Condensate and Feedwater

Question 1

List condensate pump start interlocks, autostart of standby pump and trips.

Answer 1

Auto Start Interlocks: Suction isolation valve fully open, Hotwell level greater than 21%, turbine not tripped and both MFPs latched

Auto Starts: Feeder breaker for running pump trips open, P-8 trip or Discharge pressure sense by 2 pressure switches < 350# for >2 sec

Condensate pumps will trip on motor fault and SU2 Load shed

Question 2

List the heater drain pump trips and start interlocks.

Answer 2

Trips: at 42” or 75 psig and SU2 load shed.

Start interlocks: > 85#, 96”

Question 3

What supplies cooling water to the condensate pump motors?

Answer 3

ACW

Question 4

What are the 4 condenser sprays and their functions?

Answer 4

Exhaust hood: Opens when temperature reaches 160 degrees F

FW pump recirc: Used during MFP SU or SD to lower exhaust temp from MFP. Controlled from HS in TB Basement

TBV – Used during SU/SD when TBV in operation. Operated in CR

Low Level – Used for O2 scavenging. Operated in CR

Question 5

What seal cooling does condensate pumps supply?

Answer 5

Condensate, Heater drain pumps, Aux Feed Pump and MFP Seal Cooling

Question 6

How do the GS Condenser valves operate?

Answer 6

CV-2905 maintains 3 psid across the condenser. When DP drops to 0.6 psid (low flow 1600 gpm), CV-2906 will open until DP gets to 2.3 psid

Question 7

What are the flow limits for the polishers and why?

Answer 7

Low flow: 1500 (channeling)

Hi Flow: 3550 (compacting)

Question 8

What are the starting interlocks for P-75?

Answer 8

• Suction Pressure > 450#
• X-over valve CV 2827 100% open

Question 9

What causes P-75 to trip?

Answer 9

• Suction < 100#
• Motor fault or loss of power to A-2

Question 10

Discuss operation of the Hotwell makeup valve and how its affected during waterbox isolation?

Answer 10

Controls hotwell level 43 – 51% in automatic. Must be controlled in manual during waterbox isolation due to D/P. Level is read from A, Makeup is to B condenser.

Question 11

How are the condensate pumps impacted by SU2 load shed?

Answer 11

ACB – A will always remain running. C if C and B are running.

Question 12

What FW heaters are allowed to be bypassed and what is required?

Answer 12

5,6,8

3 and 4

Power must be reduced when bypassing FW heaters

Question 13

What is the purpose of maintaining level in FW heater integral drain cooler?

Answer 13

Reduce flashing downstream of the NLC valve.

Question 14

What are the trips associated with the MFP?

Answer 14

• Electronic Overspeed
• Low suction pressure – 230# alarm and permissive, 200# for 40 sec will trip preferred, 10 s later (50 sec) will trip other pump
• High discharge pressure (2 of 3 pressure switches) 1350#
• Low Bearing oil pressure – 1 pressure switch at 15#, 2 @ 10#

Question 15

What is the source of steam for the MFPs during normal operation? < 40%?

Answer 15

Normal steam supply is from A MSR. Main steam provides steam during plant startup until Reheat steam can take over

Question 16

What occurs at 1275# to limit high discharge pressure? What happens at 1300#?

Answer 16

1275# discharge pressure setback to lower discharge pressure. Will clear when < 1275# for 30 sec. At 1300# recirc valve opens.

Question 17

What causes MFP Discharge crosstie (CV-2827) to automatically open? What would happen if it was inadvertently open < 80% power?

Answer 17

CV-2827 auto opens on MFP trip. If < 80% and X-tie opened, MFW block valve would close in slow speed.

Question 18

What action occurs when MFP trips due to low lube oil pressure?

Answer 18

MFP recirc valve receives signal to close to prevent damage to pump.

Question 19

Following RFR, when are the SU and LL valves released to operate?

Answer 19

40” SG Level

Question 20

What causes RFR and what happens?

Answer 20

RFR occurs on reactor trip to limit FW flow and prevent overcooling RCS. MFP reduced to minimum speed (3000 rpm). SU, LL and MFW block valves receive closed signal. MFP will begin controlling when SG level @ 45”, SU and LL valves receive signal @ 40”

Question 21

Discuss operation of MFW system during startup.

Answer 21

Aux FW pump runs up to 3% when 1st MFW pump is started. SU valve will open up to ~ 20%. When SU valve reaches 80%, the LL block will open. When SU valve @ 90%, LL valve will begin controlling. At ~ 50% the MFW block valve receives open signal based on MFW demand which will freeze the low load valve @ current position.

Question 22

How is the MFW block valve affected during a MFP trip?

Answer 22

> 80% the MFW block valve close signal is blocked. When < 80% it then closes in fast speed until FW demand < 45%. If FW demand and FW flowrate error +/- 10% block valve will freeze.

Question 23

What are the different modes of operation based on MFW block valve status?

Answer 23

When MFW block valves are closed, D/P mode is in operation maintaining > 70 psid across the block valve. When open, operates based on FW flow control.

Question 24

What is the TS requirement for the MFW valves?

Answer 24

All MFIVs, Block valves, LL control valves, and startup control valves OPERABLE in modes 1,2,3.

Question 25

What is the power supply for MFW Discharge Cross-tie valve (CV-2827)?

Answer 25

B-25