CVCS Flashcards
What are the CCP auto Starts?
- SI (3 sec time delay on load shed)
What are the CCP Trips?
- Loadshed - Train Specific
- Overcurrent
- Overload
What are the VCT Lvl auto actions?
- 87% Full Divert to CVCSHUT (QLC-451/452)
- 78% Divert starts to Open (QLC-452)
- 24% Stops auto Makeup (QLC-451)
- 14% Starts auto Makeup (QLC-451) (alarms)
- 7% Low Lvl Alarm (QLC-452)
- 2.5% RW Sequence (QLC-451/452)
What does QRV-301 (LD # Ctrl Valve) do and how does it fail?
- Maintains backpressure (300-350#) on the LD orifices to keep the water from flashing to steam
- Fails open
What does QRV-302 (Demin Divert Valve) do and how does it fail?
- Diverts LD flow from demins to RC Filter if temp measured by QTS-301 is > 143°F ***
- Fails to RC filter (Divert)
What does QRV-251 (CCP disch flow ctrl valve) do and how does it fail?
- Ctrls CCP flow and is used to maintain Pzr Lvl
- Position controlled by QFI-200 when in auto
- Fails open
- Has a minimum output of 23.5% (47gpm) while in auto *** (protect RCP seals)
What does QRV-200 (CCP header # ctrl valve) do and how does it fail?
- Used to maintain required flow to RCP seals (32 gpm)
- Fails close
What does QLC-451 control for the VCT?
- Make up **
What does QLC-452 control for the VCT?
- Divert **
What does QRV-303 (Inlet Valve to VCT) do and how does it fail?
- Diverts LD to CVCS HUTs if VCT lvl is too high
- fails flow to VCT
What will close/happen when Pzr is at 17% lvl on the CVCS System?
- QRV-160/161/162 (LD orifice isolations) and QRV-111/112 (LD isolation valves)
When do QRV-160/161/162 (LD orifice isolations) auto close and how do they fail?
- Close on Phase A
- Close when either letdown isolation closed.
- Close on loss of both CCPs
- Close @ 17% Pzr Lvl
- LD relief is AFTER the orifice isolations (SV-51) and reliefs at 600# to PRT ***
- Fail Closed
What interlock is associated with QRV-111/112 (LD iso valves)?
- Will not open if any QRV-160/161/162 (orifice isolation)is open
What happens on an SI in the CVCS System?
- Both CCP auto start
- IMO-910 and IMO-911 (RWST) open
- ICM-250/251 and IMO-255/256 (BIT) open
- QMO-451 and QMO-452 (VCT) close
- QMO-200 and QMO-201 (to Regen Hx) close
- QMO-225 and QMO-226 (CCP ELOs) close then cycle based on pressure (1812-1825#)
What happens on an Phase A in the CVCS System?
- QRV-160/161/162 (orifice valves) close
- QCR-300 and QCR-301 (Letdown isolation) close
- QCM-250 and QCM-350 (RCP seal return) close
- CCW to EXLD HX Closes
What happens on an RW Sequence in the CVCS System?
- 2.5% lvl in VCT from BOTH QLC-451 and 452 ***
Auto Actions:
- CCP suction from RWST Opens
- When one of the suction valves from RWST is open, VCT outlet valves close
Will the BAT pump automatically shift to FAST speed during Emergency Boration?
- No, it must be manually shifted to Fast Speed***
What are the CCP recirc valves (QMO-225/226) controlled by?
- NPP-151/153 (Pzr #) ***
- Valves will cycle 2 sec after a SI signal is received and maintain 1812-1825#
- Valves will cycle until SI is reset and the switch is taken to Pull-to-Stop