1. Transfer heat from SR/NSR loads to SW during normal operations and DBAs. CCW pressure is < SW pressure. CCW design pressure is 150 psig @ 200 F, except in Containment- RCP thermal barrier 650F and 2485 psig.
2. ESF System: 2 independent parallel trains consisting of one Pp and one HX. Each train Powered by Class 1E and Diesel. Each train capable of bringing the plant to cold Shutdown following postulated LOCA, Concurrent with LOP and DBA earthquake
3. Sized such that SW at 90F, will make CCW <99F at all times.
4. Provided with Design features to detect leakage
5. RCP thermal barrier Leak detection isolation
6. CCW Surge Tank relief valve can hold postulate RCP thermal Barrier leak to CCW
7. Relief valves provided to CCW HX to prevent overpressurization due to thermal expansion
8. Containment Auto isolation Valves
9. Designed for Shutdown Concurrent with MCR evacuation (operation from HSD Panels)

CCW Surge Tank:

Purpose and Specs

Provides NPSH to CCW Pps, Accommodates volume of RCS entering the CCW for 3.5 minutes following a RCP thermal barrier rupture, Accommodates System Surges and Provides means for chemical mixing.

1. 2000 gallons max, normal 50% full, 2 level detectors
2. Internal Baffle at 37.5%
3. Make Up Water provided by DR (via DR107) or alternate source-PWST, fill valves are CC145/146
4. Vented to Aux Bldg Exhaust Filter Inlet Header via CC149, CC149 auto closes on RMS 17 a/b high rad or failed monitor alarm
5. Tank Relief Valve CC147, set point 100 psig, passes > 285 gpm to  contaminated floor drains and then WHUT.

CCW Pps:

Purpose and Specs

Circulate hot CCE thru CCW HX, cooled by SW. The cooled CCW is then supplied to all heat loads.

3 pps-

• 21 in 21 HX Room powered by A 4 KV VB,
• 22/23 in 22 HX Room powered by B and C 4 KV VB respectively
• Centrifugal PP max- 4600 gpm @ 200 psig, min 1100 gpm 
• Suction Header relief valve CC138, setpoint 150 psig
•  Normal Operation is two Pps running and one in auto standby.

Auto Starts:

Low Header Pressure, <70psig

SEC Mode 2 blackout auto sequencer

Auto Trips:

Vital Bus Overload

Vital Bus Diff

SEC Trip Signal

Mtr Overcurrent

SEC:

Mode I, if in auto will remain in auto

Mode II, III, IV take to manual and Pp will restart as needed.

CCW HX:

Purpose

• RHR HX
• RHR Mechanical Seal HX
• SI PP Mechanical Seal HX
• Charging Pp (23) lube oil cooler/speed changer

• SFP Cooling HX
• LTDN HX
• Seal Water HX
• Waste Gas Compressor
• Excess LTDN HX
• Sample System HX
• Pass Racks
• SGBD RMS
• RCPs- Upper Motor Cooler/ Lower Motor Cooler/ Thermal Barrier HX

System Pressure is greater than CCW pressure

1. RCP Thermal Barrier
2. Excess LTDN HX
3. LTDN HX
4. RHR HX
5. Mechanical Seals of Running Pps

CC149 CC Surge Tank Vent Valve

Interlocks

Auto Close on Hi Rad from R17A/B or RMS failure

Close on Loss of Control Air and

Loss of Power (28/125 V DC)

Containment Isolation Vlv

Auto Close if flow is > 175gpm for > 4 seconds (for leak isolation, normal flow is 160 gpm), this will mannually override the auto functions of this valve.

CC215(inlet to HX), CC113 (Outlet from HX) 

Auto Close on: 

Loss of Air

Loss of 28/125V DC

Containment Phase A

Safety Related  AOV

"Auto" maintains 100F CVCS LTDN

"Manual" adjust temperature by pressing increase/decrease bezels in MRC

CV7 closes and CC71 will close (CV7 closed limit swithch de-energizes the CC71 solenoid)

Mode I: Pps in auto and manual will be blocked until reset by SEC. What you have is what you get. After Reset, the third pp may come on as needed.

Mode II: All pps stopped and restarted in required sequence

Mode III: All pps stopped, SW122 closed and PPs do not restart.

Mode IV: Trip CCW Pp, affected SW122 closes and pps shift from auto to manual operation. Pps do not auto restart.