The Czech deep geological repository project
The Czech deep geological repository (DGR) project envisages waste disposal in a crystalline rock environment based on the Swedish KBS-3 model. This model further assumes the disposal of spent nuclear fuel (SNF) in metal, hermetically-sealed waste packages in boreholes sealed with a bentonite buffer.
This concept was considered as early as in 1999 in the “Reference Project for a Deep Geological Repository for Radioactive Waste” which took into account the various related requirements of Czech legislation (nuclear, mining, construction and environmental). The reference project took the form of a model of a hypothetical site and assumed the vertical disposal of the waste package. The project also set out basic requirements concerning the layout and logistics of the surface area.
The “Update of the Reference Project”, compiled in 2011, further considered the horizontal disposal of waste packages in long boreholes.
In connection with the assessment of candidate sites and the reduction in their number for the continuation of investigation and survey work at selected sites in 2017-2018, the technical designs outlined in both reference projects were used in the Site and Preliminary Feasibility Studies of the Březový potok, Čertovka, Čihadlo, Hrádek, Horka, Janoch, Kraví hora, Magdaléna and Na Skalním candidate sites. Four disposal variants were considered for each of the assessed sites, i.e. combinations of vertical and horizontal disposal and the fully-mechanised and conventional excavation of the DGR underground complex.
These studies also took into account the requirements of current legislation, the “Update of the Radioactive Waste Management Concept”, especially with regard to the possible extension of the SNF storage period, the assumption of the construction of new nuclear power plant units and the latest results of ongoing research and development work, especially in the field of engineered barriers.