Evidence of Trivalent Am Substitution into UO.

UO is considered to be the most stable phase for uranium oxide. Its structural properties must be accurately understood to foresee and manage aspects such as its leaching behavior when spent nuclear fuel is stored in an oxidative environment. Moreover, as fuel irradiation causes the formation of fission products and activation products such as plutonium and minor actinides, it is probable that UO will be mixed with other chemical elements under real conditions of oxidation.

In situ characterization of uranium and americium oxide solid solution formation for CRMP process: first combination of in situ XRD and XANES measurements.

Transmutation of americium in heterogeneous mode through the use of U1-xAmxO2±δ ceramic pellets, also known as Americium Bearing Blankets (AmBB), has become a major research axis. Nevertheless, in order to consider future large-scale deployment, the processes involved in AmBB fabrication have to minimize fine particle dissemination, due to the presence of americium, which considerably increases the risk of contamination. New synthesis routes avoiding the use of pulverulent precursors are thus currently under development, such as the Calcined Resin Microsphere Pelletization (CRMP) process.