Classical nuclear fuel recycling processes, such as PUREX, rely on dissolution and separation steps to recover valuable elements (uranium and plutonium), enabling the production of new MOx fuels. However, with the development of 4th-generation reactors in France and the closure of the fuel cycle, there is a growing need for innovative reprocessing methods tailored to future fuels. This PhD thesis proposes exploring a promising approach: selective dissolution of uranium and plutonium, where these elements are dissolved in an organic phase while fission products remain in solid form within the residue. This process could simplify separation steps while optimizing waste management.
The thesis will focus on studying the selectivity of this dissolution process for uranium and plutonium relative to fission products, depending on initial conditions (fuel characteristics, solvent nature, and chemical environment), to optimize the recovery of valuable elements. Additionally, a detailed investigation of the speciation of dissolved cations and the residue will enhance the understanding of the underlying dissolution mechanisms. To achieve this, you will have access to state-of-the-art equipment in a nuclearized laboratory, including advanced characterization techniques. Your work will contribute to advancing knowledge in actinide chemistry applied to the development of innovative processes, while allowing you to develop expertise in a unique research environment.