After the water is turned into steam, the sequence in a fossil fuel generating plant and a nuclear generating plant are approximately the same. The only essential difference between U-238 and U-235 is...After the water is turned into steam, the sequence in a fossil fuel generating plant and a nuclear generating plant are approximately the same. The only essential difference between U-238 and U-235 is their atomic masses; as a result, the two isotopes are separated by a physical means that takes advantage of the difference in mass. It is the uranium-235 that is fissionable (will undergo fission) and therefore, this is the uranium isotope than can be used for fuel in a nuclear reactor.
