RRS, RPCB (Reactor Regulating System, Reactor Power Cut Back) Flashcards
Group 5 CEAs are 140 inches withdrawn with CEDMCS in Auto sequential.
A Control Channel detector fails high.
RRS is selected to the failed detector.
Which of the following describes the RRS Response?
A. No CEA motion will occur due to the AMI being generated.
B. CEAs may insert a few steps due to the Rate of Change circuit sensing a power error.
C. No CEA motion will occur due to the Rate of Change circuit eliminating the effects of the instrument failure.
D. CEAs may attempt to withdraw a few steps due to the Rate of Change circuit sensing a power error.
B. CEAs may insert a few steps due to the Rate of Change circuit sensing a power error.
The loss of which power supply causes the following impact on RRS?
No input to rod control system.
Auto rod control is inoperable.
Loss of input to Pressurizer Level Control System.
A. NNN-D11
B. NNN-D12
C. NNN-D15
D. NNN-D16
B. NNN-D12
The function of the Dropped Rod Contact (DRC) is to…
A. Reset the individual CEA pulse counter.
B. Stop all rod motion in any CEDMCS mode.
C. Reset Reactor Power Cutback (RPCB) flag in COLSS.
D. Initiate an auto reactor trip if two or more rods drop in the core.
A. Reset the individual CEA pulse counter.
Unit is operating at rated power.
Regulating Group 5 has been transferred to the hold bus.
The ‘B’ Main Feed Pump trips.
Which of the following describes the plant response?
A. A normal RPCB will be initiated with all RPCB selected subgroups dropping into the core.
B. The reactor will trip if group 5 is not inserted manually within 40 seconds following the RPCB signal.
C. A RPCB will initiate with group four providing sufficient negative reactivity to offset the reduction of feedwater.
D. A RPCB will initiate but the reactor will trip immediately.
D. A RPCB will initiate but the reactor will trip immediately.
How is a CEA determined to be fully inserted?
A. Lower Group Stop (LGS)
B. CEA Withdrawal Prohibit (CWP)
C. Automatic Motion Inhibit (AMI)
D. Lower Electrical Limit (LEL)
D. Lower Electrical Limit (LEL)
In response to a Continuous Gripper High Voltage alarm, an operator is transferring a subgroup to the hold bus. What operator action actually energizes the upper gripper from the hold bus?
A. Operating the transfer toggle switch.
B. Selecting the appropriate subgroup on the SG/SEL thumbwheel.
C. Pushing the red light above the subgroup number on the hold bus panel.
D. Closing the Individual CEA breakers on the Hold Bus Power Switch Assembly.
A. Operating the transfer toggle switch.
In the CPCs which one of the following describes how the ‘A’ CPC determines where its ‘Target CEAs’ are located?
CEA position information is provided by:
A. RSPT-1 to CPP-1A to CEAC-1A to CPC A
B. RSPT-1 to CPP-1A to CEAC-2A to CPC A
C. RSPT-2 to CPP-1A to CEAC-1A to CPC A
D. RSPT-2 to CPP-1A to CEAC-2A to CPC A
A. RSPT-1 to CPP-1A to CEAC-1A to CPC A
Which of the following conditions will cause a CWP?
A. ASI pre trip
B. Reactor Power Cutback
C. VOPT pre trip
D. Low SG pressure pre trip
B. Reactor Power Cutback
Unit is operating at 100% power.
RRS Tavg is selected to LOOP #2.
TAVG-TREF HI-LO alarms.
Loops Temp Hi alarms.
All Control Systems in their normal Full Power Line-up.
Which of the following would be an immediate consequence of the above indications, if the alarms were caused by an instrument malfunction?
A. Pressurizer spray full on.
B. CEAs driving in.
C. Letdown increasing dramatically.
D. SBCS permissive signal in for all valves.
B. CEAs driving in.
Which one of the following RRS failures would result in an AMI (Automatic Motion Inhibit) and an AWP (Automatic Withdrawal Prohibit)? Assume all switches are in AVERAGE.
A. Tcold fails low.
B. TLI fails high.
C. UIC #1 fails low.
D. Tcold fails high.
D. Tcold fails high.
With the plant operating at 100% power steady state conditions, which of the following describes plant response to a T-hot input failing high when RRS is selected to that channel?
(Assume all controls are in automatic and NO operator action)
RRS will send…
A. An AMI signal to CEDMCS.
B. An AWP signal to CEDMCS due to Tref>Tavg.
C. A signal to CEDMCS causing CEA’s to withdraw.
D. A signal to CEDMCS causing CEA’s to insert.
D. A signal to CEDMCS causing CEA’s to insert.
A large load rejection has resulted in a RPCB.
This load rejection was due to a spurious failure in the EHC system and did NOT result in a turbine trip.
The operating crew desires to pick up load on the Main Turbine.
RPCB has been taken to Test Reset and Auto Actuate Out of Service.
In order to accomplish this, the Secondary Operator must…
A. Reduce turbine load below 15% to clear the SETBACK, then raise load as desired using the LOAD LIMIT potentiometer.
B. Raise the setting of the LOAD LIMIT potentiometer, since the setting of this control follows the SETBACK and RUNBACK down.
C. Simply reduce the LOAD LIMIT potentiometer until the LOAD LIMITING light comes on, then pick up load as necessary.
D. Perform this manipulation with the LOAD SET pushbutton since the LOAD LIMIT potentiometer is out of the circuit until the original (pre-rejection) load has been established.
C. Simply reduce the LOAD Limit potentiometer until the LOAD LIMITING light comes on, then pick up load as necessary.
Unit 1 is operating at rated power. A Main Turbine trip occurs. A RPCB fails to automatic actuate. The Primary Operator IMMEDIATELY depresses the following two push buttons simultaneously: ‘DROP SUBGRPS’ ‘LOSS OF FEEDPUMP’ Comparing the plant response to this action versus how the plant would have responded if the ‘LARGE LOAD REJECT’ pushbutton has been depressed, which of the following is accurate? The actions taken would result in....
A. More CEAs dropped on the RPCB.
B. A larger rise in pressurizer pressure.
C. Fewer CEAs dropped on the RPCB.
D. A smaller rise in pressurizer pressure.
B. A larger rise in pressurizer pressure.
Which one of the following describes how a loss of NNN-D12 effects the operation of the RPCS?
A. A turbine setback and runback will function, the CEAs will not drop.
B. The system will function to drop CEAs and all turbine features will not operate.
C. The system will function to drop CEAs and runback the turbine and the setback feature will not function.
D. The system will function to drop CEAs, the runback feature will not function and the turbine will setback.
D. The system will function to drop CEAs, the runback feature will not function and the turbine will setback.
Unit 1 is operating at rated power with the Reactor Power Cutback System in service.
The TEST/RESET pushbutton is inadvertently pressed and backlit, he presses it again to get the light to go out and doesn’t tell anyone.
Several minutes later, one of the Main Feed Pumps trip.
Which ONE of the following describes the plant response?
A. A normal RPCB will occur.
B. CEAs will drop, but a turbine setback and runback will not occur.
C. A RPCV will not occur.
D. A turbine setback and runback will occur, but the CEAs will not drop.
D. A turbine setback and runback will occur, but the CEAs will not drop.
