AOP-17 "Loss of 125V DC Panel(s)"

Question 1

AOP-17 entry conditions

Answer 1

Loss of status light indications

• ED-11A - P-8A Bkr indication OR Bus 1C Control Power Available indication
• ED-11-1 - CV-0510, S/G E-50A MSIV, position indication OR Bus 1A Control Power Available indication
• ED-11-2 - K-7A, Feedwater Pump P-1A Turbine Driver, trip power OR CV-0847, SW Supply to Containment, position indication
• ED-21A - P-8C Bkr indication OR Bus 1D Control Power Available indication
• ED-21-1 - CV-0501, S/G E-50B MSIV, position indication OR Bus 1B Control Power Available indication OR Bus 1E Control Power Available indication
• ED-21-2 - K-7B, Feedwater Pump P-1B Turbine Driver, trip power OR CV-1359, Non-Critical SW Header Isol, position indication OR EK-0542 “Annunciator DC Failure”

Question 2

AOP-17 automatic actions

Answer 2

• Deenergizing Bus ED-10R results in the loss of EY-10, and the following actions occur:
  
  • P-8A/B AFW control circuitry transfers to EY-30 power.
  • Main Feedwater control for A S/G transfers to EY-30 power.
  • P-8B, Steam Driven Aux Feed Pump, starts.
• Deenergizing Bus ED-20R results in the loss of EY-20 and the Main Feedwater control for B S/G transferring to EY-40.
• Deenergizing Panel ED-11-1 results in P-8B, Steam Driven Aux Feed Pump, starting.

Question 3

AOP-17 reactor trip criteria

Answer 3

-Loss of ED-20R or ED-21-2:
CV-1359, Non-Critical SW Header Isol, fails closed on loss of either of these 2 buses, as indicated by BOTH of the following:
-K-7B, Feedwater Pump P-1B Turbine Driver, “Trip Power” light is extinguished
-CV-1359 position indication lights are extinguished

Question 4

AOP-17 immediate actions

Answer 4

1. Verify the following conditions exist (loss of Bus ED-20R):
   - “Annunciator DC Failure” (EK-0542) is in alarm
   - K-7B, Feedwater Pump P-1B Turbine Driver, “Trip Power” light is extinguished
   - CV-0501, S/G E-50B MSIV, position indication lights are extinguished
   - —-If all 3 conditions exist, then trip the reactor and place HS-0510A, Main Steam from S/G E-50A, to close.If all 3 don’t exist, then continue to step 2.
2. Verify the following conditions exist (loss of Panel ED-21-2):
   - “Annunciator DC Failure” (EK-0542) is in alarm
   - K-7B, Feedwater Pump P-1B Turbine Driver, “Trip Power” light is extinguished
   - —-If both conditions exist, then ensure reactor and turbine are both tripped. If both conditions don’t exist, then go to Section 6.0 “operator actions”