X-ray Absorption Spectroscopy of Nuclear Materials at the Rossendorf Beamline, ESRF

The Rossendorf Beamline is a dedicated X-ray absorption spectroscopy beamline for research on actinides. Embedded in the Helmholtz research program Safety of Nuclear Waste Disposal, inhouse research deals with the chemical behavior of actinides and fission products in the context of nuclear waste disposal, encompassing both near-field and far-field retention mechanisms. In the framework of European research programs, e.g. ACTINET, TALISMAN, ESRF, there is also a vivid body of research conducted on nuclear materials in the context of GenIV fuels, minor actinide transmutation, and the behavior of fuels under operational and accident conditions. In this talk I will focus on the latter aspect, presenting results from collaborations with CEA and ITU on a variety of topics including the oxidation state and local structure of Am in uranium dioxide and MOX fuels, self-irradiation effects of minor actinides in fuel matrices, and structure and oxidation state of U in sodium uranates.