Analysis of radioactive waste and glass for a defense waste solidification plant

Analytical methods have been developed and evaluated for supporting a high-level radioactive waste solidification plant. Radioactive defense waste from the Savannah River Plant will be combined with glass-making chemicals and melted at 11500C to form borosilicate glass. This glass will be placed in safe permanent disposal. Remote methods for dissolving and analyzing melter feed and glass containing actual radioactive waste were demonstrated in shielded cells. Microwave technology was used to dissolve samples and measure moisture content. A colorimetric method for measuring the Fe(II)/Fe(III) ratio in the glass was developed and demonstrated using a fiber optic-coupled spectrophotometer. Other methods for characterizing feed and glass samples include elemental analysis by ion chromatography, inductively coupled plasma-atomic emission spectroscopy, and atomic absorption spectrometry. Major radionuclides, 137Cs, 90Sr, and 238Pu could be measured directly by counting techniques. Minor radionuclides such as 99Tc required separation procedures prior to counting