AOP-35, Loss of Service Water Flashcards
What is the purpose of AOP-35, Loss of Service Water?
To maintain:
- Critical Service Water Header pressure greater than 42 psig
- Service Water Bay Level greater than 574’.
What are the entry conditions for AOP-35, Loss of Service Water?
EK-1124, “TRAVELING SCREEN HI DP” (9”H2O)
EK-1129, “SERVICE WATER PUMP BAY LO LEVEL” (Elevation 574’3”)
EK-1163, “CRITICAL SERV WATER HEADER “B” LO PRESSURE” (45 psig)
EK-1164, “CRITICAL SERV WATER HEADER “A” LO PRESSURE” (45 psig)
EK-1165, “NON-CRITICAL SERV WATER LO PRESS” (45 psig)
What are the AOP-35, Loss of Service Water, automatic actions?
Standby Service Water Pump starts at 40 psig discharge pressure on an operating Service Water Pump.
Screen Wash Pump P-4 starts at 6” H2O Δ Level across the Traveling Screens.
What are the trip criteria of AOP-35, Loss of Service Water?
Service Water Bay level lowers to 572’
Operator actions are not maintaining either Critical Service Water Header Pressure greater than or equal to 42 psig
Loss of Non-Critical Service Water as indicated by the following alarms:
EK-1165, “NON CRITICAL SERV WATER LO PRESS” (45 psig)
AND
PPC Urgent Alarm, “EXC FIELD COLD AIR RTD-31” [T_EXCITER_31] (48°C)
OR
PPC Urgent Alarm, “EXC DIODE COLD AIR RTD-32” [T_DIODE_32] (48°C)
OR
EK-0259, “EXCITER COOLER HI TEMP” (50°C)
What is the basis for the trip criteria in AOP-35, Loss of Service Water?
Loss of Non-Critical Service Water reactor trip criteria provided since exciter can be
damaged due to overheating within 10 seconds.
Service Water Bay level at 572’ reactor trip criteria is indicative of imminent loss of Service Water Pump suction.
Continued operation with Critical Service Water pressures below 42 psig reactor trip criteria indicate that the current situation does not warrant continued plant operation.
What are the immediate actions of AOP-35, Loss of Service Water?
IF EK-1165, “NON CRITICAL SERV WATER LO PRESS” (45 psig) is in alarm,
THEN VERIFY the following annunciators clear:
- PPC Urgent Alarm, “EXC FIELD COLD AIR RTD-31” (48°C)
- PPC Urgent Alarm, “EXC DIODE COLD AIR RTD-32” (48°C)
- EK-0259, “EXCITER COOLER HI TEMP” (50C)
Why is condenser vacuum broken on a loss of non-critical service water with REC-C11A-01, Generator Temperature Recorder, points 33 and 34 Exciter Cold Air Temperature is greater than 80C or rising?
Minimizes the amount of time the exciter is subjected to overheating conditions, and will minimize or eliminate exciter damage.
What do you do prior to starting a service water pump in AOP-35?
Normal operator practice is to verify a suction source, Service Water Bay level,
prior to starting a pump.
Calls out great than 569 feet.
When do traveling screens start and alarm?
Start - 6 inches
Alarm - 9 inches
What tech spec could be violated by aligning P-5?
LCO 3.7.9 requires Ultimate Heat Sink temperature to be less than or equal to 83.5 F
If not, shutdown.
If F-4B is degraded, which fire pump do you utilize?
P-41.
F-4B is north filter.
P-41 is outside SW bay by South Filter.
What are some possible actions for lowering SW bay?
- Trip an operating dilution water pump - preferrably on affected side if screen issue.
- Reduce power per GOP-8
- Trip other operating dilution water pump.
- Reduce power per GOP-8
- Align P-5 for Service/Siphon
- Trip Unit/Off-Line at 572 feet.
- Secure CT Pumps
- Close/Throttle Water Box inlets
- Maintain Cooling Tower makeup basin
lower than weir overflow
- Secure CT Pumps
- Isolate SW to Containment
What are some possible actions for broken SW piping?
Identify and Isolate
Un cross-tie critical headers. Walk-downs.
What are some actions on low SW pressure?
Less than 42 psig:
- Secure SW from containment
- Secure CAC SW
- Supply via Fire Pumps
- Check SW to C-2A/C
