Abstract: Radioactive waste, such as expended radioactive ion exchanger mass, can be transformed in a continuous process to a stable state for final storage in the following manner. The waste is mixed with an aqueous solution of a chemical agent which liberates radioactive substances from the waste, and with an inorganic sorbent for the thus liberated radioactive substances. The mixture is now dried and calcinated during the supply of air or oxygen so that the organic material is combusted. Subsequently the calcined material is placed in a refractory storage container, which is now heated with its contents to a temperature at which said material sinters or fuses to a stable product.