In a nuclear fission reactor, what is the job of the moderator?
Answer and explanation
Correct answer: D. To slow down the neutrons
- Step 1: Fast neutrons released in fission are unlikely to cause further fission. Step 2. The moderator, such as water or graphite, slows them down so they can split more uranium-235 nuclei. Answer: To slow down the neutrons. Why not the others: Absorbing neutrons to control the rate is the job of the control rods, carrying heat away is the job of the coolant, and stopping radiation leaving is the job of the shielding.
Practise more Radioactivity.
Free questions with an explanation for every one, and full timed General Secondary Certificate (Tawjihiya Kuwait) mock tests.
More Radioactivity questions
- A radioactive sample has a half-life of 2 days. Its mass of the radioactive nuclide is 240 g. How much remains after 6 days?
- A radioactive sample has a half-life of 5 days. Its mass of the radioactive nuclide is 80 g. How much remains after 15 days?
- Which type of nuclear radiation carries no electric charge?
- Uranium-238, , decays by emitting an alpha particle. Which nucleus is formed?
- The activity of a radioactive sample falls from 800 Bq to 100 Bq in 24 hours. What is its half-life?
- How much energy is released when kg of mass is converted into energy? ( m/s)