Study of zirconium-plutonium mixed oxides and silicates

In severe nuclear accidents with reactor core meltdown, interactions between nuclear fuel, zircaloy cladding, and structural materials can form (An,Zr)O₂ and (Zr,An)SiO₄ compounds. The behavior of plutonium in these conditions remains poorly understood. An international collaborative study focuses on (Pu,Zr)O₂ and (Zr,Pu)SiO₄, which are crucial for understanding such systems and may serve as actinide storage matrices. The project aims to clarify the structure of these compounds using optimized synthesis protocols. High-resolution powder X-ray diffraction (HR-PXRD) will determine their crystalline structure, while high-resolution X-ray fluorescence (HERFD) at Pu’s M4 edge and EXAFS at the L3 edge will analyze plutonium speciation. These characterizations will support solubility experiments and future thermodynamic data determination.