In China, 55 commercial nuclear power units are in operation, generating ~420 billion kilowatt hours electricity in 2022, and more than 20 nuclear power units are currently under construction. More than 1,000 m3/y of the dry waste, mainly including the high efficiency particulate air (HEPA) filter, cotton, polyethylene, and absorbent paper will be produced during the operation and maintenance of the nuclear power plants (NPPs). Those dry wastes usually have the low-level radioactivity but the high volume.
To efficiently reduce the volume and safely treat those dry waste, China started to develop thermal plasma technology (TPT) to treat the dry waste since 2009 and has constructed the plant in Gansu Province. The organic matter of the dry waste will be gasified by thermal plasma torch in a gasification furnace, and then the inorganic residual ashes will be melted with glass additives at temperature below 1300 ℃ in a melter, and finally the homogenized melt discharges in the steel canister to form a stable glass waste form.
This talk will provide an overview of the development of TPT to treat the dry waste from NPPs in China. The process of TPT to treat the dry waste will be introduced, and the formulations of the dry waste including the media of HEPA filter, cotton, polyethylene, and absorbent paper for vitrification was investigated. According to the feature of the inorganic residue composition, the glass composition-property model for the high CaO and TiO2 waste was figured out. In addition, the glass fiber as the main component of the HEPA filter used as a glass matrix to immobilize the other residual ashes was studied. Finally, the challenge of TPT for treatment of radioactive waste will be discussed as well.