// Long-term Safety Studies

SAnToS

Investigation on long-term safety aspects of a radioactive waste repository in a diagenetic clay formation

In 2001, the topic of radioactive waste disposal was integrated into the agreement between the former Russian Ministry of Atomic Energy (Minatom, now Rosatom) and the German Ministry of Labour (BMWA), on cooperation regarding R&D on the peaceful utilization of nuclear power (agreement on “Wissenschaftlich-Technische Zusammenarbeit” WTZ). Based on the WTZ agreement, a comprehensive and versatile cooperation has been implemented in the past 13 years. Joint R&D activities regarding radioactive waste disposal in claystones based on-site investigation activities in the Leningrad region were agreed as a permanent part of this cooperation in 2011. The final report describes the geological situation, the current geoscientific database at the "Radon site" in the Leningrad region, the repository concept and a conceptual approach of a complete sealing system. The developed sealing concept consists of disposal drift seals, access drift seals, shaft seals and a ramp seal. Furthermore, it presents the methodology that is used in Germany to demonstrate the integrity of sealing elements in repositories, and it provides and exemplary demonstration of the integrity of the proposed ramp sealing element. Finally, it presents and applies the modelling framework existing in Germany to simulate the radionuclide release from the repository to the biosphere using deterministic and probabilistic methods.