The ‘Interfaces of Materials in Evolution’ group (LIME) aims to describe and understand the various phenomena occurring at the solid/solid and solid/liquid interfaces, and of interest for the (current and future) nuclear fuel cycles. They are mainly related to the sintering (densification) of ceramic materials as well as to their alteration (leaching or dissolution) under various chemical and/or physical stresses.
The experiments dedicated to the solid/solid interfaces are mainly devoted to preparation of inorganic powder samples with tailored properties (morphology, size, composition, …) and the study of their sintering. In this framework, coupling of in situ and ex situ techniques allowed us not only to analyze the different steps of the densification but also to yield original data usually only accessible through modeling. Sintering maps (which represent the variation of grain size vs. densification rate) were also obtained, which resulted in an improved monitoring of the ceramics final microstructure. In the case of the solid/liquid interface, the final goal is also to optimize several properties of some materials in use (or to be used) both in the front- or back-end of the nuclear fuel cycle. Particularly, the approach developed consists in the understanding of the links existing between the chemical composition and/or the morphology of a solid, and its ability to dissolve.
Ceramic matrices: fuel, host phases for actinides storage
Tailored properties of materials: light chemistry, hydrothermal synthesis, sintering
Solid/liquid interfaces: dissolution, lixiviation, long-term behavior, structural et microstructural evolution
Environmental impact of nuclear fuel cycle activities: thorium and uranium mineral phases, mining, remediation, geologic disposal