An Experimental Study on Treatment of Typical Low and Intermediate Level Radioactive Wastes with Thermal Plasma Melting Technology

Abstract

With the active development of the nuclear industry in China, it is extremely urgent to study and develop advanced technologies for the radioactive waste treatment and disposal. With features of high temperature, high energy density and broad applicability, the thermal plasma melting technology has been considered as one of the key subjects in the radioactive waste treatment research field. A pilot scale experimental study was carried out on the treatment of typical low and intermediate level radioactive wastes (LILWs) from the nuclear power plant in China with thermal plasma melting technology. Two representative wastes, thermal insulation waste and cotton, were selected and melted in the plasma melting furnance at 1250°C for ~ 100 minutes until they were completely vitrified. Meanwhile, tracers of Co 2 O 3, CsCl and SrCO 3 were added to the original wastes to simulate the containment effect of 58 Co and 60 Co, 134 Cs and 137 Cs as well as 90 Sr in the vitrification during the treatment process. The XRD patterns of both vitrification samples displayed as the typical amorphous state. Performances of resultant glass waste-forms, including the physical property, the leachability and the mechanical capacity, were in accordance with the standard requirements of the hign level radioactive waste glass vitrificaton, and were better than those of the cement solidified waste. Further experimental work is in need to better understand the radioactive nuclide migration regularity and to improve the performance of the plasma melting system.