Its Uses and Hazards Some of the terms used in this factsheet are defined in IEER's on-line glossary . First discovered in the 18th century, uranium is an element found everywhere on Earth, but mainly in trace quantities. In 1938, German physicists Otto Hahn and Fritz Strassmann showed that uranium could be split into parts to yield energy. Uranium is the principal fuel for nuclear reactors and the main raw material for nuclear weapons.
Uranium isotopes are radioactive.
This process, known as radioactive decay, generally results in the emission of alpha or beta particles from the nucleus. It is often also accompanied by emission of gamma radiation, which is electromagnetic radiation, like X-rays. After several more alpha and beta decays, the series ends with the stable isotope lead-206. Main Branch Read from left to right. Arrows indicate decay.