Second exploratory drilling started

Members of staff of the Asse-GmbH check the drilling rig for correct functioning before start of second drilling

On 30 April, the Asse-GmbH started the second exploratory drilling in the context of the trial phase (fact-finding) in front of emplacement chamber 7 in a depth of 750 metres. With this drilling more findings regarding the state of the chamber and the waste stored therein are to be gained. Among others, a possible propagation of radioactivity, the state of the waste in the chamber, the stability of the chamber and, if possible, gases detected in the chamber are to be examined.

Based on findings from the first drilling

As the upper edge of the emplacement chamber was reached with the first drilling and the position of the chamber was determined, the second drilling will now be placed in a shallower angle of descent. The plans are mainly based on findings from radar measurements gained from the first drilling.

A drill depth of about 23 metres is planned. Once this depth has been reached, it is planned to carry out a comprehensive measuring and prospecting program. Also in the case of this drilling, it is particularly important not to drill into waste drums.

Drilling works are continuously being monitored

The current plans can be updated and adapted while works are progressing, e. g. in case larger radioactive contamination should be detected or the radioactive waste should be hit in the process of drilling. Drilling works are therefore continuously being monitored.

By collecting samples on a regular basis it is determined whether there is radioactive material in the rock or in the immediate surroundings. For the duration of the works, the area in front of emplacement chamber 7 is separated from the rest of the mine by a lock. This way no radioactivity can get into the rest of the mine, even if there is contamination.

Special safety measures necessary

To speed up the necessary conversion works required for setting up the rig for the second drilling, the area in front of chamber 7 was temporarily declared non-radiation protection area. With the beginning of the current works, however, the special safeguards will apply again.