4. Conclusion

Studies carried out as part of the optimization of specific matrices for conditioning minor actinides, iodine and caesium have enabled us to acquire significant elements of feasibility in terms of manufacture and shaping, as well as analysis of long-term behavior. For each (family of) radionuclide(s), it appears possible to propose one (or more) matrix(es) optimized in terms of formulation (radionuclide insertion capacity) and laboratory-scale production. The weathering behavior of these materials under conditions of high turnover systematically reveals low weathering rates (below 10 ² g · m ^–2 · d ^–1 ). These are associated with rapid saturation phenomena, including the formation of passivation layers and the precipitation of secondary phases, which are...