W7 | Uncertainties in geological 3D-Modells: A Challenge in the nucleare waste repository site selection procedure
Uncertainties in geological 3D-Modells: A Challenge in the nucleare waste repository site selection procedure
Main Session Organizers: Ute Maurer-Rurack, Maik Schilling | Deputy Session Organizer: Maik Schilling
Orals
| Fri, 19 Sep, 10:00–11:20 (CEST)|Room Studio 1
Fri, 10:00
The workshop deals with the questions how to identify, analyse and thus minimize uncertainties at an early stage of geological 3D-model creation.
During the site selection procedure for a deep geological repository for the disposal of high-radioactive waste (HLW) the 3D models are playing an increasingly important role. Only with the support of 3D-models it is possible to obtain a holistic picture of the geological subsurface. Experiences gained from dealing with uncertainties in other countries will be shown.

I. Introduction (5 min.)
II. Presentations (each 15+5 min., 20 min. total):
1) Ingelise Møller, Anne-Sophie Høyer, Rasmus Bødker Madsen and Peter Sandersen: “Uncertainties in geological modelling – the GEUS perspective“, Geological Survey of Denmark and Greenland (GEUS), Aarhus, Denmark
The presentation focused on the experience over 20 years in Denmark with the description and quantification of uncertainties in geological models. It is linked to published work on uncertainties of geological models developed mainly for hydrogeological purposes. The models are primarily based on lithological information from boreholes and dense near-surface geophysical data. The importance of understanding the uncertainties embedded in the entire modelling workflow from the conceptual understanding, the data uncertainties, the modelling approach to the geological modelling itself will be presented.

2) Arto Laikari and Pirjo Hellä : “Management of the monitoring data acquisition uncertainties within deep geological repositories”, VTT Technical Research Centre of Finland, Espoo, Finland Ltd.
The presentation shows that digital twins and 3D models can be used to identify and mitigate risks, ensuring the repository's long-term safety and enhance stakeholder trust about the repository's status and safety measures. The Monitoring Equipment and Data Treatment for Safe Repository Operation and Staged Closure (MODATS) work package of the European Joint Programme on Radioactive Waste Management (EURAD) focused on the monitoring during the operational phase of repository programmes. Its aim is to gain understanding on the processes affecting the barrier and host rock performance and evolution, and to build further confidence in the long-term safety case. The project was based on the six deep geological disposal test cases from Europe. A workflow for data handling from acquisition to decision support was proposed. Some of these experiments have been running for decades and within this time frame data science has evolved widely providing many new methods and tools.

3) Valentina Zampetti, Michele Claps and Alex Papafotiou:: „Performance assessment for site selection in Switzerland: Treatment of uncertainty in the model abstraction chain“, NAGRA, Schwitzerland
Nagra has implemented a modelling workflow for the assessment of performance of site-specific repository projects in support of the site selection and the general license application for a deep geological repository in Switzerland. The workflow integrates modelling tools for total system and component analyses embedded in a comprehensive uncertainty management framework. The assessment is performed in deterministic as well as probabilistic fashion integrated with an indicator-based approach that allows the consistent, traceable, and verifiable comparison of the candidate sites.

III. Roundtable - Discussion (15 min)

Orals: Fri, 19 Sep, 10:00–11:20 | Room Studio 1

Chairpersons: Ute Maurer-Rurack, Maik Schilling
10:00–10:05
10:05–10:25
10:25–10:45
|
safeND2025-147
|
Arto Laikari and Pirjo Hellä

Digital twins and 3D models can be used to enhance the understanding of repository evolution, particularly in the context of monitoring data management, modelling, and visualisation. These tools can be used to identify and mitigate risks, ensuring the repository's long-term safety and minimizing potential hazards as well as enhance stakeholder trust and engagement by providing transparent and accessible information about the repository's status and safety measures.​

The Monitoring Equipment and Data Treatment for Safe Repository Operation and Staged Closure (MODATS) work package of the European Joint Programme on Radioactive Waste Management (EURAD) focused on the monitoring during the operational phase of repository programmes to gain understanding on the processes affecting the barrier and host rock performance and evolution, and to build further confidence in the long-term safety case. Work was based on the six deep geological disposal test cases from Europe. The project has proposed a workflow for data handling from acquisition to decision support. Some of these experiments have been running for decades and within this time frame data science has evolved widely providing many new methods and tools.

Modelling, simulations and various monitoring campaigns provide increasing amount of data which can be utilised throughout the entire lifecycle of the deep geological disposal facility including the siting, pre-operational, operational and post-closure periods. Monitoring data can be used to visualise the operations and improve the reliability of the models, simulations and digital twins.

Within the MODATS project a transparent and flexible data curation pipeline has been defined to support the overall data management process. This process is an important tool to manage and reduce monitoring data uncertainties. This paper will present the concept.

Reliable data treatment and analysis require extensive additional information beyond the acquired sensor values from one or a few sensors. Datasets from multiple sensors need to be treated and analysed together, incorporating cross-checking and adding information about known events. Applying domain knowledge of the entire environment and the used sensors and data acquisition setup is crucial to ensure correct interpretations. Over a long timeframe, the amount of data accumulates, and data management concepts evolve, making it possible to revisit the old datasets and find new interdependencies between unforeseen phenomena.

Use of Artificial Intelligence (AI) is rapidly increasing and bringing new tools to manage acquired data and build and improve models. AI requires extensive data cleaning to avoid outcomes reflecting sensor problems. Each AI result is subject to data pre-treatment. Defining Digital Twins (DT) involves determining its scope, purpose, and whether it is used for "as is representation" or predicting future behaviour of an entity, as well as identifying the target group of users. There is no one-size-fits-all solution, but there need to be definitions for specific purpose DTs.

Connecting and opening complex data and model systems and platforms to the DT reliably and securely is essential. Interoperability of various actors and systems, as well as the creation of common definitions and standards, must be addressed. Confidentiality and information security versus openness need also to be considered.

How to cite: Laikari, A. and Hellä, P.: Management of the monitoring data acquisition uncertainties within deep geological repositories, Third interdisciplinary research symposium on the safety of nuclear disposal practices, Berlin, Germany, 17–19 Sep 2025, safeND2025-147, https://doi.org/10.5194/safend2025-147, 2025.

10:45–11:05
11:05–11:20

Additional speakers

  • Ingelise Møller, Geological Survey of Denmark and Greenland, Denmark
  • Valentina Zampetti, Nagra, Switzerland