LEACHING FACTORS FOR A PHOSPHATE RADIOACTIVE WASTE FORM UNDER DEEP DISPOSAL CONDITIONS

The article presents the results of experiments on the interaction of model phosphate waste form materials of various phase compositions containing simulators of RW elements with leaching solutions simulating groundwater and changes in its composition due to the impact produced by bentonite barrier material, radiolysis and alkaline plume from Portland cement concrete at temperatures of 25, 90 and 120°Ñ under static water mode considered typical for deep RW disposal facilities. It provides numerical data on the equilibrium saturation concentrations of leaching solutions saturated with barrier and waste form components and simulators of RW elements during phosphate waste form leaching. The paper also discusses the degree of influence produced by the main leaching factors (the phase waste form composition, elevated temperature, the consequences of radiolysis and groundwater interaction with barrier and structural materials) on the concentrations of elements in RW phosphate waste form leachates under the disposal conditions.

Keywords: radioactive waste disposal, phosphate radioactive waste form, heat release, host rock, underground water, radiolysis, structural materials, engineered safety barriers, clay material, bentonite, Portland cement, physical and chemical interaction, alkali plume, radioactive waste form leaching, saturation concentration, radioactive waste.

Martynov K. V., Zakharova E. V. Leaching Factors for a Phosphate Radioactive Waste form Under Deep Disposal Conditions. Radioactive Waste, 2023, no. 2 (23), pp. 63—81. DOI: 10.25283/2587-9707-2023-2-63-81. (In Russian).