Question

Graphite is used in nuclear reactors:

• A. as a lubricant
• B. as a fuel
• C. for lining inside of the reactor as an insulator
• D. for reducing the velocity of neutrons

Answer 1

Answer:

D. for reducing the velocity of neutrons

Moderator in nuclear reactors:

• A neutron moderator is a medium that reduces the speed of fast neutrons. 
• This turns these neutrons into thermal neutrons.
• Thermal neutrons are capable of sustaining a nuclear chain reaction.

Graphite:

• Graphite is the only non metal element that is a good conductor of electricity.
• Graphite is used in nuclear plants due to its extreme purity and its ability to withstand extremely high temperatures and high irradiation.
• Graphite is used as a moderator in nuclear reactors.
• Hence, graphite is used to reduce the speed of velocity of neutrons.