Nuclear energy appears from the splitting of uranium atoms in a process called fission.The main fuel used to undergo nuclear fission to produce energy is uranium. It can be easily split by shooting neutrons at them. Multiple neutrons from the uranium nucleus are released and used to split other uranium nuclei. It is called a chain reaction. The heat from fission boils water and creates steam to turn a turbine. As the turbine spins, the generator turns and its magnetic field produces electricity.