Abstract: An improved heat treatment for spent ion exchange resins containing radioive inorganic compounds is described for converting the resin into a form which can be safely stored, either directly or embedded in concrete or bituminous. The resin is heated, in the presence of an inert gas such as nitrogen or a reducing gas such as carbon monoxide, to a temperature sufficient to effect a carbonization of the resin but too low to cause the radioactive compounds in the resin to evaporate or sublimate. The resulting low-temperature carbonization of the resin effectively fixes the non-volatile compound to the resin, and prevents a later radiolytic decomposition of such compounds during storage.

Abstract: Solid radioactive or toxic wastes are prepared for long-term storage by adding a hardenable binding agent to a container filled with the waste under a partial vacuum. The improved homogeneity of mixing of the binder and waste is enhanced by removing the partial vacuum prior to the hardening of the binder. The temperature of the container is maintained, during the addition of the binder agent to the waste, at a temperature at least equal to the melting temperature of the binder to assure thorough impregnation of the waste thereby. Preferably, the container supporting the resultant waste-binder matrix is placed in a larger container, and the space between the two containers is filled with bituminous material or concrete to provide added security against water penetration during storage.