Multiple choice

Which of the following are used as moderators in nuclear reactors?

  1. Heavy water
  2. Graphite
  3. Beryllium

  1. Both (1) and (2)

  2. Both (2) and (3)

  3. Both (1) and (3)

  4. All of the three

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Commonly used moderators include regular (light) water (roughly 75% of the world's reactors), solid graphite (20% of reactors) and heavy water (5% of reactors). Beryllium has also been used in some experimental types, and hydrocarbons have been suggested as another possibility.