would require a manual Reactor Trip and entry into E-0?

A) 88 PSIG
B) 85 PSIG
C) 79 PSIG
D) 82 PSIG

Answer 9

C) 79 PSIG