Colloids from the aqueous corrosion of aluminium-based nuclear fuel

Abstract 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 × 10 11 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.