Sorption of Pu(IV) and Tc(IV) on concrete and mortar and effect of the complexation by isosaccharinic acid.

ABSTRACTBatch sorption experiments were carried out, in a glove box under N2 atmosphere, for analysing the effect of increasing ISA (isosaccharinic acid) concentrations on sorption of Tc(IV) and Pu(IV) onto previously characterised Spanish concrete and mortar used in a radioactive waste repository. Results clearly showed that concentrations of ISA around 10-4–10-3 M are able to decrease the distribution coefficients (Rd) of the tetravalent elements analysed, both on concrete and mortar. The decrease in Rd experimentally observed was approximately 2 orders of magnitude for technetium and between 3 and 5 orders of magnitude for plutonium.