The Asse mine is a former salt mine in Lower Saxony, which was operated as a research mine from 1965 onwards. Between 1967 and 1978, the final disposal of radioactive waste was tested and practiced on a large-scale. The mine is located in the Asse hills of the same name, ten kilometers southeast of Wolfenbüttel. The entire facility is also called Asse II after the older of its two surface shafts, sunk in 1906. Since 1965, the facility has been operated on behalf of the federal government (Physikalisch-Technische Bundesanstalt) by a research institute initially called the Gesellschaft für Strahlenforschung mbH (GSF) and, after several name changes, now operates as the Helmholtz Zentrum München (HMGU). Research into the final disposal of radioactive waste ended in 1995. From 1995 to 2004, remaining cavities from the former salt mining operations were filled. In 2007, an application was made for final closure. The closure concept was politically controversial; The decision was made under time pressure, as the mining stability of the mine seemed to be guaranteed for only a few years. Following press reports in 2008 about radioactively contaminated brine, the operator was accused of inadequately informing the regulatory authorities. This was later officially confirmed. In order to be able to close the facility appropriately under nuclear law, it is no longer operated under mining law, but since January 1, 2009, as a repository under nuclear law. Therefore, from that date, the Federal Office for Radiation Protection (BfS) was responsible for the operation and decommissioning of the facility. With the change of operator, political responsibility shifted from the Federal Ministry of Education and Research to the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety. The new operator rejected his predecessor's closure concept, compared three options for dealing with the stored materials, and presented a plan for the retrieval of the stored waste in January 2010. The Federal Agency for Final Storage (BGE) has been the operator of the facility since 2017.