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72 Cards in this Set

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Moderator temperature coefficient is defined as the change in core reactivity per degree change in... A. fuel temperature. B. fuel clad temperature. C. reactor vessel temperature. D. reactor coolant temperature.
D.
Which one of the following isotopes is the most significant contributor to resonance capture of fission neutrons in a nuclear reactor core at the beginning of core life? A. U-233 B. U-238 C. Pu-239 D. Pu-240
B.
Factors that affect the probability of resonance absorption of a neutron by a nucleus include... A. kinetic energy of the nucleus, kinetic energy of the neutron, and excitation energy of the nucleus. 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. excitation energy of the neutron, kinetic energy of the nucleus, and kinetic energy of the neutron.
A.
Which one of the following isotopes is the most significant contributor to resonance capture of fission neutrons in a nuclear reactor core near the end of a fuel cycle? A. U-235 B. U-238 C. Pu-239 D. Pu-240
B.
Which one of the following has the smallest microscopic cross section for absorption of a thermal neutron in an operating nuclear reactor? A. Uranium-235 B. Uranium-238 C. Samarium-149 D. Xenon-135
B.
Under which one of the following conditions is a nuclear reactor core most likely to have a positive moderator temperature coefficient? A. Low coolant temperature at beginning-of-life B. Low coolant temperature at end-of-life C. High coolant temperature at beginning-of-life D. High coolant temperature at end-of-life
A.
A nuclear reactor has operated at steady-state 100 percent power for the past 6 months. Compared to 6 months ago, the current moderator temperature coefficient is... A. more negative due to control rod withdrawal. B. less negative due to control rod insertion. C. more negative due to decreased reactor coolant system (RCS) boron concentration. D. less negative due to increased RCS boron concentration.
C.
Which one of the following contains the pair of nuclides that are the most significant contributors to the total resonance capture in the core near the end of a fuel cycle? A. Pu-239 and U-235 B. Pu-239 and Pu-240 C. U-238 and Pu-240 D. U-238 and Pu-239
C.
Which one of the following conditions will cause the moderator temperature coefficient (MTC) to become more negative? (Consider only the direct effect of the indicated change on MTC.) A. The controlling bank of control rods is inserted 5 percent into the core. B. Fuel temperature decreases from 1500EF to 1200EF. C. Reactor coolant boron concentration increases by 20 ppm. D. Moderator temperature decreases from 500EF to 450EF.
A.
Which one of the following contains the nuclides responsible for most of the resonance capture of fission neutrons in a nuclear reactor core at the beginning of the sixth fuel cycle? (Assume that each refueling replaces one-third of the fuel.) A. U-235 and Pu-239 B. U-235 and U-238 C. U-238 and Pu-239 D. U-238 and Pu-240
D.
Which one of the following contains two isotopes, both of which are responsible for the negative reactivity inserted when fuel temperature increases near the end of core life? A. U-235 and Pu-239 B. U-235 and Pu-240 C. U-238 and Pu-239 D. U-238 and Pu-240
D.
As the reactor coolant boron concentration increases, the moderator temperature coefficient becomes less negative. This is because a 1EF increase in reactor coolant temperature at higher boron concentrations results in a larger increase in the... A. fast fission factor. B. thermal utilization factor. C. total nonleakage probability. D. resonance escape probability.
B.
In which of the following conditions is the moderator temperature coefficient most negative? A. Beginning of core life (BOL), high temperature B. BOL, low temperature C. End of core life (EOL), high temperature D. EOL, low temperature
C.
During a nuclear power plant heat-up at end of core life, the moderator temperature coefficient becomes increasingly more negative. This is because... A. as moderator density decreases, more thermal neutrons are absorbed by the moderator than by the fuel. B. the change in the thermal utilization factor dominates the change in the resonance escape probability. C. a greater density change per EF occurs at higher reactor coolant temperatures. D. the core transitions from an undermoderated condition to an overmoderated condition.
C.
The moderator temperature coefficient will be least negative at a __________ reactor coolant temperature and a __________ reactor coolant boron concentration. A. high; high B. high; low C. low; high D. low; low
C.
A nuclear reactor is operating at full power following a refueling outage. In comparison to the current moderator temperature coefficient (MTC), the MTC just prior to the refueling was... A. less negative at all coolant temperatures. B. more negative at all coolant temperatures. C. less negative below approximately 350EF coolant temperature and more negative above approximately 350EF coolant temperature. D. more negative below approximately 350EF coolant temperature and less negative above approximately 350EF coolant temperature.
B.
During a reactor coolant system cooldown, positive reactivity is added to the core if the moderator temperature coefficient is negative. This is partially due to... A. a decrease in the thermal utilization factor. B. an increase in the thermal utilization factor. C. a decrease in the resonance escape probability. D. an increase in the resonance escape probability.
D.
As the core ages, the moderator temperature coefficient becomes more negative. This is primarily due to... A. fission product poison buildup in the fuel. B. decreasing fuel centerline temperature. C. decreasing control rod worth. D. decreasing reactor coolant system boron concentration.
D.
The moderator temperature coefficient will be most negative at a __________ reactor coolant temperature and a __________ reactor coolant boron concentration. A. low; low B. high; low C. low; high D. high; high
B.
Which one of the following describes the net reactivity effect of a moderator temperature decrease in an undermoderated nuclear reactor core? A. Negative reactivity will be added because more neutrons will be absorbed at resonance energies while slowing down. B. Negative reactivity will be added because more neutrons will be captured by the moderator. C. Positive reactivity will be added because fewer neutrons will be absorbed at resonance energies while slowing down. D. Positive reactivity will be added because fewer neutrons will be captured by the moderator.
C.
Which one of the following describes why the moderator temperature coefficient is more negative near the end of core life (EOL) compared to the beginning of core life (BOL)? A. Increased nucleate boiling near the EOL amplifies the negative reactivity added by a 1EF moderator temperature increase. B. Increased control rod insertion near the EOL amplifies the negative reactivity added by a 1EF moderator temperature increase. C. Decreased fuel temperature near the EOL results in reduced resonance neutron capture for a 1EF increase in moderator temperature. D. Decreased coolant boron concentration near the EOL results in fewer boron atoms leaving the core for a 1EF moderator temperature increase.
D.
Which one of the following describes the net reactivity effect of a moderator temperature decrease in an overmoderated reactor core? A. Positive reactivity will be added because fewer neutrons will be captured by the moderator. B. Positive reactivity will be added because fewer neutrons will be absorbed at resonance energies while slowing down. C. Negative reactivity will be added because more neutrons will be captured by the moderator. D. Negative reactivity will be added because more neutrons will be absorbed at resonance energies while slowing down.
C.
A nuclear reactor is operating at full power following a refueling outage. Compared to the moderator temperature coefficient (MTC) just prior to the refueling, the current MTC is... A. less negative at all coolant temperatures. B. more negative at all coolant temperatures. C. less negative below approximately 350EF coolant temperature and more negative above approximately 350EF coolant temperature. D. more negative below approximately 350EF coolant temperature and less negative above approximately 350EF coolant temperature.
A.
Which one of the following describes the net reactivity effect of a moderator temperature increase in an overmoderated nuclear reactor core? A. Negative reactivity will be added because more neutrons will be absorbed at resonance energies while slowing down. B. Negative reactivity will be added because more neutrons will be captured by the moderator. C. Positive reactivity will be added because fewer neutrons will be absorbed at resonance energies while slowing down.. D. Positive reactivity will be added because fewer neutrons will be captured by the moderator.
D.
How does the addition of boric acid to the reactor coolant affect the moderator temperature coefficient in an undermoderated nuclear reactor core? A. The initially negative MTC becomes more negative. B. The initially negative MTC becomes less negative. C. The initially positive MTC becomes more positive. D. The initially positive MTC becomes less positive.
B.
As compared to the moderator temperature coefficient (MTC) of reactivity near the beginning of core life, the MTC near the end of core life is: (Assume 100 percent power for all cases.) A. more negative because as U-235 depletes, more fission neutrons are able to escape resonance capture. B. less negative because as U-238 depletes, more fission neutrons are able to escape resonance capture. C. more negative because as reactor coolant boron concentration decreases, the thermal utilization of fission neutrons increases. D. less negative because as control rods are withdrawn from the core, the thermal utilization of fission neutrons increases.
C.
Which one of the following describes the overall core reactivity effect of a moderator temperature increase in an undermoderated nuclear reactor core? A. Negative reactivity will be added because more neutrons will be absorbed by U-238 at resonance energies while slowing down. B. Negative reactivity will be added because more neutrons will be captured by the moderator while slowing down. C. Positive reactivity will be added because fewer neutrons will be absorbed by U-238 at resonance energies while slowing down. D. Positive reactivity will be added because fewer neutrons will be captured by the moderator while slowing down.
A.
When compared to the beginning of a fuel cycle, the moderator temperature coefficient at 100 percent power near the end of a fuel cycle (EOC) is... A. more negative, because fewer boron-10 nuclei are removed from the core for a given moderator temperature increase. B. less negative, because more boron-10 nuclei are removed from the core for a given moderator temperature increase. C. more negative, because a smaller fraction of the neutron flux will leak out of the core following a given moderator temperature increase. D. less negative, because a larger fraction of the neutron flux will leak out of the core following a given moderator temperature increase.
A.
Why does the fuel temperature (Doppler) coefficient becomes less negative at higher fuel temperatures? A. As reactor power increases, the rate of increase in the fuel temperature diminishes. B. Neutrons penetrate deeper into the fuel, resulting in an increase in the fast fission factor. C. The amount of self-shielding increases, resulting in less neutron absorption by the inner fuel. D. The amount of Doppler broadening per degree change in fuel temperature diminishes.
D.
Which one of the following will cause the Doppler power coefficient to become more negative? A. Increased clad creep B. Increased pellet swell C. Lower power level D. Higher reactor coolant boron concentration
C.
As core age increases, for the same power level the fuel temperature coefficient of reactivity becomes ______________ negative because average fuel temperature ______________. A. more; decreases B. more; increases C. less; decreases D. less; increases
A.
Which one of the following pairs of isotopes is responsible for the negative reactivity associated with a fuel temperature increase near the end of core life? A. U-235 and Pu-239 B. U-235 and Pu-240 C. U-238 and Pu-239 D. U-238 and Pu-240
D.
A nuclear power plant is operating at 70 percent power. Which one of the following will result in a less negative fuel temperature coefficient? (Consider only the direct effect of the change in each listed parameter.) A. Increase in Pu-240 inventory in the core B. Increase in moderator temperature C. Increase in fuel temperature D. Increase in void fraction
C.
Compared to operation at a low power level, the fuel temperature coefficient of reactivity at a high power level is ____________ negative due to ____________. (Assume the same core age.) A. less; improved pellet-to-clad heat transfer B. more; buildup of fission product poisons C. less; higher fuel temperature D. more; increased neutron flux
C.
Refer to the drawing of microscopic cross section for absorption versus neutron energy for a resonance peak in U-238 (see figure below). If fuel temperature increases, the area under the curve will ___________ and negative reactivity will be added to the core because ____________. A. increase; neutrons of a wider range of energies will be absorbed by U-238 B. increase; more neutrons will be absorbed by U-238 at the resonance neutron energy C. remain the same; neutrons of a wider range of energies will be absorbed by U-238 D. remain the same; more neutrons will be absorbed by U-238 at the resonance neutron energy
C.
Which one of the following describes how the magnitude of the fuel temperature coefficient of reactivity is affected over core life? A. It remains essentially constant over core life. B. It becomes more negative due to the buildup of Pu-240. C. It becomes less negative due to the decrease in RCS boron concentration. D. It becomes more negative initially due to buildup of fissions product poisons, then less negative due to fuel depletion.
B.
The fuel temperature (Doppler) coefficient of reactivity is more negative at the ____________ of a fuel cycle because ________________. (Assume the same initial fuel temperature throughout the fuel cycle.) A. end; more Pu-240 is in the core B. end; more fission products are in the core C. beginning; more U-238 is in the core D. beginning; less fission products are in the core
A.
Refer to the drawing of microscopic cross section for absorption versus neutron energy for a 6.7 electron volt (ev) resonance peak in U-238 for a nuclear reactor operating at 50 percent power (see figure below). If fuel temperature decreases by 50EF, the area under the curve will ___________ and positive reactivity will be added to the core because ____________. A. decrease; fewer neutrons will be absorbed by U-238 overall B. decrease; fewer 6.7 ev neutrons will be absorbed by U-238 at the resonance energy C. remain the same; fewer neutrons will be absorbed by U-238 overall D. remain the same; fewer 6.7 ev neutrons will be absorbed by U-238 at the resonance energy
C.
Refer to the drawing of microscopic cross section for absorption versus neutron energy for a resonance peak in U-238 in a nuclear reactor operating at 80 percent power (see figure below). If reactor power is increased to 100 percent, the height of the curve will _________ and the area under the curve will _________. A. increase; increase B. increase; remain the same C. decrease; decrease D. decrease; remain the same
D
Refer to the drawing of a curve showing the neutron absorption characteristics of a typical U-238 nucleus at a resonance neutron energy (see figure below). The associated nuclear reactor is currently operating at steady-state 80 percent power. During a subsequent reactor power decrease to 70 percent, the curve will become ________; and the percentage of the core neutron population lost to resonance capture by U-238 will ________. A. taller and more narrow; decrease B. taller and more narrow; increase C. shorter and broader; decrease D. shorter and broader; increase
A.
Refer to the drawing of microscopic cross section for absorption versus neutron energy for a resonance peak in U-238 in a nuclear reactor operating at 80 percent power (see figure below). If reactor power is decreased to 60 percent, the height of the curve will _________ and the area under the curve will _________. A. increase; increase B. increase; remain the same C. decrease; decrease D. decrease; remain the same
B.
If the average temperature of a fuel pellet decreases by 50EF, the microscopic cross-section for absorption of neutrons at a resonance energy of U-238 will ____________; and the microscopic cross-sections for absorption of neutrons at energies that are slightly higher or lower than a U-238 resonance energy will ____________. A. increase; increase B. increase; decrease C. decrease; increase D. decrease; decrease
B.
Which one of the following groups contain parameters that, if varied, will each have a direct effect on the power coefficient? A. Control rod position, reactor power, moderator voids B. Moderator temperature, RCS pressure, Xenon level C. Fuel temperature, xenon level, control rod position D. Moderator voids, fuel temperature, moderator temperature
D.
Which one of the following adds the most positive reactivity following a reactor trip/scram from full power near the beginning of core life? (Assume reactor coolant system parameters stabilize at their normal post-trip values.) A. Void coefficient B. Pressure coefficient C. Fuel temperature coefficient D. Moderator temperature coefficient
C.
A nuclear power plant is initially operating at 50 percent power. Which one of the following contains only parameters that, if varied, will each directly change the magnitude of the power defect? A. Control rod position, reactor power, and moderator voids B. Moderator voids, fuel temperature, and moderator temperature C. Fuel temperature, xenon concentration, and control rod position D. Moderator temperature, reactor coolant pressure, and xenon concentration
B.
A nuclear reactor is exactly critical at the point of adding heat during a xenon-free reactor startup near the beginning of core life. Reactor power is ramped to 50 percent over the next 4 hours. During the power increase, most of the positive reactivity added by the operator is necessary to overcome the negative reactivity associated with the... A. buildup of core Xe-135. B. increased fuel temperature. C. burnout of burnable poisons. D. increased reactor coolant temperature.
B.
A nuclear reactor has been operating at steady state 50 percent power for one month following a refueling outage. Reactor power is ramped to 100 percent over the next 2 hours. During the power increase, most of the positive reactivity added by the operator is necessary to overcome the negative reactivity associated with the... A. increased reactor coolant temperature. B. buildup of core Xe-135. C. burnout of burnable poisons. D. increased fuel temperature.
D.
As reactor coolant boron concentration is reduced differential boron reactivity worth (¥K/K per ppm) becomes... A. less negative due to the increased number of water molecules in the core. B. more negative due to the increased number of water molecules in the core. C. less negative due to the decreased number of boron molecules in the core. D. more negative due to the decreased number of boron molecules in the core.
D.
With higher concentrations of boron in the reactor coolant, the core neutron flux distribution shifts to ____________ energies where the absorption cross-section of boron is ____________. A. higher; lower B. higher; higher C. lower; lower D. lower; higher
A.
Differential boron reactivity worth will become _______ negative as moderator temperature increases because, at higher moderator temperatures, a 1 ppm increase in reactor coolant system boron concentration will add _______ boron atoms to the core. A. more; fewer B. more; more C. less; fewer D. less; more
C.
Differential boron worth (¥K/K/ppm) becomes more negative as... A. burnable poisons deplete. B. boron concentration increases. C. moderator temperature increases. D. fission product poison concentration increases.
A.
The following are the initial conditions for a nuclear power plant: Reactor power is 50 percent. Average reactor coolant temperature is 570EF. After a power increase, current plant conditions are as follows: Reactor power is 80 percent. Average reactor coolant temperature is 582EF. Assume that the initial and current reactor coolant boron concentrations are the same. Which one of the following describes the current differential boron worth (DBW) in comparison to the initial DBW? A. The current DBW is more negative because a 1EF increase in reactor coolant temperature will remove more boron-10 atoms from the core. B. The current DBW is more negative because a 1 ppm increase in reactor coolant boron concentration will add more boron-10 atoms to the core. C. The current DBW is less negative because a 1EF increase in reactor coolant temperature will remove fewer boron-10 atoms from the core. D. The current DBW is less negative because a 1 ppm increase in reactor coolant boron concentration will add fewer boron-10 atoms to the core.
D.
The amount of boric acid required to increase the reactor coolant boron concentration by 50 ppm near the beginning of core life (1,200 ppm) is approximately ____________ as the amount of boric acid required to increase boron concentration by 50 ppm near the end of core life (100 ppm). A. the same B. four times as large C. eight times as large D. twelve times as large
A.
The amount of pure water required to decrease the reactor coolant boron concentration by 20 ppm near the end of core life (100 ppm) is approximately ______________ the amount of pure water required to decrease reactor coolant boron concentration by 20 ppm near the beginning of core life (1,000 ppm). A. one-tenth B. the same as C. 10 times D. 100 times
C.
A reactivity coefficient measures a/an ________________ change in reactivity while a reactivity defect measures a _________________ change in reactivity due to a change in the measured parameter. A. integrated; total B. integrated; differential C. unit; total D. unit; differential
C.
Given the following initial parameters, select the final reactor coolant boron concentration required to decrease average coolant temperature by 4EF. (Assume no change in rod position or reactor/turbine power). Initial reactor coolant system boron concentration = 600 ppm Moderator temperature coefficient = -0.015% ¥K/K per EF Differential boron worth = -0.010% ¥K/K per ppm Inverse boron worth = -100 ppm/% ¥K/K A. 606 ppm B. 603 ppm C. 597 ppm D. 594 ppm
A.
Given the following initial parameters, select the final reactor coolant boron concentration required to increase average coolant temperature by 6EF. (Assume no change in rod position or reactor/turbine power.) Initial boron concentration = 500 ppm Moderator temperature coefficient = -0.012% ¥K/K per EF Differential boron worth = -0.008% ¥K/K per ppm Inverse boron worth = -125 ppm/% ¥K/K A. 491 ppm B. 496 ppm C. 504 ppm D. 509 ppm
A.
Given the following initial parameters: Total power coefficient = -0.016% ¥K/K/% Boron worth = -0.010% ¥K/K/ppm Rod worth = -0.030% ¥K/K/inch inserted Initial reactor coolant system (RCS) boron concentration = 500 ppm Which one of the following is the final RCS boron concentration required to support increasing plant power from 30 percent to 80 percent by boration/dilution with 10 inches of outward control rod motion. (Assume no change in xenon reactivity.) A. 390 ppm B. 420 ppm C. 450 ppm D. 470 ppm
C.
A nuclear power plant is operating at steady-state 100 percent power. Given the following initial parameters, select the final reactor coolant boron concentration required to decrease average coolant temperature by 6EF. (Assume no change in control rod position or reactor/turbine power.) Initial boron concentration = 500 ppm Moderator temperature coefficient = -0.012% ¥K/K per EF Differential boron worth = -0.008% ¥K/K per ppm Inverse boron worth = -125 ppm/% ¥K/K A. 509 ppm B. 504 ppm C. 496 ppm D. 491 ppm
A.
Given the following initial parameters: Total power coefficient = -0.020% ¥K/K/% Boron worth = -0.010% ¥K/K/ppm Rod worth = -0.025% ¥K/K/inch inserted Initial reactor coolant system (RCS) boron concentration = 500 ppm Which one of the following is the final RCS boron concentration required to support increasing plant power from 30 percent to 80 percent by boration/dilution with 10 inches of outward control rod motion? (Assume no change in xenon reactivity.) A. 425 ppm B. 450 ppm C. 550 ppm D. 575 ppm
A.
Given the following initial parameters: Total power coefficient = -0.020% ¥K/K/% Boron worth = -0.010% ¥K/K/ppm Rod worth = -0.025% ¥K/K/inch inserted Initial reactor coolant system (RCS) boron concentration = 500 ppm Which one of the following is the final RCS boron concentration required to support decreasing plant power from 80 percent to 30 percent by boration/dilution with 10 inches of inward control rod motion? (Assume no change in xenon reactivity.) A. 425 ppm B. 475 ppm C. 525 ppm D. 575 ppm
D.
Given the following initial parameters: Total power coefficient = -0.020% ¥K/K/% Boron worth = -0.010% ¥K/K/ppm Control rod worth = -0.025% ¥K/K/inch inserted Initial reactor coolant system (RCS) boron concentration = 600 ppm Which one of the following is the final RCS boron concentration required to support increasing plant power from 40 percent to 80 percent with 40 inches of outward control rod motion? (Ignore any change in fission product poison reactivity.) A. 420 ppm B. 580 ppm C. 620 ppm D. 780 ppm
C.
Given the following initial parameters: Reactor power = 100% Total power coefficient = -0.020% ¥K/K/% Boron worth = -0.010% ¥K/K/ppm Rod worth = -0.025% ¥K/K/inch inserted Initial reactor coolant system (RCS) boron concentration = 500 ppm Which one of the following is the final RCS boron concentration required to support decreasing plant power to 30 percent by boration/dilution with 20 inches of inward control rod motion? (Assume no change in core xenon reactivity.) A. 410 ppm B. 425 ppm C. 575 ppm D. 590 ppm
D.
During power operation, while changing power level, core reactivity is affected most quickly by... A. boron concentration adjustments. B. power defect (deficit). C. xenon transients. D. fuel depletion.
B.
Which one of the following statements concerning the power defect is correct? A. The power defect necessitates the use of a ramped Tave program to maintain an adequate reactor coolant system subcooling margin. B. The power defect increases the rod height requirements necessary to maintain the desired shutdown margin following a reactor trip. C. The power defect is more negative near the beginning of core life because of the higher boron concentration. D. The power defect causes control rods to be withdrawn as reactor power is decreased.
B.
Neglecting the effects of changes in core Xe-135, which one of the following power changes requires the greatest amount of positive reactivity addition? A. 3% power to 5% power B. 5% power to 15% power C. 15% power to 30% power D. 30% power to 60% power
D.
Neglecting the effects of core Xe-135, which one of the following power changes requires the smallest amount of positive reactivity addition? A. 2% power to 5% power B. 5% power to 15% power C. 15% power to 30% power D. 30% power to 50% power
A.
Neglecting the effects of core Xe-135, which one of the following power changes requires the greatest amount of positive reactivity addition? A. 3% power to 10% power B. 10% power to 25% power C. 25% power to 60% power D. 60% power to 100% power
D.
Neglecting the effects of core Xe-135, which one of the following reactor power changes requires the greatest amount of positive reactivity addition? A. 3% power to 10% power B. 10% power to 25% power C. 25% power to 65% power D. 65% power to 100% power
C.
A nuclear reactor startup is in progress with the reactor at normal operating temperature and pressure. With reactor power stable at the point of adding heat, a control rod malfunction causes an inadvertent rod withdrawal that results in adding 0.3 %¥K/K reactivity. Given: All control rod motion has been stopped. No automatic system or operator actions occur to inhibit the power increase. Power coefficient = -0.04 %¥K/K / % power Average effective delayed neutron fraction = 0.006 What is the approximate power level increase required to offset the reactivity added by the inadvertent control rod withdrawal? A. 3.0 percent B. 5.0 percent C. 6.7 percent D. 7.5 percent
D.
Neglecting the effects of changes in core Xe-135, which one of the following power changes requires the smallest amount of positive reactivity addition? A. 3% power to 10% power B. 10% power to 15% power C. 15% power to 30% power D. 30% power to 40% power
B.
A nuclear reactor startup is in progress with the reactor at normal operating temperature and pressure. With reactor power stable at the point of adding heat, a control rod malfunction causes an inadvertent rod withdrawal that results in adding 0.2 %¥K/K reactivity. Given: All control rod motion has been stopped. No automatic system or operator actions occur to inhibit the power increase. Power coefficient = -0.04 %¥K/K / % power Average effective delayed neutron fraction = 0.006 What is the approximate reactor power level increase required to offset the reactivity added by the inadvertent control rod withdrawal? A. 3.3 percent B. 5.0 percent C. 6.7 percent D. 7.5 percent
B.