Former nuclear waste repository exploration shaft at Gorleben, sunk from 1986 as the second shaft of the Erkundungsbergwerk Gorleben and now in active backfilling by the BGE following the exclusion of the Salzstock Gorleben from the repository siting proc
Schacht Gorleben 2 is the second exploration shaft of the Erkundungsbergwerk Gorleben, located immediately adjacent to Schacht Gorleben 1 in the Gorlebener Wald, Landkreis Lüchow-Dannenberg, Niedersachsen. It was planned and sunk simultaneously with Schacht 1 as part of the programme to investigate the Salzstock Gorleben-Rambow as a potential repository for heat-generating high-level radioactive waste. Both shafts were conceived as components of a facility that, as investigations progressed and high-level government sources later confirmed, was developed far beyond a purely exploratory installation.
Schacht 2 fulfilled the Zweischachtverordnung requirement for a second mine access and provided independent ventilation and personnel transport for the underground exploration workings. The 840-metre exploration level was reached by Schacht 2 in November 1995; the breakthrough between the two shafts was completed in October 1996. Exploration was interrupted by moratorium between October 2000 and October 2010 and ended definitively by the Standortauswahlgesetz in December 2012.
In September 2020 the BGE excluded the Salzstock Gorleben from the siting process. The BGE was commissioned to close the mine in September 2021. Backfilling of approximately 400,000 cubic metres with excavated salt from the surface stockpile began at end of November 2024.
Both shafts are being backfilled by Redpath Deilmann and Thyssen Schachtbau. Total expenditure on the Gorleben site to its exclusion was approximately two billion euros.
Schacht Gorleben 2 was sunk beginning in 1986 simultaneously with Schacht Gorleben 1 as part of the programme initiated by the federal government's 1983 resolution to investigate the Gorleben salt stock as a repository for Wärme entwickelnde radioaktive Abfälle. Like Schacht 1, the sinking of Schacht 2 was subject to complex approval procedures and extremely high safety and quality-assurance requirements. The shaft was designed to serve as the second access point required by the Zweischachtverordnung and to provide independent ventilation and personnel transport for the underground exploration level.
Both shafts are located within the same surface compound (Schachtanlage) in the Gorlebener Wald; the two shaft installations stand only metres apart. Schacht 2 was completed to the 840-metre exploration level in November 1995. The underground breakthrough between the two shafts was completed in October 1996, establishing the connected underground infrastructure required for systematic exploration of the salt stock. Comprehensive geological, geotechnical, hydrogeological, and geochemical investigations were conducted on both levels, including in-situ experiments and laboratory analyses of rock samples. The principal scientific concern raised by the exploration was the role of the Hauptanhydrit as a potential water conduit, which was treated as the critical barrier question for long-term repository safety.
The moratorium agreed in October 2000 suspended all underground work for ten years. Following the end of the moratorium in October 2010, exploration resumed and the Vorläufige Sicherheitsanalyse Gorleben (VSG) was conducted in parallel until December 2012, when the Standortauswahlgesetz ended all exploration activities and placed Gorleben in the new comparative siting process.
In September 2020 the BGE's Zwischenbericht Teilgebiete concluded that the Salzstock Gorleben failed the Abwägungskriterien for a repository site, specifically because of the absence of an adequate overburden barrier under § 36 StandAG. In September 2021 the Bundesumweltministerium commissioned the BGE to close the mine. In November 2024, backfilling of both shafts commenced using excavated salt from the surface stockpile. Schacht 2 shares both the physical backfilling programme and the broader site decommissioning timeline with Schacht 1; when backfilling is complete, the site is intended to return to 'grüne Wiese' (open land) within approximately ten years. The adjacent Zwischenlager for 113 CASTOR containers remains in operation pending the eventual commissioning of a permanent repository elsewhere in Germany.