A thermal nuclear reactor relies on various physical processes to operate safely and efficiently.
Explain why the kinetic energy of neutrons must be significantly reduced in a thermal nuclear reactor. [2][2][2]
As a result of a collision with an atom of a particular moderator, a neutron loses 64%64\%64% of its kinetic energy. A neutron initially has a kinetic energy of 2.2 MeV2.2\text{ MeV}2.2 MeV. Calculate the kinetic energy of this neutron after five collisions. Give your answer in eV\text{eV}eV. [3][3][3]
The kinetic energy of a neutron in a thermal nuclear reactor is reduced from about 2.2 MeV2.2\text{ MeV}2.2 MeV to about 1 eV1\text{ eV}1 eV. Explain why the number of collisions required to achieve this reduction depends on the nucleon number of the moderator atoms. [3][3][3]
One fission process that can occur in the reactor is represented by the following equation:
92235U+01n→56141Ba+3692Kr+301n ^{235}_{92}\text{U} + ^{1}_{0}\text{n} \rightarrow ^{141}_{56}\text{Ba} + ^{92}_{36}\text{Kr} + 3^{1}_{0}\text{n} 92235U+01n→56141Ba+3692Kr+301nCalculate, in MeV\text{MeV}MeV, the energy released in this single fission process. [3][3][3]
Data:
128 exam-style questions on AQA A Level Physics Radioactivity (A-level only), covering Rutherford scattering (A-level only), $\alpha$ , $\beta$ and $\gamma$ radiation (A-level only), Radioactive decay (A-level only), Nuclear instability (A-level only), Nuclear radius (A-level only), Mass and energy (A-level only), Induced fission (A-level only), and Safety aspects (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.