Pyrolysis and High Performance Plasma Treatment Applied to Spent Ion Exchange Resins

Abstract

Treatment and conditioning of spent ion exchange resins from nuclear facilities is a complex process that not only should contemplate obtaining a stable product suitable for long-term storage and/or disposal, but also have to take into account the treatment of secondary currents generated during the process. The combination of low temperature pyrolysis treatment and high performance plasma treatment (HPPT) of the off-gas generated could be a novel solution for organic matrix nuclear wastes with economic and safety advantages. In the present work, results of lab scale studies associated with the pyrolysis off-gas characterization and the performance and operating parameters influence on the removal of model compounds in a laboratory-scale flow reactor, using inductively coupled plasma under subatmospheric conditions, are shown. The pyrolysis off-gas stream was largely characterized and the evolution of main compounds of interest as function of temperature process was established. The results of plasma assays with the model compound demonstrate a high destruction and removal efficiency (>99.990%) and a good control over the final gas products. First results of a bench scale arrangement combining both processes are presented and bode well for the application of this combined technology.