Sustainable Spent Resin Management Focusing on Volume Reduction

Abstract

Resins are an efficient but volume intensive approach to remove impurities from system media. The carbon structure (e.g. polystyrene) of the resins represents with roughly 70 wt.-% the majority of the total mass, while the actual waste stored on the resins is in the magnitude of 1 wt.-%.Framatome’s chemical treatment process for spent resins consist of four flexible steps. First the inorganic radiocarbon (¹⁴CO₃^2- ) is rinsed from the resin and stored in a CO₂ trap. Afterwards the carbon structure of the resin is decomposed and liquefied by an enhanced Fenton process resulting in a TOC concentration of ca. 1000 ppm. In the third step, the TOC concentration is reduced via UV Fenton to about 50 ppm. For final disposal, the liquefied resin is conditioned by e.g. dewatering in cask, cementation, evaporation or precipitation. Beside the specific C14 separation a reduction of waste volume up to a factor of 20 can be achieved.