Effect of Platinum Group Metals Deposition on Vitrification in High-Level Radioactive Waste

Abstract

Platinum group metal(PGM) elements such as ruthenium(Ru), rhodium(Rh) and palladium(Pd) in the high-level radioactive waste solution will aggregate and deposit at the bottom of the furnace during the process of vitrification. The deposition of PGM will lead to the change of glass density, conductivity and viscosity of melt in the furnace, which will easily cause the short circuit of the heating electrodes and the blockage of the discharge hole in the Joule heated ceramic furnace, and affect the performance of the glass. In this paper, based on the research progress of the deposition mechanism and properties of PGM during the process of vitrification at home and abroad, the crystallization mechanism of PGM in glass melt was reviewed, and the growth, agglomeration and distribution of PGM were analyzed and observed. The mechanism of the influence of PGM on the conductivity and viscosity of glass melt was studied, and the factors affecting the conductivity and viscosity were summarized. The effect of PGM deposition on the leaching rate of glass was discussed. Finally, the solutions about deposition of platinum group metals in the process of vitrification were put forward and summarized.

Keywords

• vitrification
• platinum group metals
• conductivity
• viscosity
• leaching rate