Abstract: Process for solidifying radioactive waste wherein the waste is in solid or aqueous, flowable or liquid form, by mixing the waste with a binder to form a mixture and then leaving the mixture to harden. A mixture of the waste, the binder and an additive which is natural volcanic rock detritus, is formed. The detritus has a total content of CaO+MgO up to a maximum of 6.5 percent by weight and less than 50 percent by weight of residue insoluble in mineral acid. The detritus additive is mixed in an amount between 1 percent by weight and 60 percent by weight of the binder employed.

Abstract: A process for solidifying radioactive wastes by producing compact blocks which are to be disposed in transporting or permanent storage containers. The compact blocks are produced from prefabricated ceramic tablets which contain radioactive substances and a matrix which continuously surrounds these ceramic tablets and is solid in its final state. Glass powder or a mixture of oxidic non-clay minerals or a mixture of both is used as the matrix material. The ceramic tablets and the matrix material are filled into the container and are compressed. The resulting compressed mixture is heated to a temperature in the range from 1423.degree. K. to 1623.degree. K., is held at this temperate range for one to three hours, and is finally gradually cooled to room temperature.