Questions on the KONRAD repository concept
- Does the Konrad mine licensed in 2002 still represent the state of the art of science and technology?
- What kind of radioactive waste storage do experts recommend: retrievable, recoverable or non-retrievable?
- Why should radioactive waste be disposed of in the first place?
These and other questions go along with the conversion of the Konrad mine into a repository. The BfS deals with some of the frequently addressed aspects in more detail.
Is there evidence that the Konrad mine does already today not correspond to the state of the art of science and technology?
No. The Konrad mine is the first repository in the Federal Republic of Germany which has been and will be planned, constructed, operated and sealed pursuant to the stringent specifications of nuclear law, from the beginning of filing the application until the sealing of the mine later on. That distinguishes Konrad from the previous project such as the Asse or Morsleben mines, for which no long-term safety considerations including the planning of safe enclosure were conducted prior to storing wastes.
The first plans for a Konrad repository date from the 1980s: The licence, which was granted in 2002, reflects the status as of this year, however. The nuclear licensing procedure was also audited by various judicial bodies and was confirmed by the Federal Administrative Court in 2007.
The long-term effects of a repository were analysed by safety considerations and were a prerequisite for licensing the Konrad mine as a repository. In this process it was proven that the Konrad repository does not pose a risk for man or environment, neither now nor in the long run. Such considerations were never made for the Asse mine.
In the case of the Konrad mine, the BfS as operator is monitored by the federal state of Lower Saxony as licensing authority under nuclear and mining law and as supervisory authority under mining law and by the Federal Environment Ministry as functional and legal control body. These supervisory and licensing authorities have not given any indications, either, that the licence for the Konrad repository is no longer in compliance with the state of the art of science and technology.
The repository will be operated over several decades. The BfS will take into account the state of the art of science and technology which will develop further during this period of time. It is planned to do a first revision of the safety-related requirements prior to taking the repository into operation, which is also in accordance with the commitment of the BfS. It is also planned to carry out further current reviews for the operational and closure phase.
Will the wastes be disposed of in the Konrad repository in such a way that they can be retrieved?
No. For safety reasons, the wastes are to be enclosed in the existing geological barrier in the Konrad repository and thus be sealed from the biosphere. Both in the Federal Republic of Germany and also at the international level, this is consensus among most of the experts. As opposed to this, storage with the option to entirely retrieve the waste would involve compromising safety.
Does the Repository Commission recommend radioactive waste disposal with the option to retrieve the waste?
Basically wastes can also be retrieved from sealed repositories. However, what is meant by this term is whether the concept actively provides for the option to retrieve the wastes.
Terms such as retrievability, recoverability or non-retrievability describe different repository concepts, each with a different emphasis. The responsible working group of the Repository Commission opts for disposal in deep geological formations. It supplements this with elements that should additionally provide for a possible recovery of the wastes. For several years, the BfS has recommended the same basic approach and also the safety requirements for disposal that are currently effective updated in 2010 provide for the additional element of recoverability.
Background of these considerations: In the long run, wastes are to be stored in a manner that is safe for man and environment, in repositories that have been sealed from the biosphere by natural and impermeable geological barriers. The protection is to be guaranteed without further measures being required such as guards or technical barriers. Furthermore, it should be possible to facilitate the recovery of the wastes, should this be desired or necessary. This includes e.g. the exact documentation of the site and the content of the emplaced wastes or the utilisation of containers that are durable over centuries which would be easier to handle in the case of a recovery.
Storage with the option to entirely retrieve the wastes, on the other hand, would mean to give up the storage in deep geological formations and to store the wastes on the surface, e.g. in long-term interim storage facilities or underground in mines that are openly accessible. This involves cuts in safety, since safety would then depend on the staff or human technology. Guards and artificial barriers such as concrete or barbed wire would have to be ensured over thousands of years, in order to replace the lacking natural geological barriers.
Will the wastes be disposed of in the Konrad repository in such a way that they can be recovered?
No. For Konrad, the concept of a long-term safe storage in deep geological formations described above is planned but without the additional element of recoverability.
Compared to the criteria of the safety requirements or of the Repository Commission: are double standards applied for the Konrad repository? Why is Konrad not adapted to recoverable storage?
No, that would mean comparing different types of repositories with each other. The current debate on the recoverability of the wastes refers solely to repositories for high-level radioactive wastes. Also according to the safety requirements updated in 2010, recoverability is only demanded for a repository for high-level radioactive waste. In contrast, the Konrad mine is exclusively planned for low-level and intermediate-level radioactive wastes.
Basically it is also conceivable that the additional requirements for high-level radioactive wastes – which involve an enormously higher risk potential – be applied to low-level and intermediate-level radioactive wastes, too. In contrast to most other European countries, the basic safety consideration, the long-term safe enclosure in deep geological formations, applies in Germany also to low-level and intermediate-level radioactive wastes and to the Konrad repository. Just the additional element of recoverability is not provided for. This would have to be taken into account in the conception of a repository for low-level and intermediate-level radioactive wastes.
However, this concept cannot be adapted ad lib to a project such as the Konrad repository which is under construction. In contrast to the Asse mine, detailed information on the content and location of the wastes stored in the Konrad repository is to be documented and maintained. Other aspects of recoverability cannot be supplemented retroactively. That concerns for example the issue of container durability. For the Konrad repository waste acceptance requirements apply that are continuously updated and are already being applied by waste producers for packaging the waste in a way that is suitable for disposal. These requirements provide for a long-term safe storage but not for a durability of the containers of hundreds of years.
Why is it planned to store the wastes in the Konrad repository in the first place? / Isn’t it safer to store the wastes on the earth’s surface?
Wastes can be safely stored in interim storage facilities on the earth’s surface for a limited period of time. However, since no natural barriers exist there, the wastes need to be secured by technical barriers such as concrete or barbed wire and by corresponding personnel and they must be monitored continuously.
Experience has shown that containers used for interim storage so far can already be exposed to constant corrosion after a few decades and can be damaged. The longer this storage is planned the more difficult and complicated become the necessary security measures.
For example, the corrosion of drums stored in Brunsbüttel is due to the fact that they have not been monitored sufficiently and were also not packed in compliance with the Konrad waste acceptance requirements in a way that they are suitable for disposal. If one was searching for a new site for the low-level and intermediate-level radioactive wastes instead of the Konrad mine, the existing wastes would have to be stored intermediately on the surface for more decades. Furthermore, it would not be possible for decades to pack the wastes safely in a way that they are suitable for disposal.
State of 2016.02.05