Effect of partial substitution of the sand by the fireclay in cementitious matrix of confinement of ions exchange resins

In Morocco, the spent radioactive ion exchange resins are generated from the purification of the water circuits of the nuclear reactor TRIGA MARK II of the Center for Nuclear Studies of Maamoura (CENM). A strategy for the effective management of these wastes from generation to storage is necessary to ensure their safe handling, conditioning and storage to avoid detrimental effects on health and the environment. The immobilization of radioactive waste of low and intermediate activity in cement matrices, which constitutes the first barrier to curb the radiation of these wastes, is the most widely used technique for producing radioactive waste packages that are compliant with regulatory requirements. The incorporation of clay in mortar produces similar materials to ordinary cement mortar but with superior characteristics. The aim of this study is to find a new formulation of a cement matrix of confinement of ions exchange resins by gradually substituting the sand in the mortar by a fireclay. The monitoring of physical, chemical properties and the influence on the mechanical behavior of mortars has identified, an optimal formulation consisted of 52.57% of cement, 10.4% sand, 8% of fireclay, 15.153% of the water and 13.915% resin. Indeed, the compressive strength for this formulation is 7.4292 MPA seems most suitable for packaging resins.