Function of Moderator in Atomic Power Plant

1. Nuclear Reactor:  It is an apparatus in which nuclear fuel (U235) is subjected to nuclear fission. It controls the chain reaction that starts once the fission is done. If the chain reaction is not controlled, the result will be an explosion due to the fast increase in the energy released.

A nuclear reactor is a cylindrical stout pressure vessel and houses fuel rods of uranium, moderator & control rods. The fuel rods constitute the fission material and release huge amount of energy when bombarded with slow moving neutrons. Moderator consists of graphite rods/Heavy water which enclose the fuel rods. Moderator slow down the neutrons before they bombard the fuel rods. The control rods are of Boron / Cadmium are inserted into the reactor. Cadmium is a strong absorber of neutron and thus regulates the supply of neutrons for fission process according to the load variations. When the control rods pushed in deep, they absorb almost all neutrons and stops the chain reaction ie, the stops. The heat produced in the reactor is removed by the coolant, generally sodium metal and  water is used. The coolant carries the heat to the heat exchanger.

2. Function of Moderator in Atomic Power Plant

Moderator consists of graphite rods/Beryllium/Heavy water which enclose the fuel rods. Moderator slows down the neutrons in nuclear reactor. Moderators are made up of materials with light nuclei that do not absorb neutrons but slow down the speed of neutrons by a series of successive collisions.