Glass waste form options for rare-earth fission products from electrochemical reprocessing

摘要

This paper describes a first-of-a-kind study where lead tellurite (Pb-Te-O), iron phosphate (Fe-P-O), and lanthanide aluminoborosilicate (LABS) glass waste forms were evaluated for treating and/or immobilizing waste streams containing high rare-earth (RE) content in different forms, e.g., RECl3, REOCl, and/or REOx. Results from this study show that NdOCl can be immobilized in 78TeO(2)-22PbO glass at up to 10 mass%. Higher loadings of up to 15 mass% were demonstrated, but with a small fraction of crystallization. Two Fe-P-O glasses produced from either RECl3 (RE = Nd,Ce) or NdOCl revealed products with very similar properties, demonstrating that the phosphate process can be used to dechlorinate a variety of RE-containing halide-based waste streams. The LABS glasses produced from Nd2O3 or NdOCl showed similar properties, but the LABS-NdOCl glass did have some residual Cl present. Characterization is provided for all waste forms including chemical analysis, X-ray diffraction, and bulk density.