Possible Complex Formation of Actinides with Organic Matter and Phosphate in Deep Groundwaters. Speciation Calculations and Data Evaluation

Abstract

ABSTRACTCalculations of solubility and speciation of U, Th, Ip, Pu, and An in a deep groundwater, containing humlc acid and phosphate have been performed, using the PHRBEQB equilibrium code. Where equilibrium data are missing, estimates have been made.Some of the studied complexes and solid phases may be of importance to the actinide behaviour in deep groundwaters, eg AmPO4(s) and several aqueous phosphate species and also humic acid for trivalent actinides.