Condenser Air Removal

Question 1

How fast can the Air Removal Pumps lower condenser pressure to 5HgA ?

Answer 1

In 1.5 hours

Question 2

What condenser shell can the ‘D’ AR unit be aligned to ?

Answer 2

It’s a standby unit that can be aligned to any condenser shell

Question 3

Where can you operate a Air Removal unit from?

Answer 3

Can be operated from control room

Question 4

Where is each AR Pump powered from ?

Answer 4

Powered from a Non-class 480VAC MCC(NH)

Question 5

What components does each AR unit consist of ?

Answer 5

-Vacuum pump
-Moisture separator
-Seal water Recirc. Pump
-Seal Water Cooler

Question 6

What does the vacuum pump “hogging” operation do ?

Answer 6

First stage will compress & discharge to moisture separator bypassing the second stage

Question 7

For the AR Vacuum Pump “hogging” operation,why is the second compression stage no needed ?

Answer 7

2nd stage isn’t required since there is small differential between condenser & atmospheric pressure

Question 8

What is the check valve used for in the first stage discharge line do ?

Answer 8

Allows vacuum pump to auto shift to hogging mode when first stage discharge volume exceeds capacity of 2nd stage

Question 9

When is AR Vacuum Pump hogging mode used?

Answer 9

Used during plant startup

Question 10

How does normal “Holding” operation work for the AR Vacuum pump ?

Answer 10

-1st stage partially compresses gas &discharges to 2nd stage
-2nd stage compresses slightly above atmospheric pressure &discharges to moisture separator

Question 11

What sealant do the rebuilt AR Pumps have ?

Answer 11

-Rebuilt has grease bearing instead of oil lubricated bearing
-Grease bearing should have no leakage

Question 12

What does the AR Pump moisture separators do ?

Answer 12

Separates AR discharge gas from sealant & provides surge volume & reservoir for sealant

Question 13

What is the gas flow path entering moisture separator ?

Answer 13

Gas rises through separator screens, exits through check valve at top of tank, & enters exhaust piping

Question 14

Where does makeup water get added from when moisture separator level decreases ?

Answer 14

Makeup water from condensate service header will auto add water

Question 15

What does the solenoid operated valves in the condensate seal water makeup lines do ? What happens when there is excess sealant ?

Answer 15

-Maintains seal water level in each supply line
-Overflow line from separator allows excess sealant to return to hotwell or be directed to floor drain

Question 16

What removes heat from seal water ?

Answer 16

Uses plant cooling water to remove heat from seal water

Question 17

Why is sealant sprayed into the inlet manifold during high vacuum operation ?

Answer 17

It cools incoming gases and condenses any steam

Question 18

What does seal water recirculation pumps do?

Answer 18

Takes suction on separator tank & discharges to shell side of seal water cooler

Question 19

What does the Charcoal Adsorption Train do ?

Answer 19

Removes moisture,particulate contamination, gaseous iodine, & methyl iodide from condenser exhaust gas

Question 20

What does the Charcoal Adsorption Train filter unit consist of ?

Answer 20

-Moisture separator
-Electric Heating Coil
-Exhaust Pre-Filter
-Activated Charcoal Filter
-Exhaust Post-Filter

Question 21

What does Charcoal Adsorption moisture separator do ?

Answer 21

Moisture separator removed moisture through mechanical filtration

Question 22

What does the Charcoal Adsorption heating element do ? What’s heating element controlled by?

Answer 22

-Reduces exhaust gas humidity below 70% to prevent charcoal damage
-Auto controlled by signals from humidistat mounted in unit

Question 23

What does the Charcoal Adsorption charcoal filter ?

Answer 23

Removes gaseous iodine

Question 24

What alarms are on the charcoal filter ? What is used during fire for charcoal filter?

Answer 24

-HI temperature
-HI-HI Temperature
-Has water deluge system in case of fire

Question 25

What is required before entering Post Filter Unit ?

Answer 25

Radiation Exposure Permit

Question 26

What does the AR Post Filter Blower do ?

Answer 26

Assist AR Pump in maintaining flow when using Charcoal Adsorption Train

Question 27

What will start the Post Filter Blower ?

Answer 27

-Can be started manually
-Can auto start when high rad signal from RU-141

Question 28

Where is the AR Post Filter Blower powered from ?

Answer 28

Powered from 480VAC MCC (NH)

Question 29

When will the ‘D’ Air Removal Pump start ?

Answer 29

Will auto start if Main Condenser pressure in any shells increases preset value

Question 30

What pressure is each condenser shell normally operate at ?

Answer 30

‘A’ 4.2HgA
‘B’ 4.8HgA
‘C’ 5.4HgAv

Question 31

What is the normal flow path for the AR discharge ?

Answer 31

Normally bypasses Charcoal Adsorption Train and goes through RU-141 to plant vent

Question 32

What happens during normal operation if RU-141 exceeds radiation limit ?

Answer 32

Bypass valves will close,inlet & outlet of charcoal adsorption will open, & post filter blower will start

Question 33

What will happen if Condenser Air Removal system is lost ?

Answer 33

-Vacuum decreases then turbine efficiency decreases
-If vacuum decreases enough than turbine will trip
-Oxygen could also increase in condensate which requires power reduction