CBerry Test prep exam 1 Flashcards
Weeks 1 and 2
Which non class but essential panels are load shed on SIAS(NOT on LOP)?
- NHN-M19, M-20, M-71, M-72 these panels are tripped on SIAS signal but are not shed on LOP.
What are the meaning of the following breaker indication lights?
Red:
Green:
Bright Green:
White:
Clear:
- Red: Breaker is CLOSED and continuity exists through the breaker trip coil
- Green: Breaker is OPEN and racked in
- Bright Green: Breaker TRIPPED on fault or in TEST position
- White: 86 Lockout is reset and has continuity
- Clear: Breaker closing springs are charged
Why do Train Bravo breakers have remote and local switches?
What position should they always be in?
Are the breaker protection trips still in effect?
- On “B” train breakers for control room fire. Separates the control circuits from the breakers.
- Remote and Local
- Breaker protection trips still will be in effect. (For example “B” CCP Suction Trip)
What is the PS to AFN-P01 including control power and what happens to the pump on a SIAS?
- Supplied by PBA-S03 and trips upon receipt of a SIAS (can be started by overriding)
- Receives control power directly from PK bus (norm) can be aligned to directly downstream from the “A” class battery charger (alt)
What is the PS to the A Normal Chiller?
What happens on a SIAS signal?
- PBA-S03
- Tripped upon receipt of a SIAS (Can be started by overriding)
What must be met to close PB class supply breakers?
- No Lockouts on the bus
- Synch Switch on (If from the CR)
- All other supply breakers open (If from the Switchgear)
- If closing the alternate supply breaker then DG breaker must be open to ensure not cross tying Class DG
What conditions must be met for the DG supply breaker to automatically close
on to PB bus?
- Normal and Alternate Supply breakers open
- NO Lockouts on the BUS (don’t confuse this with a transformer fault on just an ESF transfer fault the DG will start and load the PB Bus)
- DG at rated speed AND voltage
What happens if a lockout condition exists on the PB bus?
What operator actions if any are required?
- DG will start and DG breaker will not close therefore No Spray Pond Flow
- DG must be emergency stopped locally
A class 4160V breaker fully racked down renders adjacent breakers inoperable.
What must be done to prevent this?
- Must rack the breaker up from the floor ~ 1” OR
- Remove the breaker from the cubicle OR
- Use seismic restraints
Do class LC breakers have KKI’s?
Why or why not?
- NO
- Only 1 LC per each 4160 breaker
What will follow a trip of the class LC overcurrent relay?
- overcurrent relay trips BOTH:
- The LC Main Feeder breaker (B2)
- The 4.16 kV supply breaker
How does one reset class LC breakers in a lockout condition?
- From the control room by taking the switch to the trip position
- Locally at the breaker
What Undervoltage relays and trips exist on PB breakers?
-
4: Under Voltage relays @ <75%
- 727-1, 727-2, 727-3, 727-4
-
4: 90% degraded 30 sec delay
- 727-5, 727-6, 727-7, 727-8
-
2 of 4 relays needed to actuate a LOP
- But there is a catch………if the 2 relays are separated by 4 for example 727-1 & 727-5 or 727-2 & 727-6 they won’t cause a LOP
What are the operating characteristics of the controls associated with
NAN-S05 and NAN-S06?
- Controls are HARDWIRED
- Indications are MULTIPLEXED
- This means breaker control may still be available while breaker positions are not indicating. Or Vice Versa
What conditions will result in a WRF load shed?
Why?
- Degraded voltage as measured on (NAN-S05/S06 in UNIT 1)
- While simultaneously receiving a SIAS signal
- WRF breakers will open de-energizing WRF to prevent double sequencing
What are the requirements for a fast bus transfer on NAN-S01 and NAN-S02 from the UAT to NAN-S03 and NAN-S04?
- BUS XFR SWITCH must be in AUTO
- Generator Trip must have occurred
- Early “B” contact energized
- Synch Check is SAT
- NO BUS LOCKOUT
- Voltage is available on NAN-S03/S04
WHen would a coastdown trip occur?
What happens regarding NAN-S01 and NAN-S02?
- Coast down trip occurs:
- When the generator trips (On Reverse Power) concurrent with a loss of off-site power (Loss of Off-site power as sensed by NAN-S03/S04 voltage).
- Reactor Trip is also required
- When this happens there is nowhere for NAN-S01/S02 to receive power
- NAN-S01/S02 stay aligned to the UAT and sheds all breakers except RCP breakers
- Keeps RCPs running maintaining flow through the core
What are the conditions that would result in a fast transfer of NBN-S01 and NBN-S02 to the other train?
What loss would prevent this fast transfer from occuring?
- Normal Service Transformer fault
- Normal Supply Breaker Open
- Voltage sensed on opposite bus
- Synch Check SAT
- NO Lockout on either bus
- Loss of NKN-D41/D42 result in failure of fast bus transfer
Describe the synch switch positions and operational characteristics associated with a manual transfer of NBN-S01 NBN-S02?
-
3 position SYNC switch for the x-tie breaker:
- S01 XFER S02 XFER OFF
- MUST ALIGN THIS SWITCH TO THE BUS BEING TRANSFERRED
- After the Synch switch is properly aligned the x-tie breaker is taken to close. When the switch is released after the breaker is closed the switch will spring return to normal………when it goes back to normal it will open the normal supply breaker for the bus now being powered from the opposite XFMR
- For example when the X-tie breaker is closed with the synch switch in S02 XFER then when the breaker control switch is released NBN-S02 normal supply breaker will open.
- IF THIS SYNCH SWITCH IS MISALIGNED THEN THE WRONG SUPPLY BREAKER WILL GO OPEN CAUSING A LOSS OF BOTH BUSSES
- So to sum it up the synch switch position controls which normal supply breaker opens when the X-tie breaker is closed. So if you go through the OFF position after cross tying properly then that supply breaker will also open.
Do the Non class load centers operate with KKI’s?
Why or why not?
Yes.
- Prevents damaging the disconnect if it was operated under load.
Where are the nonclass MCC’s control power supplied from?
- MCC Control Power supplied by it’s on XFMR within the MCC bucket.
How many detector assy’s and what are their configuration, height position in the core?
-
61 incore detector assemblies
- Each assemble has 5 self-powered rhodium detectors
- Detectors are at 10, 30, 50, 70, and 90% of active core height
- Each assemble has 5 self-powered rhodium detectors
Why is there a full length background detector included in the ICI’s?
- It is assumed that part of the overall signal generated is not related to neutron flux at the detector, but to noise or background
- A full length signal wire is run alongside the detectors to measure current produced by the wire this signal is subtracted from the detector signal to determine true signal level.
What is the range of the included CET, what is it’s position in the detector assy, and how accurately does it read at normal power?
-
Process range: 200-2300F
- Does not read accurately at power due to neutron flux
What is the design pressure of the RCS?
What is the maximum pressure as stated in the SL’s?
What is the basis for this pressure?
- Design pressure: 2500 psia
- SL maximum pressure: 2750 psia
- allows not more than 10% increase above design pressure due to accidents and AOO’s. Protected by Safety valves set at 2475 psia.
Why do flow restrictors exist in the sample lines and instrumentation lines in the RCS?
- limits the loss of coolant rate to within the capacity of the charging pumps should they rupture
Where are the sample points in the RCS?
- LOOP 1 Hot leg
- Surge Line
- PZR steam space
Where can the RC Gas Vent System be discharged to?
What happens if RCB-HV-109 is exposed to a sudden increase in downstream pressure?
- Can be directed to EITHER containment or RDT via Solenoid valves
- RCB-HV-109 will be damaged if exposed to a sudden increase in downstream pressure if the upstream side isn’t at RCS pressure.
Where is the Core Support Barrel and what is it’s function?
- Suspended from a ledge on the inside surface of the vessel closure flange
- Supports vessel internals including fuel assemblies and allows for core expansion
Describe the RX Vessel flow path?
- Cold Leg => around support barrel => flow skirt => lower plenum => fuel rods => outlet plenum => hot leg
How many CEA’s are there and what are their configuration?
- 89 total
- Shutdown CEAs are all 12 finger
- Groups 4 & 5 are all 4 finger
How is the Rx vessel flange sealed against leakage?
- Sealed by: two self-energized silver plated o-rings
- Both o-rings have a 100% capacity
- High pressure seal alarm @ 1500 psia
What is the motive force for PZR main spray?
What is the spray bypass flow and why have it?
- Spray force is RCP D/P
- 1.5 gpm bypass flow to minimize thermal shock
Concerning the Safety Valves:
What is the setpoint?
Why?
How is flow verified to exist?
- Installed on top of the PZR
- Lift @ ~ 2475 PSIA
- Ensures that the safety limit of 2750 psia isn’t exceeded during:
- Loss of condenser vacuum
- Other Loss of RCS heat removal events
- Each safety valve has acoustic monitors powered by NNN-D11
- Board indication is 0%, 9%, 100%
At what temperatures and RCP combinations are allowed to operate the RCPs?
Why?
Why is there a flywheel at the upper bearing?
-
CAN ONLY RUN 2 RCPS ≤ 200F, CAN RUN 3 RCPS >200F ≤ 500F
- This prevents core lift due to higher density of cooler water
- Equipped with a flywheel on the upper bearing that allows for a longer pump coastdown on a loss of power to the pump. (Ensures adequate heat removal during a LOOP)
When will an RCP oil lift pump AUTO start and under what conditions will it auto stop?
- When in AUTO the lift oil pump auto starts when a RCP is stopped and MUST be stopped manually
- When a RCP starts the pump de-energizes after 2 min
What is the RCP start criteria?
-
RCP Start criteria
- (B) Seal Bleed-off valve fully open
- (O) Lift Oil
- (N) NC Flow is sufficient
- (E) No electrical fault
In what condition are the RCP Seal cooler isolation valves normally kept?
- HP Seal cooler valves are normally OPEN w/ Power Removed
What are the power supplies to RWLIS?
How is level compensated for SD cooling flow?
WHat are the NR and WR measuring points?
- Powered from NNN-D11 and NNN-D12
- Flow compensated by:
- Selecting the switch to the running side of SDC
- Narrow Range:
- 40” Range measured from the bottom of the hot leg to 40” above it
- Wide Range:
- 485” Range measured from the bottom of the hot leg to 485” (the top of the refueling pool)
How long can each battery independently supply at full loading above minimum bus voltage?
- Each battery can independently supply 2 hours of full loading without the charger and still maintain minimum bus voltage. (Less load will give more time)
Is PK grounded or ungrounded?
- PK is ungrounded
- Ground detector installed
- Alarms in the control room and has a white light locally.
- Ground detector installed
What are the control power and field flashing ps’s to the DG?
What happens on a loss control power prior to or following a DG start?
- PKA-D21 (“A” DG)
- PKB-D22 (“B” BG)
- If PK is lost prior to DG start the DG WILL NOT start.
- If PK is lost after DG start then the DG CAN be tripped but output breaker WILL NOT open!
What mechanical interlock exists on the PK battery chargers?
- Prevents having a swing charger tied to both busses.
- For example AC swing charger will never power both PKA and PKC
What alarms exist in the control room concerning teh PK battery chargers and battery breakers?
- Whenever a normal charger AC or DC breakers are open brings in an alarm in the control room
- When a battery breaker is open the control room will receive an alarm
- Remember you must lose a battery and a charger to drop a PK bus
What are the conditions of the PKC and PKD battery chargers concerning large loads such as SDC DC powered suction valves?
- PKC and PKD battery chargers do not have enough capacity to solely carry large loads
-
Battery must be connected to the bus when Operating SIC-UV-653 or SID-UV-654 (SDC DC Powered Suction Valves)
- Note: It doesn’t say the charger has to be connected to the bus
-
Battery must be connected to the bus when Operating SIC-UV-653 or SID-UV-654 (SDC DC Powered Suction Valves)
What happens on a loss of PK bus with regards to the RTSG breakers?
ADV’s?
-
Losing a PK bus causes it’s associated RTSG breaker to open
- For a Rx Trip to occur you would need a loss of two PK buses and if it were only two the combination could not be PKA and PKC or PKB or PKD due to CEDMCS power distribution
- 1 PK bus causes 2 ADV’s not to work.
Which battery chargers and breakers have transfer switches?
What are their positions?
-
Transfer Switches (Local/ Local & Remote)
- Battery Chargers B, D, & BD
- A, B & D Battery Breakers
Is PN an ungrounded system?
Yes.