Characterization and radionuclide retention properties of heat-treated concrete

•Characterization of Fukushima relevant heat-treated concrete.•Fission product interactions experiments with heat treated concrete.•Quantification of europium, cobalt and caesium retention.

This study was performed to obtain insight into the characteristics of contaminated cementitious materials which may result from a light water reactor core melt down accident. Such material arose in a huge amount from the Fukushima disaster. We analyzed the elemental and mineralogical composition of similar, heat-treated material and investigated its radionuclide retention properties.We present the radionuclide retention properties of concrete samples which originally were part of an experiment using a thick-walled concrete recipient that had been heated by simulating a reactor melt down. Batch sorption experiments have been performed with the elements Cs(I), Co(II), and Eu(III) in seawater under aerobic conditions. Sorption coefficients were measured: Rs(Eu) ∼5800 ml g−1 and Rs(Co) ∼110 ml g−1. A tentative value for Cs was determined, adulterated by the relatively high release of Cs from the concrete itself.