BOP/ESS Electrical Flashcards

1
Q

What is the design capacity of Transformer TR-12-EP-1?

A

Designed to handle an accident in one unit with Containment Spray with Blackout

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2
Q

Why are the EP breakers to T-bus interlocked to prevent closure unless all other feed breakers to that bus are open?

A

EP is 30° out of phase with other grid connections through reserve power and unit auxiliaries

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3
Q

What is the maximum loading for EP per unit?

A

600 amps because of Aluminum cables

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4
Q

What is the SDG output breaker trip coil voltage ?

A

48 VDC

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5
Q

What is the SDG output breaker closing coil voltage?

A

230 VAC

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6
Q

When will 11BCMC automatically close?

A

For a fault located on either TR11BMC or on TR11CMC

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7
Q

When will 11BCMC not automatically close?

A

For a fault located on either bus (11BMC or 11CMC)

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8
Q

What is regarded as the RUN bus?

A

The RUN bus is the supply source

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9
Q

What is regarded as the START bus?

A

The START bus is the bus that will be “started” or connected to the power source

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10
Q

How do you reset a Reserve Feed breaker to the RCP bus?

A

Clear the anti pumping circuit first by:

Open knife switch, trip HEA, or remove control power

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11
Q

How must the EP Feed Breaker to a T bus be closed to supply power from EP which can be supplied from either the 69kV grid or the SDGs ?

A

Manually to a dead bus because EP is 30° out of phase

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12
Q

Why should a T bus power source transfer to/from EP always be a dead bus transfer?

A

Because EP is 30° out of phase

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13
Q

What do you have to do with both power sources lost to U1 Main Transformer cooling?

A
  • Power is reduced to 50% using the RAPID POWER REDUCTION procedure. - If cooling cannot be restored within 2 hours, TRIP the Reactor.
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14
Q

What do you have to do with both power sources lost to U2 Main Transformer cooling?

A

Restore one group immediately or Trip Reactor

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15
Q

What is the backup power supply to the RAT cooling?

A

Step down transformer upstream of RAT

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16
Q

How do you reset the Anti-Pumping Circuit?

A

Take the control switch to trip/reset

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17
Q

Which power supply provides power to TCSN?

A

11/21C

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18
Q

Which power supply provides power to TCSE?

A

11/21D

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19
Q

Both SDGs are sized to support?

A

Sized to power one unit/one train of vital equipment needed to ensure RCS inventory control following a Station Blackout.

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20
Q

SDGs power which RCS Makeup loads?

A

CCP, NESW pump, ESW pump, CCW pump, MDAFW pump, Ctrl Air Compressor

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21
Q

What is the SDG auto start sequence on a loss of EP?

A

-Senses the undervoltage on the 69kV EP bus, waits 150 seconds. - Sends the open signal to the MDS. - Verifies the MDS is open, and then sends the start signal to the SDGs - 1st SDG to reach speed and voltage (25 secs) closes its breaker (12-52-SDGS-2 or 12-52-SDGS-3) onto the dead bus. - The remaining SDG auto synchronizes to the bus and closes its output breaker. - PowerLynx then closes the tie breaker (12-52-SDGS-4) to the station EP bus.

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22
Q

What is meant by QUALIFIED?

A
  • Each offsite circuit must be capable of maintaining rated frequency and voltage and accepting the required loads during an accident. - A qualified offsite circuit consists of all breakers, transformers, switches, interrupting devices, cabling and controls required to transmit power from the offsite transmission network to the onsite class 1E emergency buses
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23
Q

Which Tech Spec states if you have 1 required offsite circuit inoperable, that you must preform SR 3.8.1.1 for required operable offsite circuit within 1 Hr?

A

T.S. 3.8.1 Condition A (AC Sources - Operating)

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24
Q

What does TS 3.8.1 B state? (AC Sources - Operating)

A

If you have 1 required EDG inop, WITHIN 1 hr: - Verify both SDGs are available and perform the lineup SR 3.8.1.1

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25
Q

What does TS 3.8.1 H state? (AC Sources - Operating)

A

If you have 3 or more required AC sources inop, IMMEDIATELY: - Enter L.C.O. 3.0.3

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26
Q

Load Shed is sensed on which buses and at what voltage is it caused by in both units?

A

T11/21A, T11/21B, T11/21C, T11/21D. And it has to sense 94V on Unit 1, and 93V on Unit 2 for 2 sec on 2/3 sensors

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27
Q

What buses is degraded bus voltage sensed on?

A

T11/21A and T11/21D. 2/3 sensors at 113 V

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28
Q

What will happen if your T11A Bus is at 113v for 8 sec?

A

Nothing yet, At 9 seconds, an alarm will come in for degraded bus voltage

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29
Q

What will happen if your T11D Bus is at 113v for 99 sec?

A

It will cause a fast bus transfer to associated RAT

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30
Q

What will happen if you T11A Bus is at 113v for 120 sec?

A

It will trip the A and B RCP Bus x-tie bkrs and cause a load shed. AB EDG will start and load to the T11A and T11B bus and ESF equip will sequence on. Rx does not trip unless RCP bus is lost

31
Q

Which transformer normally provides power to the AB RAT?

A

Transformer 5

32
Q

Which transformer normally provides power to the CD RAT?

A

Transformer 9

33
Q

Which offsite power source must you close in manually and why?

A

EP, because EP is 30° out of phase

34
Q

How long is the wait for the fast bus transfer to RAT if you have a generator trip?

A

Instant

35
Q

How long is the wait for the fast bus transfer to RAT if you have a Turbine trip?

A

30 Sec

36
Q

How long is the wait for the fast bus transfer to RAT if you have a Reactor trip?

A

30 Sec

37
Q

If an overcurrent is sensed on TR11B, what happens first?

A

It trips the low side breaker (11B11)

38
Q

If an overcurrent is sensed on TR11B, what happens after the low side breaker trips and the fault is still sensed on TR11B after 30 cycles?

A

The HEA will activate causing a open signal to go to the RCP Bus tie bkr (T11B1), EP supply bkr (T11B2), and AB EDG supply bkr (T11B4). and if in modes 5 and 6 with 11BD (crosstie) racked in it will close due to a close signal to cross tie B and D 600V buses, An alarm will come in as well in CR

39
Q

If an overcurrent is sensed on TR11A, what happens after the low side breaker trips and the fault is still sensed on TR11A after 30 cycles?

A

Sends an open signal to the low side and high side bkrs, and the close signal to the 11AC crosstie bkr. An alarm will come in as well in CR

40
Q

What train is power for bus AFW and AFWX fed from?

A

Train A

41
Q

What train is power for ELSC and ELSCX fed from?

A

Train B

42
Q

What does T.S. 3.8.9 E state? (Distribution Systems - Operating)

A

If required Train N 250 VDC electrical power distribution subsystem inoperable IMMEDIATELY: Declare Turbine Driven Aux Feed N-Train inoperable

43
Q

What does T.S. 3.8.9 F state? (Distribution Systems - Operating)

A

If one or more required Unit 2 electrical distribution subsystems inoperable IMMEDIATELY: Declare associated ESW train(s) inoperable

44
Q

What does T.S. 3.8.9 G state? (Distribution systems - Operating)

A

If two or more electrical power distribution subsystems inoperable that result in a loss of safety function IMMEDIATELY: Enter L.C.O. 3.0.3

45
Q

What does T.S. 3.8.10 A state? (Distribution Systems - Shutdown)

A

If one or more required AC, DC, or 120 VAC vital bus electrical power distribution subsystems inoperable, IMMEDIATELY: - Declare associated supported required feature(s) inoperable OR - Suspend core alterations, suspend fuel movement activities, do not reduce SDM or Boron concentration, initiate action to restore to operable, and declare RHR subsystems inop

46
Q

What does T.S. 3.8.2 A state? (AC Sources - Shutdown)?

A

If required offsite circuit is inoperable, IMMEDIATELY: - Declare associated supported required feature(s) inoperable - Suspend core alterations, suspend fuel movement activities, do not reduce SDM or Boron concentration, initiate action to restore to operable

47
Q

What does T.S. 3.8.2 B state? (AC Sources - Shutdown)?

A

If required EDG is inoperable, IMMEDIATELY: - Declare associated supported required feature(s) inoperable - Suspend core alterations, suspend fuel movement activities, do not reduce SDM or Boron concentration, initiate action to restore to operable

48
Q

What does Load Conservation do?

A
  1. Trips and locks out selected non-essential vital bus loads (only trips 600 V loads) 2. Prevents restarting any stripped loads until either the 75 second load conservation timer times out or SI is reset after the 60 second SI timer times out. 3. Trips NESW pump
49
Q

What will give you a Load Conservation?

A
  1. LOOP with a SI
  2. LOOP with a CTS Actuation
  3. SI followed by a Load Shed
  4. CTS followed by a Load Shed
50
Q

What is a Load Shed?

A

Under Voltage 2/3 Phases on ANY T-Bus 94 (U2 93) V ind 2 sec

51
Q

What happens on a Load Shed?

A

Trips RCP X-Tie Bkrs and trips Load Shed loads, Starts EDG and sequences loads on.

52
Q

What switch [CR & Yard] configuration must you have to be able to close Generator Output Breakers?

A

Control Switch in Yard and in CR must be in close to be able to close breaker.

53
Q

Where do the Generator Output Breakers get their Control Power from?

A

Powered from 125VDC Yard power

54
Q

Where do SDG and EP bkrs get their control power from?

A

48V DC

55
Q

What powers the SDG output breaker closure?

A

230V AC from SDG output

56
Q

Which ONE of the following correctly identifies the response to a differential (HEA) fault condition on Transformer TR21BMC?

A

Transformer TR21BMC high-side and low-side breakers trip, then the bus 21BMC and bus 21CMC crosstie breaker closes.

57
Q

What is the design capacity of both Supplemental Diesels?

A

Sized to power one unit/one train of vital equipment needed to ensure RCS inventory control following a Station Blackout.

58
Q

Describe the design capacity of EP?

A

EP is designed to handle a Concurrent Blackout in both Units with a CTS in one of those two Units

59
Q

The Supplemental Diesel Generators (SDGs) are used to provide power to?

A

ESW, CCW, CCP, AFW, NESW, and CAC in a SINGLE unit to maintain the core covered during a Station Blackout.

They can also power DIS

60
Q

RAT cooling comes from?

A

11/21 D

61
Q

Unit 2 is in MODE 3 with the Unit 2 East ESW crosstied to Unit 1. The Unit 2 West ESW crosstie is closed. Which TBUS breakers are required to be operable?

A

T21A, T21B, T21C, T21D and T11A

62
Q

The UNIT Differential (HEA) is powered by train?

A

Train B (AB buses)

63
Q

33VED is powered by which train?

A

33VED powered by Train A (CD)

64
Q

OVERALL Differential (HEA) is powered by?

A

Switchyard Cabinet

65
Q

What voltages does the RAT LTC try to maintain (OOS and In Service)

A

Out of Service - 130V

In Service - 120V

66
Q

What is the normal position of breaker BD

A

Open

67
Q

What is the voltage for breaker protection/control for switchyard breakers

A

125 VDC

68
Q

What is backfeed credited for

A

NOT credited for tech specs

IS credited for shutdown risk

69
Q

What measures are taken to prevent a single failure during backfeed operation from resulting in a loss of power to the RCP buses

A

Both generator output breakers are closed.

70
Q

What precautions are taken with regards to the SDG’s when placing EP in service

A

SDG’s are placed in manual to prevent possible overload of SDG if EP is lost, then returns

71
Q

Where is the GSU cooling power supplied from

A

CD 600v busses

72
Q

When the GSU is out of service what must be done with transformer cooling

A

Cooling is removed to extend transformer life

73
Q

Where is UAT cooling supplied from

A

11(21)C

74
Q

Where are the RAT LTC and cooling powered from

A

11(21) D9