Complex sentence: Note that in the case a release of radioactivity from a power reactor or used fuel that only some elements are released, as a result the isotopic signature of the radioactivity is very different from an open air nuclear detonation where all the fission products are dispersed.
Split into simpler sentences: Note that in the case of a release of radioactivity from a power reactor or used fuel, only some elements are released. As a result the isotopic signature of the radioactivity is very different from an open air nuclear detonation where all the fission products are dispersed.