Essential Auxiliary Power Distribution System: 4160V Essential, 4160V Blackout, 600V Essential, and 600V Blackout(EPC). Flashcards
What is the purpose of the 4160V Essential Auxiliary Power System?
The 4160V Essential Auxiliary Power System(EPC) provides power to:
- 4160V Essential Motor Loads
- 600V Essential Load Centers through 4160V/600V Essential Load Center Transformers.
- The 4160V Blackout Power System during a loss of normal power, unless the loss of normal power is coupled with a Safety Injection actuation.
What is the purpose of the 4160 Blackout Auxiliary Power System?
The 4160V Blackout Auxiliary Power System supplies power to those non-Class 1E loads that are required or may be required following a loss of offsite power.LOOP).
Essential power is supplied to Nuclear Safety Related Auxiliary Equipment during what plant conditions?
- Normal plant operation
- Hot and Cold Shutdown
- Refueling
- Blackout Conditions
- Safety Injection actuations coupled with a blackout condition.
What is the system designator associated with 4160V Essential Auxiliary Power Distribution?
EPC
What is the system designator associated with 4160V Blackout Auxiliary Power?
ETB
What is the system designator associated with 600V Blackout Auxiliary Power?
ETC
What is the system designator associated with 600V Essential Auxiliary Power?
EPE
Where is normal power to the 4160V Essential Power System supplied from?
Normal power to the 4160V Essential Power System is supplied from the 6.9KV bus through two 6.9KV/4160V auxiliary transformers per train(1ATC and 1ATD).
Where is alternate power to the 4160V Essential Power System supplied from?
Alternate power to the 4160V Essential Power System is supplied from either Unit 1 or Unit 2 6.9KV bus through two 6.9KV/4160V auxiliary transformers(SATA and SATB).
What protection is provided to the 4160 V Essential Power Alternate Supply Transformers(SATA and SATB) to prevent closing both feeder breakers?
There is a Kirk-Key interlock such that only one 6.9KV feeder to SATA/SATB can be racked in at a time. This ensure that Unit 1 and Unit 2 6.9KV power systems are not tied together.
What type of breaker closing operation is associated with a Kirk-Key Interlock?
Whenever a Kirk-Key Interlock is used to connect a bus the breaker closing operation will be a “Dead Bus Transfer.”
What are the designators for the 4160V Essential Power Buses?
- ETA
2. ETB
Where are the breakers for the 4160V Essential Power System controlled from?
All of the breakers are controlled from MC-11 in the Control Room.
What is the normal alignment of the feeder breakers for the Alternate Power Transformers(SATA and SATB)?
SATA
- The Unit 1 Feeder Breaker is normally closed.
- The Unit 2 Feeder Breaker is normally racked out and open.
SATB
- The Unit 1 Feeder Breaker is normally racked out and open.
- The Unit 2 Feeder Breaker is normally closed.
What prevents closing both feeder breakers to the Alternate Power Transformers(SATA and SATB)?
A Kirk-Key Interlock prevents closing both feeder breakers at the same time.