Processing method for radioactive metal waste

Radioactive metal wastes containing a great amount of at least one of magnesium, aluminum and beryllium used as fuel rod cladding tubes, reflecting materials and moderators for a reactor are dissolved by using an acidic solution, and the solution is processed by alkali to precipitate metal compounds and then filtered and the filtrates are released, while the filtration residue is put into a disposal treatment. Further, radioactive metal wastes are also dissolved with an acidic solution and the solution is neutralized, concentrated by evaporation and then put to disposal. The disposing method is selected depending on the radioactivity concentration of the radioactive metal wastes. Since magnesium and aluminum as highly reactive metals can be solidified as stable hydroxides, stable disposal can be conducted. The processing speed is fast and the filtrates can be released to sea water. The volume of the products solidified by using cement or the like is less than 1/3 compared with that in the prior art method, to enable remarkable devoluming. (N.H.)