Within the framework of the establishment of a repository for negligible heat-developing radioactive waste located in the former Konrad mine in Salzgitter, underground units are being excavated and expanded. In addition to the shafts re-conversion and the performance of the storage chambers, the so-called side mine chambers for the required storage facility infrastructure are being built up and eventually enlarged.

Lot 2:
These include: a dosing and mixing room, a grinding room, a second room for electrical transformers, a place for access to the transport vehicle and an enlargement of an existing passage.
Excavation of the mine chambers for the relocation-conditioning on the third level. This includes the mine chambers for the dosing- and mixing plants, the grinding, the transformer room II, the spinning-transfer vehicles access and the enlargement of an existing stretch.

Typical profile in partial sections: 46 - 135 m²
Excavation of a new section: 130 m
Extensions of existing sections: 145 m

Methods of advancement:

• Roadheader
• Hydraulic excavator with attachment
• Two-arm jumbo

Interior lining (inner and outer ring):

• Anchors
• Shotcrete

Special features:
Due to the expected deformations in almost all excavation areas, a convergence-settlement time of 12 months is assumed. The excavation by means of drill and blasting is not permitted.

The geological formation on the work level consists of Malm, Dogger and upper Jura, which follows the iron-ore basin horizon