Ordinary water is not used as a moderator in nuclear reactors because

What is used as moderator in nuclear reactor:

Which is used as moderator in nuclear reactor?

A substance used as a moderator in nuclear reactors is

Deuterium oxide is used as a moderator in nuclear reactors because

Substance used as a moderator in nuclear reactor is-

Assertion : Heavy water is widely used as a moderator in nuclear reactors. Reason : It slows doen the fast moving neutrons and thus helps in controlling the nuclear reactions.