New exploratory borehole in the Asse mine

From 5 May 2023, the Bundesgesellschaft für Endlagerung (BGE) will continue its exploration programme at the 750-metre level in the Asse II mine. With the new exploratory boreholes in the direction of emplacement chamber 12, the BGE hopes to obtain essential knowledge for the further planning of radioactive waste retrieval.

First borehole leads into rock above chamber

The work will begin with B 12/750-B, a 120-metre-long exploratory borehole that will run entirely above emplacement chamber 12. “With this first borehole, we aren’t aiming to cross paths with the emplacement chamber yet,” explains Dr Thomas Lautsch, Technical Managing Director of the BGE. Once the target length is reached, the next step will be to carry out radar measurements and magnetic analyses. These methods can be used to determine the ceiling (roof) contour of the emplacement chamber and to make initial statements regarding the position of the drums inside it.

From this borehole, a diverted borehole is then to be created with a view to entering the chamber at its highest point. It will then be possible to explore the interior of the emplacement chamber with a camera, for example.

What insights can these investigations provide for the retrieval process?

As well as images from inside the emplacement chamber, these explorations are intended primarily to provide information on the actual composition of the chamber atmosphere and the activity levels within the chamber. They will also provide insights into the condition of the surrounding rock.

All of the measured values will be utilised in the further planning of retrieval and in future licensing procedures. Among other things, they will allow us to determine which recovery technologies can be used in emplacement chamber 12. “These measurements will replace previous assumptions with concrete facts,” says Dr Thomas Lautsch.

Data and facts relating to emplacement chamber 12

Emplacement chamber 12 was created in 1922 for the extraction of salt. There are no further mining chambers above the emplacement chamber. From 1973 to 1974, it was filled with 7,464 waste containers, which is equivalent to a volume of around 2,514 cubic metres of waste. Of these containers, 717 are drums encased in concrete – this is referred to as lost concrete shielding. The drums were stored on their sides, and the remaining space in the cavity was not backfilled. 

About the BGE

The BGE is a federally owned company within the portfolio of the Federal Environment Ministry. On 25 April 2017, the BGE assumed responsibility from the Federal Office for Radiation Protection as the operator of the Asse II mine and the Konrad and Morsleben repositories. Its other tasks include searching for a repository site for the disposal of high-level radioactive waste produced in Germany on the basis of the Repository Site Selection Act, which entered into force in May 2017. The managing directors are Stefan Studt (Chair), Steffen Kanitz (Deputy Chair) and Dr Thomas Lautsch (Technical Managing Director).