Results of vitrifying Fernald K-65 residue

Two silos, designated as K-65, at the Feed Materials Production Center in Fernald, Ohio, contain residues from the processing of pitchblende ores. The K-65 residue, which contains radium, uranium, uranium daughter products, and heavy metals (primarily lead), was vitrified in a bench-scale system that allowed the volume and composition of the off gas to be determined. Chemical analyses of both the vitrified and nonvitrified residue were performed, including Toxicity Characteristic Leachate Procedure (TCLP) and Extraction Procedure (EP) toxicity testing. Both the radon emanation rates and the specific gravity of the vitrified and nonvitrified residue were also measured. The nonvitrified K-65 residue tested open-quotes hazardousclose quotes by the EP toxic procedure, and the radon emanation rate (52,400 pCi/m2/s) was over 2500 times the EPA limit of 20 pCi/m2/s. After vitrification, the K-65 residue tested open-quotes nonhazardousclose quotes by the TCLP; the volume was 35% that of the original material (a 65% reduction); and the radon emanation rate was reduced by a factor of over 33,000 from 52,400 pCi/m2/s to 1.56 pCi/m2/s, an order of magnitude below the EPA limit. Thus to vitrify this residue is an attractive option