Pressemitteilung Nr. 11/25 - Asse

After around 50 years: first view of drums in emplacement chamber 12 of the Asse II mine

08/27/2025: The Federal Company for Radioactive Waste Disposal (BGE) made significant progress in early August in its preparations for retrieving radioactive waste from the Asse II mine.

At the start of August, the Bundesgesellschaft für Endlagerung mbH (BGE) achieved a key step in its preparations for the retrieval of radioactive waste from the Asse II mine. An exploratory borehole at a depth of 750 metres provided the first indications of the condition of the drums stored in emplacement chamber 12 at the 750-metre level.

“Through a hole the size of a tennis ball, we were able to take a look inside emplacement chamber 12 for the first time in decades. Our first impression is that at least the visible drums are in good condition. Now we will find out the exact composition of the chamber atmosphere and measure the activity values in the chamber. To do so, we need more space and we’ll therefore need to expand the borehole,” says Iris Graffunder, Chair of the BGE Management Board.

Background information on emplacement chamber 12

Emplacement chamber 12 contains 7,464 packages, including 6,747 drums and 717 packages with “lost concrete shielding” (VBA). The packages were stacked on their sides. Emplacement took place in 1973 and 1974. This emplacement chamber became well-known because a sump of contaminated solution formed in its access area. Among other things, this led to the Asse II mine being placed under nuclear law in 2009.

Emplacement chamber 12 is one of the highest radon emitters in the Asse II mine. At the end of May 2024, miners began drilling the targeted borehole into emplacement chamber 12 in accordance with the most stringent radiation protection standards. A borehole with a length of around 117 metres was drilled at a depth of 750 metres in order to reach the chamber. On 6 August 2025, radiation protection measurements during the drilling work showed an increased level of radon, indicating that the chamber had been reached.

The BGE continues to explore the chamber

A planned gas measurement will show the composition of the chamber atmosphere and indicate which influencing factors it depends on. Geological exploration is also continuing. Preliminary investigations revealed that the roof of the chamber was lower than expected, and the first images from the chamber confirm these radar and magnetic measurements. A planned 3D scan should provide a more complete picture of the emplacement chamber.

Further information on the exploration programme can be found in issue 20 of the Einblicke magazine, entitled “Wie sieht’s aus?” (“How does it look?”).

The BGE has also reported on this work in the series “Concerning Asse”. A post-event report and the recording of the YouTube stream can be found on our website.

About the BGE

The BGE is responsible for proposing the site for a repository for high-level radioactive waste that offers the best possible safety for one million years. It is also building the Konrad repository for low- and intermediate-level radioactive waste in Salzgitter. The BGE is decommissioning the Morsleben repository, planning the decommissioning of the Asse II mine following retrieval of the low- and intermediate-level radioactive waste, and closing the Gorleben mine.