Hydrogeological modelling of the Morsleben nuclear waste repository
Country / Region: Germany / Saxony-Anhalt
Begin of project: August 31, 2020
End of project: December 31, 2025
Status of project: January 20, 2025
The Morsleben radioactive waste repository (Saxony-Anhalt, Germany) is used for the storage of low and intermediate level radioactive waste and is to be decommissioned. As part of the decommissioning process, long-term safety studies are to be carried out. Previous numerical calculations of regional groundwater flow and transport in the repository area were found to be inadequate because the density-driven flow was not calculated in the three spatial dimensions. In this project, an adequate mathematical and conceptual model for the transient numerical simulation of flow and transport in the three spatial dimensions was developed according to the current state of knowledge. The model was then applied to numerical calculations for long-term safety analyses.
Conceptual flow model for regional groundwater systems
Source: Peche et al. (2021)
A new conceptual model for the site was developed based on an analysis of existing data and the current state-of-the-art numerical modelling of regional density-driven groundwater flow. The model domain, boundary conditions, source terms, initial conditions and calibration/validation procedure, recommendations for spatial and temporal discretisation, parameter distribution for flow and transport, and recommendations for future scenarios were elaborated. In addition, relevant uncertainties of the mathematical and conceptual model were highlighted and the water chemistry at the site was analysed in detail.
The HYPAGS method was developed by the Federal Institute for Geosciences and Natural Resources (BGR) as part of the development of the flow parameter database at the site. This method can be used to estimate flow parameters for saturated and unsaturated flow from minimal input information. The method is applicable to uniform porous media. In addition, incomplete groundwater hydrographs were completed using machine learning methods.
As part of the project, the BGR dealt with the fundamentals of site modelling. In addition, the BGR is carrying out the 2D numerical modelling of the density-driven flow and transport in the "Camp H" section. Three-dimensional numerical calculations were carried out by the project partner delta h. The project was coordinated by the Federal Company for Radioactive Waste Disposal (BGE).
Literature:
Technical reports
- ORILSKI, J., PECHE, A., KRINGEL, R. & ALTFELDER, S. (2022): Hydrogeologische Modellbildung des ERA Morsleben – Kurzbericht zur Erweiterung der Datenbasis für den Parameter effektive Porosität. - Federal Institute for Geosciences and Natural Resources (BGR) on behalf of Federal Company for Radioactive Waste Disposal (BGE).
- PECHE, A., KRINGEL, R., ORILSKI, J. & SKIBA, P. (2021): Hydrogeologische Modellbildung des ERA Morsleben – Zwischenbericht. - Federal Institute for Geosciences and Natural Resources (BGR) on behalf of Federal Company for Radioactive Waste Disposal (BGE).
Peer-reviewed papers
- PECHE, A., HOUBEN, G. & ALTFELDER, S. (2024): Approximation of van Genuchten Parameter Ranges from Hydraulic Conductivity Data. - Groundwater. doi: 10.1111/gwat.13365
- PECHE, A. & HOUBEN, G. J. (2023): Estimating characteristic grain sizes and effective porosity from hydraulic conductivity data. - Groundwater, 61: 574-585. doi: 10.1111/gwat.13266
- PECHE, A. et al. (under review): Timescales and solute breakthrough distances of diffusive radionuclide transport in low-permeability porous media. – Environmental Earth Sciences, Springer.
- TRAN, T. V. et al. (under review): Machine Learning-Based Reconstruction and Prediction of Groundwater Time Series in the Allertal, Germany. - Water, MDPI.
Posters
- PECHE, A., HOUBEN, G. & ALTFELDER, S. (2024): HYPAGS: approximation of virtual sieve curves and hydraulic parameter ranges for variably saturated flow from single input values of hydraulic conductivity. - 29th Congress of the Section Hydrogeology e.V. in the DGGV e.V., 20 – 23 March, Aachen, Germany.
- PECHE, A., TRAN, T. V. & ALTFELDER, S. (2024): Timescales of diffusion-dominated radionuclide migration–an evaluation of selected existing nuclear waste repository sites and test sites. - European Geosciences Union (EGU) General Assembly 2024, 14 –19 April, Vienna, Austria, doi: 10.5194/egusphere-egu24-15090.
- TRAN, T. V., PECHE, A., BRÖMME, K., KRINGEL, R. & ALTFELDER, S. (2024): Machine learning-based prediction of gaps in groundwater time series in the overburden of the Morsleben radioactive waste repository, Germany. - European Geosciences Union (EGU) General Assembly 2024, 14 – 19 April, Vienna, Austria, doi: 10.5194/egusphere-egu24-17411.
Software
Partner: