If the nuclear reaction is made to take place in a controlled manner, then the energy released during this reaction can be used for peaceful purposes. A nuclear reaction can be controlled by using rods of cadmium and boron. We know that when a slow moving neutron hits a nucleus of uranium-235 atom, it produces smaller nuclei of barium and krypton, three neutrons and a lot of energy. Now, let’s remove two neutrons out of three neutrons produced by absorbing them in rods of cadmium or boron. Then we will be left with only one neutron, which can cause the fission of only one more uranium atom and release small amount of energy. Now, if we continue to remove two neutrons at each step then only one uranium atom will undergo fission at a time. This reaction is also known as critical fission reaction. The energy produced during controlled fission reaction can be used to produce electricity in nuclear power stations.
Test Your Understanding and Answer These Questions:
- What is controlled nuclear fission reaction?
- What is critical fission reaction?