Vitrifiable concrete for disposal of spent nuclear fuel reprocessing waste at I.N.E.L

A cement capable of being Hot Isostatically Pressed (HIP'ed) into a glass-ceramic has been proposed for use as the waste form for SNF reprocessing wastes at the Idaho National Engineering Laboratories. Such an ''intermediate'' cement, with a composition based on that of common glasses, has been designed and tested. The cement formulations included mixed I.N.E.L. wastes, blast furnace flag, reactive silica, alumina, and I.N.E.L. soil or vermiculite, which was activated with potassium or sodium hydroxide. Modified FUETAP processing was performed and the cement was subsequently characterized. Results of compressive strength testing ranged from 1,452 psi to 4,163 psi, exceeding the NRC-suggested standard of >500 psi. Total dissolved solids concentrations in waste form leachates were calculated from a static leach test in which leachate conductivity was measured. Effective diffusivities for radioisotopes Cs and Sr were calculated from leachate analysis data. Diffusivity values were on the order of 10-15 to 10-10 cm2/sec, which compare favorably with diffusivities in other materials