At the same time the decontamination factors obtained in evaporation must be high to ensure that the activity of the condensate is negligible, though there remains the problem of accidental dispersion. Much effort is current in many countries on the establishment of the ultimate disposal methods. These are defined to those who fix the fission product activity in a non-leakable solid state, so that the general dispersion can never occur. The most promising outlines in the near future are; 'the absorbtion of montmorillonite clay' which is comprised of natural clays that have a good capacity for chemical exchange of cations and can store radioactive wastes, 'fused salt calcination' which will neutralize the wastes and 'high temperature processing'. Even though man has made many breakthroughs in the processing, storage and disintegration of radioactive wastes, there is still much work ahead to render the wastes absolutely harmless.…