This post-doctoral project is part of the French project “D-CLIC” within the investment program “France 2030” to innovate in terms of radioactive waste management in deep geological disposal. The D-CLIC project focuses more particularly on the fate of three long-lived radionuclides, namely 14C, 36Cl and 129I, characterized by a high mobility in the environment. The objective is thus to confine them efficiently in a matrix with high chemical durability (i.e. presenting a low level of alteration by interaction with dissemination vectors such as water). To achieve this goal, it is proposed to design calcium phosphate –based materials with an apatitic structure. Indeed, apatites are a class of minerals with remarkable durability properties and their structural flexibility makes it possible to consider both an isolated or joint incorporation of each of the targeted elements.