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Disposal > Gorleben > Introduction to Gorleben
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Introduction to the Gorleben site
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On the basis of the recommendation on disposal in rock salt formations given in 1963 by the Federal Institute for Ground Research (today Federal Institute for Geosciences and Natural Resources) and the concept of the „Integrated Nuclear Waste Management Centre“ (reprocessing of spent fuel elements, fuel element fabrication plants, installations for the handling of all types of radioactive waste at one site) presented by the federal government in 1974, eight sites were investigated in a feasibility study. In 1975, three sites were selected which were then to be compared in a federal research programme lasting three years. Parallel to the exploration at the three sites through the federal government, a project group consisting of members of different ministries was established in May/June 1976 by the government of the Land to search for a site for a nuclear waste management centre. In the last phase Gorleben remained the sole site of 140 investigated salt domes.
Work on the exploration of the Gorleben site which had been suggested by the Land of Lower Saxony started on April 17, 1979. Initially a site investigation was performed from above ground to determine the position for two shafts and to develop a site-specific hydrogeological model which is necessary to evaluate the barrier effect of the salt dome´s overlying and adjoining rock.
Results on the Gorleben site were published by the Federal Institute of Physics and Metrology (PTB) in a summarising interim report in May 1983. The report arrived at the conclusion that the suitability of the site for the disposal of the planned radioactive waste could be expected and included a recommendation given to the federal government to take up underground exploration work in the salt dome. In July 1983, the federal government approved of the underground exploration of the salt dome. Following German reunification, an above-ground site investigation programme was also carried out in the area located north of the river Elbe on the terrain of the former GDR. Field work started in April 1996 and was terminated in November 1998 with a large-scale pumping test.
After having performed preparatory work, the underground investigation started with the sinking of the two shafts of the exploration mine in October 1986 with shaft 1 or, respectively, in April 1987 with shaft 2. Starting in October 1996, the cut-through between the two shafts on the 840-m exploration level took place and the infrastructure area was drifted. To the north-east of the infrastructure area there is the so-called exploration area 1 which is defined by the drifted galleries. This area was intensively explored by geotechnical measurements and geological mapping. The interim report of 1983 which served to establish the underground exploration, was continued in 1990, since data evaluation for the site exploration had then been concluded so far. In 1996 it was updated with the objective to inform the general public about the exploration results gained so far and the state of the suitability assessment.
As agreed on June 14, 2000, between the federal government and the utilities with respect to the phase-out of nuclear energy, the underground exploration of the Gorleben salt dome was interrupted on October 1, 2000, for three to ten years (moratorium). This period should be used to efficiently clarify conceptual and safety-related disposal issues. Among these are the control of gas generation due to the corrosion of the casks and the decomposition of the waste, as well as the suitability of salt as host rock compared with other rocks such as clay and granite.
The „Conceptual and Safety-related Questions of Radioactive Waste Disposal – Host Rocks in Comparison“ published by BfS in November 2005 answered basic questions of disposal which did, however, not refer to the Gorleben salt dome.
Furthermore, BMU commissioned the working group Arbeitskreis Auswahlverfahren Endlagerstandortsuche (AkEnd) to develop a transparent procedure for searching and selecting repository sites. With its final report presented in December 2002, the AkEnd submitted a recommendation for such a selection procedure. The necessary geoscientific data bases for the evaluation of exclusion criteria, minimum requirements and consideration criteria of the AkEnd recommendation were evaluated on the national level on behalf of BfS, taking into account all types of host rock coming into question for the disposal of radioactive waste.
Since October 1, 2000, solely measures and work are carried out in the Gorleben exploration mine which maintain the mine in a safe-to-operate state. These measures include the preservation of previous capital investments and work results in order to adhere the possibility of resuming exploration work following an unprejudiced clarification of open questions.
To secure the Gorleben site against measures that could aggravate the continuation of the exploration, the federal government decreed the Gorleben-Veränderungssperren-Verordnung (Gorleben Modification Ban Ordinance) in August 2005. With the modification ban a planning area has been determined where modifications leading to increases in value or considerably aggravating the site exploration must not be carried out.
The governing coalition of CDU/CSU and FDP announced in its coalition contract of October 24, 2009 that it would cancel the Moratorium for the exploration of the salt dome in Gorleben. Exploration works should be taken up again, not anticipating the result. Furthermore, an international peer review group should accompany the works and examine if Gorleben complies with the latest international standards. The entire process is to be designed in a public and transparent way. On this basis, BfS is currently developing a concept of how to carry on with the exploration of Gorleben and the search for a repository site, which will be the basis for further decisions in politics.
Gorleben still is an exploration mine and not a repository. Whether the Gorleben site is suitable for hosting a repository for radioactive waste can currently not be judged. This requires further extensive work. A statement on the suitability is given with the plan-approval decision in the plan-approval (licensing) procedure under nuclear law. However, in connection with the discussion about a site-selection procedure for a repository for high-level radioactive waste, the Federal Office for Radiation Protection has stated several times that the costs in Gorleben are higher than would be required for an exploration within the scope of such a procedure. The facilities have been designed for the case that their suitability for being used or developed to host the planned repository in future has been proved. This especially concerns the two shafts, the size of the salt heap and the size of the external facility, and the buildings.
A statement about the suitability of the Gorleben site has not been made so far and can only be made following comprehensive safety assessments. In order to further develop the methods for a safety-analytical comparison of sites with different host rocks, BfS started the VerSi project.
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