Colloids from the aqueous corrosion of aluminium-based nuclear fuel

Nuclear wastes to be buried in the proposed repository underneath Yucca Mountain, Nevada, may produce colloids and contribute to the release of radioactivity from the repository. As a component of non-commercial nuclear fuels slated for disposal, aluminium-based fuels may release the colloids during aqueous corrosion. This paper reports on the characterization of such colloids, which are predominantly clays >100 nm. Colloid concentrations never exceeded 8 × 1011 particles/L, which is well within the range of values used in the repository release models. These colloids carry 99% of the released uranium and highlight the potential importance of the colloid phase in determining radionuclide transport from the uranium-aluminium fuels.