On behalf of GNS (Gesellschaft für Nuklear-Service mbH), DBE TECHNOLOGY GmbH developed an alternative to the existing reference concept for a final repository in a salt formation, which includes drift emplacement of POLLUX® casks and borehole emplacement of BSK3 canisters. In this context, the direct disposal concept of transport and storage casks (TSC) was developed and assessed with regard to its technical feasibility.
This concept is expected to have the following advantages:
For the implementation of the concept of direct disposal of TSC, the shaft hoisting equipment as well as the drift transport and emplacement equipment need to be adapted to the significantly higher payload of 160 t. For thermomechanical reasons (design temperature 200°C), the disposal of TSC in a final repository in salt can only be realized in short horizontal or vertical boreholes. In this context, the corrosion behaviour and criticality safety of the casks have to be taken into account. A long-term criticality safety can be achieved by backfilling the void spaces in the TSC with magnetite fine-particle granulate. Analyses of the shaft hoisting equipment and of the transport and emplacement equipment showed that according to the current state of the art in science and technology they are technically feasible in theory. The next step is to demonstrate that this alternative disposal concept meets the requirements for licensing by building the technical components and carrying out demonstration tests.