Fission and Fusion College of Engineering University of Wisconsin - Madison University of Wisconsin Nuclear Reactor Tour Nuclear Energy Atoms are the building blocks from which matter is formed. Everything around us is made up of atoms.
Nuclear energy is contained within the center of the atom in a place known as the nucleus .
Particles within the nucleus are held together by a strong force. Using this strong force that holds the nucleus together to produce energy is essentially what the field of nuclear power generation is about. In the fission process certain heavy elements, such as some forms of Uranium , are split when a neutron strikes them. The process not only produces energy but also additional neutrons that can be used to fission other Uranium nuclei and start a chain reaction. In fusion, nuclei of light elements are brought together under conditions of high pressure and temperature, causing them to combine and produce new elements and energy.