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18 Cards in this Set
- Front
- Back
- 3rd side (hint)
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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. |
ANSWER: D.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P545 (B1845) |
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Delayed neutrons are the 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 certain fission fragments. D. are responsible for the majority of U-235 fissions. |
ANSWER: C.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P845 (B1945) |
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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. |
ANSWER: C.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P1145 (B1545) |
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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 |
ANSWER: B.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P1445 (B1345) |
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A neutron that is expelled 1.0 x 10^-6 seconds after the associated fission event is a ____________ neutron.
A. thermal B. delayed C. prompt D. capture |
ANSWER: B.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P1545 |
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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 |
ANSWER: B.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P1945 (B1146) |
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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. |
ANSWER: A.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P2045 (B2046) |
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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. |
ANSWER: A.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P2145 (B2145) |
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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 |
ANSWER: A.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P2345 (B2345) |
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As compared to a prompt neutron, a delayed neutron, produced from the same fission event, requires _______ collisions in the moderator to become thermal and is _______ likely to cause fission of a U-238 nucleus. (Neglect the effects of neutron leakage.)
A. more; more B. more; less C. fewer; more D. fewer; less |
ANSWER: D.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P2445 (B3345) |
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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. leak out of the core while slowing down. B. be captured by a U-238 nucleus at a resonance energy. C. be captured by a Xe-135 nucleus. D. cause thermal fission of a U-235 nucleus. |
ANSWER: A.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P2545 (B2545) |
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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. |
ANSWER: C.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P2645 (B2645) |
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During a brief time interval in a typical commercial nuclear reactor operating near the beginning of a fuel cycle, 1.0 x 10^3 delayed neutrons were emitted. Approximately how many prompt neutrons were emitted during this same time interval?
A. 1.5 x 10^5 B. 6.5 x 10^6 C. 1.5 x 10^7 D. 6.5 x 10^8 |
ANSWER: A.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P2845 (B3145) |
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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 |
ANSWER: B.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P2945 (B2945) |
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During a brief time interval in a typical commercial nuclear reactor operating at the beginning of a fuel cycle, 1.0 x 10^5 delayed neutrons were emitted. Approximately how many prompt neutrons were emitted in the reactor during this same time interval?
A. 1.5 x 10^5 B. 6.5 x 10^6 C. 1.5 x 10^7 D. 6.5 x 10^8 |
ANSWER: C.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P3545 (B3545) |
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A neutron that appears 1.0 x 10^-16 seconds after the associated fission event is classified as a ____________ fission neutron.
A. delayed B. prompt C. thermal D. spontaneous |
ANSWER: B.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P4123 (B4123) |
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During a brief time interval in a typical commercial nuclear reactor operating at the beginning of a fuel cycle, 4.25 x 10^5 delayed neutrons were emitted. Approximately how many prompt neutrons were emitted in the reactor during this same time interval?
A. 1.5 x 10^6 B. 6.5 x 10^6 C. 1.5 x 10^7 D. 6.5 x 10^7 |
ANSWER: D.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P4923 (B4923) |
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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. require a greater number of collisions to become a thermal neutron. C. be absorbed in a B-10 nucleus. D. leak out of the core. |
ANSWER: C.
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TOPIC: 192001
KNOWLEDGE: K1.02 [2.4/2.5] QID: P5023 (B2245) |
