Determination of uranium(VI) sorbed species in calcium silicate hydrate phases: A laser-induced luminescence spectroscopy and batch sorption study

► Strong sorption of (UVI) by CSH phases illustrated by Rd values up to 106 L kg−1. ► Identification of an U(VI) surface complex and an incorporated U(VI) species. ► Incorporation into the CSH structure is a slow process. ► The solid U(VI) speciation appears to be independent of the pH. ► At high U(VI) loadings (1.0 mol kg−1) a Ca-uranate precipitate was observed.