Method for solidifying aqueous radioactive wastes for noncontaminating storage

摘要

Method for solidifying high and medium radioactivity and/or actinide containing aqueous waste concentrates or fine-grained solid wastes suspended in water for final noncontaminating storage. The waste concentrates or suspensions are set, by evaporation, to a water content in the range between 40 and 80 percent by weight, and a solid content whose metal ion and/or metal oxide component lies between 10 and 30 percent by weight of the evaporate being formed. The pH of the evaporate is set to between 5 and 10. The resulting evaporate is then pelletized with the aid of a clay-like substance. The pellets are then heat treated, including drying at temperatures between room temperature and about 150 DEG C., then calcining at room temperatures up to about 800 DEG C. and subsequently firing at temperatures between 800 DEG C. and 1400 DEG C. to form practically undissolvable mineral phases. The pellets are then enclosed on all sides in a dense, continuous ceramic or metallic matrix.