Radioactive Waste-Portland Cement Systems: I, Radionuclide Distribution

Crystal chemical stabilization of radioactive wastes can be achieved during clinkering of, or with, ordinary portland cement. Waste loadings of 20 to 30 wt% are achieved by dilute solid solution of waste ions into cementitious host lattices. Higher waste loadings result in compatible noncementitious radiophases. The cementitious phases hydrate without loss of compressive strength. Crystallochemical relationships predict that the radionuclide partitioning in the anhydrous clinkered phases will be maintained in the hydration products. These cementitious hydroxylated radiophases would be in internal equilibrium under anticipated repository conditions. The radio‐nuclide distributions observed are described in the context of established phase equilibria for commercial waste‐cement systems, but are applicable to transuranic, medium‐, and low‐level wastes.