1.9.2 Nuclear fission
The fuel inside the reactor is a metal called uranium. Uranium exists asan isotope in the orm of U 235 , U 234 and U 238 . Out of these isotopes U 235 is moreunstable. When a neutron is captured by a nucleus of an atom of U235, itsplits up roughly into two equal fragments and about 2.5 neutrons arereleased and a large amount of energy (nearly 200 million electron voltsMeV) is produced. This is called fission process. The neutrons so producedare very moving neutrons and can be made to fission other nuclei of U 235thus enabling a chain reaction to take place. When a large number of fissionoccurs, enormous amount of heat is produced. The following fig.1.8. showsthe chain reaction