Question

Which of the following statements are true regarding a nuclear reactor?

• A. It uses control rods usually made of cadmium to regulate the energy generation.
• B. It uses moderators to slow down the neutrons while generating the energy.
• C. Moderators like heavy water, are used to cool down the reactor, during the fission reaction.
• D. None of the above.

Answer 1

Answer: (A), (B)

The correct options are
A It uses control rods usually made of cadmium to regulate the energy generation.
B It uses moderators to slow down the neutrons while generating the energy.

• Control rods are the neutron absorbers. Elements like cadmium and graphite, have a property of absorbing fast neutrons, and therefore, are useful in egulating the rate of nuclear fission in the reactor.
• Moderators are used to moderate the energy of neutrons. The neutrons emitted in the fission possess very high energy which needs to be reduced for the proper functioning of the reactor.
• Moderators are not coolants. The heat released in the fission is used to vaporize water and hence, to generate steam that rotates the turbines to produce electricity.
• Coolants like heavy water, help in cooling down the steam thereby controlling the heat and avoiding any possible explosion during the fission.