Impact of copper(II) on activation product removal from reactor decommissioning effluents in South Korea

Decommissioning is one of the most important phases in the life of a nuclear reactor, having a major influence on public perception of such technology. Therefore, development of technologies that make decommissioning more safe, effective and efficient is integral to the success of the nuclear industry. In this paper, phosphonic acid functionalised silica has been studied to determine its suitability for treating nuclear decommissioning effluents produced in the HYBRID process, developed in South Korea. Cu2+ recovery from HCl media in both static and dynamic modes was investigated, as well as the effect of Cu2+ on Co2+ and Ni2+ recovery in a column loading system. Isothermal loading studies predicted a maximum loading capacity for Cu2+ of 22.82 mg g-1, however complex loading behaviour was observed. Cu2+ sorption followed pseudo-second order kinetics with rapid uptake. Thermodynamic parameters have been extracted from collected kinetic data. Cu2+ outcompetes both Co2+ and Ni2+ for binding to the silica in column studies, which has implications for the use of phosphonic acid functionalised silica in treating decommissioning effluents. This work presents initial lab scale experiments, but shows the potential of Si based extractants for use in metals recovery in the nuclear industry.