The Effect of Colloids on Actinide Migration

Abstract

Radiocolloids can be a factor in radionuclide migration because they have different physical and chemical characteristics, compared with dissolved species. The presence of inadvertently generated radiocolloids in tracer solutions can produce misleading results in laboratory experiments, designed to understand radionuclide migration in the geosphere. The modelling of radionuclide migration through the geosphere may be complicated by the formation of pseudo-radiocolloids in groundwater. Preliminary investigations have shown that some groundwaters have enough natural colloids for pseudo radiocolloid formation. The formation of radiocolloids in 241Am tracer solutions has been demonstrated and is used to explain Am migration through a machined fracture in granite.