Closure of Underground Cavities

In addition to site selection, repository design and construction, the proper and safe closure of repository mines is another, essential element for the long-term safe containment of radioactive waste. During the operating phase, backfilling measures can stabilise mine workings, and sealing constructions can prevent brine intrusion or the propagation of solutions that have already entered the mine. Similarly, stabilising measures for conventional mines or closure of abandoned parts of production mines are based on special know-how which always has been provided by BGE TECHNOLOGY GmbH.

Due to our participation in the national and various international projects, we have comprehensive know-how and a broad spectrum of knowledge concerning the sealing of mine workings and the use of suitable construction materials. From planning and conceptualisation to the development of construction material to its practical application – we cover it all. We develop closure concepts – some of them elaborate – that are adapted to the site-specific requirements, the radionuclide inventory emplaced, and the respective disposal concept. Their implementation ensures the long-term safe enclosure of the radioactive waste. In Germany and abroad, we have both planned and implemented sealing measures. Furthermore, the design of the engineered barriers and the sealing of the contact and excavation damaged zones to the surrounding rock are adapted to the site-specific safety requirements. In some cases, special measures are required, e.g. to influence the chemical environment in the emplacement chambers or to stabilise the mine workings.

Our range of expertise includes:
  • Planning and implementation of backfilling and sealing measures in the Morsleben repository and in the Asse II mine as well as carrying out the required safety demonstrations
  • Analysis and optimisation of the design of geotechnical barriers for shafts and drifts in various host rocks within the framework of national and international research projects
  • Development of building materials taking into account their rock-specific long-term stability and the requirements for long-term safety
  • Ensuring compliance of the design of sealing measures by means of verification calculations and monitoring their implementation by means of construction supervision and quality assurance measures

References

  • Construction of flow barriers in the Asse mine
  • Design and safety assessment of in-situ pilot sealing structures in the Morsleben repository
  • Development of shaft closure concepts for a HLW repository (R&D project ELSA)
  • Investigation on the THM behaviour of a heated bentonite barrier by measurements and numerical calculations (R&D project MUSTER)
  • Development of a concept for the closure of an emplacement chamber in the Richard repository (Czech Republic)