AFW

Question 1

What are the MDAFP Auto Starts?

Answer 1

• Both MFP Trips (in Auto)
• AMSAC (C-20)
• Load Shed
• Low-Low SG Lvl (2/3) on 1 SG
• SI

Question 2

What are the TDAFP Auto Starts?

Answer 2

• Undervolt on the RCP Bus (2/4 RCP busses at 88v)
• SG low low lvl (2/3) on 2 SGs
• AMSAC (C-20)

Question 3

What are the suction sources of the AFW pumps?

Answer 3

• Own CST
• Other Unit CST
• ESW

Question 4

What happens on an AFW Flow Conservation signal?

Answer 4

• SG Blowdown Isolations Close
• AFW Pump Test Valves Close
• MDAFP FMOs OPEN (regardless of position)
• seals in for 45 seconds to ensure the FMOs OPEN

Question 5

What causes an AFW Flow Conservation Signal?

Answer 5

Anything that starts MDAFW pump auto start

Question 6

What does the AFW flow retention signal do?

Answer 6

Protect against run-out after steam/feed break by limiting flow from the AFW pumps that may be supplying the faulted SG

Question 7

What happens on a AFW flow retention?

Answer 7

Pump discharge valves throttles back
- MDAFP 575 gpm
- TDAFP 955 (975) gpm

Question 8

What causes an AFW Flow Retention Signal?

Answer 8

High AFW pump discharge flow

Question 9

Which AFW signal overrides the other? (Retention or Conservation)

Answer 9

Flow Retention overrides Flow Conservation

Question 10

What is the TDAFP Turbine oil Cooler and Governor Oil Cooler cooled by?

Answer 10

TDAFP discharge

Question 11

If you put the TDAFP ELO switch in Manual what will the valve do?

Answer 11

Stay open

Question 12

How do the TDAFP ELO fail on loss of air and ctrl power?

Answer 12

Open

Question 13

Where does the back up water supply to the suction of the MDAFPs come from?

Answer 13

East ESW Header

Question 14

Where does the back up water supply to the suction of the TDADPs come from?

Answer 14

West ESW Header

Question 15

What will cause an AMSAC Signal?

Answer 15

FW Flow less than 25% (3/4 feed flows)

Question 16

How can you tell if it’s an electronic or mechanical overspeed on the TDAFP?

Answer 16

Electronic Overspeed
- Overspeed will bring in both alarms. (Drop 10 and 50) Drop 50 will clear when seal in alarm is reset

Mechanical Overspeed
- Overspeed will bring in both alarms. (Drop 10 and 50) But Drop 50 will not clear even if the seal in alarm is reset

Question 17

What is the Low Low SG Level for Unit 1?

Answer 17

5%

Question 18

What is the Low Low SG Level for Unit 2?

Answer 18

22%

Question 19

What does an AMSAC actuation do?

Answer 19

Trips the turbine and starts all AFW Pumps

Question 20

What is C-20?

Answer 20

Enables AMSAC
2/2 Turbin 1st stage Impulse Pressures greater than 40%

Question 21

What conditions cause AMSAC to actuate?

Answer 21

Feed flow less than 25% on 3/4
(1 channel from each SG)
(channels are 1, 2, 1, 2)

Question 22

What is the time delay for AMSAC?

Answer 22

Variable. 27 secs - 220 secs from 100% to 40% power

Question 23

What steps are taken to align ESW to AFW?

Answer 23

1. Locally Close the Tell-Tale Drain
2. Open associated manual isolation
3. Open MOV from control room

Question 24

Which steam generators do the East MDAFP Feed?

Answer 24

2 and 3 on own unit
1 and 4 on opposite unit

Question 25

Which steam generators do the West MDAFP Feed?

Answer 25

1 and 4 on own unit
2 and 3 on opposite unit

Question 26

Which MDAFP auto start is NOT available if the control switch is in neutral?

Answer 26

Loss of both MFPs