(228i) Synthesis and Microstructural Analysis of Sr and La Doped Synroc Powders Made By Solution Combustion Synthesis

Perovskite (CaTiO3) together with hollandite, BaAl2Ti6O16, and zirconolite, CaZrTi2O7 are main phases in SYNROC (synthetic Rock). Most of the elements in HLW can be immobilized into solid solutions in these phases. This synthesis process is simpler, the synthesized synroc can immobilize waste loading up to 30wt% Sr and La with satisfied physical and chemical properties (density and porosity). The proper selection of the type and composition of the fuels are important to obtain the crystalline solid solution of Synroc. When glycine or mixtures of organic acid with stoichiometric composition were used, the solid solution of Synroc was entirely produced. The microstructure analysis by XRD and SEM/EDS shows that the major phases are perovskite, hollandite and zirconolite which well agrees with the design. It proves that combustion synthesis offer a suitable Sr and La-waste into synroc which is favorable for geological disposal.