What is a fuel moderator?
A fuel moderator reduces the speed of fast neutrons thereby turning them into thermal neutrons that are capable of sustaining a nuclear chain reaction. In a thermal nuclear reactor the nucleus of a heavy fuel element such as uranium absorbs a slow moving free neutron, becomes unstable, and then splits into two smaller atoms.
A fuel moderator reduces the speed of fast neutrons thereby turning them into thermal neutrons that are capable of sustaining a nuclear chain reaction. In a thermal nuclear reactor the nucleus of a heavy fuel element such as uranium absorbs a slow moving free neutron, becomes unstable, and then splits into two smaller atoms.