Vitrification of a glass matrix impregnated with a HAW-MTR simulated solution

A process has been studied in which a liquid radioactive waste after absorption into a porous matrix (strips of commercial glass wool), has been dried, calcined and vitrified. Being the glass wool the main glass forming component, other additives like LiNO3 and H3BO3 are to be added to improve quality of the vitrified product. Results are reported of the experimental work carried out on a simulated liquid waste of the type HAW-MTR at laboratory level and in a pilot plant. The influence of experimental conditions and operating parameters on the vitrified product properties has been examined. Glass samples having a density of 2.5 g cm-3, without showing indication of devitrification and a leaching velocity (Soxhlet) of 1.3 10-4g cm-2 d-1, have been currently produced with HAW-MTR type simulated wastes. Microscopic examinations have shown an excellent homogeneity of the glass produced. (J.P.N.)