ML16167A397
| ML16167A397 | |
| Person / Time | |
|---|---|
| Issue date: | 06/21/2016 |
| From: | Jacob Dolecki NRC/NRR/DIRS/IOLTB |
| To: | |
| Dolecki J W, NRR/DIRS, 301-415-2947 | |
| Shared Package | |
| ML16173A341 | List: |
| References | |
| Download: ML16167A397 (34) | |
Text
1 UNITED STATES NUCLEAR REGULATORY COMMISSION BOILING WATER REACTOR GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 - FORM A Please Print Name:
Docket No.:
Facility:
Start Time:
Stop Time:
INSTRUCTIONS TO EXAMINEE Answer all the test items using the answer sheet provided, ensuring a single answer is marked for each test item. Each test item has equal point value. A score of at least 80 percent is required to pass this portion of the NRC operator licensing written examination. All examination materials will be collected 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> after the examination begins. This examination applies to a typical U.S.
boiling water reactor (BWR) nuclear power plant.
SECTION QUESTIONS
% OF TOTAL SCORE COMPONENTS 1 - 22 REACTOR THEORY 23 - 36 THERMODYNAMICS 37 - 50 TOTALS 50 All work performed on this examination is my own. I have neither given nor received aid.
Examinee's Signature
2 RULES AND INSTRUCTIONS FOR THE NRC GENERIC FUNDAMENTALS EXAMINATION During the administration of this examination the following rules apply:
NOTE: The term "control rod" refers to the length of neutron absorber material that can be positioned by the operator to change core reactivity.
NOTE: Numerical answers are rounded to the nearest whole number unless otherwise indicated.
- 1.
Print your name in the blank provided on the cover sheet of the examination.
- 2.
Fill in your individual docket number.
- 3.
Fill in the name of your facility.
- 4.
Fill in your start and stop times at the appropriate times.
- 5.
Two aids are provided for your use during the examination:
(1) An Equations and Conversions Sheet contained within the examination copy, and (2) Steam tables and Mollier Diagram provided by your proctor.
- 6.
Place your answers on the answer sheet provided. Credit will only be given for answers properly marked on this sheet. Follow the instructions for filling out the answer sheet.
- 7.
Scrap paper will be provided for calculations.
- 8.
Cheating on the examination will result in the automatic forfeiture of this examination.
Cheating could also result in severe penalties.
- 9.
Restroom trips are limited. Only one examinee may leave the room at a time. In order to avoid the appearance or possibility of cheating, avoid all contact with anyone outside the examination room.
- 10. After you have completed the examination, sign the statement on the cover sheet indicating that the work is your own and you have neither given nor received any assistance in completing the examination. Either pencil or pen may be used.
- 11. Turn in your examination materials, answer sheet on top, followed by the examination copy and the examination aids, e.g., steam tables, handouts, and scrap paper.
- 12. After turning in your examination materials, leave the examination area as defined by the proctor. If after leaving you are found in the examination area while the examination is in progress, your examination may be forfeited.
GENERIC FUNDAMENTALS EXAMINATION EQUATIONS AND CONVERSIONS SHEET EQUATIONS 3
Q = m cpT A = Aoet Q = m h N = S/(1 Keff)
Q = UAT CR11 Keff1= CR21 Keff2 Q m Nat Circ 3
1/M = CR1/CRx T m Nat Circ 2
A = r2 Keff = 1/(1 )
F = PA
= (Keff 1)/Keff m = Av SUR = 26.06/
W Pump = m P
=
+
eff 1 + eff PT = 3IEpf
= 1.0 x 104 sec PR = 3IEsin eff = 0.1 sec1 (for small positive )
Thermal Efficiency = Net Work Out/Energy In DRW tip 2 / avg 2
g(z2 z1) gc
+ (v2 2 v1 2) 2gc
+ (P2 P1) + (u2 u1) + (q w) = 0 P = Poet/
P = Po10SUR(t) g = 32.2 ft/sec2 gc = 32.2 lbm-ft/lbf-sec2 CONVERSIONS 1 MW = 3.41 x 106 Btu/hr
= (5/9)(32) 1 ftwater 3
= 7.48 gal 1 hp = 2.54 x 103 Btu/hr
= (9/5)() + 32 1 galwater = 8.35 lbm 1 Btu = 778 ft-lbf 1 kg = 2.21 lbm 1 Curie = 3.7 x 1010 dps
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 4
QUESTION: 1 Which one of the following is a difference between a typical relief valve and a typical safety valve?
A. The actuator closing spring on a relief valve is in a compressed state whereas the actuator closing spring on a safety valve acts in tension.
B. A relief valve gradually opens as pressure increases above the setpoint pressure whereas a safety valve pops open at the setpoint pressure.
C. Relief valves are capable of being gagged whereas safety valves are not.
D. The blowdown of a relief valve is greater than the blowdown of a safety valve.
QUESTION: 2 Which one of the following statements describes the flow rate characteristics of a typical gate valve in an operating water system?
A. The first 25 percent of valve disk travel in the open direction will produce a smaller change in flow rate than the last 25 percent of valve disk travel.
B. The first 25 percent of valve disk travel in the open direction will produce a greater change in flow rate than the last 25 percent of valve disk travel.
C. The first 25 percent of valve disk travel in the open direction will produce approximately the same change in flow rate as the last 25 percent of valve disk travel.
D. A gate valve that has been opened to 25 percent of valve disk travel will result in approximately 25 percent of full flow rate.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 5
QUESTION: 3 To verify a manual valve in an operating system is closed, the operator should observe valve position indication and operate the valve handwheel in the...
A. open direction at least one full rotation, then close the valve using normal force.
B. open direction until system flow is observed, then close the valve using normal force.
C. close direction using normal force and verify there is no substantial handwheel movement.
D. close direction using normal force, then operate the valve handwheel an additional one-quarter turn in the close direction.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 6
QUESTION: 4 Refer to the drawing of a water storage tank with a differential pressure (D/P) level detection system (see figure below).
The water storage tank is 40 feet tall. The level detection system is calibrated to provide a level indication of 30 feet when the tank and reference leg levels are equal.
If the tank is completely filled with water, the tank level will indicate...
A. less than 30 feet.
B. 30 feet.
C. greater than 30 feet, but less than 40 feet.
D. 40 feet.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 7
QUESTION: 5 Which one of the following parameters requires square root compensation when measured by a differential pressure detector?
A. Reactor vessel level B. Condenser vacuum C. Reactor vessel pressure D. Recirculation pump flow rate QUESTION: 6 Which one of the following is a characteristic of a resistance temperature detector but not a thermocouple?
A. Sensing element is made from a single metal or alloy.
B. Requires a reference junction for accurate temperature measurement.
C. Extension leads made from relatively expensive metals or alloys are required for accurate temperature measurement.
D. Temperature measurement relies on a sensor material property that varies directly with the change in the measured temperature.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 8
QUESTION: 7 A fission chamber detector is initially operating in the proportional region to measure neutron flux in the source range. If the voltage applied to the detector is changed such that the detector is operating in the ion chamber region, the detector will produce __________ pulses; and will experience a
__________ positive space charge effect.
A. larger; larger B. larger; smaller C. smaller; larger D. smaller; smaller QUESTION: 8 An outside water storage tank is equipped with submerged heaters. The heaters energize at minimum power when water temperature decreases to 48°F. If water temperature continues to decrease, heater power will increase directly with the temperature deviation from 48°F until maximum power is reached at 40°F. On cold days, the tank water temperature is usually maintained at about 44°F with the heaters energized at half power.
Which one of the following types of control is used in the heater control circuit to produce these characteristics?
A. Proportional only B. Proportional plus integral only C. Proportional plus derivative only D. Proportional plus integral plus derivative
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 9
QUESTION: 9 Refer to the drawing of a pressure alarm circuit (see figure below). The orientation of the bistable symbol indicates the characteristics of the bistable, as is normal for a control circuit diagram.
The bistable will turn on at a system pressure of 100 psig. The bistable has a 5 psig deadband, or neutral zone.
If system pressure is currently 98 psig, which one of the following describes the status of the alarm?
A. The alarm is not actuated.
B. The alarm is actuated and will turn off at 95 psig.
C. The alarm is actuated and will turn off at 105 psig.
D. Additional information is needed to determine the status of the alarm.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 10 QUESTION: 10 Refer to the drawing of a centrifugal pump with a water storage tank for its suction source. The storage tank is open to the atmosphere and contains 20 feet of water at 90°F. The pump is currently stopped.
If the temperature of the water in the storage tank and pump suction piping decreases to 70°F, with the accompanying water contraction, the suction head for the pump will __________; and the available net positive suction head for the pump will __________.
A. decrease; increase B. decrease; remain the same C. remain the same; increase D. remain the same; remain the same
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 11 QUESTION: 11 When a centrifugal pump is operating at shutoff head, it is pumping at __________ capacity and
__________ discharge head.
A. maximum; maximum B. maximum; minimum C. minimum; maximum D. minimum; minimum QUESTION: 12 Given the following parameters for two independent centrifugal water pumps:
Pump A: Pump flow rate is 500 gpm at a water temperature of 70°F.
Pump B: Pump flow rate is 1000 gpm at a water temperature of 90°F.
If both pumps have the same discharge head, which pump has the lower discharge pressure, and why?
A. Pump A, due to the lower pump flow rate.
B. Pump A, due to the lower water temperature.
C. Pump B, due to the higher pump flow rate.
D. Pump B, due to the higher water temperature.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 12 QUESTION: 13 A section of pipe is being hydrostatically tested to 1,400 psig using a positive displacement pump.
The operating characteristics of the positive displacement pump are shown in the drawing below.
Which one of the following could cause the observed difference between the expected and the actual pump performance?
A. Pump internal leakage is greater than expected.
B. Pipe section boundary valve leakage is greater than expected.
C. A relief valve on the pump discharge piping opened prior to its setpoint of 1,400 psig.
D. Available NPSH decreased more than expected, but remains slightly above required NPSH.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 13 QUESTION: 14 A cooling water pump is being driven by an AC induction motor. Which one of the following describes how and why pump motor current will change if the pump shaft seizes?
A. Increases due to decreased pump flow.
B. Increases due to decreased counter electromotive force.
C. Decreases due to decreased pump flow.
D. Decreases due to increased counter electromotive force.
QUESTION: 15 An axial flow ventilation fan is being driven by an AC motor. The fan is operating at 90 percent of rated flow with its discharge damper partially closed. How will the fan motor current change if its discharge damper is fully opened?
A. The motor current will increase in accordance with the centrifugal pump laws.
B. The motor current will increase, but not in accordance with the centrifugal pump laws.
C. The motor current will decrease in accordance with the centrifugal pump laws.
D. The motor current will decrease, but not in accordance with the centrifugal pump laws.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 14 QUESTION: 16 A nuclear power plant is shut down with core decay heat being removed by the residual heat removal (RHR) system. Assume that only the RHR heat exchangers are removing heat from the reactor vessel (RV), and that the RHR system provides complete thermal mixing in the RV.
Given the following information:
Reactor core rated thermal power = 2,950 MW Core decay heat rate
= 0.6% rated thermal power RHR system heat removal rate
= 8.1 x 107 Btu/hr RHR and RV coolant cp
= 1.05 Btu/lbm-°F Combined RV and RHR inventory = 450,000 lbm Which one of the following actions will establish a reactor cooldown rate between 20°F/hour and 30°F/hour?
A. Reduce RHR heat exchanger flow rate to decrease the cooldown rate by 10°F/hour.
B. Reduce RHR heat exchanger flow rate to decrease the cooldown rate by 20°F/hour.
C. Increase RHR heat exchanger flow rate to increase the cooldown rate by 10°F/hour.
D. Increase RHR heat exchanger flow rate to increase the cooldown rate by 20°F/hour.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 15 QUESTION: 17 Refer to the drawing of an operating cooling water system (see figure below).
Which one of the following will occur as a result of the indicated tube failure in the heat exchanger?
A. Level in the surge tank decreases.
B. High pressure (HP) fluid inventory increases.
C. Pressure in the low pressure (LP) system decreases.
D. Temperature in the low pressure (LP) system increases.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 16 QUESTION: 18 Refer to the drawing of an operating lube oil heat exchanger (see figure below).
The heat exchanger is operating with the following initial parameters:
Cooling water inlet temperature (Tcw-in)
= 75°F Cooling water outlet temperature (Tcw-out) = 95°F Oil inlet temperature (Toil-in)
= 150°F Oil outlet temperature (Toil-out)
= 110°F Air leakage into the heat exchanger causes some of the heat exchanger tubes to become uncovered.
As a result, Tcw-out decreases to 89°F. Assume the inlet temperatures, mass flow rates, and specific heats of both fluids do not change.
Which one of the following will be the resulting temperature of the lube oil exiting the heat exchanger (Toil-out)?
A. 116°F B. 122°F C. 130°F D. 138°F
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 17 QUESTION: 19 A condensate demineralizer differential pressure (D/P) gauge indicates 4.0 psid at 50% flow rate.
Over the next two days plant power changes have caused condensate flow rate to vary between 25%
and 100%.
Which one of the following combinations of condensate flow and demineralizer D/P, observed during the power changes, indicates an increase in the accumulation of insoluble corrosion products in the demineralizer?
Condensate Flow Rate Demineralizer D/P (psid)
A.
100%
15.0 B.
75%
9.0 C.
40%
3.0 D.
25%
1.0 QUESTION
20 During a nuclear power plant cooldown, the reactor experiences a large crud burst. After 10 minutes, with stable reactor coolant chemistry parameters, the operators begin to record parameters for the in-service reactor coolant purification ion exchanger. The ion exchanger was recently filled with fresh resin.
Assuming no additional operator actions, what trend will the recorded parameters show during the next few hours?
A. Increasing ion exchanger inlet water conductivity.
B. Increasing ion exchanger outlet water conductivity.
C. Increasing flow rate through the ion exchanger.
D. Increasing radiation levels around the ion exchanger.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 18 QUESTION: 21 Given the following indications for an open 4,160 VAC breaker:
All phase overcurrent trip flags are reset.
The control power fuses indicate blown.
The line-side voltmeter indicates 4,160 VAC.
The load-side voltmeter indicates 0 VAC.
Assuming no operator actions were taken since the breaker opened, which one of the following could have caused the breaker to open?
A. A ground fault caused an automatic breaker trip.
B. A loss of control power caused an automatic breaker trip.
C. An operator tripped the breaker manually at the breaker cabinet.
D. An operator tripped the breaker manually from a remote location.
QUESTION: 22 If a breaker is racked to the TEST position, the...
A. remote position indication for the breaker is still operational.
B. breaker can only be operated remotely from its associated remote control panel.
C. electrical jumpers must be connected to the operating coils to operate the breaker.
D. normal breaker opening and closing operations cannot be tested because the TEST position is for overload testing only.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 19 QUESTION: 23 Which one of the following is a characteristic of a prompt neutron?
A. Expelled with an average kinetic energy of 0.5 MeV.
B. Accounts for more than 99 percent of fission neutrons.
C. Released an average of 13 seconds after the fission event.
D. Usually emitted by the excited nucleus of a fission product.
QUESTION: 24 Which one of the following is a benefit of installing excess reactivity (Kexcess) in a reactor?
A. Ensures that sufficient control rod negative reactivity is available to shut down the reactor.
B. Ensures that the reactor can be made critical during a peak xenon condition after a reactor scram.
C. Ensures that positive reactivity additions result in controllable reactor power responses.
D. Ensures that the U-235 fuel enrichment is the same at the beginning and the end of a fuel cycle.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 20 QUESTION: 25 Which one of the following is the primary reason that delayed neutrons are more effective than prompt neutrons at controlling the rate of reactor power changes?
A. Delayed neutrons have a longer mean generation time than prompt neutrons.
B. Delayed neutrons produce a larger amount of core fissions than prompt neutrons.
C. Delayed neutrons make up a larger fraction of fission neutrons than prompt neutrons.
D. Delayed neutrons are born with a lower average kinetic energy than prompt neutrons.
QUESTION: 26 A reactor is operating at 100 percent power immediately following a refueling outage. In comparison to the moderator temperature coefficient (MTC) at 100 percent power just prior to the refueling outage, the current MTC is...
A. less negative at all coolant temperatures.
B. more negative at all coolant temperatures.
C. less negative below approximately 350°F coolant temperature and more negative above approximately 350°F coolant temperature.
D. more negative below approximately 350°F coolant temperature and less negative above approximately 350°F coolant temperature.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 21 QUESTION: 27 Factors that affect the probability of resonance absorption of a neutron by a nucleus include...
A. excitation energy of the neutron, kinetic energy of the nucleus, and kinetic energy of the neutron.
B. kinetic energy of the neutron, excitation energy of the nucleus, and excitation energy of the neutron.
C. excitation energy of the nucleus, excitation energy of the neutron, and kinetic energy of the nucleus.
D. kinetic energy of the nucleus, kinetic energy of the neutron, and excitation energy of the nucleus.
QUESTION: 28 Which one of the following describes the change in magnitude (absolute value) of differential control rod worth during the complete withdrawal of a fully inserted control rod?
A. Increases, then decreases.
B. Decreases, then increases.
C. Increases continuously.
D. Decreases continuously.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 22 QUESTION: 29 Which one of the following control rods, when repositioned by 2 notches, will have the greatest effect on the axial neutron flux shape?
A. Deep rod at the center of the core B. Deep rod at the periphery of the core C. Shallow rod at the center of the core D. Shallow rod at the periphery of the core QUESTION: 30 Reactor power is increased from 50 percent to 60 percent in one hour. What is the most significant contributor to the initial change in xenon-135 reactivity?
A. Production of xenon-135 from fission.
B. Production of xenon-135 from iodine-135 decay.
C. Loss of xenon-135 due to absorption of neutrons.
D. Loss of xenon-135 due to decay to cesium-135.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 23 QUESTION: 31 A reactor had been operating at 50 percent power for two weeks when power was increased to 100 percent over a three-hour period. To maintain reactor power stable during the next 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, which one of the following incremental control rod manipulations will be required?
A. Insert rods slowly during the entire period.
B. Insert rods slowly at first, and then withdraw rods slowly.
C. Withdraw rods slowly during the entire period.
D. Withdraw rods slowly at first, and then insert rods slowly.
QUESTION: 32 Gadolinium (Gd-155, Gd-157) is used instead of boron (B-10) as the __________ material; when compared to boron, gadolinium has a much __________ cross section for absorbing thermal neutrons.
A. control rod; larger B. burnable poison; larger C. control rod; smaller D. burnable poison; smaller
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 24 QUESTION: 33 A nuclear power plant was operating at steady-state 100 percent power near the end of a fuel cycle when a reactor scram occurred. Four hours after the scram, reactor pressure is currently being maintained at 600 psig in anticipation of commencing a reactor startup.
Which one of the following will cause the core fission rate to increase?
A. The operator fully withdraws the first group of control rods.
B. Reactor vessel pressure is allowed to increase by 20 psig.
C. Reactor coolant temperature is allowed to increase by 3°F.
D. An additional 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> are allowed to pass with no other changes in plant parameters.
QUESTION: 34 After taking critical data during a reactor startup, the operator establishes a positive 48-second reactor period to increase reactor power to the point of adding heat (POAH). Which one of the following is the approximate amount of reactivity needed to stabilize power at the POAH? (Assume eff =
0.00579.)
A. -0.10 %K/K B. -0.12 %K/K C. +0.10 %K/K D. +0.12 %K/K
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 25 QUESTION: 35 A reactor was operating for several months at 100 percent power when a reactor scram occurred.
Which one of the following is primarily responsible for the reactor period value 2 minutes after the scram?
A. The Keff in the core.
B. The rate of source neutron production in the core.
C. The effective delayed neutron fraction in the core.
D. The decay rates of the delayed neutron precursors in the core.
QUESTION: 36 A reactor is critical below the point of adding heat when a fully withdrawn control rod fully inserts into the core. Assuming no operator or automatic actions, core neutron flux will slowly decrease to...
A. zero.
B. an equilibrium value less than the source neutron flux.
C. an equilibrium value greater than the source neutron flux.
D. a slightly lower value, then slowly return to the initial value.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 26 QUESTION: 37 Refer to the drawing of two water storage tanks with four differential pressure (D/P) level detectors (see figure below).
The tanks are identical and are being maintained at 2 psig overpressure, 60°F, and the same constant water level. The tanks are located within a sealed containment structure that is being maintained at standard atmospheric pressure. All level detectors have been calibrated and are producing the same level indication.
If a ventilation malfunction causes the containment structure pressure to decrease to 13 psia, which detectors will produce the lowest level indications?
A. 1 and 3 B. 2 and 4 C. 1 and 4 D. 2 and 3
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 27 QUESTION: 38 Consider 1.0 lbm of dry saturated steam at 200 psia. If pressure does not change, which one of the following will be caused by the addition of 6.0 Btu to the steam?
A. The steam will remain saturated at the same temperature.
B. The steam will become superheated at the same temperature.
C. The steam will remain saturated at a higher temperature.
D. The steam will become superheated at a higher temperature.
QUESTION: 39 A nuclear power plant is operating near rated power with the following initial conditions:
Main steam pressure
= 900 psia Main steam quality
= 100 percent, saturated vapor Main condenser pressure = 1.0 psia Air leakage into the main condenser results in the main condenser pressure increasing and stabilizing at 2.0 psia. Assume that all main steam parameters (e.g., pressure, quality, and mass flow rate) remain the same and that the main turbine efficiency remains at 100 percent.
Which one of the following is the percent by which the main generator MW output will decrease as a result of the main condenser pressure increase?
A. 5.0 percent B. 6.3 percent C. 7.5 percent D. 8.8 percent
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 28 QUESTION: 40 A nuclear power plant is initially operating at 85 percent reactor power when extraction steam to a high pressure feedwater heater is isolated. Main generator load is returned to its initial value. When the plant stabilizes, reactor power will be __________ than 85 percent; and the steam cycle thermal efficiency will be __________.
A. greater; lower B. greater; higher C. less; lower D. less; higher QUESTION: 41 Pump cavitation occurs when vapor bubbles are formed at the eye of a pump impeller...
A. because the localized flow velocity exceeds sonic velocity for the existing fluid temperature.
B. because the localized pressure exceeds the vapor pressure for the existing fluid temperature.
C. and enter a high pressure region of the pump where they collapse causing damaging pressure pulsations.
D. and are discharged from the pump where they expand into larger bubbles causing damaging pressure pulsations.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 29 QUESTION: 42 A vented water storage tank contains 30 feet of water at 70°F. A cracked weld at the bottom of the tank causes an initial leak rate of 12 gpm. If makeup water flow rate is 8 gpm, at what water level will the tank stabilize?
A. 24.5 feet B. 20.0 feet C. 13.3 feet D. 0.0 feet QUESTION: 43 The order of reactor coolant heat transfer modes, from the least efficient to the most efficient, is...
A. transition boiling, stable film boiling, nucleate boiling.
B. transition boiling, nucleate boiling, stable film boiling.
C. stable film boiling, nucleate boiling, transition boiling.
D. stable film boiling, transition boiling, nucleate boiling.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 30 QUESTION: 44 Which one of the following characteristics will enhance steam bubble formation in water adjacent to a heated surface?
A. Chemicals dissolved in the water.
B. The absence of ionizing radiation exposure to the water.
C. A highly polished heat transfer surface with minimal scratches or cavities.
D. The presence of gases dissolved in the water.
QUESTION: 45 Given:
- Reactors A and B are identical except that reactor A has no core orifices while reactor B is equipped with orifices.
- Both reactors always operate with identical recirculation system flow rates.
- Both reactors are operating at steady-state 80 percent power.
- Both reactors have the same core power distribution.
Compared to reactor A, the critical power ratio (CPR) in the central fuel bundles of reactor B is
__________; and the average power in the peripheral fuel bundles of reactor B is __________.
A. larger; larger B. larger; smaller C. smaller; larger D. smaller; smaller
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 31 QUESTION: 46 Which one of the following statements describes natural circulation in a shutdown reactor? (Assume no isolation condenser exists.)
A. The moisture separators return the liquid portion of the coolant mixture exiting the core to the downcomer where it cools and increases in density.
B. The jet pump diffusers establish a thermal driving head by increasing the velocity of the coolant as it flows downward through the diffuser.
C. Coolant flows from the downcomer into a reactor recirculation loop and is returned to the core.
D. Emergency coolant injection establishes a thermal driving head by providing cold coolant to the downcomer.
QUESTION: 47 The ratio of the highest pin heat flux in a node to the average pin heat flux in the same node is called the __________ peaking factor.
A. local B. radial C. axial D. total
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 32 QUESTION: 48 The linear heat generation rate (LHGR) for a reactor core is acceptable if __________ is being maintained at __________.
A. LHGRlimit/LHGRmeasured; 0.95 B. LHGRmeasured/LHGRlimit; 1.05 C. LHGRlimit/LHGRmeasured; 1.10 D. LHGRmeasured/LHGRlimit; 1.15 QUESTION: 49 What is the primary purpose of the gap between a fuel pellet and the surrounding cladding?
A. To allow insertion of fuel pellets into the fuel rods.
B. To provide a collection volume for fission product gases.
C. To maintain the design fuel thermal conductivity throughout the fuel cycle.
D. To accommodate different expansion rates in the fuel pellets and the cladding.
USNRC GENERIC FUNDAMENTALS EXAMINATION DECEMBER 2015 BWR - FORM A 33 QUESTION: 50 Which one of the following comparisons will result in a higher probability for brittle fracture of the reactor vessel?
A. A high gamma flux in the reactor rather than a high neutron flux.
B. A high oxygen content in the reactor coolant rather than a low oxygen content.
C. A high material strength in the reactor vessel rather than a high material ductility.
D. A rapid 100°F reactor cooldown at a high temperature rather than at a low temperature.
- FINAL ANSWER KEY ***
DECEMBER 2015 NRC GENERIC FUNDAMENTALS EXAMINATION BOILING WATER REACTOR - ANSWER KEY FORM A FORM B ANS.
1 15 B
2 16 B
3 17 C
4 18 B
5 19 D
6 20 A
7 21 D
8 22 A
9 23 D
10 24 A
11 25 C
12 26 D
13 27 A
14 28 B
15 29 D
16 30 B
17 31 A
18 32 B
19 33 C
20 34 D
21 35 C
22 36 A
23 37 B
24 38 B
25 39 A
FORM A FORM B ANS.
26 40 B
27 41 D
28 42 A
29 43 C
30 44 C
31 45 B
32 46 B
33 47 A
34 48 A
35 49 D
36 50 C
37 1
C 38 2
D 39 3
C 40 4
A 41 5
C 42 6
C 43 7
D 44 8
D 45 9
B 46 10 A
47 11 A
48 12 C
49 13 D
50 14 C