BGR Bundesanstalt für Geowissenschaften und Rohstoffe

Repository sites selection

Which options are available for repository sites?

The search and selection of a site for a repository for heat-generating radioactive waste was regulated since July 2013 by the "Act governing the search and selection of a site for a repository for heat-generating radioactive waste", which has been replaced by the "Act governing the search and selection of a site for a repository for high-level radioactive waste" (Site Selection Act - StandAG).

In a new multi-phased comparative process, the site with the "best-possible safety" is to be determined, and then defined by an act of parliament. One of the new aspects here is increased public involvement right from the start of the process. Every step of the procedure must be transparent and comprehensible. The potentially suitable host rocks salt, claystone and granite for a repository for radioactive waste in Germany will be taken into consideration as part of this process.


Why was a "Repository Commission" established?

Pursuant to Section 3 of the StandAG, the Bundestag and Bundesrat established a commission in 2014 whose job was to make the necessary preparations for the actual search for a repository site. The members of the "Storage of high-level radioactive waste" Commission (Repository Commission) included politicians from the Bundestag and the Länder governments, as well as representatives of science and society. The 34-member commission chaired by Ursula Heinen-Esser and Michael Müller, worked for two years to elaborate scientific and societal recommendations for action.

As the federal government's consultant on geoscientific issues involving repositories, BGR provided technical advice to the Repository Commission. BGR experts were present as permanent guests at every meeting of the commission. BGR submitted numerous expert reports and independent opinions. The topics included the geoscientific criteria for repository site selection in other countries (K-MAT 23a, download in German), and easily understandable facts on claystone and clay research (K-MAT 16, download in English).
The Repository Commission finished its work with the hand-over and presentation of its final report at the beginning of July 2016. In its 681-page final report (K-Drs. 268, download in German), the commission states its position on aspects including:

  • other disposal options
  • general safety requirements
  • geoscientific exclusion criteria, minimum specifications and assessment criteria
  • planning science criteria
  • preliminary safety analyses
  • criteria for the potential correction of errors during the course of the process
  • organisational structure and public involvement

The Repository Commission recommends deep-geological storage as the means of disposal. The geoscientific criteria elaborated by the commission in this report will guide the comparative selection process. This means that the criteria used to select a site with the "best possible safety" have already been defined before the selection process begins. The process is also intended to offer possibilities for correcting errors by the recoverability and retrievability of the waste.


Start of the selection process

The selection process for a repository site for heat-generating nuclear waste was launched by Federal Minister for the Environment, Nature Conservation, Building and Nuclear Safety Barbara Hendricks on 5 September 2017.


What steps are involved in the site selection process?

The Repository Commission elaborated detailed recommendations on how the selection process should proceed. They are documented in the final report (K-Drs. 268, Download in German). The site regions to be explored will be identified based on the pre-defined criteria across the whole of the country – based on a white map of Germany. This means that those regions in Germany considered to be worthy of investigation after taking into consideration all of these criteria will only be revealed during the course of this site selection process. The potential host rocks which have been identified are salt, claystone and crystalline rocks.

Phase 1 of the site selection process begins with the exclusion of regions based on the exclusion criteria and minimum requirements. A comparative analysis is then undertaken on the basis of the existing data by applying the assessment criteria and the representative preliminary safety investigations. Surface exploration then takes place in phase 2 (involving drilling and seismic surveys) of those site regions identified in phase 1. This is then followed by underground exploration (constructing a mine and carrying out underground investigations) at those sites selected at the end of phase 2.

According to the StandAG, the site selection process should be completed by 2031. The decision on which sites are to be investigated underground should be made by 2023. The commission is of the opinion that the emplacement of high-level radioactive waste at the chosen site with the "best possible safety" will not begin until 2050, insofar as there are no unforeseen delays.

The Bundesgesellschaft für Endlagerung mbH (BGE) is the responsible actor for the execution of the selection procedure.


Which host rocks are being considered in the site selection process?

Salt

Salt structures in north GermanySalt structures in north Germany Source: BGR

The nature, composition and properties of the rocks at the repository sites primarily determine how well these natural barriers protect the environment from radiation. Rock salt has particularly good isolating properties for high-level radioactive heat-generating waste in particular.
BGR has gained a leading international reputation in the exploration of salt domes as potential repository formations for radioactive waste. BGR published a geological map on the salt structures in north Germany in 2008. The "Salt structures of north Germany" map at a scale of 1:500,000 is the first overall map of all of the approximately 450 salt domes, salt pillows and salt formations in north Germany, including the German sector of the North Sea.
BGR compiled a catalogue in 1994 describing the salt structures in Germany, and evaluated them in terms of their potential as repository sites. This salt study (download PDF, 6.3 MB, in German) was not, however based on the new criteria which have now been developed. The salt study was published by the Repository Commission as K-MAT 5.

Claystone

Map of rock salt and claystone formations deemed worthy of investigation in Germany in previous studiesMap of rock salt and claystone formations deemed worthy of investigation in Germany in previous studies Source: BGR

In addition to salt formations, other potential host rocks, such as claystone formations, are also being investigated to assess their suitability for a nuclear repository. BGR carries out these investigations on the basis of international co-operation projects in underground laboratories, primarily in Switzerland and France. This work involves developing and testing methodologies and equipment for the geoscientific exploration of potential repository sites. Another objective of the work is to extrapolate the findings from the joint international projects to analogous geological formations in Germany.

BGR was authorised by the Federal Ministry for Economic Affairs and Energy (BMWi) in 2003 to implement a study on the distribution of claystones as potential host rocks for a repository for high-level radioactive waste in Germany. This clay study (download PDF, 16 MB, in English) with the title "Final disposal of radioactive wastes in deep geological formations of Germany. Investigation and evaluation of argillaceous rock formations" was published on 18.04.2007. However, the clay study was not based on the new criteria of the selection process.

The investigations used to study the claystone formations are based on the internationally recognised exclusion and assessment criteria formulated by BGR for the salt and crystalline host rocks. Investigations were supplemented by the host-rock-independent exclusion criteria and minimum requirements defined in 2002 by the Committee on a Site Selection Procedure for Repository Sites (AkEnd). In addition, BGR also included in its original selection process other assessment criteria considered to be crucial from a geoscientific point of view. The evaluation was based on all of the available data in maps, archive material and boreholes. No field work was carried out. The clay study was published by the Repository Commission as K-MAT 6.


Crystalline rocks

BGR published a catalogue in 1995 of the crystalline rock formations in Germany worthy of further investigation for the disposal of high-level heat-generating radioactive waste: the crystalline rock study (download PDF, 2 MB, in German). The crystalline rock study was published by the Repository Commission as K-MAT 4.

The summary report "Investigation and evaluation of regions with potentially suitable host rock formations" (download PDF, 1.2 MB) summarises the research findings on the host rocks in Germany: rock salt, crystalline rocks and claystones. The summary report was published by the Repository Commission as K-MAT 7.


Contact

    
Gerhard Enste
Phone: +49-(0)511-643-2442
Fax: +49-(0)511-643-3660

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