Chemical durability of soda-lime-silicate glass for vitrification of radioactive waste

Abstract

This study examined the use of soda-lime-silicate glasses for the vitrification of radioactive waste. Tasks performed include: production of glass samples with the incinerator ash from the processing of low-level radioactive waste; testing the chemical durability of the glasses by using the MCC-1 leach test; analyzing the leachate samples with inductive coupled plasma (ICP) mass spectrometric technique; and performing scanning electron microscope (SEM) testing and desk top spectrum analysis on the samples. To understand how the durability of the glass product was influenced by the composition variations within the waste feed, sensitivity study experiments were also performed. All of the leach rate data obtained in this study fell within a factor of 3 of the reported forward dissolution rate of the borosilicate glass. Although the long-term performance issue was not investigated, the results may indicate a role for the soda-lime-silicate glasses in the immobilization of low-level or mixed waste. Increases in CaO or Na2O caused the most significant increase in the leach rates in the sensitivity studies. Durability of the proposed waste glass could be improved with proper use of oxides such as Al2O3, Fe2O3, or P2O5-3.