Validation of performance assessment model by large scale in situ migration experiments

Large scale three dimensional in situ migration experiments in the Boom clay formation below Mol for the validation of performance assessment models are reported. The experiments involve multipiezometer nests in which radionuclides are injected in one filter and the concentration evolution in the neighbouring filters is measured and compared with the model prediction. A large scale injection experiment with tritiated water is reported. The agreement between the predictions and the experiment is quite good. A large scale injection experiment with 125I, using both vertical and horizontal injection, is reported. The aim of this experiment is to validate the anisotropic concept of the performance assessment model. The results of the predictions are given and the experimental results are expected within a few months. (author). 7 refs, 4 figs