Laboratory tracer tests assuming an engineered barrier system and a comparison with numerical analyses

For the performance assessment of radioactive waste disposal system in the ground, the transport of radionuclides leaking out of the waste form must be predicted as accurately as possible. While experiments are very useful for understanding the phenomena, the prediction should be carried out by a numerical method because there are too many restrictions on measurements and conditions with laboratory and/or in-situ experiments to predict future phenomena. Thus, the validation of transport analyses is one of the critical problems involved with the safe disposal of radioactive waste. In this paper, laboratory experiments are introduced whose aim is to observe the phenomena of solute transport in an engineered barrier system. Flow and transport analyses are applied to verify comparisons with the measured concentration distributions from the experiments.