Delayed neutrons are generated: Immediately after the fission. After fragmentation of cosmic rays. After the radioactive decay of some fission fragments that are called precursors of delayed neutrons. During slowing-down of fast neutrons. Answer: c) The multiplication factor is: The ratio between the number of neutrons in one generation to the number of neutrons in the previous generation. The ratio between the number of fast neutrons produced in fast and thermal fission and the number of fast neutrons produced in the thermal fission. Proportion of delayed neutrons in the total number of neutrons. Answer: a) Thermal non-leakage factor is: Pt The probability that a thermal neutron will not escape from the core. The probability that a thermal neutron will escape from the core. The probability that a thermal neutron will be absorbed in resonances. Answer: a) Fast non-leakage factor tells: Pf The probability that a fast neutron escapes from the core. The probability that a neutron that is slowing-down will not be absorbed in resonances. The probability that fast neutron begins slowing-down in the core. Answer: c) Select 2 correct answers: If multiplication factor is = 1, then the reactivity of the core is > 0. k ρ If multiplication factor is = 1, then the reactivity of the core is = 0. k ρ If multiplication factor is > 1, then the reactivity of the core is < 0. k ρ If multiplication factor is > 1, then the reactivity of the core is > 0. k ρ If multiplication factor is < 1, then the reactivity of the core is > 0. k ρ Answer: b) and c)
Delayed neutrons are generated: Immediately after the fission. After fragmentation of cosmic rays. After the radioactive decay of some fission fragments that are called precursors of delayed neutrons. During slowing-down of fast neutrons. Answer: c) The multiplication factor is: The ratio between the number of neutrons in one generation to the number of neutrons in the previous generation. The ratio between the number of fast neutrons produced in fast and thermal fission and the number of fast neutrons produced in the thermal fission. Proportion of delayed neutrons in the total number of neutrons. Answer: a) Thermal non-leakage factor Pt is: The probability that a thermal neutron will not escape from the core. The probability that a thermal neutron will escape from the core. The probability that a thermal neutron will be absorbed in resonances. Answer: a) Fast non-leakage factor Pf tells: The probability that a fast neutron escapes from the core. The probability that a neutron that is slowing-down will not be absorbed in resonances. The probability that fast neutron begins slowing-down in the core. Answer: c) Select 2 correct answers: If multiplication factor is k = 1, then the reactivity of the core is ρ > 0. If multiplication factor is k = 1, then the reactivity of the core is ρ = 0. If multiplication factor is k > 1, then the reactivity of the core is ρ < 0. If multiplication factor is k > 1, then the reactivity of the core is ρ > 0. If multiplication factor is k < 1, then the reactivity of the core is ρ > 0. Answer: b) and c)
Module01%20%20Nuclear%20physics%20and%20reactor%20theory-QUESTIONS.docx