The possibility of gaining energy by a nuclear power plant is based on the thermal energy that is released during the fission of atomic nuclei.
We run from nuclear fission in nuclear power plants?
For fission only be very heavy atoms such as Uranium with 92 protons and 143 neutrons used. Inside some neutrons from nuclear power plants are baked to this atom. This is done with such precision that they are included here in the atomic nucleus. The extra neutron in the nucleus now increased because of its attraction, the distances between the protons of the atom to be divided.
It creates the nucleus of its nuclear power will no longer hold together all the protons it undoes.
Through this division, in addition to the basic fragments remain and the neutrons that are released, then hit other uranium atoms can, in order to divide them again. In nature, this does not happen, because such a concentration of uranium is not present.
But for the power station to keep a chain reaction going, the fissile material is enriched so the atoms are very close. This ensures that even his own heart is broken when caught by the original’s fission neutrons.