Workshop "40 years research and development for the safe disposal of high-level radioactive waste: Where we are ?"

At the 10th and 11th of June, 2008, the Project Management Organisation Karlsruhe Research Centre (PTKA) organized in cooperation with DBE TECHNOLOGY GmbH a workshop on the current state of science and technology in German research on radioactive waste disposal in Peine.

The final disposal of high-level radioactive waste and spent fuel is inseparable from the peaceful use of nuclear energy. The Federal Government has the legal obligation to construct repositories. This task includes to care for the necessary technological and scientific know-how.

Therefore, the Federal Ministry of Economy and Technology and the Federal Ministry of Education and Research fostered research projects in the field of hazardous waste management since 4 decades.

Because of the complexity of a repository system including a broad spectrum of themes from many natural and engineering sciences as well as from basic research up to technical applications has to be dealt with. Therefore, during a time-frame of four decades many companies and research institutions were involved in the research work and contributed to the development of a well sophisticated know-how especially in final disposal in salt rock. This know-how ranges from rock and building material investigations to the development of conceptual models for repositories, the development and testing of repository technologies up to methods for long-term safety analyses. Hence, it was the objective of the workshop to inform especially energy supply companies operating nuclear power plants as well as service companies in the nuclear field on the current state of research and development for final disposal.

In the course of the two-days-workshop 10 speakers from five institutions reported on important results of research work in the field of final disposal of radioactive waste. So, the highlights of the German research and development program have been described. Furthermore, the Federal Office on Geosciences and Resources (BGR) reported on her investigations on different kinds of potential host rocks in Germany, on results from the exploration of the Gorleben salt dome as well as on relevant aspects of the previous site selection procedure. Meanwhile, most of the relevant technical components of a future repository in salt rock have been tested in large-scale demonstration tests in the course of the R&D-program "Direct Disposal" and are now ready for certification. The knowledge on an alternatively discussed disposal in German clay is not yet as well developed. Basic research is also necessary in the field of geochemistry to advance in the understanding of relevant processes for long-term safety assessment in waste and host rock during the post-operational phase and to reduce unnecessary conservative assumptions. In this context, it would be desirable to perform this research work at a specific site.

An other group of presentations dealt with long-term safety assess­ments for reposi­tories in salt and clay. Principally, the methodology for long-term safety analysis is well developed. For salt host rock, the confirmation of the safe enclosure of the waste is in the focus of discussion. For clay, first results from R&D-work resulting from a generic analysis could be presented.

The three presentations of DBE Technology GmbH dealt with the following issues:

• International status of final disposal of radioactive waste,
• Development and status of concepts for the final disposal of high-level radioactive waste in salt, and
• development of concepts for the final disposal of high-level radioactive waste in clay formations.

You will find the corresponding presentations at "publications".

Finally, the promoters as well as the participants agreed that the workshop was successful and has well met his objectives.