Instrument/Service Air

Question 1

Instrument Air Compressors power supplies

Answer 1

C-2A/C - LCC-11

C-2B - LCC-12

Question 2

Header pressure maintained by Instrument Air Compressors

Answer 2

95-105 psi

Question 3

Instrument Air Compressors controls

Answer 3

Hand - breaker closes, compressor cycles 95-105 psi
Off - breaker opens
Auto - breaker will close on low header pressure of 92 psi

Question 4

Describe IAC sleep mode

Answer 4

Compressor runs unloaded for 10 minutes, it goes into sleep mode
Starts back up when header pressure drops below 95 psi
Breaker remains closed, so you still have red light indication in the CR

Question 5

IAC auto trips

Answer 5

Overcurrent
Undervoltage
Loadshed - SIS (will not auto start, have to manually restart the compressor after EDG sequencing)
Microprocessor trip (doesn’t trip the breaker, so you will still have red light indication in the CR)

Question 6

What cools the IAC’s

Answer 6

Air cooled by V-201A/B/C

Question 7

IAC cooling fan controls

Answer 7

Auto - fan runs with compressor (NORMAL)
Manual - fan runs
Off - fan doesn’t run

Question 8

IAC aftercooler cooling water supply

Answer 8

C-2A/C - Critical Service Water

C-2B - Non-Critical Service Water

Question 9

Instrument air filter/dryer functions/specs

Answer 9

2 pre-filters, 2 post filters, 1 of each in service at a time
Max DP of 4 psi on the filters
2 air dryer towers, 1 in service at a time

Question 10

Instrument Air to Containment CV-1211 function

Answer 10

Fails open

Has N2 backup to allow closure on loss of air

Question 11

Service Air Header Isolation CV-1212 function

Answer 11

Isolates service air from instrument air
Fails closed
Auto closes on low header pressure of 85 psi

Question 12

What is lost when service air is isolated

Answer 12

C/T level instrumentation bubblers
VRS area fire protection valves
Pumping trap for SIRWT HX
ALPS
Breathing air

Question 13

Service Air/Instrument Air to FWP Cross Tie CV-1221 function

Answer 13

Fails open

Controlled from the CR

Question 14

HP air compressor power supplies

Answer 14

C-6A - MCC-8 - D Bus
C-6B - MCC-7 - C Bus
C-6C - MCC-4 - E Bus

Question 15

HP air compressor operating range

Answer 15

310-325 psi

Question 16

HP air tank sizing specifications

Answer 16

At 260 psi, and the compressor not running, all valves can be stroked 2 times

Question 17

What is safety related in the HP air system

Answer 17

A/B receiver tanks and piping from the tanks to the control valves

Question 18

Limitation on cross-tying HP air

Answer 18

A/B can’t be cross-tied when safeguards equipment is required (Modes 1-3)

Question 19

What is the pressure setpoint that service air automatically isolates?

Answer 19

85 psig

Question 20

Where does service air isolation valve and alarm sense pressure?

Answer 20

Downstream of Instrument Air Dryer and filters

Question 21

Where does Instrument Air Compressor auto start sense pressure?

Answer 21

Upstream of Instrument Air Dryer and filters

Question 22

What are the Feedwater Purity Air Compressors power supplies?

Answer 22

Both are supplied from LCC 91

Question 23

Which HP Air Receiver Tanks can be cross-tied?

Answer 23

T-9C can be cross-tied to either T-9A or T-9B

Question 24

What is the pressure setpoint for Instrument Air Compressor standby start?

Answer 24

92 psig