An Application of Soil Solution Chemistry in Long-Term Radioactive Waste Modeling.

Chemistry of the soil solution has laid the groundwork for modeling transport of analytes from soil to other environmental media and to potential human receptors. We have developed combined multi -pathway contaminant transport and risk assessment models using the GoldSim modeling platform. Because the models use probabilistic input distributions for parameter values, sensitivity analyses can be performed to investigate whether or not parameters, such as solubility, are sensitive and need revisiting to reduce uncertainty in the results. This modeling differs from previous radiological performance assessments in that the modeling parameters are intended to be representative of the current knowledge of parameter values rather than reflective of a conservative assessment approach. While a conservative model may be sufficient to demonstrate regulatory compliance, a parametrically honest model can also be used for more general site decision-making. Without Dr. Lindsay’s work pioneering soil solution chemistry, we would be far behind on building representative models of the behavior of chemicals in the environment and would be held to more conservative approaches.