Controlling Actinide Extraction Chemistry (Separation of Actinides from Lanthanides as Part of Nuclear Fuel Recycling)

Abstract

This article outlines some of the techniques and processes involved in the extraction of actinides that are present in spent nuclear fuel (SNF). Owing to the very similar chemistries of the actinides and lanthanides, it is difficult to differentiate the elements in a complex matrix of elements that are present in SNF. However, exploiting subtle covalent differences in the actinide bonding with certain ligands has opened a whole area of research aimed toward the development of actinide‐selective ligands. It is vitally important to separate the actinides from the spent fuel removed from nuclear reactors as it is the actinides themselves, and specifically the minor actinides (americium, curium, and neptunium) that contribute to the long‐lasting radiotoxic properties of the used fuel. Once separated, these elements can be transmuted into shorter‐lived, more stable isotopes by bombardment with neutrons in fast neutron reactors (Generation IV), which are due to phase online over next decade. The much larger concentration of neutron absorbing lanthanides in the spent fuel, together with their very similar chemistry to the actinides, renders the separation a very difficult challenge.