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Cards In This Set
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The term “neutron generation time” is defined as the average time between...
A. neutron absorption and the resulting fission.
B. the production of a delayed neutron and subsequent neutron thermalization.
C. neutron absorption producing a fission and absorption or leakage of resultant neutrons.
D. neutron thermalization and subsequent neutron absorption.
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C. neutron absorption producing a fission and absorption or leakage of resultant neutrons.
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Which one of the following is the definition of the term prompt neutron?
A. A high-energy neutron emitted from a neutron precursor, immediately after the fission process.
B. A neutron with an energy level greater than 0.1 MeV, emitted in less than 10-4 seconds following
a nuclear fission.
C. A neutron emitted in less than 10-14 seconds following a nuclear fission.
D. A neutron emitted as a result of a gamma-n or alpha-n reaction.
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C. A neutron emitted in less than 10-14 seconds following a nuclear fission.
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Delayed neutrons are neutrons that...
A. have reached thermal equilibrium with the surrounding medium.
B. are expelled within 10-14 seconds of the fission event.
C. are expelled with the lowest average kinetic energy of all fission neutrons.
D. are responsible for the majority of U-235 fissions.
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C. are expelled with the lowest average kinetic energy of all fission neutrons.
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Which one of the following types of neutrons has an average neutron generation lifetime of 12.5
seconds?
A. Prompt
B. Delayed
C. Fast
D. Thermal
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B. Delayed
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A neutron that is expelled 1.0 x 10-2 seconds after the associated fission event is a ____________
neutron.
A. thermal
B. delayed
C. prompt
D. capture
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B. delayed
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Which one of the following is a characteristic of a prompt neutron?
A. Expelled with an average kinetic energy of 0.5 MeV.
B. Usually emitted by the excited nucleus of a fission product.
C. Accounts for more than 99 percent of fission neutrons.
D. Released an average of 13 seconds after the fission event.
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C. Accounts for more than 99 percent of fission neutrons.
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Delayed neutrons are fission neutrons that...
A. are released at the instant of fission.
B. are responsible for the majority of U-235 fissions.
C. have reached thermal equilibrium with the surrounding medium.
D. are expelled at a lower average kinetic energy than most other fission neutrons.
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D. are expelled at a lower average kinetic energy than most other fission neutrons.
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Delayed neutrons are fission neutrons that...
A. have reached thermal equilibrium with the surrounding medium.
B. are expelled within 10-14 seconds of the fission event.
C. are produced from the radioactive decay of specific fission fragments.
D. are responsible for the majority of U-235 fissions.
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C. are produced from the radioactive decay of specific fission fragments.
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In a comparison between a delayed neutron and a prompt neutron produced from the same fission
event, the prompt neutron is more likely to...
A. require a greater number of collisions to become a thermal neutron.
B. be captured by U-238 at a resonance energy peak between 1 eV and 1000 eV.
C. be expelled with a lower kinetic energy.
D. cause thermal fission of a U-235 nucleus.
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A. require a greater number of collisions to become a thermal neutron.
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In a comparison between a delayed neutron and a prompt neutron produced from the same fission
event, the prompt neutron is more likely to... (Assume that both neutrons remain in the core.)
A. cause fast fission of a U-238 nucleus.
B. be captured by a U-238 nucleus at a resonance energy between 1 eV and 1000 eV.
C. be captured by a Xe-135 nucleus.
D. cause thermal fission of a U-235 nucleus.
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A. cause fast fission of a U-238 nucleus.
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In a comparison between a delayed neutron and a prompt neutron produced from the same fission
event, the delayed neutron is more likely to... (Assume that each neutron remains in the core unless
otherwise stated.)
A. cause fission of a U-238 nucleus.
B. travel to an adjacent fuel assembly.
C. be absorbed in a B-10 nucleus.
D. leak out of the core.
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C. be absorbed in a B-10 nucleus.
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A neutron that is released 1.0 x 10-10 seconds after the associated fission event is classified as a
____________ fission neutron.
A. delayed
B. prompt
C. thermal
D. spontaneous
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A. delayed
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In a comparison between a delayed neutron and a prompt neutron produced from the same fission
event, the prompt neutron is more likely to...
A. be captured by a Xe-135 nucleus.
B. cause thermal fission of a U-235 nucleus.
C. leak out of the core while slowing down.
D. be captured by a U-238 nucleus at a resonance energy between 1 eV and 1000 eV.
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C. leak out of the core while slowing down.
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In a comparison between a delayed neutron and a prompt neutron produced from the same fission
event, the delayed neutron is more likely to...
A. leak out of the core.
B. cause fission of a U-238 nucleus.
C. become a thermal neutron.
D. cause fission of a Pu-240 nucleus.
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C. become a thermal neutron.
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Which one of the following types of neutrons in a nuclear reactor is more likely to cause fission of a
U-238 nucleus in the reactor fuel? (Assume that each type of neutron remains in the reactor core
until it interacts with a U-238 nucleus.)
A. Thermal neutron
B. Prompt fission neutron beginning to slow down
C. Delayed fission neutron beginning to slow down
D. Neutron at a U-238 resonance energy
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B. Prompt fission neutron beginning to slow down
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