TH OWL teaches in a practice-oriented manner, which is why twelve participants from the faculty visited the Federal Company for Final Storage (BGE) and gained exciting insights into the current work and investigations into sealing the mine. We'll reveal another time whether the students sang the miners' song and where the miners wear their leather.
Program
After being welcomed at the BGE information center, the guests first received a safety briefing and historical insights into the development of the mine. Potash and rock salt have been mined here since the end of the 19th century. Tools, drills, and historical mining vehicles provided a vivid underground demonstration of how salt was once extracted and transported. In the meantime, poultry farming had also been carried out in the mine.
Mine rescue service
Modern aspects of underground work were also discussed: the mine rescue service presented its new fleet of electric vehicles and explained its operational concepts for fire and rescue situations in the salt dome. Since water and salt are not a good combination, the specialists rely on controlled burning through oxygen deprivation and regular exercises to rescue and recover people.
Morsleben final repository – an underground insight
A central point of the excursion was a look at the future of the Morsleben final repository. Around 37,000 cubic meters of low- and medium-level radioactive waste are currently stored in the mine. The BGE has been preparing for years to decommission the facility while retaining the waste – a project that is unique in Germany. The aim is to secure the repository permanently and keep the radioactive materials away from the environment for up to a million years.
Two demonstrators – TH OWL developed
To this end, two demonstration closures are being or have been examined in the mine: one closure in harder anhydrite rock with magnesia building material and one variant with salt concrete in rock salt. In 2011, the Geotechnical Section, headed by Professor Schlötzer, developed a method for grouting the joints between rock salt and salt concrete when sealing a tunnel in rock salt. The creeping rock salt automatically closes joints over time, as salt is constantly in motion and is subjected to high pressure from above. As this time delay needed to be eliminated, the team developed a method for filling the joints.
Findings from these investigations provided the basis for the current demonstration structure in anhydrite rock. In anhydrite rock, a magnesium building material is used which expands as it sets and could thus ensure a tight seal.
Decommissioning of the final repository
The measurements and evaluations of these demonstration closures are used to apply for the final decommissioning of the mine. They are part of the comprehensive decommissioning concept, which provides for the extensive backfilling of the mine, sealing structures, and the closure of the Marie and Bartensleben shafts. Approval of the nuclear decommissioning procedure is still pending. Until then, the BGE is keeping the mine open, taking safety measures, and testing new techniques for long-term closure.
"For us as aspiring civil engineers, this visit was an impressive combination of history, technology, and responsibility for future generations," summarized one participant from TH OWL. The visit ended with a hearty "Glück auf!" (good luck!), giving the participants a further insight into the range of work carried out by civil engineers.
The Faculty of Civil Engineering would like to express its sincere thanks to Wenke Nielebock and Peter Osbelt from the BGE.
