Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

At the Grimsel Test Site (Switzerland), several in situ tracer tests aim at studying the possible radionuclide release from the bentonite engineered barrier system and the processes which may lead to their subsequent migration though the granodiorite host rock. We investigate the diffusion of Tc-99 and actinides (AN) through bentonite and the remobilization over a time period of several years of the AN tracers employed in previous in situ tests. AMS is the ultra-trace analysis method of choice for studying the behaviour of Tc-99 and AN with concentration at and below fg/g levels in such dedicated long-term in situ tests, providing results that contribute to the safety evaluation of future nuclear waste repositories.