Solubility of Unirradiated Uranium Oxide in Granitic Groundwater

Abstract

The dissolution of unirradiated U0 2 fuel pellets in synthetic groundwater has been investigated. A sequential dissolution procedure was used, and the extent of dissolution was measured for uranium in groundwater. Dissolution was performed under different pH and redox conditions in two synthetic groundwaters, one simulating the undisturbed chemical conditions deep in granitic bedrock and the other simulating the effects of bentonite. The measured uranium concentrations under oxidizing conditions in the undisturbed synthetic groundwater and bentonite water varied between 1...4 and 1...3 mg U/1, and under reducing conditions between 1...25 ug U/1 and 10...190 ug U/1, respectively. The formation of the surface layer was observed.