Radionuclide Release from Slag and Concrete Waste Materials: Part 1: Conceptual Models of Leaching from Complex Materials and Laboratory Test Methods

摘要

The technical literature was surveyed to evaluate test methods and modeling approaches used to characterize the release of contaminants during the weathering of portland cement-based materials and slag wastes from metal processing and recycling operations. Data sets were selected to represent various approaches used to study contaminant leaching, mineral dissolution, and waste material corrosion, and both the testing methods and data interpretations were evaluated. Models were evaluated with regard to both interpreting the test results and predicting long-term behavior. This study concludes that test results can be misinterpreted if testing artifacts are not taken into account, such as the interval used in solution replacement tests, the flow rate used in dynamic tests, and failure to reach steady-state, or if an inappropriate process is modeled. Contaminant release may be controlled by a diffusion process (mass transport) or by the chemical reaction affinity, and oxidation reactions can affect the releases of multivalent contaminants, such as Tc.