UO2 as new filling material for cesium retention in high-level nuclear waste repositories

Abstract

Depleted uranium dioxide has been proposed as an inert material to fill spent nuclear fuel canisters in geological repositories. Sorption capacity of this material to retain radionuclides released from the fuel was determined. Radiocesium is one of the radionuclides of concern in case of a nuclear accident or in a high-level nuclear waste repository and is highly mobile in aquatic systems. Results obtained in this work show that sorption of cesium on UO2 is a fast process (the equilibrium is reached in less than 1h at pH 9).