General Flashcards
Reactor coolant pumps power supply
13.8 kV
Circ water pump power supply
13.8 kava
Power supplied to load centers
13.8 kV
Plant cooling water pumps (PW)
4160V non class
Power supply to nuclear cooling water pumps (NC)
Non class 4160 V
Power supply to turbine cooling water (TC)
Non class 4160 V
Power supply to extraction/heater drain pumps (ED)
Non class 4160 V (b S01, a S02)
Power supply to condensate pumps (CD)
4160 V non class (a&b S01, c S02)
Power supply to normal chiller (WC)
Non class 4160 V
HPSI pump power supply
4160 V class power
LPSI pump power supply
4160 V class
Containment spray pump power supply
4160 class
Power supply to class load center
Class 4160 V
Power supply to essential cooling water (EW)
Class 4160 V
Power supply to essential chilled water pumps (EC)
Class 4160 V
Power supply to spray ponds (SP)
Class 4160 V
Power supply to AFN valve
Class 4160 V off “a” bus
What voltage do the SBOGs generate
13.8kV
Where do the SBOGs tie in
S07 tie in breaker and supplies power via ESF
What items are the only things that supply their own control power?
480 V MCCs
When a MCC is poem does the control have indication?
No
If a 480 V MCC is open does it have control power?
No
What supplies normal control power to 13.8 & 4.16kV breakers and 480 V load centers?
125 Vdc for class and non class respectively.
What is a SIAS load shed
Sheds non safety related loads from 4160 V buses. Must be manually restored.
What causes an alternate supply breaker to trip?
If electric load shed signal is received from the control room
A fault occurs on the related ESF transformer
86 lockout
What causes the normal supply breaker to trip?
Electric load shed signal from the control room
Alternate supply breaker is closed from the control room on B01
86 lockout
Class 4160 automatic safety features
Degraded voltage- <75% instantaneously.
What is a blackout
Loss of all AC power
What is a loss of offsite power (LOOP)
Loss of NAN-S01&S02
Must be both.
What is a loss of power (LOP)
Loss of either PBB-S04 or PBA-S03
Describe a 4160 V lockout relay
Can be rest from CR SEIS alarm in CR Brighter than green light Prevents DG from closing on faulted bus A trip also prevents closing other supply breakers
What safety feature does the B train 4160V switchgear have that makes it special
Allows the operator to shutdown and isolate from the control room in case of control room fire
What are the ESF transformer indications
Hot oil temp-top of trx
Hot spot indicator-measures high voltage winding temp
Level indicator- measures tank oil level
ESF phase and ground over current
Causes a lockout if excessive current is detected in the neutral-ground on secondary side of transformer winding.
Also trips a lockout relay on NAN-S03, PBA-S03, PBB-S04
What is an ESF transformer differential
Monitors current leaving NAN-S03 and checks for a difference between PBA-S03 & PBB-S04.
A difference trips a lockout relay and opens the breakers mentioned.
ESF automatic transfer relay
Monitors cooling power supply and initiates auto transfer to alternate power upon loss of normal aux power
Initiates an alarm locally and in the control room.
What is BOP ESFAS
Balance of plant engineered safety feature actuation system
(Starts DG in emergencies)
(Sequences loads and opens proper valves in emer situation)
How does the PB system respond to a loss of it’s associated support systems?
Loss of 4160 V bus= DG unavailability, even from opposite train
If dc control power lost, must be manually operated and no trip protection or CR indication available.
Causes loss of one train and relies on one train for safe shutdown
What are the automatic features associated with the PG/PH systems?
SIAS load shed panels
What are the ESF transformer indications?
Hot oil temperature
Hot spot temp indicator
Liquid level indicator
ESF service transformer protection- sudden pressure relay
Detects rapid pressure increase in transformer caused by pressure increase
Trips lockout relay (trips transformers high side breaker)
What are the three positions of class load center circuit breakers?
Operating
Test
Withdrawn
What do load centers do?
They transform 4160 V to 480V for distribution throughout the plant.
Naturally cooled until temp>180*C then forced air natural circ
Why do non class 480 V load centers have a KIRK key interlock but not class 480 V?
This provides a method for working on a single load center while still supplying power to other MCCs
What’s the purpose, operation and location of the class load center feeder breakers?
Supplies power to the LC 480 V
On secondary side of the 4160/480 V bus
Breaker trip causes a lockout that can be reset locally and from the control room.
What is the cooling method for the unit aux transformer
Forced air natural circulation
Single bank of cooling with one backup
What are the class 480V MCC breaker positions?
On
Off
Tripped (only occurs on ground fault)
What is the method for cooling for the main transformer?
Forced oil and air
First bank starts when energized
Second @70C
Third @75C
