Incorporation of actinides into iron (oxyhydr)oxides: A long-term environmental barrier to radionuclide migration

Computational study of the interactions of tetravalent actinides (An = Th–Pu) with the α-Fe13 Keggin cluster

“…2 Following on from this work, Smith et al performed a similar experiment while spiking Pu( iv ) into solution at low pH to monitor Pu( iv ) uptake during the formation of Fh and subsequent transformation to more stable phases such as hematite and goethite. 8 Stagg et al also discuss such processes, 9 and the surface complexation of other actinide species such as Th( iv ), U( vi )O 2 2+ , Np( v )O 2 + and Am( iii ) with Fh. 3,9–15 Smith et al 's study revealed that 85% of the Pu( iv ) was removed simultaneously with Fe( iii ) at low pH (1.5–3.0) where Fe 13 Keggin formation occurs.…”

“…8 Stagg et al also discuss such processes, 9 and the surface complexation of other actinide species such as Th( iv ), U( vi )O 2 2+ , Np( v )O 2 + and Am( iii ) with Fh. 3,9–15 Smith et al 's study revealed that 85% of the Pu( iv ) was removed simultaneously with Fe( iii ) at low pH (1.5–3.0) where Fe 13 Keggin formation occurs. This is a surprising result, as one might expect Fh to form first followed by Pu( iv ) adsorption in the form of PuO 2 due to Fh's large surface area and affinity for contaminants.…”