Question

Heavy water is used as moderator in a nuclear reactor. The function of the moderator is

• A. To control the energy released in the reactor
• B. To slow down the neutrons to thermal energies
• C. To cool the reactor faster
• D. To absorb neutrons and stop chain reaction
  

Answer 1

The correct option is B To slow down the neutrons to thermal energies

The function of moderators is to slow down the fast moving neutrons and again involving in the nuclear fission reaction.

Hence, option $\left(B\right)$ is correct.