Uranium minerals, their crystal chemistry and behavior during weathering


Project is focused on the uranium minerals, namely those, containing in the crystal structure hexavalent form, uranyl ion. Project aims to broaden the knowledge of the structures, chemistry and thermodynamics of supergene minerals formed during weathering of uraninite. Besides contribution to the general knowledge in mineralogy, proposed research brings also a practical aspect, due to analogy between minerals and phases that may occur during alteration of the spent nuclear fuel during storage in underground repositories. Minerals, collected directly during field-works, or picked from the collection, will be studied by the combination of modern analytical methods, including not even more or less usual single-crystal X-ray diffraction, electronprobe microanalysis, but also recently introduced electron precession diffraction, or high-resolution scanning electron microscopy, micro-XANES, or calorimetric measurements. Expected results will be new data for the crystal structures and crystal chemistry of uranyl minerals and better understanding what happens during alteration processes.