Instrument and Service Air Flashcards

1
Q

What is the purpose of the Instrument Air system and is it safety related?

A

Not Safety Related

  • Portions of the system are treated as safety-related.
    • The containment isolation portion of this subsystem is safety-related.
    • Safety-related control valves have nitrogen backup.

Designed to provide dry, oil-free air for instrumentation and controls.

Flow Requirements

  • 80 standard cubic feet per minute (scfm) for the Nuclear Steam Supply System
  • 115 scfm for the remainder of the plant.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the purpose of the service air system and is it safety related?

A

Not Safety Related

Provides unfiltered, undried air, directly from Instrument Air to Service Air hose stations and components throughout the plant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the purpose of the High Pressure Air System and is it safety related?

A

Has Both Safety Related and Non-Safety Related Portions

Safety Related

  • Provides high-pressure control air for operation of vital valves located in each of the Engineered Safeguards rooms.
  • Supplied via T-9A/B

Non-Safety Related

  • Provides high-pressure control air for operation of non-vital valves located in Turbine Building.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the purpose of the Feedwater Purity Air System and is it safety related?

A

Non-Safety Related

It is an independent air system providing filtered, moisture-free air to Feedwater Building components.

It also can supply filtered, dried air directly to the Instrument and Service Air system if needed. This is done using air dryer M-993 along with pre and post filters.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the design and capacity of the C-2 instrument air compressors?

A

Compressors C-2A, C-2B and C-2C

  • Air cooled rotary screw type compressor
  • Rated for 288 SCFM - considered full capacity
  • Operating range: 95-105 psig
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the power supplies for Compressors C-2A, C-2B and C-2C?

A

C-2A - LCC-11 (52-1106)

C-2C - LCC-11 (52-1107)

C-2B - LCC-12 (52-1207)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What starts an Instrument Air Compressor?

A

​Control Room Handswitch on C-13

HAND

  • 52‑1106/52-1207/52‑1107 closes
  • Red light on in Control Room

OFF

  • 52‑1106/52-1207/52‑1107 opens

AUTO

  • Amber Light is Lit
  • 52‑1106/52-1207/52‑1107 controlled by header pressure
  • 92 psig on PS-1213 starts compressor
  • Compressor will load after 7 seconds if pressure <95 psig
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How long after the red light is lit in the control before the compressor can assume loading?

A

7-10 seconds

Startup checks for the microprocessor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

If an Instrument Air Compressor is running more than 10 minutes unloaded, what happens?

A

Compressor goes to “sleep”

  • Compressor motor shuts down
  • Local digital display reads “READY TO START”
  • Breaker stays closed and handswitch indication in the Control Room will continue to have a red light on.
  • Compressor will restart when discharge pressure is sensed to be less than 95 psig
  • There is no alarm for this condition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What trips an instrument air compressor?

A

Breaker trips (overcurrent or low voltage on bus 1C)

Load shed due on a Loss of Offsite Power (LOOP).

Compressor shutdown initiated by microprocessor due to various ALARM conditions

  • Includes low oil pressure, and Emergency Stop (local pushbutton) for example.
  • Breaker is NOT tripped
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What powers the ventillation for the instrument air compressors?

A

MCC-3 powers Control panel C-1034 which powers V‑201A/B/C.

V-201 A/B/C individual handswitch in manual - runs, auto - runs if compressor running.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the cooling medium for the instrument air compressor aftercoolers?

A

A is cooled by ‘B’ Critical Service Water

B is cooled by non-critical service water

C is cooled by ‘A’ Critical Service Water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the capacity of T-8A/B/C?

A
  • Design Pressure: 125 psig
  • Capacity: 57 Cubic feet each
  • Normal operating range: 95-105 psig.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How are instrument air pre and post filters aligned and what is their max dp?

A

1 of each aligned for service

4 psid max

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the function of CV-1211 “Penet. MZ-65 Instrument Air Cont. Isolation”?

A

CHP/CHR do NOT impact.​

  • Isolates Instrument Air from Containment Instrument Air
  • Normally open. Air to Open.
  • Operated by hand switch in the Control Room.
  • No automatic functions associated with CV‑1211.
  • Fails open on loss of air or loss of power (DC Bus D-11) to operating solenoid.
  • Nitrogen Backup from N2 Station 5 to allow closure in case of loss of operating air.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the function of CV-1212 “Service Air Header Isolation”?

A
  • Isolates Instrument Air header from the Service Air header.
  • Normally open, air to open
  • No Control Room Handswitch
  • Auto closes on low Instrument Air header pressure.
    • PS-1210 - Sensed downstream of the After- filters F-5A/F-5B
    • Setpoint: 85 psig
  • Fails closed on loss of air
  • Fails closed on loss of power (DC Bus D-11) to operating solenoid.
17
Q

What is the function of CV-1221 “Service/Inst Air Tie in from FWP Bldg?”

A
  • Isolates Instrument Air header and the Feedwater Purity Building Air header
  • Normally closed air to CLOSE
  • No automatic functions associated with CV‑1221.Operated by hand switch in the Control Room.
  • Fails OPEN on loss of air
  • Fails OPEN on loss of power (DC Bus D-11) to solenoid.
18
Q

What is the capacity of the high pressure air compressors?

A
  • High Pressure, oil lubricated air compressors.
  • External after cooler (medium is non-forced air), desiccant dryer and receiver tank.
  • 22.3 scfm @ 325 psig
  • NOP: 310–325 psig
19
Q

What are the power supplies for the HP air compressors?

A

C-6A – MCC-8 (Bus 1D)

C-6B – MCC-7 (Bus 1C)

C-6C – MCC-4 (Bus 1E)

20
Q

What is the design of the high pressure air receiver tanks?

A

57.7 ft3 @ 350 psig

Design basis of tank allows all valves it supplies to be stroked twice at a starting pressure of 260 psig assuming no compressor running.

Must be >= 260 psig in Modes 1 and 2 or Mode 3 with temp >325F.

21
Q

What is the restriction on T-9A operations?

A

T-9A less than 260 psig in Mode 1, 2, or 3 (greater than or equal to 325°F),

  • Tank is Inoperable.
  • The instrument air and N2 supply valves to all CVs supplied by the inoperable tank shall be checked to ensure correct alignment.
    • Refer to P&ID M-225, Sh 1 and/or SOP-3, Attachment 10, “Checklist CL 3.1, Engineered Safeguards System Checklist (Shutdown Cooling In Service).”
  • Technical Specifications LCO 3.5.2 should be reviewed for LCO requirements
22
Q

What is the restriction on T-9B operations?

A

T-9B provides the minimum air supply required for operability of CV-3027 and CV-3056.

IF T-9B pressure lowers to less than 260 psig in Mode 1, 2, or 3 (greater than or equal to 325°F), THEN DECLARE T-9B inoperable AND ENTER LCO 3.0.3.

23
Q

Is tank 9-C safety related and when can it be cross-tied?

A

Not Safety Related

Can be crosstied to either T-9A or T-9B in any mode, but not both at the same time.

24
Q

What is the design and capacity of the feedwater purity air compressors?

A
  • Two stage reciprocating, oil lubricated.
  • Internal Inner-Cooler, external After-Cooler and Receiver Tank
  • 876 scfm @ 125 psig
  • Normally only use 50 to 100 scfm
  • NOP: 95-110 psig
25
Q

What are the power supplies to FWP Air Compressors, C-90A/B?

A

C-903A - LCC-91 (Bus 1E)

C-903B - LCC-91 (Bus 1E)

26
Q

What happens to C-903A/B on SIAS?

A

E-Bus is load shed.

Compressors loose power

27
Q

What is the normal supply and backup to C-903A/B

A

Normal

  • Non-Critical Service Water

Backup

  • Fire Water
28
Q

What does N2 STATION 1 supply?

A

N2 STATION 1

Provides a nitrogen backup to CV-0727, P-8A/B Flow Control to E-50B and CV-0749, P-8A/B Flow Control To E-50A.

OPERABLE

  • Supply pressure >2000
  • Header pressure (PI-2273B) shall be 40 to 100 psig.

INOPERABLE

  • Restore within 30 days
29
Q

What does N2 STATION 1A supply?

A

N2 STATION 1A

Provides a nitrogen backup to CV-0847, SW Supply to Cont (MZ-12).

OPERABLE

  • Supply pressure >2000
  • Header pressure (PI-2280B) shall be 54 to 150 psig.

INOPERABLE

  • Restore within 30 days
  • IF Station 1A becomes non-functional AND Station 3B is non-functional for CV-0824, THEN ENTER Technical Specifications LCO 3.7.8.
30
Q

What does N2 Station 2 supply?

A

Provides a nitrogen backup to CV-0522B, Steam supply to P-8B Auxiliary Feedwater Pump

OPERABLE

Supply pressure >2000

Header pressure (PI-2274B) shall be 48 to 150 psig.

INOPERABLE

Restore within 30 days

31
Q

What does N2 Station 3A Supply?

A

STATION 3A

Provides a nitrogen backup to CV-3027 and CV-3056, Safety Injection Pumps Minimum Flow Stop Valves.

OPERABLE

  • Supply pressure >2000
  • Header pressure (PI-2276B) shall be 164 to 221 psig.

INOPERABLE

  • Restore to a functional status within 72 hours.
32
Q

What does N2 Station 3B supply?

A

STATION 3B

Provides a nitrogen backup to:

  • CV-0824, Service Water return from Containment
  • CV-3070, Subcooling to P-66B High Pressure Safety Injection Pump (HPSI).

OPERABLE

  • Supply pressure >2000
  • Header pressure (PI-2277B) shall be 73 to 130 psig.

INOPERABLE

  • IF Station 3B becomes non-functional for CV-0824 for any reason other than nitrogen bottle replacement AND Station 1A is non-functional for CV-0847, SW Supply to Cont (MZ-12), THEN ENTER TS LCO 3.7.8.
33
Q

What does N2 Station 5 supply?

A

STATION 5

Provides a backup nitrogen supply to:

  • CV-3001 and CV-3002, Containment Spray Isolation Valves
  • CV-3071 Subcooling to P-66A HPSI Pump
  • CV-1211, Instrument Air to Containment

OPERABLE

  • Supply pressure >2000
  • Header pressure (PI-2279B) shall be 73 to 134 psig.

INOPERABLE

  • IF Station 5 becomes non-functional for CV-3071, THEN DECLARE P-66A non-functional AND ENTER Technical Specifications LCO 3.5.2.
  • IF Station 5 becomes non-functional for CV-3001 AND CV-3002, THEN DECLARE P-54A non-functional AND ENTER Technical Specifications LCO 3.6.6.
34
Q

What does compressed air Sation 8 supply?

A

Provides a compressed air bottle backup supply to CV-3018, SI Tank Test Line Redundant High Pressure Injection

OPERABLE

  • Normal bottle pressure shall be > 1800 psig.
  • Header pressure (PI-2295) shall be 108 to 148 psig

INOPERABLE

  • Restore to a functional status within 30 days
35
Q

What does bulk N2 supply backup to?

A

Atmospheric Steam Dump Valves (ADVs)

The bulk nitrogen backup system is not required for ADV operability

36
Q

What does service air header supply?

A

Service Air header supplies:

  • Cooling Tower level instrumentation bubblers
  • Hose bibs
  • Air to P-972 “Pumping Trap for E-57 Condensate”
  • Control air to Fire Protection deluge systems
  • Spent Resin Storage and Liquid Rad Waste Processing air system. (ALPS)
37
Q

What instrument air indications are in the control room?

A

Panel C-13

  • PIA-1210 Instrument Air Pressure
38
Q

Where is PS-1210, SERVICE AIR-COMPR C-2A,B&C PRESS SWITCH, and what does it do?

A

PS-1210, SERVICE AIR-COMPR C-2A,B&C PRESS SWITCH

Located downstream on Air Filters/Dryer

Closes CV-1212 on Low Instrument Air Pressure of 85 psig.

If CV-1212 is closed with Instrument Air Header Pressure lowering, AND no standby compressor running, filters will need to be swapped.

PS-1213 which starts standby air compressors at 92 psig is located upstream of air filters/dryer.

39
Q
A