Asse II mine

The Asse II mine is a former salt mine used as a deep geological repository for radioactive waste in the Asse Mountains of Wolfenbüttel, Lower Saxony, Germany.HistoryThe Asse II mine was developed between 1906 and 1908 to a depth of 765m. Initially extracting potash, the mine also produced rock salt from 1916 to 1964. Potash production ceased in 1925.Between 1965 and 1995, the state-owned Helmholtz Zentrum München used the mine on behalf of the Federal Ministry of Research to test the handling and storage of radioactive waste in a repository. Between 1967 and 1978 low-level and intermediate-level radioactive waste were emplaced in 13 chambers in the Asse II mine. Two chambers are located in the middle part and ten in the southern flank of the mine at depths from 725 m to 750 m below surface. Between 1972 and 1977, exclusively medium-level radioactive waste was emplaced in a chamber on the 511 m level. Research was stopped in 1995; between 1995 and 2004 cavities were filled with salt. After media reports in 2008 about brine contaminated with radioactive caesium-137, plutonium and strontium, politicians accused the operator, Helmholtz Zentrum München – German Research Center for Environmental Health, of not having informed the inspecting authorities. On 8 September 2008, the responsible ministers of Lower Saxony and the German government replaced the operator with Bundesamt für Strahlenschutz - the Federal Office for Radiation Protection. In 2009, Greenpeace published a letter of the Bundesamt für Strahlenschutz to the German Bundesumweltministerium from 1996 in which the former had warned the latter that there is the risk of severe radioactive contamination if the mine runs full of water and that further investigation is urgently needed.