Review on Solidification of Chlorine-Containing Radioactive Molten Salt Waste From Dry Reprocessing

Abstract

The molten salt waste produced by disposal of spent fuel via molten salt electrolysis is classified as high-level waste. Because of high water solubility, complex elemental composition, high radioactivity, strong corrosiveness and high volatility, the nuclear waste forms used to immobilize molten salt waste needs to be thermal and chemical stabilities and irradiation resistance, which forms a stable leaching-resistant nuclear waste to isolate from the human living environment. Due to low compatibility with chloride, conventional silicate glass cannot be directly used to immobilize molten salt waste. Therefore, a great deal of research is focused on finding new suitable waste forms. This paper reviewed the treatment and disposal methods of chlorine-containing molten salt waste generated from reprocessing of spent fuel at home and abroad. There might be two routes to deal with chlorine-containing molten salt: the first one is to find a suitable host matrix for direct solidification, and common substrates are sodalite, apatite or phosphate glass; the second one is to convert the chloride to other forms of compounds, such as phosphates and oxides, followed by solidification. In view of the fact that China’s research in this field started late, this paper summarizes the chloride molten salt waste treatment and disposal methods that have been developed domestically and internationally, and introduces the principles, routes, and performance characteristics of each method.

Keywords

• spent fuel
• dry reprocessing
• molten salt waste
• chloride
• waste disposal