Radioactive waste generated in various forms needs to be technically stabilized for safe treatment, disposal, and long-term safety. Overseas, research on vitrification with excellent mechanical and physicochemical properties of high-level waste is being actively conducted. Vitrification is a process of converting radioactive waste into a stable and durable glass-like material, which is then safe storage and disposal. The stability of vitrified form is an important concern for environment safety, as any leakage or release of radionuclide could have serious consequences for health and the environment. Therefore, several studies are being conducted on the disposal stability of vitrification of radioactive waste. In order to evaluate the stability of the solidified form, mechanical properties such as density, microhardness, and compressive strength and chemical durability such as leaching properties should be performed. There are several types of leaching test methods to evaluate the chemical durability, which is important in the characterization of solidified forms. In this study, the leaching test method for chemical durability evaluation and the evaluation results of leaching characteristics according to pH were reviewed.

In order to vitrify the combustible dry active waste (DAW) generated from Korean Nuclear Power Plants, a glass formulation development based on waste composition was performed. A borosilicate glass, DG-2, was formulated to vitrify the DAW in an induction cold crucible melter (CCM). The processability, product performance, and volume reduction effect of the candidate glass were evaluated using a computer code and were measured experimentally in the laboratory and CCM. The glass viscosity and electrical conductivity as the process parameters were in the desired ranges. Start-up and maintaining glass melt of the candidate glass were favorable in the CCM. The product of the glass product such as chemical durability, phase stability, and density was satisfactory. The vitrification process using the candidate glass was also evaluated assuming that it was operated as economically as possible.