Preferred AC & DC Flashcards
“LCO 3.8.9 - Distribution Systems - Operating” requirements
Left and right train AC/DC and Preferred AC Bus electrical power distribution systems operable
“LCO 3.8.10 - Distribution Systems - Shutdown” requirements
The necessary portion of AC/DC and Preferred AC Bus electric power systems shall be operable to support equipment required to be operable
What is the required action if in modes 1-4 and 2 or more preferred AC/DC subsystems are inoperable that result in a loss of function?
IMMEDIATELY enter LCO 3.0.3
What is the required action if in mode 5 or 6 or during movement of irradiated fuel assemblies and one or more AC/DC or preferred AC Bus electrical power distribution subsystem are inoperable?
IMMEDIATELY declare associated supported required feature(s) inoperable
OR
IMMEDIATELY
- Stop Core Alterations
- Stop irradiated fuel moves
- Stop positive reactivity additions
- Restore the required AC/DC or Preferred AC subsystems to operable
- Declare associated SDC Train inoperable
“LCO 3.8.7 - Inverters - Operating” requirements
All 4 inverters operable
“LCO 3.8.8 - Inverters - Shutdown” requirements
Inverter for the required train shall be operable
What are the required actions if one or more required inverters are inoperable in mode 5 or 6 or during movement of irradiated fuel assemblies?
IMMEDIATELY declare affected required features inoperable
-OR-
IMMEDIATELY
- Stop Core Alterations
- Stop irradiated fuel moves
- Stop positive reactivity additions
- Restore the required inverters to operable
“LCO 3.8.4 - DC Sources - Operating” requirements
Left and Right train DC power sources operable
DC power source = 1 battery and directly powered charger
“LCO 3.8.5 - DC Sources - Shutdown” requirements
Required DC electric Power Source(s) shall be operable
What are the required actions if one or more DC electrical Power Source(s) is/are inoperable in mode 5 or 6 or during the movement of irradiated fuel assemblies?
IMMEDIATELY declare affected required features inoperable
-OR-
IMMEDIATELY
- Stop Core Alterations
- Stop irradiated fuel moves
- Stop positive reactivity additions
- Restore the required DC Power Source(s) to operable
“LCO 3.8.6 - Battery Cell Parameters” requirements
Battery Cell parameters for the LEFT/Right train Batteries shall be within limits
What are the required actions if one or more Batteries have one or more Battery Cell Parameters not within Category A or B limits?
-Verify Pilot cells electrolyte Level and Float Voltages are within category C limits within 1 hour
AND
-Verify battery cell parameters are within category C limits within 24 hours
How long are the batteries rated for with a loss of offsite power?
4 hours
How long are the batteries rated for in the event of a Cable Spreading Room fire?
Supply D11A/21A for 72 hours to get to cold shutdown
What are the 4 features that ensure 125 VDC power to the EDG in the event of a fire in Cable Spreading Room?
1- Batteries are fused
2- Non Automatic Breaker between battery fuse and bus
3- Distribution panels D11A/21A fused
4- Cabling and Circuits routed to avoid Cable Spreading and opposite trains EDG and switchgear rooms
What are the power supplies to Y-50?
MCC-1 normal
MCC-2 emergency
ABT is normal seeking, meaning that it will automatically transfer to MCC-1 once it’s back for 5 minutes
What can be supplied by the bypass regulator?
1 preferred AC bus at a time (kirk key interlock)
Why do Y-30/40 need to be supplied from the bypass regulator when they are being powered up?
CRD clutch power supply will overload the inverter.
Once Y-30/40 are powered up, they are placed back on their inverters
What is required for the inverters to be considered operable?
Must supply its preferred AC bus
What is required for Y10/20/30/40 to be considered operable?
Considered operable regardless of power source
What causes 125 VDC bus undervoltage/trouble alarm?
- DC Bus Tie breaker open
- PA System under voltage
- Under voltage on Battery
- Under voltage on Bus
What causes 125 VDC bus ground alarm?
3 milliamps ground
What causes preferred AC bus trouble alarm?
Any local alarm on the inverter panel
If no alarm on the inverter panel, then it is high temp
What causes annunciator DC failure alarm?
Internal Electronic Drop out
Trip the turbine or RX if the “B” MFP “Trip Power Light” is out
