Rare earth elements in uranium compounds and important evidences for nuclear forensic purposes

Abstract

At the beginning of the 1990’s, the first incidents involving nuclear or other radioactive material were reported mainly in Europe, with the breakdown of the Soviet Union. At that period, the International Atomic Energy Agency (IAEA) recorded more than 800 cases of illicit trafficking of nuclear or radioactive materials. Since then, related cases have became known worldwide, as the contamination by radioactive source elapsed from a theft in 1987 in Goiânia, Brazil, and the death of Alexander Litvinenko in 2006 poisoned with the radioactive isotope Polonium-210. As a result of these and other events, nuclear and radioactive materials have been targeted for forensic investigations, creating from there the concept of nuclear forensics. Nuclear forensics mainly focuses on the nuclear or radioactive material and aims to providing indication on the intended use, the history and even the origin of the material. Uranium compounds have isotopic or chemical characteristics that provide unambiguous information concerning their origin and production process. Rare Earth Elements (REE) are a set of sixteen chemical elements in the periodic table, specifically the fourteen Lanthanides in addition Scandium and Yttrium. A large amount of uranium is in rare earths deposits, and may be extracted as a by-product. Accordingly, REE in uranium compounds can be used as an evidence of uranium origin.