Systems Comp Study Sesh Flashcards
Explain the SDG sequence.
Senses UV
Opens MDS
Starts SDGs
First up to speed closes in
Second diesel auto synchs
Tie Breaker closes
If there is a differential on the BMC/CMC Transformer, how does the protective scheme work?
Both high and low side opens at the same time, then the creoss tie will close without any delay
How does the Degraded Bus Voltage work?
Sensed on A & D T Buses
9 sec delay for alarm. If SI or LoLo SG, then loadshed
+90 seconds of correction before Fast transfer to RATs
+21 seconds of RATs trying to correct before Load Shed
If sensed on A or D, that whole train will be loadshed
What is the normal source of power to the CRIDs?
250 vDC
What is the alternate power source to the CRIDs?
600 vAC
Which 600 v bus goes with which CRID?
C -1
D -2
A - 3
B - 4
What does the In Synch light being lit on the CRID tell you?
Alternate source is available
What does the ALT Source to Load PB on the CRID do?
electronically transfers on static switch to alternate source of power
How does the Auto Retransfer Lockout work on the CRID?
After transfer to the alternate load, if the event clears, and is normal for 30 seconds, the statis switch auto transfers the load back to the normal source. If a 2nd transfer to alt source occurs before the autoretransfer capability is reset manually, the alternate source supplies the load. The static transfer switch locks out on alternate source until reset.
What does a rectifier do?
Changes AC to DC
What normally powers the batteries?
Battery Chargers from 600 vAC
What is the order of starts with time delays for all the fire pumps?
Motor/Electric 140 psi for 2 secs
East Diesel 130 psi for 15 secs
West Diesel 120 psi for 25 secs
What are the SDGs sized for?
1 Unit, 1 Train of RCS Inventory Control
How does the LoadShed Scheme work?
Sensed on EACH T Bus at 94 (93) Volts and lowering for 2 seconds. Loadsheds that one bus
If there is a differential on the B/C bus 600 v transformer, will that bus be powered from the EDG?
NO. No high side disconnect, so entire bus is dropped
Who has command function?
Shift Manager
What is the fire protection provided to both Units CRCVs?
Auto Halon
Manual CO2
Auto Water for Unit 2 Only
Define the Modes of Operation Per Tech Specs
Mode 1 - Keff Greater than or equal to 0.99 and Rated Thermal Power > 5%
Mode 2- Keff Greater than or equal to 0.99 and Rated Thermal Power less than or equal to 5%
Mode 3 - Keff < 0.99 and RCS Tavg Greater than or equal to 350 degrees
Mode 4 - Keff < 0.99 and RCS Tavg btween 200 and 350 degrees
Mode 5 - Keff < 0.99 and RCS Tavg less than or equal to 200 degrees
What is the pressure safety limit?
2735 psi
If the safety limit for pressure is violated, what must be done?
Modes 1&2, Be in Mode 3 and restore within 1 hour
Modes 3-5, Restore within 5 mins
Whats the purpose of the safety limits in section 2 of Tech Specs?
Protect from fuel damage and maintain vessel integrity.
Who is responsible for overall safe operations?
Plant Manager
What are the Tech Spec credited sources for Offsite Power?
RATs and EP
SDGs are NOT credited
What is the normal Split Bus alignment?
BXfmr 5 to Train B
Xfmr 9 to Train A
BD is Open
What is the purpose of Xfmr 4?
Connects the 345 and 765 kV Yards
What are the requirements regarding shift staffing?
May be less than minimum for less than or equal to 2 hours for unexpected absence, provided immediate action is take to restore
If a surveillance is MISSED, what must be done?
Performed within 24 hours or the normal surveillance frequency, whichever is GREATER
Can Grace be applied to the first performance of an EIS?
Nope! Only subsequent
How much grace is allowed for surveillances?
25%
What is the maximum extension time for a TS Entry?
additional 24 hours from the first inoperability, without making the second INOP go greater than the original spec time
What supplies power to the pressurizer heaters?
T Busses A & D
What causes a load conservation?
LOOP + SI/CTS
How are the Plant Batteries Sized?
4 hours for SBO
What are the trips available to the EDGs during a SI or LOOP?
Generator Phase Differntial
Electronic Overspeed at 110%
Manual Push Button
If using the control switch, must HOLD it to keep if from restarting.
What is the minimum pressure in the EDG Air Receiver?
190 psi
What is the minimum volume of the Diesel FOST? Good for how long?
> 46,000 gallons good for 1 EDG at full load for 7 days
What happens if the electronic governor for the EDG fails high?
speed rises and machine will be controlled by the mechanical governor (if not paralleled, otheriwse speed droop takes over and grid maintains speed)
If control air is lost, will the EDG continue to run / start?
No! Throttle Control Cylinder will be extended, stopping fuel
where is the EDG field flash powered from?
1 kV interter until 80% speed
When do the LO upper valve gears open for the EDGs?
ON the EDG start signal (95% run relay)
What is the Circ Water Pump Auto Start?
failure of running pump, if the control switch is in AUTO
What is a Circ Water Pump Trip?
Undervoltage on associated 4 kV Bus
When does the circ water pump discharge valve auto open?
on auto pump start only, NOT manual
What are the power supplies to the CW Pumps?
1 - D
2 - A
3 - B
4 -C
RCP Buses
What does De-Ice Look like?
WMO-30 is closed
WMO-16 or WMO-26 Open
done slowly to prevent debris agitation
Which valves are used if the center intake is crushed?
WMO-17/27
What are the Tech Spec Pressure Limits for containment?
-1.5 psig to +0.3 psig
What are the tech spec containment temperature limits?
Upper = 60-100 degress
Lower = 60-120 degrees
What are the power supplies to SFP Pumps?
North = 11C
South = 21C
What will isolate CCW to the SFP Hx?
Phase A
If there is a rupture on the suction piping for the SFP Pump, what is the lowest the water will drain below the normal level?
19 inches
Will X-tie through SFP purification piping prevent boiling?
No! Just delays it
Per the bases, why is there greater than 23 feet of water above the fuel?
Iodine Decon Factor
What are the NESW Pump Auto Starts?
Load Shed
SI
Low Pressure 55 (60) psi in auto
*For pressure, it is unit specific. A low pressure on Unit 1 N NESW will start the Unit 1 S NESW. It will not autostart any Unit 2 pumps
What are the ESW Pump auto starts?
SI - Either Unit, Train Specific
Load Shed
Low Header Pressure of 40 psig in AUTO
If the EDG starts but power is lost to the normal cooling valve is lost (A/D did not repower ), will the EDG have cooling?
Manual from Opposite train is available, but without Operator Action, NO
What happens to ESW from CCW Hx on a SI?
Throttles to ~5,000 gpm
What are the auto starts of the CCW Pumps?
SI
Load Shed
Low pressure on running pump discharge of 80 psi if in AUTO
What is the makeup to the CCW Surge Tank?
MANUAL Demin Water
What happens on a high rad in the CCW Surge Tank?
Vent Valve (CRV-412) goes closed
What happense to the CCW Hx Outlet valves on a SI?
They go Full Open
What happens to the CCW Outlets from RHR Hx on a SI?
Throttles to ~3500 gpm
What manual action must be done on a Phase B?
RCPs must be tripped because CCW has been isolated to the thermal barrier and MACs
What happens on a Low Low Glycol Expansion Tank LeveL?
Outside containment isolation valves VCR-10 and 20 close
Glycol Expansion Tank Outlet Valves VSO-20 and 21 Close
Which Containment Fans trip on a Phase B?
CLVs
CRDMs
Prssurizer Fans
Rx Cavity Fans
What happens if an odd numbered radiation monitor receives a High Rad Signal? (ie. 1300 or 2300)
Inside Containment Valves close and Instrument Room Purge Supply Fan Trips
What happens if an even numbered radiation monitor receives a High Rad Signal? (ie. 1400 or 2400)
Outside containment isolation valves close and all fans other than instrument room purge supply trip
Where do CEQ Fans take suction?
SG Enclosures
Pzr Doghouse
CLV Fan Rooms
Instrument Room
What are the auto starts of the AES Fans?
ECCS Pump Starts
SI
(Train Specific)
Train Specific
What accident condition will place the AES Fan in charcoal filter mode?
Phase B
Where do AES Fans take suction from?
Vestibule
CTS and RHR Hx Roms
SI, RHR, CCP and CTS Pump Rooms
When moving fuel, what happens on a High Rad on RRC-330?
Fuel Supply Fans TRIP
Filter Bypass Damper gets a close signal
Charcoal filter inlet face dampers gets an open signal
If air is lost to VRV-315/325 for the control room chilers, how does it fail?
full flow to chillers
How do the control room dampers fail on a CRCV fire?
1/1A Closed
2/2A Part Open
3 Closed
Control Room Pressurization Fan also auto starts.
How do the control room dampers fail on a Hi Rad Alarm?
1/1A Closed
2/2A Part Open
3 Open
How do the control room dampers fail on a SI?
1/1A Closed
2/2A Part Open
3 Open
How are the control room dampers aligned on a toxic gas?
All dampers are manually closed!
When cross-tying the 600 vAC buses 11B and 11C, how is it done?
Break before Make. Crosstie has to see the normal feeder breaker open. These come from the T buses, and may be out of phase, depending on the power supply to the T bus.
When cross-tying the 600 vAC buses BMC and CMC, how is it done?
Make before Break because they come from the RCP buses and will ALWAYS be in phase.
What is the purpose of the volts over herts alarm?
Telling operators that there is too much excitation which could lead to damage due to voltage. Will cause a trip if the turbine is not paralleled.
What voltage does the main generator exciter produce?
3 phase AC that gets rectified and sent to the main generator.
Where is 11PHA and 11PHC powered from?
11PHA - T11A
11PHC - T11D
What is the power supply to the logic cabinets for Rod Control?
120 vAC which was stepped down from the 260 vAC from the MG Set Output.
What powers the CRIDs on a loss of all AC?
the 250 vDC Batteries
What powers the slave relays for Train A?
CRID 1 (120 vAC)
What powers the slave relays for Train B?
CRID 4 (120 vAC)
What is the DIRECT result of pushing the emergency trip push botton?
Unit HEA trips
the button is in the UNIT
What happens if the excitation breaker to the generator opens at power?
Excitation is lost and the HEAs will trip
What prevents you from opening the exciter field breaker at power?
Interlocked with the generator output breaker.
When paralleling the EDG, how do you prevent becoming a load on the grid?
By making sure EDG frequency is slightly higer than the grid. (Slow in the fast direction)
What are the 3 parameters on the Generator Capability Curve?
Hydrogen Pressure
Vars
Megawatts
What is the purpose of the Thyristor / Converter?
to turn AC into DC
(fancy names for rectifiers)
What happens if the TSCUPS battery is lost?
Nothing. It is normally supplied by 11C
Where are the AB/CD battery chargers normally supplied from?
600v Vital Buses
What happens to a pump if 250 vDC control power is lost?
Pump cannot be operated remotedly. Protective trips are also unavailable.
Where does the voltage regulator sense voltage?
At the output of the main generator
How can you lower amperage to lessen heat if bus duct cooling temperature is a concern?
Get closer to Unity. So, in MVARs are in, raise voltage. If MVARS are out, lower voltage.
Where are the Generator output breakers powered from?
125 vDC Yard Power
Unit 1 is from 345 kV yard
Unit 2 is from 765 kV yard
How is the anti-pumping circuit cleared?
Taking control switch to TRIP
How does the protection scheme for BMC/CMC work if there is a high current sensed on the transformer?
Transformer output breaker (low side) opens
If the high current remains, then it is faulted and the HEA will trip
If no longer sensed, then the high side breaker will open and another signal is sent to reopen the low side.
11BCMC will close to repower the bus
How do the master valves for CO2 fail on a loss of DC?
OPEN
What is the maximum number of fire pumps expected to be running at any time?
2! For a unit 1 main transformer fire.
How do the selector valves for fail on a loss of DC?
CLOSED
If the invidividual selector switch is in isolate for CO2, what protection is available?
No automatic. Only manual.
How does CO2 put out a fire?
It displaces Oxygen
Can the Before and After pump provide all the LO needed for the EDG while it is running?
NO! Engine/Shaft drive pump is required.
What trips are available to the EDG if 250 vDC is lost?
Worthington manual fuel valve
Mechanical Overspeed at 112% of 514 RPMs
Will the EDG stay running if the 250 vDC is lost?
Yep!
What is the design of the fuel oil transfer pumps?
Both will start on low level and cycle off and on to maintain level
If there is a hole in the downstream piping of the starting air receiver, will the EDG still start?
Yes! Only one starting air valve is needed, but the crosstie downstream gets air to all of the cylinders
What are the indication that the field flash did not work?
No field volts
Why is the EDG INOP during surveillance testing?
A loadshed signal will not be generated.
What are the loads on the EDG 1 kV Inverter?
Field Flash Power
Local / Remote Control Transfer Relays
Dynalco Speed Transmitters
Bearing Temp Monitor (SG 40)
How do the EDG Starting air valves fail on a loss of control air?
As Is
What will cause the EDG ventilation to start?
EDG Start or 95 degree room Temp
What can cause the EDG supply/exhaust fans to stop?
CO2 Actuation, 70 degree room temperature or 30 minutes after EDG is shutdown
What are the 3 parts to the Hi-Storm Dry Cask System?
- Hi-Storm Overpack
- MPC
- Hi-TRAC Transfer
What main purpose does the MPC serve?
Confinement boudnary
Why is helium used in the MPC?
Cooling, Inert atmosphere to prevent chemical reaction with fuel cladding and leak detection.
What is the purpose of the COC?
Approves the design of the dry cask storage system.
What produces most of the heat in the SFP ?
Fission products
What is a support function of the SFP System?
Used to clean up the RWST
How does a NESW pump respond to a loadshed with a CTS?
The pump will restart with the loadshed and then trip
What happens to the NESW system on a Load Conservation?
LO Cooler WMOs close
NESW closes to CUVs, CIRs and MACS
Unit cross tie to the misc hder closes
What supplies control air to the strainer backwash for ESW?
Unit 1
What supplies a backup water supply to the Aux Feed Pumps?
East ESW Header = MDAFPs
West ESW Header = TDAFPs
What would happen if ESW was lost to the CRAC?
They may trip without a Heatsink
What does Containment Chill water provide cooling for?
CLVs, CUVs and CIRs
RCP MACs
SG BD Hx
What is the purpose of the divider barrier seal?
Prevents flow of steam and air from bypassing the ice condenser