Nuclear Fission is a reaction (or radio decay process) in which the nuclear of an atom splits into two, smaller and lighter nuclei. This process produces gamma photons, and releases extremely large amounts of energy, which we then use to make our own usable energy. The release of the heat energy can be used to spin turbines and produce electricity. Uranium is the most common “fuel” for nuclear fission. Uranium is not a renewable energy source, but is found commonly worldwide. There are two types of reactors: Thermal-Neutron and Fast-Neutron Reactors. Thermal-Neutron Reactors are the most commonly used types today, while Fast-Neutron Reactors are currently seen as the next step in progression for Nuclear Energy.