Primary Coolant Pump Alarms Flashcards
EK-0901, EK-0902, EK-0903, EK-0904 - “PRI COOLANT PUMP P-50A, B, C, D TRIP”
Breaker open with H/S in “after-close” position (i.e. breaker trip due to Undervoltage, Overcurrent or Differential)
Reactor Trip from the Reactor Protective System on PCS Flow less than full flow
Redundant Indications
- Pump amps on C-12
- Control Switch indicating lights on C-02
- Pump ΔP indications and total flow indication on C-12.
EK-0907, EK-0908, EK-0909, EK-0910 - “PRI COOLANT PUMP P-50A, B, C, D HI TEMP OVERLOAD”
Guide Bearing Temp
- P-50 A/B/C - 175F
- P-50D - 190F
Thrust Bearing Temp
- P-50 A/B/C - 175F
- P-50D - 190F
Stator Temperature
- P-50A, B, C - 140°C
- P-50D - 145°C
Controlled Bleed-off Temperature - 180°F
Lower Seal Temperature - 170°F
Secure Pump For:
- Any bearing temperature alarm
- Lower seal temperature exceeds 185°F
- Controlled Bleedoff temperature exceeds 185°F
EK-0913, “PRI COOLANT PUMP VIBRATION ALERT/MONITOR TROUBLE”
Excessive vibration can cause damage to the PCP motor and/or pump.
- P-50A - 13 mils
- P-50 B/D - 15 mils
- P-50D - 16 mils
OK Relay - Loss of power to monitor or Gap voltage out of range
Redundant Indications
- Bentley Nevada) located on Panel EC-12
Trip Criteria
This alarm accompanied by corroborated indications such as:
- Erratic or sudden change in motor amps
- Rapid or unexplained rise in motor bearing temperature
- Sudden drop in PCS flow
- Continuing rise in vibration
- One vibration axis monitor fails high and the other fails low
- Abnormal noises or tangible vibration reported by personnel
EK-0914, “PRI COOLANT PUMP VIBRATION DANGER
P-50A, B, C, D - 25 mils
Redundant Indications:
- Bentley Nevada on C-12
Vibration level exceeds 29 mils or;
- This alarm accompanied by corroborated indications such as:
- Erratic or sudden change in motor amps
- Rapid or unexplained rise in motor bearing temperature
- Sudden drop in PCS flow
- Continuing rise in vibration
- One vibration axis monitor fails high and the other fails low
- Abnormal noises or tangible vibration reported by personnel
EK-0925, EK-0926, EK-0927, EK-0928 “PRI COOLANT PUMP P-50A, B, C, D OIL LEVEL HI-LO”
P-50A, B, C Upper Reservoir
- High - 88% to 96% Low - 23% to 30%
P-50D Upper Reservoir
- High - 95% Low - 5%
P-50A, B, C Lower Reservoir
- High - 80% to 90%; Low - 20% to 33.3%
P-50D Lower Reservoir
- High - 95%; Low - 40%
EK-0931, EK-0932, EK-0933, EK-0934, “PRI COOLANT PUMP P-50A, B, C, D CLG WTR LO FLOW”
P-50A, B, C - 80 gpm
P-50D - 145 gpm
No direct indication in Control Room; monitor PCP Bearing and Seal bleedoff temperature indications on LTVR-0901 on Panel EC-11
EK-0937, EK-0938, EK-0939, “PRI COOLANT PUMP P50A, B, C, BACKSTOP OIL LOW FLOW”
<= 0.24 gpm flow
Slight rise in the Upper Oil Reservoir level indication (3-4%) is expected upon complete loss of backstop oil flow.
Standby Backstop Oil Pump starts.
- Alarm should clear on standby pump start unless power is lost to the pump that was initially running.
The only indication that backstop pumps are running other than the alarm is to take a current reading at the respective breaker
Trip Criteria
IF the combined current of both breakers is less than 2.4 amps per phase (indicating less than 3 backstop oil pumps operating), THEN trip the Reactor and remove the PCP from service.
EK-0943, EK-0944, EK-0945, EK-0946, “PRI COOLANT PUMP P50A, B, C, D SEAL LEAKAGE FLOW LOW”
Low leakoff flow can cause damage to the PCP seal due to inadequate cooling and lubrication.
- <= 0.50 gpm for P-50A/B
- <= 0.75 gpm for P-50C/D
EK-0949, EK-0950, EK-0951, EK-0952, “PRI COOLANT PUMP P-50A, B, C, D SEAL PRESSURE OFF NORMAL”
Abnormal seal differential pressure can lead to a seal “de-staging” which can lead to seal failure and a loss of coolant accident.
P-50A, B, C, D
Upper Seal
- High 900 psig; Low 500 psig
Middle Seal
- High Pressure – 1600 psig
The PCP may be operated with one Main Pressure Seal or the Vapor Seal failed as long as other seal pressures are as expected, temperatures remain near normal, and positive indication of some seal bleedoff flow continues.
EK-0953, “PRI COOLANT PUMP DC LIFT PUMPS OVERLOAD”
Breaker thermal overload
- Lift Pump trip.
Redundant Indication
- Look at Control Switch indicating lights on C-02
EK-0955, EK-0956, EK-0957, EK-0958, “PRI COOLANT PUMP P-50A, B, C, D SEAL HEAT EX HI TEMP LEAKAGE HI FLOW”
Seal Heat Exchanger temperature - 120°F
Seal Leakage Flow - 2.0 gpm
Excess flow device will close at 10 to 15 gpm and will reopen when high flow condition is cleared and backpressure is increased.
EK-0959, “PRI COOLANT PUMPS CONT BLEEDOFF HDR HIGH PRESS”
Controlled Bleedoff pressure - 120 psi
This alarm is expected for a Containment Isolation or loss of instrument air condition.
Redundant Indications
- PIA-0215, PCP Controlled Bleedoff Header pressure indication on C-02
EK-0960, “PRI COOLANT PUMPS CONT BLEEDOFF HDR HI-HI PRESS”
Controlled Bleedoff pressure - 240 psi
Redundant Indications
- PIA-0215, PCP Controlled Bleedoff Header pressure indication on C-02
- PCP seal leakoff flow on REC-C11-02 and REC‑C11-03. EK-0960 indicates a loss of controlled bleedoff flow.
If no controlled bleedoff flow can be established or there is no pressure breakdown between seal stages then an immediate plant shutdown and securing of PCPs is required.
