An Improved Method to Evaluate Radionuclide Migration Model Parameters from Flow-through Diffusion Tests in Reconsolidated Clay Plugs

An improved method for the evaluation and interpretation of the data obtained from flow-through diffusion tests is presented. After briefly introducing the meaning of the model parameters, a mathematical description of the flow-through diffusion test is given in order to clearly identify their meaning, and to demonstrate the basis for the improvement over the classical steady state interpretation method. The method is applied to data obtained from reconsolidated clay plugs of the Mol site being investigated for geological disposal of nuclear waste. Special attention is given to the reduction of the error on the estimated model parameters and to the important reduction of the time (a factor 5 to 10) needed to run the experiment. Some preliminary results of the application of the method to the evaluation of the model parameters of HTO and iodide are re-ported. The influence of the consolidation on the transport is indicated.