CEDMCS, CPC, CEAC, COLSS (Core Protection Calculator, Control Element Assembly Calculator, Core Operating Limit Safety System)

Question 1

Which of the following will directly generate a CPC auxiliary trip?

A. High SG levels.
B. High SG pressure.
C. Low condenser vacuum.
D. Asymmetric SG Temperatures.

Answer 1

D. Asymmetric SG Temperatures.

Question 2

RCS Temperature is constant.
Rx Power is constant.
Ignoring the effects of ASI, how would inserting CEA’s from ARO to 75 inches withdrawn affect the CPC calculated value of LPD?

A. No change, LPD is not affected by CEA position.
B. Gradually decrease as CEAs are inserted.
C. Gradually increase as CEAs are inserted.
D. No change until Group 5 is at 108 inches, then it will decrease.

Answer 2

C. Gradually increase as CEAs are inserted.

Question 3

Which of the following best describes why CPC Core average ASI and COLSS Core average ASI differ?

A. COLSS is limited by not having Excore NI power as an input.
B. CPC use Calibrated NI power (PID 171) and then applies a bias.
C. CPCs use the COLSS value as an addressable constant and then penalizes it for conservatism.
D. COLSS and CPC use different inputs and processes to determine ASI.

Answer 3

D. COLSS and CPC use different inputs and processes to determine ASI.

Question 4

Unit is at 100% power.
What is the affect of this dropped rod on CPCs and CEACs?

A. No CPCs will trip. CEACs will send a small penalty factor to all CPCs.
B. All four CPCs will immediately trip on LPD and DNBR due to an out of sequence condition.
C. One CPC will immediately trip on LPD and DNBR. CEACs will send no penalty factor to the other CPCs.
D. One CPC will immediately trip on LPD and DNBR. CEACs will send a penalty factor to the other CPCs.

Answer 4

D. One CPC will immediately trip on LPD and DNBR. CEACs will send a penalty factor to the other CPCs.

Question 5

With the plant at 90% power, Channel A CPC has alarmed due to a Low DNBR pre-trip. Channels B, C, and D are not in alarm.
Assuming CEAs are currently at 130” W/D on Group 5, further withdrawal…

A. Is not affected.
B. Is available using CWP bypass ONLY.
C. Is available in Manual Individual ONLY.
D. May result in a Low DNBR Trip.

Answer 5

A. Is not affected.

Note: Requires 2 of 4 Pre-trip

Question 6

In the upgraded CPC system (Advantage), the CEAC penalty factors are generated based on…

A. CEA misalignment within a subgroup.
B. Part strength Insertion limits.
C. Subgroup deviations within a group.
D. Reg Groups out of sequence.

Answer 6

A. CEA misalignment within a subgroup.

Question 7

Which ONE of the following states how the CPC calculated value of LPD would change if a dilution was started as rods were inserted into the core?
LPD would…

A. Decrease and LPD margin will increase.
B. Increase and LPD margin will decrease.
C. Remain the same and margin will remain constant.
D. Decrease and margin will initially remain constant and then decrease.

Answer 7

B. Increase and LPD margin will decrease.

Question 8

How does COLSS interface with RPS?

A. Incore detectors are used to calibrate NI’s.
B. Incore detectors are monitored for the DNBR trips.
C. JSCALOR is used to calibrate safety channel NI’s.
D. RCS flow from COLSS feeds the DNBR trip.

Answer 8

C. JSCALOR is used to calibrate safety channel NI’s.

Question 9

A COLSS CMC alarm is received.
The Group Display for COLSS CMC is displayed.
Point ID NKTMFLOW, RCS flow rate value, indicates an ‘N’.
Determine which one of the following calculations is affected?

A. ASI
B. DNBR POL
C. LPD POL
D. AZ Tilt

Answer 9

B. DNBR POL

Question 10

Which of the following describes when COLSS uses JSCALOR as selected Plant Power?

A. If NKBDELT is ‘Bad’ and JSCALOR is larger than NKCBTFSP.
B. COLSS never uses JSCALOR as Plant Power.
C. If NKBDELT is ‘Bad’ and JSCALOR is less than NKCBTFSP.
D. COLSS always uses JSCALOR as Plant Power if it is considered to be ‘Good.’

Answer 10

A. If NKBDELT is ‘Bad’ and JSCALOR is larger than NKCBTFSP.

Question 11

Maximum fuel cladding integrity is attained by…

A. Always operating below 110% of reactor coolant system design pressure.
B. Ensuring that critical heat flux is always less than actual heat flux.
C. Actuation of the reactor protection system upon a reactor accident.
D. Ensuring that actual heat flux is always less than critical heat flux.

Answer 11

D. Ensuring that actual heat flux is always less than critical heat flux.

(Note: Critical Heat Flux over Actual Heat Flux C/A)

Question 12

Which one of the following describes the basis for 2,200F maximum fuel clad temperature limit?

A. 2,200F is approximately 500F below the fuel clad melting temperature.
B. The rate of the Zircaloy-Steam reaction increases significantly above 2,200F
C. If fuel clad temperature reaches 2,200F, the onset of transition boiling is imminent.
D. The differential expansion between the fuel pellets and the fuel clad becomes excessive above 2,200F

Answer 12

B. The rate of the Zircaloy-Steam reaction increases significantly above 2,200F.

Question 13

A four finger CEA in Regulating Group 5 slips from 150” to 0” withdrawn.
All other CEAs are ARO.
Unit is at 100% power.
What is the affect of this dropped rod on CPCs and CEACs?

A. One CPC will immediately trip on LPD and DNBR. CEACs will send a 1.0 penalty factor to the other CPCs.
B. No CPCs will trip. CEACs will send a 1.0 penalty factor to all CPCs.
C. All four CPCs will immediately trip on LPD and DNBR due to an out of sequence condition.
D. One CPC will immediately trip on LPD and DNBR. CEACs will send no penalty to the other CPCs.

Answer 13

B. No CPCs will trip. CEACs will send a 1.0 penalty factor to all CPCs.

Question 14

Since rod position information is fed to the CPCs, why are the CEACs still necessary?
Only the…

A. CPCs have demanded position information (pulse counters), but CEACs have actual position information (RSPTs).
B. CEACs are capable of detecting smaller deviations to give quicker protection.
C. CPCs are used for protection, while the CEACs are used to monitor LCOs.
D. CEACs are capable of detecting a deviation between CEAs in a subgroup.

Answer 14

D. CEACs are capable of detecting a deviation between CEAs in a subgroup.

Question 15

Which of the following describes the operational bypass associated with the Core Protection Calculator trips?
These trips are automatically…

A. Bypassed when power drops to 1E-2%.
B. Placed in service when power increases to 1E-4%.
C. Bypassed when power drops to 1E-4%.
D. Placed in service when power increases to 1E-2%.

Answer 15

B. Placed in service when power increases to 1E-4%.

Question 16

Which of the following describes when the Core Protection Calculator transition to a canned value of Axial Shape Index?

A. 15% Primary Calorimetric Power and Lowering.
B. 51% Calibrated Excore Power and rising.
C. When the sum of the 3 excore channels rises to 51%.
D. When the sum of the 3 excore channels lowers to 45%.

Answer 16

D. When the sum of the 3 excore channels lowers to 45%.

Question 17

Which of the following is not a direct input to the CPC DNBR calculation?

A. Axial Shape Index.
B. Hot leg temperature.
C. When the sum of the 3 excore channels lowers to 45%.
D. Primary Calorimetric Power (CPC)

Answer 17

B. Hot leg temperature.

Question 18

Which of the following is not a direct input to the CPC LPD calculation?

A. ASI
B. CEAC Penalty Factors
C. Radial Peaking Factors
D. Pressurizer Pressure

Answer 18

D. Pressurizer Pressure

Question 19

Which of the following failures would require entry into Tech Spec 3.3.3 in modes 1 and 2?

A. CEAC 1A failure ONLY.
B. CPP1 on channel A ONLY.
C. CPP1 on channel A and CPP1 on channel B.
D. CPP1 on channel A and CPP2 on Channel B.

Answer 19

A. CEAC 1A failure ONLY.

Question 20

Which of the following will cause the CPC DNBR value to lower?

A. More RCS flow.
B. ASI less negative.
C. Pressurizer Pressure rises.
D. Power increased by 5%.

Answer 20

D. Power increased by 5%.

Question 21

Which of the following is NOT a CPC Aux Trip?

A. Hot leg saturation.
B. One RCP speed less than 95%.
C. CPC Variable Over Power Trip.
D. Asymmetric Steam Generator Transient.

Answer 21

B. One RCP speed less than 95%.

Question 22

RCS Temperature is Constant.
Rx Power Constant.
Ignoring the effects of ASI, how would inserting CEAs from ARO to 75 inches withdrawn affect the CPC calculated value of LPD?

A. Gradually decrease as CEAs are inserted.
B. No change, LPD is not affected by CEA position.
C. Gradually increase as CEAs are inserted.
D. No change until Group 5 is at 108 inches, then it will decrease.

Answer 22

C. Gradually increase as CEAs are inserted.

Question 23

Rx at 75% RTP initially CEAs are ARO A single 12 finger CEA slips to 135 inches withdrawn.
No Rx trip occurs COLSS CEA position has not been updated.
Based on these condition, the magnitude of the associated CEAC penalty factor will…

A. Decrease over time reaching a zero value after 6 hours.
B. Increase over time reaching a maximum after 6 hours.
C. Increase over time reaching a maximum value after one hour.
D. Not change for the next 6 hours, then increase over time reaching a maximum value after 24 hours.

Answer 23

B. Increase over time reaching a maximum after 6 hours.

Question 24

A twelve finger CEA in Regulating Group 3 slips from 150” to 88” withdrawn.
All other CEAs are ARO. Unit is at 100% power. What is the affect of this dropped rod on CPCs and CEACs?

A. All four CPCs will immediately trip on LPD and DNBR due to an out of sequence condition.
B. No CPCs will trip. CEACs will send a small penalty factor to all CPCs
C. One CPC will immediately trip on LPD and DNBR. CEACs will send a penalty factor to the other CPCs.
D. One CPC will immediately trip on LPD and DNBR. CEACs will send no penalty factor to the other CPCs.

Answer 24

C. One CPC will immediately trip on LPD and DNBR. CEACs will send a penalty factor to the other CPCs.

Question 25

Unit 1 is operating at rated power.
A Regulating Group 5 CEA has been determined to be UNTRAPPABLE (STUCK).
The Operating Crew is reviewing the Tech Specs associated with this problem.
While they are performing this, a trip of the ‘B’ MFP occurs.
Based on this, which ONE of the following describes how the plant will respond?

A. The reactor will trip immediately.
B. A normal RPCB will be completed.
C. The reactor will trip in approximately 30 seconds.
D. A RPCB will occur, however a building penalty factor will eventually (within 10 minutes) lead to a plant trip.

Answer 25

A. The reactor will trip immediately.

Note: Typically take ~4 seconds for rods to drop in. Other questions states after ~5seconds Rx trips

Question 26

Given a los of PND-D28, which of the following identifies the most complete stats of CEACs?

A. CEAC #1 becomes INOP due to loss of power to RSPTs.
B. CEAC #2 becomes INOP due to loads of power to RSPTs.
C. CEAC #1 loses power.
D. CEAC #2 loses power.

Answer 26

B. CEAC #2 becomes INOP due to loads of power to RSPTs.

Question 27

Unit 1 is at 80% power and dropped a 4 finger CEA.
Unit 2 is at 80% power and dropped a 12 finger CEA.
Assume that the CEAs remained misaligned.
What would be the impact on the respective CEACs?

A. Both units will eventually trip due to a penalty factors ramping in over the next 6 hours.
B. Neither unit will trip based on these misaligned CEAs.
C. In Unit 1 the 4 finger CEA will effectively generate NO CEAC penalty factor, whereas in Unit 2, the 12 finger CEA will eventually trip the reactor due to a penalty factor ramping in.
D. In Unit 2, the 12 finger CEA will effectively generate NO CEAC penalty factor, where as in Unit 1, the 4 finger CEA will eventually trip the reactor due to a penalty factor ramping in.

Answer 27

C. In Unit 1 the 4 finger CEA will effectively generate NO CEAC penalty factor, whereas in Unit 2, the 12 finger CEA will eventually trip the reactor due to a penalty factor ramping in.

Question 28

Unit 1 is operating at rated power.
A Regulating Group 5 CEA drops to the bottom.
The Rod Bottom Light on mimic illuminates, and the crew takes actions per 40AO-9ZZ11, CEA Malfunctions.
The COLSS Power Operating Limit (POL) is -99.0.
Based on these conditions, COLSS….

A. Is DEFINITELY inoperable due to the dropped rod, requiring 72ST-9RX03 (COLSS Inoperability) to be performed.
B. Is performing exactly the way it was designed, and is fully operable.
C. Is DEFINITELY inoperable and power should immediately be reduced at lease 20%.
D. MAY be inoperable, and requires a functional determination (77OP-9RJ04) to be performed.

Answer 28

D. MAY be inoperable, and requires a functional determination (77OP-9RJ04) to be performed.

(Note: It assumes the whole bank dropped so you have to do determination)

Question 29

On a loss of the Plant Computer, CEAs can…

A. Only be moved in Manual Group and Manual Individual.
B. Not be moved.
C. Only be moved in Manual Group.
D. Be moved in any CEDMCS mode, except standby.

Answer 29

A. Only be moved in Manual Group and Manual Individual.

Question 30

Which one of the following conditions will cause the calculated value of Departure from Nucleate Boiling Ratio (DNBR) to come closer to the Reactor Trip set point.

A. Grid frequency increases slightly
B. Pressurizer pressure is increased by 15 psia
C. Power is increased with CEAs remaining ARO
D. RCS temperature is lowered while maintaining power constant

Answer 30

C. Power is increased with CEAs remaining ARO

Question 31

Unit 1 is operating at 100%.
RCP 1A experiences a failure causing it to slow down at 1% per minute.
Assuming that all other input parameters remained the same, the CPC calculated value of DNBR will…

A. Not change until RCP speed reaches 95% of rated speed, then a DNBR trip will occur.
B. Not change until RCP speed reaches 95% of rated speed, then an Auxiliary trip will occur.
C. Gradually lower until RCP speed reaches 95% of rated speed, then a DNBR trip will occur.
D. Gradually lower until RCP speed reaches 95% of rated speed, then an Auxiliary trip will occur.

Answer 31

C. Gradually lower until RCP speed reaches 95% of rated speed, then a DNBR trip will occur.

(Note: Pump speed is input to the flow calculation which is used in the DNBR calculation. DNBR will reduce as speed drops. A DNBR trip will be generated when RCP speed reaches 95%.)

Question 32

Which of the following COLSS inputs will NOT substitute an unaffected paired sensor on a range check failure?

A. RCS Cold Leg Temperature RCN-TT-111Y/112Y
B. Main Steam Line Pressures SGN-PT-1024/1027
C. Main Steam Flow SGN-FT-1011/1012
D. RCP Speed RCN-ST-154/155

Answer 32

B. Main Steam Line Pressures SGN-PT-1024/1027

Question 33

Which of the following accurately describes the effect on COLSS of a single DROPPED CEA?

A. The DNBR Power Operating Limit will rise
B. COLSS no longer knows that rod position, so the calculations are no longer conservative
C. COLSS will compute peaking factors as if the entire group has dropped
D. The License Power Operating Limit will lower

Answer 33

C. COLSS will compute peaking factors as if the entire group has dropped

Question 34

Which of the following will result in a LOWER DNBR POL?

A. Group 5 is moved from 140” withdrawn to 145” withdrawn
B. Axial Shape Index (ASI) becomes more negative
C. Pressurizer Pressure rises
D. T-hot transmitter fails HI

Answer 34

B. Axial Shape Index (ASI) becomes more negative

Question 35

Define Power Operating Limit:

A. The power at which fuel damage will occur at current core conditions
B. The power at which the Reactor should be tripped at current core conditions
C. The power at which LCOs would be exceeded at current core conditions
D. The power at which all safety limits will be exceeded at current core conditions

Answer 35

C. The power at which LCOs would be exceeded at current core conditions

Question 36

If the T-colds input to COLSS rises, (assume T-hot remains constant) the DNBR POL will ____ and the NKBDELT value will ____.

A. Rise, Rise
B. Lower, Lower
C. Rise, Lower
D. Lower, Rise

Answer 36

B. Lower, Lower

Question 37

If a Reactor Coolant Pump differential pressure input to COLSS begins to read lower than the actual value, Plant Power (RJANA01) would:

A. Initially rise then lower to actual Plant Power over time
B. Initially lower then rise to actual Plant Power over time
C. Remain constant
D. Stabilize at a higher power level than actual Plant Power

Answer 37

A. Initially rise then lower to actual Plant Power over time

(Note: Think of low D/P as more flow)

Question 38

What is the effect on COLSS if Turbine First Stage Pressure Transmitter fails low?

A. NKBTFSP is BAD and COLSS is not operable
B. NKBTFSP is BAD and COLSS is operable
C. The backup First Stage Pressure Transmitter would be selected
D. Plant Power would read lower than actual until calibrated back up by JSCALOR

Answer 38

B. NKBTFSP is BAD and COLSS is operable

Question 39

Which of the following is a possible effect of RCP speed lowering due to degraded grid frequency?

A. NKBDELT will rise
B. DNBR POL will rise
C. KW/FT POL will lower
D. NKBDELT will lower

Answer 39

D. NKBDELT will lower

Question 40

U1 Reactor Power is 100%
A channel check is being performed to compare indicated power to COLSS Calorimetric power (JSCALOR).
Complete the following statement:
If Reactor power is ____ then Calorimetric Power and all indicated power levels must agree within ____.

A. Less than 20%, + or - .5%
B. Less than 80%, + or - .5%
C. Greater than or equal to 20%, + or - 2.0%
D. Greater than or equal to 80%, + or - 2.0%

Answer 40

D. Greater than or equal to 80%, + or - 2.0%

(Note: When Rx power is between 20% to 80%, the NI power levels must be no less than 0.5% below Actual power and no higher than 10% above Actual power. Above 80% the lower limit is > or + to 2% Actual power or = to > 2% above Actual power.)

Question 41

A CWP has been received.
CEDMCS in AUTO sequential.
If the operator pushes and holds the CWP bypass button, CEAs can…

A. NOT be withdrawn in any mode.
B. Be withdrawn in manual individual only.
C. Be withdrawn in manual group or manual individual only.
D. Be withdrawn in any mode except standby.

Answer 41

D. Be withdrawn in any mode except standby.

Question 42

The function of the Dropped Rod Contact (DRC) is to:

A. Initiate an auto reactor trip if two or more rods drop in the core.
B. Reset the individual CEA pulse counter.
C. Stop all rod motion in any CEDMCS mode.
D. Reset Reactor Power Cutback (RPCB) flag in COLSS.

Answer 42

B. Reset the individual CEA pulse counter.

Question 43

Unit 1 is at 100% power.
40ST-9SF01, CEA Exercising, is in progress.
CEA #14 is being exercised and CEDMCS Trouble annunciator alarms.
The AO reports that the CEA breaker on the Power Switch assembly for CEA #14 is tripped open.
CEA 14 is indicating within 2.5” of its group.
Which of the following action(s) is (are) necessary:

A. Trip the reactor and enter SPTAs.
B. Enter Tech Spec 3.1.5 for an inoperable CEA.
C. Close the breaker and realign CEA #14 in Manual Individual.
D. Continue with the Surveillance Test after realigning the other CEAs to within 1.5” of CEA #14.

Answer 43

B. Enter Tech Spec 3.1.5 for an inoperable CEA.

Question 44

There are two rows of amber card status LED indicators located on each CEDMCS subgroup logic housing front panel. These indicators will:

A. Come on if the corresponding circuit board is not fully seated in its connector or when an incorrect type of card is installed in the indicated position.
B. Go off if the corresponding circuit board is not fully seated in its connector or when an incorrect type of card is installed in the indicated position.
C. Come on if the corresponding circuit board fails its internal timing test every six seconds.
D. Go off if the corresponding circuit board fails its internal timing test every six seconds.

Answer 44

A. Come on if the corresponding circuit board is not fully seated in its connector or when an incorrect type of card is installed in the indicated position.

Question 45

Which of the following CEDM coils is energized when the CEA subgroup is on the hold bus?

A. Upper lift coil.
B. Lower lift coil.
C. Upper latch coil.
D. Lower latch coil.

Answer 45

C. Upper latch coil.

Question 46

Which of the following shows allowable CEDMCS modes with one Motor Generator Set out of service?

A. Manual Individual and Standby.
B. Manual Individual, Manual Group and Standby.
C. All modes allowed.
D. All modes EXCEPT Auto Sequential.

Answer 46

A. Manual Individual and Standby.

Question 47

On a loss of power to the logic cards associated with a subgroup, CEDMCS would respond by:

A. Energizing the upper gripper CEDM coils in the subgroup in such a manner that a high voltage would be applied to them.
B. De-energizing the CEDM coils in the subgroup causing the CEAs in the subgroup to drop.
C. Energizing the CEDM coils in the subgroup in such a manner that the CEAs would start stepping in.
D. Energizing the lower gripper CEDM coils in the subgroup in such a manner that a low hold voltage would be applied to them.

Answer 47

A. Energizing the upper gripper CEDM coils in the subgroup in such a manner that a high voltage would be applied to them.

Question 48

Plant is at 100% power.
An I&C technician is testing the UV detectors at the CEDMCS control panels.
When the UV1 test pushbutton is depressed, the UV light illuminates.
Upon release of the test button the UV light remains illuminated.
The UV2 test button is then depressed.
Which of the following occur?

A. A reactor trip is initiated.
B. RTCB’s 1 and 3 (only) will open.
C. A turbine trip is initiated.
D. An ATWS occurs.

Answer 48

C. A turbine trip is initiated.

Question 49

Which CEA positions can be displayed on the ‘Group Position LED’ on B04?

A. The lowest individual CEA pulse counter position in the selected group.
B. The lowest individual CEA RSPT position in the selected group.
C. The average CEA pulse counter position in the selected group.
D. The average CEA RSPT position in the selected group.

Answer 49

C. The average CEA pulse counter position in the selected group.

Question 50

Unit 1 is Mode 1 100% power.
Which of the following describes the configuration of the Core Mimic on B04 following a loss of PNB-D26.

A. 1/4 of the Rod Bottom Lights are illuminated.
B. 1/4 of the Rod Bottom lights are out.
C. All Rod Bottom lights are lit, the Reactor is not tripped.
D. None of the rod bottom lights are lit

Answer 50

D. None of the rod bottom lights are lit.

Question 51

A Large Load Reject Reactor Power Cutback has occurred in unit 3.
Groups 4 and 5 have fully inserted into the core and Reactor Regulating System responded to temperature as expected to drive group 3 CEAs to 135” withdrawn.
The Control Room Supervisor has directed you to ‘restore normal CEA overlap’.
Which of the following describes the proper actions?

A. Withdraw group 3 to the Upper Group Stop in Manual Sequential.
B. Withdraw group 4 to approximately 90” withdrawn in Manual Group.
C. Withdraw group 4 to approximately 40” withdrawn in Manual Group.
D. Withdraw group 4 to approximately 40” withdrawn in Manual Sequential.

Answer 51

C. Withdraw group 4 to approximately 40” withdrawn in Manual Group.

Question 52

Unit 2 is in Mode 1 100% power.
If all CEDM air cooling is lost cooling must be restored within 10 minutes or:

A. A reactor trip must be initiated.
B. Initiate a RPCB to rapidly lower power by depressing LOSS OF FEEDPUMP and DROP SUBGROUPS simultaneously.
C. Initiate a RPCB to rapidly lower power by depressing LARGE LOAD REJECT and DROP SUBGROUPS simultaneously.
D. Commence a rapid shutdown and Cooldown.

Answer 52

D. Commence a rapid shutdown and Cooldown.

Question 53

Unit 3 is operating at rated power.
Regulating group 5 CEAs are inserted to 115 inches for ASI control.
CEA 17 (group 5) begins withdrawing with no Operator action.
The crew has placed CEDMCS in standby.
CEA motion has stopped.
Which one of the following represents the maximum acceptable CEA deviation and why?

A. Any uncontrolled outward deviation requires an immediate reactor trip due to the potential loss of Shutdown Margin.
B. 5.25 inches to ensure acceptable core power distributions are maintained.
C. 6.6 inches to ensure acceptable core power distributions are maintained.
D. 9.9 inches to ensure shutdown margin is maintained.

Answer 53

C. 6.6 inches to ensure acceptable core power distributions are maintained.

Question 54

Unit 1 is operating at 100% power.
Rod testing is in progress.
CEA-18 has been inserted and then withdrawn 5 inches.
Plant Monitoring System (PMS) computer indicates CEA-18 position at 148.5 inches.
Control Element Assembly Calculators (CEACs) indicate CEA-18 position at 144 inches.
CEA-18 is at…

A. 148.5 inches. The PMS computer uses the reed switch position indication system giving actual CEA position while the CEACs use the pulse counters which indicate demand input.
B. 144 inches. The CEACs indicate actual CEA positions using the pulse counters while the PMS computer uses the Reed Switch Position Indication system which uses CEA demand input.
C. 148.5 inches. The PMS computer uses the pulse counters which indicate actual CEA position while the CEACs use the reed switch position indication system which indicate demand input.
D. 144 inches. The CEACs indicate actual CEA positions using the reed switch position indication system while the PMS computer uses the pulse counters which indicate demand input.

Answer 54

D. 144 inches. The CEACs indicate actual CEA positions using the reed switch position indication system while the PMS computer uses the pulse counters which indicate demand input.

Question 55

Unit is operating at 100% power.
Regulating Group 5 is at 135” for ASI control.
RRS selected to Control Channel #1. 
Control Channel #1 fails high.
Which one of the following is correct?

A. CEAs may insert a few steps.
B. CEAs may withdraw a few steps.
C. CEAs will insert until CEDMCS is taken out of automatic.
D. No CEA motion will occur due to an AMI being generated.

Answer 55

A. CEAs may insert a few steps.

Question 56

Unit 1 was operating at 100% power when the following occurred:
Excore power decreases to 98%.
RCS Loop T-hots are lowering.
RCS Loop T-colds are lowering.
COLSS, CPC and PDIL alarms.
Letdown flow is decreasing.
10 minutes later the following conditions are observed:
Excore power has recovered to ~100%.
T-avg has stabilized, but 2F off program low.
Pressurizer level and pressure have recovered.
COLSS, CPC and PDIL alarms are still active.
Letdown flow is increasing.
Which ONE of the following events is in progress?

A. Letdown leak, perform recovery actions per Loss of Letdown AOP.
B. Partial load reject, perform recovery action per Load Rejection AOP.
C. Slipped/dropped CEA, perform recovery actions per CEA Malfunctions AOP.
D. Instrument malfunction, perform recover actions per RRS Malfunctions AOP.

Answer 56

C. Slipped/dropped CEA, perform recovery actions per CEA Malfunctions AOP.

Question 57

Unit 3 is operating at 55% power following a Large Load Reject event.
The CRS has implemented 40AO-9ZZ08 (Load Rejection).
CEDMCS has been placed in SBY.
Reg. Group 3 CEAs are at 135 inches withdrawn.
Reg. Group 4 CEAs are fully inserted.
In accordance with 40AO-9ZZ08, proper CEA group overlap will be restored by…

A. Withdrawing Reg group 4 CEAs in manual group mode.
B. Withdrawing Reg group 4 CEAs in manual sequential mode.
C. Withdrawing Reg group 4 CEAs in manual individual mode while maintaining CEAs within 6.6 inches.
D. Lowering the load limit pot until the ‘Load Limiting’ light illuminates then allow the Reg group 4 CEAs to withdraw in auto sequential mode.

Answer 57

A. Withdrawing Reg group 4 CEAs in manual group mode.

Question 58

Unit 1 is operating at 48% power following a Reactor Power Cutback due to a trip of the B main feedwater pump.
CEA Subgroups 4, 5, and 22 drop to the bottom of the core.
CEA Reg group 3 CEAs are automatically inserting as expected to maintain RCS program temperature.
Turbine Load is approximately 850 MW and stable.
During plant stabilization the following conditions are observed:
The CRS has implemented 40AO-9ZZ09 (RPCB-Loss of Feedpump).
CEDMCS has been placed in Manual Sequential (MS).
CEA 42 (Regulating Group 3, 4 Finger CEA) is at 140 inches, the remaining CEAs in Gp 3 are at 132 inches.
CPC Pt. ID 0197 (ASI) average value is minus (-) .38 and slowly trending to the top of the core.
Which ONE of the following actions and conditions are both correct?

A. Withdraw Gp 3 CEAs to control ASI per 40AO-9ZZ09 (RPCB).
B. Withdraw Gp 3 CEAs to within 6.6 inches of CEA 42 per 40AO-9ZZ09 (RPCB).
C. Trip the reactor, perform SPTAs and enter 40EP-9EO01 (Rx Trip) due to exceeding ASI limits.
D. Trip the reactor, perform SPTAs and enter 40EP-9EO01 (Rx Trip) due to the CEA mis-alignment.

Answer 58

D. Trip the reactor, perform SPTAs and enter 40EP-9EO01 (Rx Trip) due to the CEA mis-alignment.

Question 59

Unit 3 is operating at 80%.
Group 5 CEAs at 120 inches withdrawn.
All others CEAs at UEL.
Selected CEA is #14.
Selected CEA Group is #5.
A malfunction causes CEA 15 to move 12 steps out before STANDBY is selected and motion stops.
Based on this event the pulse counter selected GROUP position reads…

A. 120 inches.
B. 122.25 inches.
C. 124.5 inches.
D. 129 inches.

Answer 59

B. 122.25 inches.

Note: Group position is the average position. 129+120+120+120=489/4=122.25

Question 60

Multiple channels of CPCs (Lo DNBR) have trip lights illuminated on B05.
The reactor failed to automatically trip.
The CRS has directed the RO to open the supply breakers fore L03 and L10 for a minimum of 5 seconds.
Which ONE of the following describes the reason for this action?
The 5 seconds allows time for the…

A. Motor generator stop contacts to close.
B. CEAs to drop to the bottom of the core.
C. Trip coils to actuate to open L03 and L10 breakers.
D. Effects of the motor generator flywheel to taper off interrupting power to the CEAs.

Answer 60

D. Effects of the motor generator flywheel to taper off interrupting power to the CEAs.

Question 61

Unit 2 is operating at 100% ARO.
A Regulating Group 5 CEA has dropped completely into the core.
All required actions are complete.
Which ONE of them following describes Technical Specification 3.1.5 (CEA Alignment)?
CEA alignment must be restored within a maximum of ____ hour(s)

A. 1
B. 2
C. 6
D. 12

Answer 61

B. 2

Question 62

Unit 1 is operating at 80% power following a SNOW outage.
Group 5 CEAs are 120 inches withdrawn.
THE CRS directs a 10 inch withdrawal for ASI control.
The operator is monitoring CEA 14 on SEN-JI-17, Selected CEA Position.
On the 4th step out CEA 16 motion stops due to a Timer Card failure.
The operator continues the CEA withdrawal.
Which ONE of the following reflects CEA 16s:
1. Reed Switch Position Transmitters, CEACs
2. Board 4 alarms that will be generated.

A. (1) 123 inches (2) CEA Withdrawal Prohibit, CWP.
B. (1) 124 inches (2) CEA Withdrawal Prohibit, CWP.
C. (1) 123 inches (2) Automatic Withdrawal Prohibit, AWP.
D. (1) 124 inches (2) Automatic Withdrawal Prohibit, AWP.

Answer 62

A. (1) 123 inches (2) CEA Withdrawal Prohibit, CWP.

(Note: 4 x .75 = 3 inches of movement. As the remaining CEAs withdrawal a CWP will be generated at 5.5 inch deviation within a subgroup.)

Question 63

Unit 1 is at 80% power.
Group 5 CEAs are at 120 inches withdrawn for ASI control.
CEDMCS is in Auto Sequential.
Reactor Operator reports indications of an inadvertent continuous CEA withdrawal.
CEA Malfunctions, 40AO-9ZZ11 directs the crew to place CEMCS in ____, CEA motion is expected to stop because in the mode of control ____.

A. (1) Standby (2) the CEDM lower gripper coils are energized.
B. (1) Standby (2) CEDMCS does not respond to automatic signals.
C. (1) Manual Sequential (2) the CEDM lower gripper coils are energized.
D. (1) Manual Sequential (2) CEMCS does not respond to automatic signals.

Answer 63

B. (1) Standby (2) CEDMCS does not respond to automatic signals.

Question 64

Unit 1 is operating at 100% power.
Group 5 CEAs are at 120 inches withdrawn for ASI control.
Class instrument bus, PKC-M43, has faulted and is de-energized.
(1) What is the correct Tech Spec as it applies to CEA alignment?
(2) What is the impact on the CEDMCS system and the ability to position CEAs.
LCO 3.1.5 is provided as a reference.

A. (1) Enter LCO 3.0.3, because the conditions of 3.1.5 B are not satisfied.
(2) Subgroup Logic PREVENTS the positioning of the group 5 CEAs in Manual Sequential.
B. (1) Enter LCO 3.1.5, Condition B.
(2) Subgroup logic ALLOWS the positioning of the group 5 CEAs in Manual Sequential.
C. (1) Enter LCO 3.1.5, Condition B.
(2) Subgroup Logic PREVENTS the positioning of the group 5 CEAs in Manual Sequential.
D. (1) Enter LCO 3.0.3, because the conditions of 3.1.5 B are not satisfied.
(2) Subgroup logic ALLOWS the positioning of the group 5 CEAs in Manual Sequential.

Answer 64

A. (1) Enter LCO 3.0.3, because the conditions of 3.1.5 B are not satisfied.
(2) Subgroup Logic PREVENTS the positioning of the group 5 CEAs in Manual Sequential.

Question 65

Unit 1 is operating at 85% power.
A group 5 CEA drops to the bottom of the core while the groups are at 135 inches.
(1) What is the effect of the dropped CEA on Shutdown Margin (SDM)?
(2) In accordance with 40AO-9ZZ11, CEA Malfunctions, what power level must be achieved within ONE (1) hour?

A.  (1) SDM was reduced.
      (2) 65%.
B.  (1) SDM was reduced.
      (2) 70%
C.  (1) SDM was NOT affected.
      (2) 65%
D.  (1) SDM was NOT affected.
      (2) 70%

Answer 65

C. (1) SDM was NOT affected.

(2) 65%

Question 66

Unit 1 is at 100% power.
Class 4.16 kVA bus PBB-S04 has faulted and is de-energized.
Subsequently
Nuclear Cooling Water valve from the CEDM ACUs A02A/A02C, NCN-HV-485 fails closed.
Which one of the following is the appropriate action per 40AO-9ZZ20, Loss of HVAC?

A. Start CEDM ACUs A02B/A02D to restore cooling.
B. Trip the reactor and perform SPTAs within a maximum of 10 minutes from the loss of cooling.
C. Limit CEA motion to that needed for ASI control and decrease power to shutdown the unit within 4 hours.
D. Commence a rapid down power within 10 minutes and have RTSG breakers opened within 40 minutes of the loss of cooling.

Answer 66

D. Commence a rapid down power within 10 minutes and have RTSG breakers opened within 40 minutes of the loss of cooling.

Question 67

Unit 1 had been operating at rated power.
The Main Turbine tripped one hour ago.
Steam Bypass Control system is maintaining reactor power at 50% in Remote/Auto.
CRS is taking actions per 40AO-9ZZ08, Load Rejection.
Subsequently
Reactor power is rising.
Tcold is stable.
Which one of the following events could be in progress?

A. Continuous CEA withdrawal.
B. Expected Xenon reactivity transient.
C. Turbine Load Index (TLI) signal has failed high.
D. SGN-PT-1024, Main Steam Header Pressure, has failed low.

Answer 67

A. Continuous CEA withdrawal.

Question 68

Which one of the following identifies the CEA position requirements of 40ST-9ZZ23, CEA Position Data Log?

(1) The indicated position for all full and part strength CEAs is within a maximum of ____ inches of ALL other CEAs in the group.
(2) All shutdown CEAs must remain above ____ inches by pulse counter indication.

A. (1) 6.6 (2) 142.50
B. (1) 6.6 (2) 147.75
C. (1) 9.9 (2) 142.50
D. (1) 9.9 (2) 147.75

Answer 68

B. (1) 6.6 (2) 147.75

Question 69

Unit 1 is operating at 90% power.
Group 5 CEAs are 85 inches withdrawn.
Group 5 CEAs are currently below the Transient Insertion Limits.
To comply with the conditions of LCO 3.1.7 (CEA Insertion Limits) group 5 CEAs are being withdrawn to 95 inches.
On the first step out CEA 15 slips to 65 inches withdrawn.
(1) If the CEA position switch is held in the outward motion position, CEA motion will stop due to…
(2) What actions are directed by 40AO-9ZZ11, CEA Malfunctions?

A. (1) A CEA Withdrawal Prohibit (CWP) being generated.
(2) Trip the reactor and enter 40EP-9EO01, SPTAs
B. (1) A CEA Withdrawal Prohibit (CWP) being generated.
(2) Start a power reduction within 10 minutes of the initial CEA deviation.
C. (1) The Automatic CEDM Timer Module (ACTM) stopping group motion.
(2) Trip the reactor and enter 40EP-9EO01, SPTAs
D. (1) The Automatic CEDM Timber Module (ACTM) stopping group motion.
(2) Start a power reduction within 10 minutes of the initial CEA deviation.

Answer 69

A. (1) A CEA Withdrawal Prohibit (CWP) being generated.

(2) Trip the reactor and enter 40EP-9EO01, SPTAs.

Question 70

Unit 1 was operating at 100% power.
Reactor Power Cutback System was out of service for testing.
A Main Turbine trip occurred.
The Reactor Protection System failed to trip the reactor, resulting in an ATWS.
How will the Supplemental Protection System (SPS) respond to trip the reactor?
SPS will open…
1. Reactor Trip Circuit Breakers.
2. L03 and L10 supply breakers.
3. CEDMCS MG Set output contractors.

A. 1 ONLY
B. 2 ONLY
C. 1 and 3 ONLY
D. 2 and 3 ONLY

Answer 70

C. 1 and 3 ONLY

Question 71

Unit 3 is operating at 2% power.
CEAs are being withdrawn for a power ascension.
On the last CEA pull, Regulating Group 4 CEA 18 continued to withdraw after releasing the Withdrawal/Insert Switch on B04.
CEDMCS Mode Selector Switch was placed in Standby and CEA 18 stopped moving.
CEA 18 stopped moving at 64” withdrawn.
All other Regulating Group 4 CEAs are 56.5” withdrawn.
I&C was able to quickly determine and correct the issue with CEA 18.
1. Per 40 AO-9ZZ11, CEA Malfunctions, the crew will restore group alignment by ____.
2. Per LCO 3.1.5, CEA Alignment, Condition A, the two-hour completion time for re-aligning CEA 18 starts ____ was >6.6 inches from the rest of Group 4.

A. 1. Inserting CEA 18 within 6.6” of Regulating Group 4
2. The moment CEA 18
B. 1. Inserting CEA 18 to within 6.6” of Regulating Group 4
2. No more than two hours after CEA 18
C. 1. Withdrawing the other 7 Regulating Group 4 CEAs to within 6.6” of CEA 18
2. The moment CEA 18
D. 1. Withdrawing the other 7 Regulating Group 4 CEAs to within 6.6” of CEA 18
2. No more than two hours after CEA 18

Answer 71

A. 1. Inserting CEA 18 within 6.6” of Regulating Group 4

2. The moment CEA 18

Question 72

Unit 1 is Mode 2.
The Primary Operator is pulling Regulating Group 4 when he receives a ‘Continuous CEA Motion’ alarm.
The Primary Operator places CEDMCS in ‘SBY’.
The CRS notices that a rod in Regulating Group 4 is continuously moving out.
At this time, the CRS should direct the following:

A. Trip the Reactor and leave the Charging System lined up in AUTO.
B. Trip the Reactor and align the Charging System for Emergency Boration.
C. Place CEDMCS in ‘Manual’ and leave the Charging System lined up in AUTO.
D. Place CEDMCS in ‘Manual Individual’ and align the Charging System for Emergency Boration.

Answer 72

A. Trip the Reactor and leave the Charging System lined up in AUTO.

Question 73

Unit 2 is at 100% power.
A Regulating Group 5 rod slips several inches into the core.
Which ONE of the following would NOT be used to confirm the control rod position?

A. CPCs
B. CEAC CRT
C. Core Mimic
D. CEAC Digital Display

Answer 73

C. Core Mimic

Question 74

Unit 1 is operating at rated power with ARO (All Rods Out).
A Regulating Group 3 CEA (non twelve finger) slips to 140 inches withdrawn.
Another CEA in Regulating Group 3 slips to 130 inches withdrawn.
The operating crew is required by procedure to…

A. Reduce turbine load to maintain Tavg and Tref within 3 degrees of each other and reduce reactor power within 10 minutes.
B. Trip the reactor and implement the Standard Post Trip Actions.
C. Reduce turbine load to maintain Tavg and Tref within 3 degrees of each other and reduce reactor power within 20 minutes.
D. Reduce turbine load to maintain Tavg and Tref within 5 degrees of each other and reduce reactor power within 10 minutes.

Answer 74

B. Trip the reactor and implement the Standard Post Trip Actions.

(Note: These rods are in the same group and deviate by more than 9.9 inches therefore a Rx scram is required. Reducing Turbine Load and Rx power w/i 10 min. Is appropriate IAW the AOP if the rods did not deviate by more than 9.9 inches)

Question 75

Unit 1 is operating at rated power.
PNA-D25 has been de-energized to permit replacement of one of its circuit breakers and is now ready to be returned to service.
As a minimum, which ONE of the following must be performed prior to re-energizing PNA-D25 to prevent a possible reactor trip?

A. Set the CEAC 1 INOP flag in CPCs ‘B’, ‘C’, and ‘D’
B. Set the CEAC 2 INOP flag in CPCs ‘B’, ‘C’, and ‘D’
C. Bypass PPS channel ‘A’ CREFAS and FBEVAS parameters.
D. Bypass PPS Channel ‘B’ CREFAS and FBEVAS parameters.

Answer 75

A. Set the CEAC 1 INOP flag in CPCs ‘B’, ‘C’, and ‘D’

Question 76

A control rod (CEA) is withdrawn from a fully inserted position to the center of the core, its Differential worth will:

A. Increase because poison concentration decreases as the control rod approaches core center.
B. Increase because relative neutron flux increases as the control rod (CEA) approaches core center.
C. Decreases because the fuel concentration decreases at the center of the core due to high burnup in that region.
D. Decrease because moderator density decreases, causing more neutron leakage as the control rod approaches core center.

Answer 76

B. Increase because relative neutron flux increases as the control rod (CEA) approaches core center.

(Note: Differential Rod Worth (DRW) - Reactivity worth per unit change in rod position. As the rod approaches the center of the core it will enter a region of higher neutron flux and therefore its reactivity worth per unit change in rod position will increase)

Question 77

Unit 1 reactor operating at 101% full power.
Pressurizer pressure 2430 psia and RISING.
Manual trip buttons on control board B05 have been depressed.
CEA positions can not be confirmed by using the CEAC CRT.
SPTAs are in progress.
The Control Room should confirms CEA position through the use of which ONE of the following:

A. Lower Electrical Limit
B. Reactor Trip phase current lights.
C. CEAC digital displace on CPC modules.
D. Verification of decreasing Reactor power.

Answer 77

A. Lower Electrical Limit

Note: A is the easiest, most time efficient method of verifying individual CEA positions.

Question 78

Unit 2 is operating at 100% power.
There was a leak in the Nuclear Cooling Water System header which resulted in a complete loss of NC.
Train ‘A’ Essential Cooling Water has been cross-connected to NC per 40AO-9ZZ03, Loss of Cooling Water.
1. Which of the following identifies the ESFAS signal that will automatically close EWA-UV-65 and EWA-UV-145, Cross-Tie Valves to/from Nuclear Cooling Water?
2. What is the purpose of these valves closing?

A. 1. SIAS
2. To ensure Containment Isolation is maintained during accident conditions.
B. 1. SIAS
2. To ensure adequate cooling flow to the SDCHX during accident conditions.
C. 1. CSAS
2. To ensure Containment Isolation is maintained during accident conditions.
D. 1. CSAS
2. To ensure adequate cooling flow to the SDCHX during accident conditions.

Answer 78

B. 1. SIAS

2. To ensure adequate cooling flow to the SDCHX during accident conditions.

Question 79

Unit 2 is operating at 100% power.
Both Nuclear Cooling Water Pumps have tripped on 86 lockout.
40AO-9ZZ03, Loss of Cooling Water, Appendix A, Cross-Connect EW to NC, is in progress.
The RO will direct the AO to throttle EWA-HCV-53, SDCHX A Outlet Isolation, until cooling flow to each RCP has been restored to a MINIMUM of ____ or EW system flow lowers to ____, whichever happens first.

A.  1.  163 gpm
      2. 8500 gpm
B.  1.  163 gpm
      2. 13,800 gpm
C.  1.  491 gpm
      2. 8500 gpm
D.  1.  491 gpm
      2. 13,800 gpm

Answer 79

C. 1. 491 gpm

2. 8500 gpm

Question 80

1. With the Essential Cooling Water System and the Spray Pond Cooling Water System in service, a tube leak in the Essential Cooling Water Heat Exchanger will send water from the…
2. In the event of a loss of both EW Pumps while operating on Shutdown Cooling, the Shutdown Cooling Heat Exchanger can be cooled directly from the…

A. 1. Essential Cooling Water System to the Spray Pond Cooling Water System.
2. Nuclear Cooling Water System
B. 1. Essential Cooling Water System to the Spray Pond Cooling Water System.
2. Spray Pond Cooling Water System
C. 1. Spray Pond Cooling Water System to the Essential Cooling Water System.
2. Nuclear Cooling Water System
D. 1. Spray Pond Cooling Water System to the Essential Cooling Water System.
2. Spray Pond Cooling Water System

Answer 80

C. 1. Spray Pond Cooling Water System to the Essential Cooling Water System.
2. Nuclear Cooling Water System.