Thermal Impact on the Damaged Zone around a Radioactive Waste Disposal in Clay Host Rocks

A proper evaluation of the Damaged Zone (DZ) in the host formation is an important item for the long-term safety of underground disposal of the spent nuclear fuel and long lived radioactive-waste. The DZ is first initiated during the repository construction. Its behaviour is a dynamic problem, dependent on changing conditions that vary from the open-drift period to the initial closure period and the entire heating-cooling cycle of the decaying waste. The TIMODAZ project focuses on the study of the combined effect of the EDZ (Excavation Damage Zone) and the thermal output on the repository host rock. The influences of the temperature increase on the evolution of the EDZ as well as the possible additional damage created by the thermal load will be studied. The TIMODAZ consortium is composed of 15 participating organisations representing in total 8 countries: EURIDICE (BE), NAGRA (CH), SCK•CEN (BE), GRS (DE), NRG (NL), CIMNE (ES), EPFL (CH), ULG (BE), UJF (FR), ENPC (FR), CEG-CTU (CZ), ITASCA (FR), ASC (UK), ITC (CH) and SOLEXPERTS (CH).