Diesel Generator Flashcards
Given the following conditions: Unit 3 is operating at rated power. A LOCA results in a plant trip with a SIAS/CIAS. The Train “B” BOP-ESFAS Load Sequencer subsequently fails. When NAN-S02 transfers to NAN-S04, Startup Transformer #1 (NAN-X01) faults. Assuming no operator action, three minutes later you should expect PBB-S04 to be…
A. de-energized with Diesel Generator “B” running unloaded.
B. energized by Diesel Generator “B”.
C. de-energized, Diesel Generator “B” never received a start signal.
D. energized by offsite power, Diesel Generator “B” running unloaded.
Answer: A
Given the following conditions: Unit 2 operating at 100% full power. NBN-X04, ESF Transformer, trips on sudden pressure. Emergency diesel generator “B” starts and loads. PKB-M42, Class 1E 125 VDC bus, trips on overcurrent. WHICH ONE of the following identifies the effect(s) on emergency diesel generator “B” due to the loss of PKB-M42?
A. Trips and the output breaker remains closed.
B. Trips and the output breaker opens.
C. Continues to run and the output breaker opens.
D. Continues to run and output breaker remains closed.
Answer: A
Given the following plant conditions: Unit 2 is operating at rated power. A full load test of the ‘B’ D/G is in progress. The ‘B’ D/G output breaker has just been closed with the D/G carrying approximately 450 KW of load. A loss of PKB-M42 occurs due to a bus fault. Which one of the following describes the impact (if any) this has on the D/G?
A. The D/G begins to assume load uncontrollably, requiring the operator’s to manually trip its output breaker.
B. The D/G trips, its output breaker remains closed and PBA-S03 de-energizes.
C. The D/G continues to run at 450 KW, however output breaker control has been lost.
D. The D/G trips but its output breaker remains closed, causing the diesel to motorize.
Answer: D
Given the following plant conditions: PBB-S04 is being powered from DG “B” power following a LOP. Normal and alternate supply breakers to PBB-S04 are open. What is the effect of going to override on the DG handswitch?
A. Speed control, voltage control and DG breaker electrical trips are restored.
B. Speed control, voltage control and test run trips are restored.
C. This has the same effect as taking the emergency mode defeat switch to ON.
D. This allows stopping the DG from the control room, but does not affect any other control circuit.
Answer: A
The plant is in Mode 5, when 1 channel of Boron Dilution Alarm system (BDAS) becomes INOPERABLE, the operator must:
A. immediately determine RCS Boron concentration, no actions are required by Technical Specifications or 40ST-9ZZ19 (Mode 5 & 6 Shiftly Surveillance Logs).
B. immediately determine RCS Boron concentration and REFER to LCO 3.3.12 Condition B.
C. immediately determine RCS Boron concentration and REFER to LCO 3.3.12 Condition A.
D. determine that no actions are required by Technical Specifications or 40ST-9ZZ19.
Answer: C
Which of the following conditions must be satisfied for the DG “B” output breaker to automatically close and supply power to PBB-S04 on a loss of power event? No lockouts on…
A. the DG output breaker, DG is at rated speed and voltage, and either the normal or alternate supply breaker is open.
B. PBB-S04, DG is running at rated speed ONLY.
C. the DG output breaker and DG at rated speed and voltage ONLY.
D. PBB-S04, DG is at rated speed and voltage, and both the normal and alternate supply breakers are open.
Answer: D
Given the following plant conditions: Unit 2 is operating at rated power. The A D/G output breaker is closed with the D/G carrying 5000 KW of load paralleled to offsite power. A loss of PKA-M41 occurs due to a bus fault. Which one of the following describes the impact, if any, this has on the D/G?
A. The D/G trips but its output breaker remains closed, causing the diesel to motorize.
B. No impact, since PNA-D25 remains energized.
C. The D/G trips, its output breaker remains closed and PBA-S03 de-energizes.
D. The D/G continues to run at 5000 KW, however output breaker control has been lost.
Answer: A
Given the following conditions: A loss of offsite power Both diesel generators started and carried the loads on their respective PB busses. The “A” DG received a “HIGH PRIORITY TROUBLE” on High Crankcase Pressure alarm. The “B” DG received a “LOW PRIORITY TROUBLE” alarm on Jacket Water Temperature (200°F) off normal. Both DGs continued to run. What will happen when the “START/STOP” control switches on B01 are operated after offsite power has been restored to the class busses?
A. After taking the control switches to start, then stop, the “A” DG will immediately stop, but the “B” DG will continue to run for 5 minutes.
B. When the control switches are taken to start, then stop, both DGs will continue to run for 5 minutes.
C. When the control switches are taken to start, the “B” DG will immediately stop, but the “A” DG will continue to run for 5 minutes.
D. When the control switches are taken to start, then stop, both DGs will immediately stop.
Answer: A
Given the following conditions: A loss of off-site power has occurred. Both Diesel Generators are supplying their respective 4.16 kV buses. After off-site power is restored, the A Diesel generator is taken to override in preparation to parallel it with off-site power. Which of the following fully describes the impact of placing this switch in override?
A. Restores speed and voltage control, places all of the protective system back into operation and satisfies a permissive in the normal supply breaker closing circuit.
B. Places all of the protective system back into operation.
C. Restores speed and voltage control and places all of the protective system back into operation.
D. Restores speed and voltage control.
Answer: D
Which of the following actuation signals will result in an automatic start of DG “A”?
A. CREFAS
B. MSIS
C. FBEVAS
D. AFAS - 2
Answer: D
The Diesel Generator is running in EMERGENCY MODE after a loss of power (LOP). What trips are enabled to protect the Diesel Generator?
A. Low lube oil pressure, overspeed, generator differential.
B. Excess engine vibration, low lube oil pressure, overspeed.
C. Overspeed, reverse power, turbocharger low lube oil pressure.
D. Main bearing high temperature, turbocharger bearing failure, generator differential.
Answer: A
Given the following plant conditions: Unit 1 has tripped from 100% power. A loss of the grid has occurred 3 minutes ago. Both DGs have started and energized their respective buses. The operator adjusts the “A” DG speed control handswitch in the raise direction for a few seconds and then takes his hand off the switch. Based on these conditions, the “A” DG speed will…
A. not increase now but will increase when the DG is taken to override.
B. increase as the handswitch is maniplated.
C. not change as the handswitch is manipulated nor when the DG is taken to override.
D. increase as the handswitch is manipulated and will increase an equal amount when the DG is taken to override.
Answer: A
Given the following plant conditions: Loss of offsite power. Both diesel generators are running with normal voltage and frequency. Normal and alternate power supply breakers for PBB-S04 are open. PBB-S04 is de-energized. A possible reason that PBB-S04 is de-energized would be that ….
A. a DG reverse power alarm/trip has actuated.
B. a fast bus transfer relay failed to actuate.
C. a bus fault has caused an 86 lockout on the normal supply breaker.
D. a synch check relay could not be satisfied because the bus was de-energized.
Answer: C
Unit 1 is operating at rated power when the following simultaneously occurs: Loss of off-site power Large break LOCA. The Train A BOP-ESFAS Load Sequencer fails. Assuming no operator action, what would be the status of PBA-S03 after 3 minutes?
A. de-energized, Diesel Generator A tripped on high temperature.
B. de-energized, Diesel Generator A running unloaded.
C. energized, Diesel Generator A supplying normal ESF loads.
D. energized by Diesel Generator A.
Answer: B
Unit 1 is operating in Mode 1. The fuses for a bus potential transformer (PT) located in on PBA-S03 blow. The PT supplies undervoltage relays 727-1 and 727-5. Assuming this is the only failure, how will the plant respond?
A. The D/G will start and run unloaded while PBA-S03 remains energized from offsite power.
B. PBA-S03 will load shed, the D/G will start and close in on the bus.
C. PBA-S03 will load shed, the D/G will need to be manually started to re-energize the bus.
D. No actuation should occur.
Answer: D
