Prototypical testing of material models for integrity verification of geological and geotechnical barriers in repositories for heat-generating waste (PRESTIGE)
Country / Region: independent
Begin of project: July 1, 2001
End of project: December 31, 2025
Status of project: November 7, 2023
Numerical demonstration model for backfilling of crushed salt in emplacement drift
Source: BGR
In the PRESTIGE project, BGR carries out numerical investigations for the assessment of the integrity of geological and geotechnical barriers in the context of final disposal of radioactive waste. These investigations cover all host rocks (rock salt, claystone and crystalline rock) as well as geotechnical barriers. The effect of material model formulations on the predicted barrier integrity is analysed by testing the different material models in prototypical application cases.
The investigations to be carried out include in particular the practical applications of suitable computational software for complex problems (e.g. large three-dimensional models, interpretation of in-situ measurements and local observations, interpretation of laboratory tests on test specimens) and take into consideration various material models.
The current focus of the project is to further develop and validate simulation strategies that describe the hydromechanical behaviour of crushed salt. This material is used as a geotechnical barrier to backfill cavities for the final disposal in rock salt. The complex processes involved in the compaction of crushed salt – as investigated in the laboratory at BGR – have to be incorporated in the investigations for integrity verification in repositories for heat-generating waste in rock salt. The modelling strategies developed for this purpose also have to meet the requirements of verification for long-term safety.
Integrity analysis: Local and temporal development of the dilatancy indicator in a 2D model
Source: BGR
In cooperation with national and international partners within the KOMPASS project, material models describing the compaction behaviour of crushed salt are tested at various temperatures and stresses. A comparison of the calculation results from all of the partners provides a valuable contribution to the validation of the different material models within the respective computational software.
With the results acquired in the PRESTIGE project, BGR makes an important contribution to the assessment of the long-term effectiveness and integrity of geological and geotechnical barriers in the exploration and evaluation of sites for repositories for heat-generating waste.