Question

The most suitable material for moderator in a nuclear reactor is

• A. $D_2$
• B. $Cd$
• C. $B$
• D. ${}_{92}{\text{U}}^{235}$

Answer 1

Answer: (A)

$D_2$

In nuclear reactor, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction.

Commonly used moderators include regular (light) water (roughly 75% of the world's reactors), solid graphite (20% of reactors) and heavy water.