sequencer

Question 1

Sequencer

What turns on after 5 seconds?

Answer 1

A/B/C SI pump starts
(B only if racked in)

SI only

Question 2

Sequencer

What turns on after 15 seconds?

Answer 2

A/B RHR pumps start

SI only

Question 3

Sequencer

What turns on after 20 seconds?

Answer 3

A/C SW pumps start
(Signal to start both SWBPs. SI auto start, SBO waits until 30psig in SW header)

Both SI and SBO

Question 4

Sequencer

What tuns on after 25 seconds?

Answer 4

B/D SW pumps start
(Signal to start both SWBPs. SI auto start, SBO waits until 30psig in SW header)

Both SI and SBO

Question 5

Sequencer

What turns on after 30 seconds?

Answer 5

1/3 HVH units start on SI

CCW pump B/C start on SBO

Question 6

Sequencer

What turns on after 35 seconds?

Answer 6

2/4 HVH units start

SI only

Question 7

Sequencer

39.5 seconds?

Answer 7

A/B AFW starts

Both SI and SBO

Question 8

List the SI sequencer

Answer 8

5 sec- A/B/C SI pumps
15 sec- A/B RHR pumps
20 sec- A/C SW pumps (SWBPs)
25 sec- B/D SW pumps (SWBPs)
30 sec- 1/3 HVH units
35 sec- 2/4 HVH units
39.5 sec- A/B AFW pumps

Question 9

List the SBO sequencer

Answer 9

20 sec- A/C SW pumps (SWBPs with 30psig)
25 sec- B/D SW pumps (SWBPs with 30psig)
30 sec- B/C CCW pumps
39.5 sec- A/B AFW pumps

Question 10

What happens if a safety injection singal comes in while a blackout sequence is in progress?

Answer 10

1. If the EDG output breaker is closed, the SI squence will start and the SBO signal is blocked and stops.

Question 11

Which sequencer sheds loads?

Answer 11

Blackout

Question 12

What loads are not shed on a blackout?

Answer 12

MCC-5/16 - MCC-6/18

Question 13

What turns off a CCW pump? Dealing with the sequencer.

Answer 13

Having 3 signals, UV, SI, and Spray

Question 14

What turns off charging pump? Dealing with the sequencer.

Answer 14

UV and SI

Question 15

SI Sequencer must have what to start?

Answer 15

Power on respective bus. If an SI sequence starts after a black out, remember that 10 seconds have to pass before the Bus has power.

Question 16

Blackout sequencer starts

Answer 16

When power on the bus is gone. 10 seconds for the edg to sync.

Question 17

When will A CCW pump start if it was not already running?

Answer 17

Low pressure if power is available on DS bus. 90 seconds required for the DS bus to receive power from the DSDG if its lost.

Question 18

If the EDG output breaker is closed what does it stop from happening?

Answer 18

CCW pump start on low pressure for affected Bus.