DC Electrical/Instrument Electrical Flashcards
250VDC Battery is sized to ensure how many hours during a Loss of Offsite Power (LOOP)?
3 Hrs
250VDC Battery is sized to ensure how many hours during a Station Blackout (SBO)?
4 Hrs
Per T.S. 3.8.4 D (D.C. Sources - Operating), If N Train DC electrical Power subsystem is INOPERABLE,
IMMEDIATELY Declare TDAFW inoperable
Per T.S. 3.8.4 E (D.C. Sources - Operating), If one or both required Unit 2 Train A and Train B electrical power subsystems inoperable,
IMMEDIATELY declare the associated ESW train(s) inoperable
Per T.S. 3.8.5 A (D.C. Sources - Shutdown), if required DC electrical power subsystem inoperable,
IMMEDIATELY Suspend core alterations, suspend fuel movement activities, do not reduce SDM or Boron concentration, initiate action to restore to operable
Per T.S. 3.8.6 F (Battery Parameters), if required Actions and associated Completion Time of Condition A, B, C, D, or E not met
OR
One or more batteries with one or more battery
cells float voltage < 2.07 V and float current > 2 amps
OR
SR 3.8.6.6 not met
IMMEDIATELY Declare associated Battery Inoperable
Per T.S. 3.8.8 A (Inverters - Shutdown ), if one or more required inverters inoperable,
IMMEDIATELY Suspend core alterations, suspend fuel movement activities, do not reduce SDM or Boron concentration, initiate action to restore to operable
If one of the two ground detection lights goes out, which one indicates the ground?
The one that is not lit indicates ground (Could be dimmer than the other as well)
Which 250V DC battery has more capacity than the others and why?
U1 CD Battery, because it has additional loads on it (WDS, Drumming Room, MUP, etc)
Where do the BOP battery Chargers get their power from?
600 V BMC/CMC
Where do the U1 AB battery Chargers get their normal power from?
11A via EZC A - AB Charger 1
11B via EZC B - AB Charger 2
Where do the U1 CD battery Chargers get their normal power from?
11D via EZC D - CD Charger 1
11C via EZC C - CD Charger 2
What is the 250V DC BOP Battery sized for?
2 hrs for Loss of Offsite Power (LOOP)
What load does not strip off the BOP battery? WHY?
Emergency Seal Oil pump to prevent H2 from leaking out of generator (explosion hazard)
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)?
Rise steadily until the design battery capacity is exhausted
CR Lights are powered by which ABT(s)?
ABT 1 and 2
What are ABT’s 1, 2, 3, & 5 normally powered from for both units?
11A South Lighting Transformer
21D North Lighting Transformer
What are ABT’s 1, 2, 3, & 5 back up power supplies for both units are?
11/21C Standby Lighting Transformer
What is the TSC-UPS Battery Charger’s normal power supply?
11C
If the CRID Normal Source is OOS, is the CRID Inverter and/or the CRID Bus Inop?
CRID Inverter is Inop, but the CRID Bus is Operable
If the CRID Bus is powered by CRP-3, is the CRID Bus considered Operable or Inoperable?
CRID Bus is Inoperable when it is powered from CRP-3
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?
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
What describes the function of the “ALTERNATE SOURCE TO LOAD” pushbutton on a CRID inverter?
Electronically transfers the static switch to the alternate source.
What does the IN SYNC light on the CRID Inverter mean?
The alternate power supply is available
Is ABT 4 a “Normal Seeking” or a “Power Seeking” ABT?
Normal Seeking
What are the normal and alternate Power Supplies to the CRID III Inverter?
MCAB 250V DC (Norm)
EZC A via isolimiter (alt)
What are the normal and alternate Power Supplies to the CRID IV Inverter?
MCAB 250V DC (Norm)
EZC B via isolimiter (Alt)
What are the normal and alternate Power Supplies to the CRID I Inverter?
MCCD 250V DC (Norm)
EZC C via isolimiter (Alt)
What are the normal and alternate Power Supplies to the CRID II Inverter?
MCCD 250V DC (Norm)
EZC D via isolimiter (Alt)
After the static switch transfer event clears, what will happen with the CRID inverter?
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
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?
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
In Unit 2, if power was lost to A Train (CD Buses) what will happen with respect to Control Room Power?
CRP 3 would no longer have a power source, nor would control room lighting
What is the Normal power supply to Rod Position Indication?
CRP 3
Norm power supply to TSC-UPS Inverter is?
The TSU-UPS Battery Charger via 11C
On the CCRP inverter, what does it mean when the in sync lights goes out?
Alt source is not available
When can you cross-tie the 250 vDC System?
Modes 5, 6 and Defueld
What does a rectifier do?
Converts AC to DC
What happens if there is a differential sensed on the BMC or CMC Transformer?
Low side and high side breakers open immediately and cross-tie breaker closes.
There is NOT a 30-cycle delay!
