No. 1/21 - Two new boreholes started at Asse

From February onwards, the Bundesgesellschaft für Endlagerung (BGE) is expanding its exploratory work east of the Asse II mine. The two new boreholes will represent an important step towards the retrieval of radioactive waste, which is expected to begin in 2033.

The BGE will use these boreholes to make a more detailed examination of the subsurface to the east of the Asse II mine, where it plans to build the retrieval mine. This will include the new Asse 5 shaft, which will then be used to bring the radioactive waste to the surface as part of retrieval operations. “The newly launched exploration programme will provide us with further insights into the conditions present deep underground. This will allow us to firm up our plans and provide the necessary factual basis for the licensing documents,” says Dr Thomas Lautsch, Technical Managing Director of the BGE.  These insights into the deep underground will help to improve safety. For example, the BGE needs to know where water-bearing structures are located in order to deliberately avoid them in its future work.

1,000 metres of depth: data and facts relating to the new Asse boreholes

The two new exploratory boreholes have been given the project names Remlingen 15-S1 (R15-S1) and Remlingen 15-S2 (R15-S2) and will each reach a length of around 1,100 metres. The planned depth is around 1,000 metres below the surface of the ground. The names of the boreholes stem from the fact that they will be formed as deviations (at a depth of around 265 metres) from the existing R15 exploratory borehole. The first deviation (R15-S1) will run towards the south-east at an angle of around 30 degrees, while the second (R15-S2) will be constructed from R15-S1 and run towards the north-east. Both boreholes will be constructed using the “core drilling” technique following successful orientation of the drilling tracks. The purpose of this core drilling is to obtain rock samples (drilling cores) for inspection, which will provide more precise information about the geological conditions deep underground. The BGE needs this vital information for its further planning work.

What happens next: drilling schedule at the Asse mine

The drilling and inspection programme is planned to take around six months. Preparatory work at the drilling site has been underway since 11 January 2021. In the first step, the working area has been set up at the existing drilling site of the exploratory borehole R15. The drilling rig will be delivered and assembled from 25 January 2021 onwards. The actual drilling work is expected to take place from 1 February 2021 onwards and will be accompanied by a comprehensive measurement programme. The BGE believes that it will be possible to complete the measurement programme in mid-2021.

Background

The BGE is currently preparing for the retrieval of radioactive waste from the Asse II mine. The necessary retrieval mine, including the new Asse 5 shaft, is to be constructed to the east of the existing mine.

The location to the east of the Asse II mine is the only one at which it is possible to construct the necessary underground infrastructure for the legally required retrieval of radioactive waste from the Asse II mine, as it is the only location with sufficient space. The area was inspected in 2013 and 2014 using the R15 exploratory borehole. Following the completion of a comprehensive measurement and inspection programme, the borehole was backfilled in 2016. The results from R15 revealed a geological situation that contrasted with existing knowledge of the geology. The BGE is therefore carrying out an extended exploratory programme by means of the R15-S1 and R15-S2 boreholes.

At the end of 2020, the BGE asked the Lower Saxony Ministry for the Environment to commence the licensing procedure for the retrieval of radioactive waste. An initial application complex addresses the construction of the new shaft as well as the connection to the Asse II mine. The special operating plan for the boreholes was approved by the competent state mining office on 22 December 2020.