In addition to site selection, design, and corresponding repository construction, the closure of a repository is a crucial element for ensuring safe, long-term isolation of radioactive waste from the biosphere.
We develop closure concepts adapted to the site-specific requirements, the emplaced radionuclide inventory, and the repository design. The adequate implementation of these closure concepts ensures the long-term isolation of the radioactive waste. We have planned and implemented closure measures for underground repositories in Germany and abroad. Furthermore, we investigate and optimise the design of geotechnical barriers for shafts and drifts in different host rocks in the course of national and international R&D projects.
Our knowledge and experience encompass all aspects of repository closure. We develop building materials for geotechnical barriers that are durable in the long-term under the site-specific conditions. We also adapt the barrier design and the sealing of the contact and excavation damaged zones within the mine to the site-specific requirements. In some cases, special measures need to be taken, e.g., to regulate the chemical conditions in the emplacement chambers or to stabilise the underground excavations. We ensure implementation of the closure measures according to requirements by means of quality assurance procedures, construction supervision and computational safety assessments.
As well as the closure of underground facilities, we also have experience in decommissioning of nuclear surface facilities.