Treatment of ion exchange resins by thermal plasma

Currently, treatments for low activity radioactive waste, such as spent nuclear grade ion exchange resins, commonly employed in the cooling pools of nuclear reactors; are inefficient and insufficient. So we opted for treatment by thermal plasma for non contaminated resins, which manages to encapsulate the materials to be treated within a glassy matrix. Due to ionization at high temperatures, the formation of dioxins, furans, greenhouse gases among other components generated by incomplete combustion is avoided. 2,000 Watts between graphite electrodes were impressed, using air as the plasma gas into a thermal plasma reactor, creating a density power of 6.32 x 10¹⁰ W / m³. Thanks to this energetic power we may exceed both, the electrical resistance of graphite, and the breakdown voltage of air to achieve and maintain the plasma column. The average time for treatment is about 5 minutes. EDS studies were performed using the Sem to determine the product composition and to observe the quality of encapsulation as well as the morphology of the products. Also by thermogravimetric analysis, it was found that the resins undergo significant reductions in weight as the temperature increases; whereby this treatment not only encapsulate them, but also degrades and reduces the final volume. The ideal proportion for these conditions reaching 86 % of volume reduction is: 1.5 grams of glass, 1.5 grams of nucleating agent (lime powder) and 1 gram resin. Proving the power of the plasma and its incredible capacity to obtain inert, resistant, stable both physically and chemically with possible value-added products. (Author)