DC Electrical/Instrument Electrical

Question 1

250VDC Battery is sized to ensure how many hours during a Loss of Offsite Power (LOOP)?

Answer 1

3 Hrs

Question 2

250VDC Battery is sized to ensure how many hours during a Station Blackout (SBO)?

Answer 2

4 Hrs

Question 3

If one of the two ground detection lights goes out, which one indicates the ground?

Answer 3

The one that is not lit indicates ground (Could be dimmer than the other as well)

Question 4

Which 250V DC battery has more capacity than the others and why?

Answer 4

U1 CD Battery, because it has additional loads on it (WDS, Drumming Room, MUP, etc)

Question 5

Where do the BOP battery Chargers get their power from?

Answer 5

600 V BMC/CMC

Question 6

What is the 250V DC BOP Battery sized for?

Answer 6

2 hrs for Loss of Offsite Power (LOOP)

Question 7

What load does not strip off the BOP battery? WHY?

Answer 7

Emergency Seal Oil pump to prevent H2 from leaking out of generator (explosion hazard)

Question 8

If a battery is supplying loads without a charger connected, and the equipment loaded on battery does not change, what will happen to current draw (amps) as the battery is expended (voltage lowers)?

Answer 8

Rise steadily until the design battery capacity is exhausted

Question 9

CR Lights are powered by which ABT(s)?

Answer 9

ABT 1 and 2

Question 10

What are ABT’s 1, 2, 3, & 5 normally powered from for both units?

Answer 10

11A South Lighting Transformer
21D North Lighting Transformer

Question 11

What are ABT’s 1, 2, 3, & 5 back up power supplies for both units are?

Answer 11

11/21C Standby Lighting Transformer

Question 12

What is the TSC-UPS Battery Charger’s normal power supply?

Answer 12

11C

Question 13

If the CRID Normal Source is OOS, is the CRID Inverter and/or the CRID Bus Inop?

Answer 13

CRID Inverter is Inop, but the CRID Bus is Operable

Question 14

If the CRID Bus is powered by CRP-3, is the CRID Bus considered Operable or Inoperable?

Answer 14

CRID Bus is Inoperable when it is powered from CRP-3

Question 15

Per 3.8.8 - Inverters Shutdown, If CRID 1 and 2 inverters are powered from their alternate power source with CRID 3 distribution powered from CRP-3 in Mode 5, is an entry into a Technical Specifications LCO required?

Answer 15

YES, OPERABILITY of the inverters requires that the 120 VAC vital bus be powered by the inverter. CRP-3 powers the CRID directly.

IMMEDIATELY Suspend core alterations, suspend fuel movement activities, do not reduce SDM or Boron concentration, initiate action to restore to operable

Question 16

What describes the function of the “ALTERNATE SOURCE TO LOAD” pushbutton on a CRID inverter?

Answer 16

Electronically transfers the static switch to the alternate source.

Question 17

What does the IN SYNC light on the CRID Inverter mean?

Answer 17

The alternate power supply is available

Question 18

Is ABT 4 a “Normal Seeking” or a “Power Seeking” ABT?

Answer 18

Normal Seeking

Question 19

After the static switch transfer event clears, what will happen with the CRID inverter?

Answer 19

After the static switch transfer event clears, and all system parameters are normal for thirty seconds, the static switch automatically re-transfers the load to normal source without interruption

Question 20

The CRID Inverter has already swapped to its alt source once and transfer back to the normal source once. If the inverter was to lose power again and transfer to its alt source, what will happen?

Answer 20

The static transfer switch will not attempt to transfer back to the normal 250vDC power due to it being locked out on alt source until it is manually reset

Question 21

In Unit 2, if power was lost to A Train (CD Buses) what will happen with respect to Control Room Power?

Answer 21

CRP 3 would no longer have a power source, nor would control room lighting

Question 22

What is the Normal power supply to Rod Position Indication?

Answer 22

CRP 3

Question 23

Norm power supply to TSC-UPS Inverter is?

Answer 23

The TSU-UPS Battery Charger via 11C

Question 24

On the CCRP inverter, what does it mean when the in sync lights goes out?

Answer 24

Alt source is not available

Question 25

What does a rectifier do?

Answer 25

Converts AC to DC

Question 26

What happens if there is a differential sensed on the BMC or CMC Transformer?

Answer 26

Low side and high side breakers open immediately and cross-tie breaker closes.

There is NOT a 30-cycle delay!