Chemical Volume and Control Flashcards
What is the purpose of CVCS?
- Maintain the required volume of water in the PCS over the range of full to zero power without requiring makeup.
- Maintain chemistry and purity of the PCS.
- Maintain the desired boric acid concentration in the PCS.
- Pressure test the PCS.
Draw CVCS
Draw
CV-2001 (Letdown Isolation Valve)
Handswitch on C-02 has 3 positions: Close/Auto/Open.
Auto (opens valve) will isolate Letdown on high temp down stream of Regen Hx as indicated on TICA-0201, Regen Heat Exchanger Temperature Indication.
Setpoint 470°F.
Has a latching circuit. Must take HS back to close to reset.
Open position will override temperature closure setpoint.
Amber = valve in automatic (open)
a. E-56 (Regenerative Heat Exchanger)
Initial cooling of letdown and preheating of charging
Two pass shell and tube. Charging in shell side.
Letdown temperature depends on amount of Letdown and Charging flow.
Designed to maintain Letdown outlet temperature <450°F with maximum Letdown and minimum Charging
TICA-0201 (Letdown Temperature Indicator)
Temperature depends on amount of Letdown and Charging flow.
Alarm @ 460°F, EK-0701 (Regen Hx Tube Outlet Hi Temp)
Auto isolation of Letdown @ 470°F (CV‑2001 closes if Handswitch is in Auto).
CVs-2003, 2004, 2005 (Letdown Orifice Stop valves)
Handswitch on C-02 has 3 positions: Close/Auto/Open
CV-2003 will close if LIC-0101A (Pressurizer Level Control Channel 1) or B (Pressurizer Level Control Channel 2) is <36%, open when level is >36%.
CV-2004 and CV-2005 open and close by either the normal Pressurizer level control system or the backup Pressurizer level control system.
The CVs send an anticipatory signal to PIC-0202 (Intermediate Pressure Letdown Controller)
RO-2003, RO-2004, RO-2005 (Letdown Orifices)
Calibrated to flow 40 gpm at rated temperature and pressure.
Reduces Letdown pressure.
CV-2002, Letdown Orifice Bypass valves
Used during PCS low pressure operation to raise letdown flow when there is not enough PCS pressure to force Letdown through the orifices.
CV-2002 - Has Two HS: Each Handswitch controls one Solenoid Valve. The Solenoid valves are in series so both have to be open to open CV-2002.
- SV-2002A: HS Open / Auto / Close
- Closes on 500 psig on PS-0220 (Intermediate Letdown Pressure Switch) prevents opening RV‑2006 (and allows for a smaller RV‑2006.
- Closes on 190 psig on PS-0222 (Letdown Pressure Switch) (protect demins)
- SV-2002B: HS Open / Auto / Close
- Closes on 500 psig on PS-0221 (Intermediate Letdown Pressure Switch) prevents opening RV‑2006 (and allows for a smaller RV-2006)
- Closes on 160 gpm on FIC‑0202 (Letdown Flow Indicator Controller) excess flow can cause channeling (protects demins).
What is the setpoint, purpose and where does RV-2006 relieve to?
RV-2006
Protects Letdown Line and Components
Lifts at 600 psi
200 gpm
Relieves to Quench Tank
When and why does TIA-0202, RV-2006 Outlet Temp come in?
TIA-0202, RV-2006 Outlet Temp
Alarms at 200F
Indicates RV-2006 has lifted
Located on C-02
Where does, Low Pressure Letdown Pressure Transmitter, PT-0202 send its signal?
PT-0202 (Low Pressure Letdown Pressure Transmitter)
Signal Sent To:
- PIC-0202 Intermediate Letdown Regulating valve (Backpressure Controller)
- PA-0202
- Alarms EK-0704 (Letdown Ht Ex Tube Inlet Hi-Lo Press) on either
- High pressure @ 500 psig
- Low @ 400 ps
What is E-58 (Letdown Heat Exchanger)?
E-58 (Letdown Heat Exchanger)
Cools Letdown from Regen Hx outlet to within design limits of the demineralizers
CCW on Shell Side, Controlled via DPIC-0909
- Limit CV-0909 opening to <12 psid
- Alarms @ 14 psid, EK-0706 (Letdown Hx Cooling Excess Flow)
What is the function of TIC-0203, Letdown Temperature Controller
TIC-0203 (Letdown Temperature Controller)
Behind Panel Cover on C-02
Normally set at 110°F
Automatic - PB raise/lower setpoint
- Red = Variable, Blue = Setpoint
- Lever has no function
Manual - Lever control output signal to CV-0909
- PB has no impact on temperature
Cascade - no function
What is the function of TICA-0204, Letdown Flow Local Temp Controller Indication?
TICA-0204 (Letdown Flow Local Temp Controller Ind)
Alarms and actuates at 130°F
- EK-0703 (Letdown Ht Ex Tube Outlet Hi Temp)
- Sends bypass signal to CV-2023 (Ion Exchange Bypass Valve) to prevents damage/melting of resins
No indication in control room
What is the function of CV-2009, CVCS Containment Isolation valve?
CV-2009 (CVCS Containment Isolation valve)
Two position HS - Open or Closed
Closes Automatically on CHP and CHR
Has latching circuit