Question

Water used as moderator in nuclear reactor is called:

• A. heavy water
• B. hard water
• C. nuclear water
• D. critical water

Answer 1

The correct option is A heavy water

In nuclear engineering, 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 involving uranium-235.
Commonly used moderators include regular (light) water, solid graphite and heavy water. Beryllium has also been used in some experimental types, and hydrocarbons have been suggested as another possibility.