Session T5g

T5g | 2nd European Programme on Radioactive Waste Management: strategic studies

2nd European Programme on Radioactive Waste Management: strategic studies

Main Session Organizers: Astrid Göbel, Louise Theodon

Orals

| Thu, 18 Sep, 10:05–11:05 (CEST)|Room Studio 2

Posters

| Attendance Thu, 18 Sep, 17:20–18:20 (CEST)|Poster area

The second European Programme on Radioactive Waste Management EURAD-2 has been launched in October 2024. Under the umbrella of this international cooperation in the field of RWM, more than 100 organisation from 52 countries conduct ten R&D projects, a valuable range of Knowledge Management activities and six Strategic Studies.
For the symposium the outcomes of EURAD-2 would be very valuable with respect to the scientifically excellent works and further development of the state of the art throughout all phases of a RWM programme and covering the broad scope of our EURAD-2 roadmap. All this within a unique international cooperative framework bringing together the different key actors and stakeholder in the field of RWM plus civil societal representatives. Whereas the R&D and KM activities have a duration of five years, all Strategic Studies will be finished after two years by september 2026. One year in future all StS will already have produced relevant and interesting results within their gap analyses, white or green papers.
It is proposed to have a few detailed talks from interested and selected work packages, supplemented by an overview talk about the rest of the EURAD-2 strategic studies, e.g.
1. EURAD-2 – programme overview and mission of the conducted strategic studies
2. Presentation of objectives and results/recommendations from WP FORSAFF (Waste management for SMRs and future fuels), WP CLIMATE (Impact of climate change on nuclear waste management), WP DITUSC (Development and Improvement of Quality Assured Thermodynamic Understanding for use in Nuclear Waste Disposal Safety Case)
3. WP ASTRA (Alternative RWM strategies)
4. WP DITOCO2030 (Next generation Digital Twins to support Optimisation, Construction and Operation of surface and subsurface radioactive waste management facilities)
5. WP OPTI (HLW repository optimisation including closure)

Orals: Thu, 18 Sep, 10:05–11:05 | Room Studio 2

10:05–10:25

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Overview of EURAD-2 Strategic Studies

Astrid Göbel and Louise Theodon

The European Partnership (EP) on Radioactive Waste Management EURAD-2 builds upon the European Joint Programme EURAD and the EC project PREDIS to further implement a joint strategic programme of research & development, strategic studies and knowledge management activities at the European level, bringing together and complementing EU Member States’ programmes. This presentation shortly introduces forerunning initiatives and gives a very broad overview of the EP, its uniqueness and the activities collaboratively performed within this frame. Through the different types of works EURAD-2 provides primarily the scientific basis for implementing safe and robust RWM solutions, whilst also contributing to building stakeholder trust, public acceptance, and training and education for the next generations of the workforce. This presentation focusses on the EURAD-2 Strategic Studies (StSt) that give the opportunity to participants and expert contributors to network on methodological and strategic issues and challenges. Currently six studies each with a duration of two years are performed within EURAD-2. Their scopes address topics throughout all phases of a Radioactive Waste Management programme (predisposal to post-closure, from cradle to grave). With the aim to foster mutual understanding, capture the knowledge base, identify gaps and recommendations for future activities all EURAD-2 Strategic Studies are developing Green and White Papers. This presentation strives for all the ongoing StSts ASTRA (Alternative waste management strategies), FORSAFF (Waste Management for SMRs and Future Fuels), CLIMATE (Impact of climate change on nuclear waste management), OPTI (High-level waste repository optimisation including closure), DITOCO2030 (Next generation Digital Twins to support Optimisation, Construction and Operation of surface and subsurface RWM facilities) and DITUSC (Development and improvement of thermodynamic understanding for use in nuclear waste disposal safety case). It will provide information about the studies’ objectives, progress and results. The provision of details takes into account that some of the strategic studies have submitted an own abstract, others not. The presentation will bridge to conducted activities in EURAD-2 and give a good insight into the work of the Strategic Studies showing the achieved outputs and the look out to upcoming steps.

How to cite: Göbel, A. and Theodon, L.: Overview of EURAD-2 Strategic Studies, Third interdisciplinary research symposium on the safety of nuclear disposal practices, Berlin, Germany, 17–19 Sep 2025, safeND2025-132, https://doi.org/10.5194/safend2025-132, 2025.

10:25–10:45

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Advancing Digital Twin Technology for Optimized Nuclear Waste Management: Bridging Disciplines and Enhancing Safety

Réka Szőke, Attila Baksay, Jacques Diederik, Arto Laikari, Alexandros Papafotiou, Pablo Cayón, Gabriela Roman-Ross, and Christophe Debayle

The nuclear sector is on the verge of adopting new technologies to enhance its safety-critical and socially significant operations. Among these innovations, Digital Twins (DT) offer a powerful tool for informed decision-making, operational efficiency, and transparency. The EURAD-2 DITOCO2030 work package aims to develop a roadmap to bridge the existing R&D gap between the currently fragmented DT applications across individual disciplines (e.g., engineering, safety, geology, infrastructure development) as well as data management systems and decision-making platforms.

This initiative will focus on identifying and integrating knowledge from various sectors to better understand the opportunities and limitations of DT technology. The goal is to support the optimization, construction, and operation of both surface and subsurface radioactive waste management facilities. A key element of this work will involve gathering and transferring existing knowledge from other industries and communities to the nuclear waste management sector. This will require combining human and technical competencies, aligned with the specific needs of DT projects and the broader industry and regulatory contexts.

The project will document and analyze current practices, conducting gap analyses to guide strategic recommendations for future DT development, with particular attention to the requirements of end-users. The WP will develop both qualitative and quantitative performance indicators to differentiate between effective and ineffective DT solutions in the long term. One of the significant challenges is aligning the various objectives and applications of DT—such as long-term safety, operational efficiency, design, optimization, and communication—while ensuring their integration in an interoperable way across all relevant disciplines. This alignment is essential for building practical knowledge that enhances and supports safety.

The work will also explore opportunities for cross-industry collaboration to advance innovation, performance, and efficiency in next-generation DT applications for the nuclear sector. Stakeholder engagement will be a focus, with workshops and dissemination activities designed to ensure feedback is incorporated and knowledge is shared efficiently. Ultimately, this work will pave the way for more integrated and effective deployment of DT throughout the lifecycle of nuclear waste management. The project will contribute to the future development and research opportunities related to how DT can support regulatory compliance, improve safety, and provide real-time monitoring, analysis, and reporting of asset performance and condition.

How to cite: Szőke, R., Baksay, A., Diederik, J., Laikari, A., Papafotiou, A., Cayón, P., Roman-Ross, G., and Debayle, C.: Advancing Digital Twin Technology for Optimized Nuclear Waste Management: Bridging Disciplines and Enhancing Safety, Third interdisciplinary research symposium on the safety of nuclear disposal practices, Berlin, Germany, 17–19 Sep 2025, safeND2025-74, https://doi.org/10.5194/safend2025-74, 2025.

10:45–11:05

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HERMES#DITOCO2023: Integrating Process Modelling into Digital Twin Concepts

Olaf Kolditz, Sergey Churakov, Eric Laloy, Enrique Garcia, Anne-Catherine Dieudonné, Nikolaos Prasianakis, Attila Baksay, Javier Samper, Jan Brezina, Lars Bilke, and Réka Szőke

Sergey Churakov, Eric Laloy, Enrique Garcia, Anne-Catherine Dieudonné, Nikolaos Prasianakis, Attila Baksay, Javier Samper, Jan Brezina, Lars Bilke, Réka Szőke, Olaf Kolditz

Digital twins are the basic concept for creating digital representations of real systems, such as deep geological repositories for radioactive waste disposal (Kolditz et al. 2023). This involves continuous data collection and integration, model prediction, and the use of virtual reality (VR) methods to represent and interact with complex systems. Process simulation plays an important role in digital twin concepts, giving digital twins predictive power in addition to representing the actual state of the system. This is a fundamental characteristic of digital twins and a strong competitive advantage for modern and innovative planning tools.

DITOCO2030 is a strategic study in the EURAD-2 programme that aims to develop a common understanding of the specific requirements of different disciplines and stakeholders within the general digital twin framework (Szoke et al. 2025). The HERMES work package aims to develop high-fidelity numerical models for the simulation of strongly coupled thermo-hydro-mechanical-chemical (THMC) processes in the near-field of repositories, for the optimisation of repository design, and for the interpretation of mock-up experiments, using a combination of physics-based models and accelerated computing supported by machine learning and artificial intelligence (Churakov et al. 2024). HERMES is divided into following main tasks: simulation of THMC processes, development of suitable surrogate models, and finally application of process modelling for safety and performance assessment for the safe deep geological disposal of radioactive waste.

Integration of HERMES components into DITOCO2030 should take place on several levels and steps. First examples are (1) The automation of computational steps: repository systems are so complex that the individual repository parts and components (e.g. emplacement drifts and sealing structures) have to be modelled separately before an overall model of the entire repository system can be developed (Samper et al. 2024); (2) Flexible simulation methods: Various simulation methods for THMC processes will be made available for plausibility and functionality testing. In addition to the usual code comparison (e.g. in DECOVALEX), process- and data-based (machine learning) methods (Prasianakis et al. 2025) will be integrated into HERMES for the first time. Technically, this will take place within the HERMES Model Hub. These will be developed and tested in (1) and (2) and then implemented in a generalised form in DITOCO2030.

References:

Churakov et al. (2024): Environ. Earth Sci. 83 (17), art. 521, 10.1007/s12665-024-11832-7

Kolditz et al. (2023): Digitalisation for nuclear waste management: predisposal and disposal. Environ. Earth Sci. 82 (1), art. 42, 10.1007/s12665-022-10675-4

Prasianakis et al. (2025): Geochemistry and machine learning: methods and benchmarking. Environ. Earth Sci. 84 (5), art. 121, 10.1007/s12665-024-12066-3

Samper et al. (2024): Multiphase flow and reactive transport benchmark for radioactive waste disposal. Environmental Earth Sciences, 83 (22), art. 619, 10.1007/s12665-024-11887-6

Szoke et al. (2025): DITOCO - Digital Twins (DT) to support Optimisation (including communication of safety), Construction and Operation of radioactive waste management facilities abstract submitted to SafeND 2025

Co-funded by European Union under Grant Agreement n° 101166718 and Research Council of Norway under the International Calls International Collaborative Project - Project number 355507

How to cite: Kolditz, O., Churakov, S., Laloy, E., Garcia, E., Dieudonné, A.-C., Prasianakis, N., Baksay, A., Samper, J., Brezina, J., Bilke, L., and Szőke, R.: HERMES#DITOCO2023: Integrating Process Modelling into Digital Twin Concepts , Third interdisciplinary research symposium on the safety of nuclear disposal practices, Berlin, Germany, 17–19 Sep 2025, safeND2025-159, https://doi.org/10.5194/safend2025-159, 2025.

Posters: Thu, 18 Sep, 17:20–18:20 | Poster area

P28

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Work package OPTI – A strategic study to develop a mutual understanding about optimisation

Philipp Herold, Anne-Catherine Dieudonné, Valéry Detilleux, and Jiri Svoboda

In general, optimisation promises improvements in technical and economic aspects as well as with regard to flexibility and robustness. As such, optimisation is a process that should involve the different stakeholders and key actors, in particular research entities, regulators, technical support organisations, waste management organisations and the civil society including representing organisations. Different stakeholders will have different objectives and strategies for optimisation. The strategic study “HLW Repository optimisation including closure (OPTI)” is part of the EURAD-2 programme and includes 23 European partners from research entities, technical support organisations, waste management organisations and civil society organisations. The participants of the study are discussing what optimisation in the context of a high-level waste (HLW) repository means and how an exchange between different stakeholders could be fostered. By this the study wants to develop a mutual understanding in general and provide recommendations on methods and further activities for the design and optimisation of specific HLW repository systems, structures and components (SSCs) and processes. For mutual understanding, it is important to know about the main drivers for optimisation. Repository designs should be technically robust but also economically efficient, environmentally sustainable, and socially acceptable. These and other objectives for optimisation were identified. Other important questions are: At which points in the programme is optimisation required, recommended, not reasonable, or maybe even limited or restricted by regulatory requirements? Within each national program, changing boundary conditions (e.g. new waste types, updated regulatory frameworks, evolving societal expectations, etc.), technological developments, or the process adaptations based on operational experience will justify and require optimisation. Optimisation in preparation of the safety case and licensing is an established engineering process considering regulatory requirements and enhancing the overall safety of repository systems. Furthermore, the Strategic Study OPTI will put strong attention to optimisation after licensing or during construction and operation. This may have a different focus as safety is already demonstrated (e.g. focus on reduction of conservative assumptions, optimisation of the procurement of materials…). The work package OPTI creates a platform to share best practices for optimisation strategies and processes. The results will notably help both advanced and emerging programmes. Knowledge transfer from advanced to developing ones will be facilitated. R&D needs for specific SSCs and procedures that could be further optimised will be identified. The proposed contribution will summarise the work and achievements of the EURAD-2 Work Package OPTI.

How to cite: Herold, P., Dieudonné, A.-C., Detilleux, V., and Svoboda, J.: Work package OPTI – A strategic study to develop a mutual understanding about optimisation, Third interdisciplinary research symposium on the safety of nuclear disposal practices, Berlin, Germany, 17–19 Sep 2025, safeND2025-126, https://doi.org/10.5194/safend2025-126, 2025.

P29

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Development and improvement of thermodynamic understanding for use in nuclear waste disposal safety case

Stéphane Brassinnes, Xavier Gaona, Jenna Poonoosamy, Eli Colas, George-Dan Miron, and Marcus Altmaier

Development and Improvement of Thermodynamic Understanding for use in nuclear waste disposal Safety Case (DITUSC) is a work package within the Eurad-2 project. This 24-month strategic study aims to enhance scientific knowledge to predict long-term safety-relevant processes in radioactive waste disposal. The work package focuses on several critical aspects, including identifying, evaluating, prioritizing, and defining strategies to fill gaps in safety-related thermodynamic databases. It also aims to advance expertise in thermodynamics, supporting current and future capabilities for using thermodynamics in assessing radioactive waste disposal configurations, conducting safety analyses, and preparing safety cases.

DITUSC program is multifaceted, focusing on several key areas. Firstly, it aims to identify data gaps crucial for understanding the transport behavior of safety-relevant radionuclides and organics. This involves examining existing data and identifying areas where additional information is needed. Secondly, the work package seeks to develop a thermodynamic description of perturbations, such as the effects of temperature and high salinity plumes. These perturbations can significantly impact the behavior of radionuclides and other substances in geological disposal environments, making it essential to understand their thermodynamic implications. Another critical focus area is the thermodynamic description of solid-solutions and their role in radioactive waste management and final disposal. Additionally, the interplay between thermodynamics and kinetics is a key area of study. This includes examining solid phase transformations, relevant redox phenomena, and the illustrative case of spent fuel dissolution. Understanding these processes is essential for developing accurate models of radionuclide behavior over extended periods. The work package also aims to document how thermodynamic approaches are currently implemented in safety cases and to identify and assess potential improvements in line with end-user needs and priorities. This involves reviewing existing practices and developing recommendations for enhancing the use of thermodynamics in safety assessments.

To achieve these objectives, DITUSC will produce two authoritative high-level documents: a Green Paper and a White Paper. The Green Paper will define the scope, framework, and reach of the strategic study, involving key players in the field. The White Paper will provide a consolidated and prioritized list of the current needs of stakeholders within the EURAD-2 colleges. It will focus on specific needs related to the safety analysis of radioactive waste disposal facilities and promote new scientific strategies to support the use of thermodynamics in safety cases.

How to cite: Brassinnes, S., Gaona, X., Poonoosamy, J., Colas, E., Miron, G.-D., and Altmaier, M.: Development and improvement of thermodynamic understanding for use in nuclear waste disposal safety case, Third interdisciplinary research symposium on the safety of nuclear disposal practices, Berlin, Germany, 17–19 Sep 2025, safeND2025-4, https://doi.org/10.5194/safend2025-4, 2025.