Finite Element Models for Sediment and Contaminant Transport in Surface WatersnTransport of Sediments and Radionuclides in the Clinch River

摘要

Radionuclide migration in rivers was simulated in this study to advance the state-of-the-art of computer modeling on radionuclide transport by including the effects of sediment-radionuclide interaction. Specifically, the finite element sediment and contaminant transport model, SERATRA, was modified and applied to the Clinch River in Tennessee to solve time-dependent, longitudinal and vertical distributions of sediments and radionuclides. Sediment transport was modeled for each sediment size fraction (i.e., sand, silt and clay), and radionuclide transport was modeled for dissolved and particulate nuclides. Furthermore, particulate radionuclides were solved for those adsorbed by each sediment size fraction.nThree radionuclides, cesium-137, strontium-90 and gold-198, were selected as sources of continuous and instantaneous releases because of their adsorption characteristics and field data availability. Agreement of predicted results and field data for continuous release cases was very good, while for instantaneous releases agreement was poor.