The Study on Microwave Process for Spent Resin

Abstract

The moisture content of spent resin from NPPs is generally 50% ∼ 60%, which concentrates radionuclides such as 60Co, 90Sr and 137Cs. It belongs to wet solid waste, accounting for about 1/4 of the total solid waste of NPPs. Pent resin is a dispersive material, which must be stabilized and packaged to meet the requirements of waste transportation and final disposal; However, the characteristics of radioactive organic waste also cause the radiolysis of spent resin and the production of H2, CH4, NH3 and other gases; The spent resin contains more sulfur and nitrogen, and the incineration products and degradation products have strong corrosive to the equipment and storage containers. Therefore, how to treat the spent resin safely and effectively is a difficult problem.Microwave process for spent resin using microwave penetration ability and body heat characteristics, remove the water and organic components from spent resin, so as to achieve the inorganic for organic waste. Compared with the original resin, the ashing product capacity and weight reduction ratio greatly. The spent resin dried by microwave does not contain free water, the volume is 1/3 of the resin volume before drying, and the mass is half of the resin mass before drying; After Microwave ashing, the ashing product of the spent resin does not contain organic components, and the ashing product is only 1/20 of the mass of the dried resin and 1/3 of the volume of the dried resin, that is, for the spent resin with a moisture content of about 50%, after microwave drying and ashing process, not only the organic components in the spent resin are removed, but also the volume and quality are greatly reduced. Most of the treated radionuclides exist in the ashing products, 60Co in the ashing products is 1011 Bq/kg and 137Cs is 108 Bq/kg. The technology processing are used to get the product, which can be convenient for subsequent processing. On the study, the technological parameters of microwave drum drying and microwave ashing of spent resin are determined.