Actinide-Nanoparticle Interaction: Generation, Stability and Mobility

Abstract

Actinide ions are widely considered immobile under environmental conditions relevant to their disposal notably under reducing conditions prevalent in subsoil systems. Colloid formation is, however, known to increase their mobility. Observations of this in environmental systems are regularly reported. Different processes may lead to actinide colloid formation, by either generation of polymeric oxide/hydroxide nanoparticles or sorption to already existing or neo-formed ground water colloids. In order to assess actinide mobilization by colloidal species, the cascade of individual colloidal processes under given geochemical conditions must be considered and quantified: colloid formation, actinide--colloid interaction, colloid stabilization and migration. This chapter describes and discusses actinide colloid reactions with a focus on the underlying mechanisms.