The former Konrad iron ore mine is located near Salzgitter, Lower Saxony, in Germany. After iron ore extraction ceased in 1976, experts studied the former pit’s geological suitability as a repository for low to intermediate-level radioactive waste. An approval procedure followed, which took years to complete before the pit could be converted into a repository. The current mine consists of six levels at around a hundred metres vertical distance from one another at depths ranging from 800 to 1,300 m.
Our expertise in shaft construction, numerics and structural engineering earned us the job of planning, 3D numerical calculation and geological consultation in the underground parts of the mine crucial to the project – storage location, workshops, backfill processing and transport routes.
The greatest challenge is the intersection of tunnelling and mining. The planning required an advanced 3D numeric, 3D drawing work with navigation capabilities and a load-bearing system with rehabilitation freedom.
Tunnelling and shoring work has begun in 2012. This involves first preparing the infrastructure required for transporting and storing of radioactive waste containers at depths of 850 m on level 2. The existing shaft 2, at a depth of around 998 m, was remediated and an existing cross-cut near the second level was developed into a new storage location. This creates a 12.5 m cross-section, and existing spaces next to the pit are to be subsequently extended. In addition, the repository will require new transport routes and spaces to be excavated for the workshop complex and backfill processing. The excavation work will be carried out mechanically while minimising interference with the mountain structure.
In the long term, up to 303,000 m³ of radioactive waste with negligible heat generation are to be stored in the Konrad repository.
Whoever does what he already can, always remains what he already is. [Henry Ford]