The subject is related to the manufacture of MOX U,Pu)O2 fuel for Fast Neutron Reactors. The current process integrates a co-grinding step of uranium and plutonium dioxides to generate a powder medium which is then shaped by uniaxial pressing to generate cylindrical fuel pellets which are then sintered at high temperature. The collected powder medium has poor flowability which limits the rates of shaping by pressing. The objective of the thesis is therefore to evaluate the impact of mechanical granulation of the powder medium on the flowability, the pressing step and the microstructure obtained after sintering. Dissolution tests in nitric acid will also be carried out on certain very specific microstructures. The thesis will be based on a formal experimental plan developed using specific software (JMP). The PhD will take place at the INB Atalante facility on the CEA Marcoule site. The candidate will work in a unique facility in Europe and will be able to develop expertise in working in a nuclear environment with a highly innovative approach that will lead to the publication of original scientific results.