Feedwater

Question 1

STATE the functions of the Main Feedwater System.

Answer 1

Maintains the proper water inventory automatically during at-power operations.
• Provide final preheat to the feedwater.
• Ensure proper steam generator water inventory during plant startup and shutdown operations.
• Provide steam generator recirculation and wet-layup capabilities.

Question 2

EXPLAIN the NORMAL mechanical and electrical lineup required for the startup feed pump to be aligned for AUTO start

Answer 2

• Prelube pump MCB C/S in AUTO
• During Mode 1 operations it’s racked onto E5 with MCB switch is in PTL (DG loading)
• During planned Startup/Shutdown’s it’s racked onto Bus 4 with MCB switch is placed in Auto on Recirculation.
• CST upper tap (CO-V-141)-OPEN
• FW PCV 4326, startup feed pump recirc control valve controller in AUTO-set for 1400 psig.

Question 3

LIST the sources of steam to the SGFP

Answer 3

Main steam

Aux Steam

Question 4

STATE the purpose of the following:

steam generator feed pumps

Answer 4

Supplies feedwater at adequate pressure to the SGs

Question 5

STATE the purpose of the following

startup feed pump

Answer 5

• During startup until @ 5% power (191 amps)
• During shutdown
• As an alternate EFW pump

Question 6

STATE the purpose of the following

feedwater recirc. and wet lay-up pumps

Answer 6

Recirculate the SGs when in wet layup to prevent chemical stratification.
Provide a means of draining SGs to the condenser hotwells or to the ocean.

Question 7

STATE the purpose of the following

hi pressure feedwater heaters

Answer 7

• Provide final FW heating prior to S/G’s
• Receive Extraction Steam from HP Turbine (3rd Stage)
• Receives drains from Reheater Drain Tanks

Question 8

STATE the purpose of the following

main feedwater regulating valves

Answer 8

Control SG level 15-100%(SGWLC)

Question 9

STATE the purpose of the following

feedwater regulating bypass valves

Answer 9

Used up to ~ 15 % power

Question 10

STATE the purpose of the following

feedwater regulating isolation valves

Answer 10

used to isolate FRV’s

Question 11

STATE the purpose of the following

feedwater containment isolation valves

Answer 11

Auto closes on Feedwater Isolation Signal

Question 12

LIST the equipment that is controlled from CP-144 and 145

Answer 12

Speed Control Governor Local/Remote Selector Switch
Turning Gear Motor control
Main Lube Oil Pumps 
Emergency  Lube Oil Pump (DC)
Lube Oil tank heaters
Vapor Extractor
Stop valve & turbine drains

Question 13

DESCRIBE the methods of manually operating the feedwater regulating valves

Answer 13

OS1090.01 Manual Operation Of Remote Operated Valves
Section 4.1- Manual operation of the Main Feed Regulating valves
Section 4.2- Return Of The Main Feed Regulating Valves To Automatic Operation

Question 14

List four of the ten automatic SGFP trips

Answer 14

SG High High Level	
90.8%
Lo Tavg with Reactor Trip Breakers Open 
557F
Safety Injection Signal 
NPSH Low			
220, 6 sec delay for A and 12 for B
Discharge Pressure High 
1635#
Thrust Bearing Wear 		
40 (PSHH) & 38 (PSH) psig
Feedpump Bearing Low Oil 
4 psig
Turbine Bearing Low Oil 
5.5 psig
Low Vacuum 
18.5 in. of mercury
Turbine Overspeed	
5940-6060 rpm