Based on well advanced international projects, this study gives a survey of the status of the design, construction, and operation of repositories for heat-generating radioactive waste in different countries, describes the site selection and exploration procedures applied, and examines the transferability to German siting regions. In addition to this, the study describes the characteristics of the different host rocks salt, clay, and crystalline rock.
There is international consensus that by emplacing high level radioactive waste and spent fuel in deep geological formations, they can be safely and permanently isolated from man and the environment. International safety standards und rules as well as national rules and regulations build the legal framework for the design, construction, operation, and closure of repositories. The search for suitable sites and their selection is based on national requirements. In this context, the available host rock formations, the kinds and amounts of waste, and socio-political aspects are most relevant. Conclusive site selection decisions have already been made in Finland and Sweden. In all countries, the technical repository concepts have been developed taking into account the local site conditions and the kinds and amounts of radioactive waste to be disposed of. The study also shows that suitable repository concepts have been developed for all kinds of potentially suitable host rocks (crystalline rock, clay, and salt). The characteristics of the host rocks determine not only the repository designs but the technologies and procedures for repository construction and operation as well. Furthermore, they have an impact on the technical solutions for a potential retrieval of the waste. The host rock properties are also decisive for the design of the technical and geotechnical barriers. While corrosion-resistant containers are the most relevant barriers for radionuclide retention in crystalline rocks, this function has to be fulfilled by the host rock itself in clay and salt formations. Due to the plasticity, high heat conductivity, dryness, and thickness of salt formations, salt domes are well suited for the final disposal of heat-generating radioactive waste. In addition to this, 150 years of experience in salt mining substantiate that mines in salt can be constructed and operated in a safe manner.
For further results of the study, click on the following link: Entwicklung und Umsetzung von technischen Konzepten für Endlager in tiefen geologischen Formationen in unterschiedlichen Wirtsgesteinen (EUGENIA)