Migration investigations

Since the end of 1985, Nagra has been cooperating with the Paul Scherrer Institute PSI in Wuerenlingen (formerly Swiss Institute for Reactor Research EIR) to carry out preliminary work for a migration experiment at the GTS. The necessity for such field tests was recognised during the course of international efforts aimed at validating current radionuclide transport models. In addition, such field tests provide the necessary expertise for conducting investigations, including migration experiments, in rock laboratories at potential repository sites. The hydraulic investigation of a test zone was completed in 1987. The work on the actual tracer test will be complemented by laboratory investigations at PSI and field studies on the mobility of natural radionuclides in the Grimsel granite, for example uranium and its decay products. (author) 13 figs