Former nuclear waste repository exploration shaft at Gorleben in the Landkreis Lüchow-Dannenberg, sunk from 1986 and now in active backfilling by the Bundesgesellschaft für Endlagerung (BGE) following the definitive exclusion of the Salzstock Gorleben fro
Schacht Gorleben 1 is the primary exploration shaft of the Erkundungsbergwerk Gorleben, situated in the Gorlebener Wald in the Landkreis Lüchow-Dannenberg, Niedersachsen, within the Salzstock Gorleben-Rambow. The site was selected in February 1977 by the then Lower Saxon Minister-President Ernst Albrecht as the location for an integrated nuclear waste management facility. Surface exploration was conducted from 1979 to 1983, and in 1986 shaft-sinking for Schacht 1 began using the permanent headframe.
At 234 metres depth an unexpectedly high rock pressure was encountered; in May 1987, steel support rings installed to manage this stress collapsed, killing one miner. The use of the freezing method for shaft-sinking was required; the completed shaft uses a novel steel ring outer lining with reinforced concrete composite lining and asphalt backfill. The 840-metre underground exploration level was reached in November 1995; the breakthrough between Schacht 1 and Schacht 2 was accomplished in October 1996.
Underground exploration continued, with a moratorium from October 2000 to October 2010, until December 2012 when the Standortauswahlgesetz came into force. Following the BGE's Teilgebietebericht of September 2020, which excluded the Salzstock Gorleben from the repository siting process on the grounds of insufficient barrier rock above the salt dome, the Bundesumweltministerium commissioned the BGE in September 2021 to close the mine. Backfilling with approximately 400,000 cubic metres of salt began in late November 2024 and is being carried out by Redpath Deilmann and Thyssen Schachtbau.
Total expenditure on the Gorleben site to its exclusion was approximately two billion euros.
The selection of Gorleben as a nuclear waste management site was announced in February 1977 by Ernst Albrecht, the then Minister-President of Lower Saxony, as the proposed location for an integrierten Entsorgungsanlage covering spent fuel reprocessing, waste conditioning, and final underground disposal. The announcement triggered sustained and sometimes violent protests across the Wendland region; in March 1979 a Treck of Gorlebener farmers marched to Hannover, which led Albrecht to declare the reprocessing facility 'politically non-enforceable', while investigation of the salt stock for disposal purposes continued.
Surface exploration of the Salzstock Gorleben-Rambow began in April 1979 and continued to 1983, including 44 salt-reflection boreholes, geophysical and hydrogeological surveys, approximately 500 borehole and piezometer installations, four deep boreholes to approximately 2,000 metres in the margins of the salt stock, and two shaft pilot boreholes to approximately 1,000 metres to confirm the shaft positions. Post-reunification supplementary surveys were conducted on the former DDR side of the Elbe from 1992.
In 1983 the federal government formally resolved to explore the Salzstock as a repository site for heat-generating radioactive waste. Shaft-sinking on Schacht 1 began in 1986, employing the permanent Förderturm for the sinking operation — an unusual choice reflecting the implicit assumption that the shaft would become a permanent facility. Already at 234 metres depth an unexpectedly high Gesteinsdruck was encountered; in May 1987, steel Stützringe installed to manage this stress collapsed, killing one miner. The lower section of the shaft was sunk using the Gefrierverfahren (ground-freezing method) to manage water-bearing strata. The shaft was completed with a novel Stahlringaußenausbau in combination with Stahlbetonverbundausbau and Asphalthinterfüllung. Construction of the near-shaft underground infrastructure rooms — including the workshop — was included in the same contract and executed by Redpath Deilmann (then Carl Deilmann).
The 840-metre exploration level was reached by both shafts in November 1995; the underground breakthrough between Schacht 1 and Schacht 2 was completed in October 1996. Comprehensive geological, geochemical, geophysical, geotechnical, and hydrogeological investigations were conducted, together with in-situ experiments and laboratory analyses on rock salt samples. The principal geological concern was the Hauptanhydrit, a klüftig (jointed) formation regarded as a potential conduit for water ingress that could cause the repository to flood. Salzlösungseinschlüsse (brine inclusions) present in the salt stock were found to be as old as the surrounding salt itself — more than 200 million years.
Despite the emerging scientific concerns, the site was maintained as 'eignungshöffig' (showing suitability promise) through a change in safety philosophy — downgrading the importance of the overburden barrier and relying solely on the salt stock. Press investigations published in 2009 attributed this adjustment to direct political influence from the CDU/FDP government under Helmut Kohl after 1983. In October 2000, within the framework of the first Atomausstiegskonsens, the federal government suspended underground exploration through a formal Moratorium. The moratorium ended after ten years in October 2010; from 2010 to December 2012 the Vorläufige Sicherheitsanalyse Gorleben (VSG) was conducted in parallel with resumed exploration. In December 2012 all exploration activities were ended when the Standortauswahlgesetz came into force, placing Gorleben as one candidate among all potentially eligible geologies.
On 28 September 2020, the BGE published its Zwischenbericht Teilgebiete, which excluded the Salzstock Gorleben from the siting process: the salt stock meets minimum requirements for a repository but fails the Abwägungskriterien, specifically the absence of an adequate barrier in the overburden capable of permanently shielding the salt stock from water ingress under § 36 Abs. 1 S. 5 Nr. 1 StandAG. On 17 September 2021, the Bundesumweltministerium (BMU) commissioned the BGE to close and backfill the mine. The surface perimeter wall had already been reduced in 2019 to an industrial standard fence. Backfilling of approximately 400,000 cubic metres of underground excavated salt, currently stored on the Gorleben surface salt stockpile, into the voids was commissioned to Redpath Deilmann and Thyssen Schachtbau; work began at end of November 2024. Total expenditure on the Gorleben site over four decades amounted to approximately two billion euros, borne by the federal state. The surface Zwischenlager at Gorleben, holding 113 CASTOR containers of high-level radioactive waste, remains in operation at the adjacent site pending the eventual commissioning of a permanent repository elsewhere.