Solid, liquid or gaseous radioactive waste is produced in the overall nuclear fuel cycle, in particular in the nuclear power plant and during reprocessing. This has to be processed for ultimate waste disposal. A distinction is made between low, medium and high active waste. Another distinctive criterion is the heat generated by radioactive decay and the resulting classification into waste which generates heat and waste that does not generate heat. Low and medium active waste is compacted in chemical or physical processes and the concentrates subsequently solidified in cement. Vitrification is a suitable method to convert high active heat-generating waste into a product for ultimate waste disposal.