MFW

Question 1

Sequence of opening steam supplies to MFP?

Answer 1

LP gov valves open first (hot reheat), not enough steam pressure to operate pump => HP gov valves open (MSS). When (hot reheat) LP has enough steam pressure, the HP will close down. At 100% power, HP closed, MFP operating off LP only

Question 2

What is FCV-420

Interlocks

Answer 2

Mainfeedwater long recirc valve
Discharge #1 fw htrs -> MN condenser

Used for chemistry cleanup of fw

If any FW htr outlet > 320 deg valve will shut (won’t open) to protect MN cond from water hammer

Question 3

What gives FWI signal?

Answer 3

SI
P-14 (Ls/g > 90% NR)
   - turbine Trip
   - MFP Trip
   - FWIV's
   - FRV and Byp 

P-4 w/ Tave < 554
- FRV and Byp

Question 4

How do you reset FWI signal (3)

Answer 4

Reset SI
Cycle RTB
Reset FWI

Question 5

Precautions and limitations for MFW (3)

Answer 5

• ensure > 2% Rx power before roll MFP
• ensure fw cut into fw htr before extraction stm
• any perturbation in condensate will affect MFP, FRV, Ls/g

Question 6

How are MFP protected from overheating during low flow conditions?

Answer 6

FCV-53 and 54 open to provide minimum recirc to condenser of 1000 gpm

Pump running for recirc valve to open (>60 d/p)

Question 7

Steam sources to #1FWHtrs (3)

Answer 7

-HP turbine 3rd stage extraction
-MSR HP drain tank
-MSR excess steam vent

Question 8

What happens to FWH #1 on a hi hi level (2)

Answer 8

-Trip closed MSR HP drain tank drips
-vent air supply to non-return valves from 3rd stage HP ext steam

Question 9

What actions happen if Hi level in #2HDT(1)

Answer 9

Trips closed the drips valve from the #1FWHTR

Question 10

What are the MFW Reg Valves and purpose(3)

Answer 10

FCV-510/520/530/540
-control S/G level via the DFWCS>30% power
-isolates on a FWI
-manual operation: reverse acting valve

Question 11

What are the MFW Reg bypass valves and purpose?(3)

Answer 11

-FCV-1510/1520/1530/1540
-controls S/G level via the DFWCS<30% power
-isolates on a FWI
-no manual operation

Question 12

What are the MFW isolation valves and purposes?

Answer 12

FCV-438/439/440/441
-isolates on a FWI