Culture is about how people make sense of the world, of each other, and of themselves. It is diverse in scale, across space, and over time. By implication, expertise on the world, its inhabitants, and ourselves is culturally relative. Indeed, culture is often about managing difference: different ideas, different people, different languages.

Applied to the need to sustain a body of knowledge and guidance for action over the long term, a cultural approach will (have to) embrace the need to adapt to cultural changes and developments. All this means that regarding nuclear waste, what we are tasked with today is transferring to future generations, who will be living in their own cultural contexts, knowledge and guidance for action that will make sense to them, not to us. Proposed messages that lack futures literacy merely perpetuate our own frameworks of meaning and eventually become irrelevant and unsustainable. There are thus good reasons why they say that nothing ages faster than the future, and nothing is more difficult to predict than the past. In this paper, I will discuss some implications of this theoretical argument for geological disposal of radioactive waste.

How to cite: Holtorf, C.: Sustainability and long-term processes: a cultural perspective, Third interdisciplinary research symposium on the safety of nuclear disposal practices, Berlin, Germany, 17–19 Sep 2025, safeND2025-6, https://doi.org/10.5194/safend2025-6, 2025.

In 2018, Austria published its National Programme for the Management of Radioactive Waste. In accordance with this program the federal government established the Austrian Board for Radioactive Waste Management (Advisory Board) to address and coordinate tasks and activities for the transparent implementation of the program.

Since the National Programme included only a rough timeline depicting the process of disposal of radioactive waste the need for a more precise outlined timetable and roadmap including milestones for the disposal of radioactive waste produced in Austria was given. In collaboration with authors from the Austrian Agency for Health and Food Safety (AGES) the Advisory Board developed a detailed timetable and roadmap, considering especially the specific Austrian situation of being a small inventory state with a radioactive waste inventory consisting of low and intermediate level waste.

In addition, the public opinion in Austria is shaped by a critical point of view regarding nuclear issues, including the disposal of radioactive waste. Early and comprehensive engagement of the public contributes significantly to the success of such a project. For this reason, public participation that goes beyond processes legally required was taken into account at every phase of the timetable and roadmap. 

The newly created timetable and roadmap starts from scratch, without any predefined guidelines or decisions regarding the type of repository, site selection criteria, and site selection process. Accordingly a timetable has been developed depicting significant phases as well as key milestones considering the disposal of radioactive waste but was designed to be generic and suitable for the different repositories considered.

The roadmap is divided into four phases:

Phase 1: Concepts for Disposal

This phase began with the publication of the National Programme in 2018 and continues until the disposal law comes into force. In this phase, key decisions are made, such as the type of repository, site criteria and safety criteria, and the specific site selection process.

Phase 2: Site Search and Selection

This phase includes the multi-stage site selection process. By the end of this phase, the safety case should be demonstrated, and a site should be selected.

Phase 3: Construction

In this phase, detailed planning is completed, the environmental impact assessment is conducted, and the repository is constructed.

Phase 4: Operation and Decommissioning

The repository is put into operation with the emplacement of radioactive waste and subsequently sealed. After a period of post-closure monitoring, this phase ends with the final decommissioning of the repository.

The planned guideline is conceived as a living document and should be seen as a framework that outlines the essential milestones and must be adapted to the final decision. In autumn 2024, the Advisory Board recommended the outlined roadmap to the Federal Government of Austria. Since the essential steps will be included in the revision of the National Programme for the Management of Radioactive Waste (planned in 2025), the path is set for their future implementation.

How to cite: Herzog, H., Lotter, K., and Schmidt, K.: From Concept Development to Disposal: Austria's Path to a Safe Repository, Third interdisciplinary research symposium on the safety of nuclear disposal practices, Berlin, Germany, 17–19 Sep 2025, safeND2025-104, https://doi.org/10.5194/safend2025-104, 2025.

The search for a final repository for high-level radioactive waste poses a current and unprecedented challenge in the global context: How to guarantee a safe containment of material that is harmful to the environment and people for up to 1 million years? For this purpose, Germany is relying on a science-based and participatory procedure. However, time requirements due to the complexity and expense of outstanding research work are increasingly pushing the decision into the distance. While the site selection law (StandAG) originally aimed for a decision by 2031, a final selection was postponed until between 2046 and 2068.

The article provides a sociological analysis of the role of ignorance and raises the question of how specific ways of interpreting and processing the ‘unknown’ influence the site selection procedure in Germany. To answer this question, the article combines a socio-theoretical discussion and conceptualization of ignorance with empirical results of a qualitative discourse analysis.

Drawing on social constructivist theories, it is argued how non-knowledge forms an independent object in relation to knowledge, developing its own social and political relevance. Following current approaches in the field of sociology of ignorance, the article explores and discusses types and conceptions of ‘not knowing’, such as dimensions and cultures of ignorance, making it a tangible object for empirical analysis. Ignorance is conceptualized as a contingent, socially constructed definition of meaning, referring to what must, can, or should be known. The relevance and production of ignorance in the German site selection procedure are illustrated, using debates on seismic activities and temperature development as examples.

The results of an empirical discourse analysis are then presented. The analysis focuses on the legal foundations and political implementation of the site selection procedure. Various publicly available text materials were analyzed, including legal documents, position papers, expert opinions, and documented public debates.

The results illustrate how the site selection procedure oscillates between different understandings of controllability, responsibility, and the temporal stability of non-knowledge. The procedure's structures establish spatial, but not temporal, boundaries of ignorance, creating paradoxes in the relationship between knowledge and non-knowledge. The self-description of the procedure as “science-based” and “participatory,” along with its practical implementation, leads to an inability to commit to (especially temporal) boundaries and responsibilities of non-knowledge. Consequently, the procedure fails to establish an internal, socially constructed definition of the finiteness of ignorance, which is crucial for decision-making processes from a socio-theoretical perspective. This generates conflicts of ignorance, resulting in procedural paralysis, as evidenced by the political decision to postpone the site selection. 

In conclusion, the article argues for a recognition and further research on dimensions and cultures of ignorance and their essential role in the implementation of precautionary and environmental policy, as well as their implications on science-based political decision-making processes in general.

How to cite: Hirn, A.: Paradoxes of Ignorance: The Role of ‘Not Knowing’ in the Repository Search for Nuclear Waste, Third interdisciplinary research symposium on the safety of nuclear disposal practices, Berlin, Germany, 17–19 Sep 2025, safeND2025-154, https://doi.org/10.5194/safend2025-154, 2025.

The Site Selection Act requires key stakeholders to adopt a science-based, learning-based, and self-critical approach. The requirement for a science-based approach was rooted in the difficult history of selecting the Gorleben site, which involved learning and critical scenarios such as those observed during the Asse mine.

The site selection process, with its timelines from the proposal for the site region for exploration, the exploration itself, to the determination of a repository site, is a highly complex, extensive, and lengthy project fraught with uncertainty. Implementing the Act requires a clear organizational implementation to avoid drift into failure scenarios (Woods, 2006).

The site selection process has a significant time dimension and demands the highest possible level of safety. The current discussion on shortening the project duration is a key trigger for drift into failure. Such discussions make it even more important to structure the organizations of the key players in such a way that a drift into failure will not occur. To achieve this, the key requirements of the Site Selection Act must be implemented on the operational level by the key players.

With the major projects of site selection, construction of the Konrad repository, decommissioning of the Asse II mine, and decommissioning of the Morsleben repository, BGE is responsible for corresponding major projects with project durations of ≥ 20 years at almost every stage of the radioactive waste disposal pathway. The aim of this presentation is therefore to demonstrate how the requirements of the Site Selection Act and the ESK Guidelines on Safety Management (ESK 2021) can be implemented with regard to a science-based, learning, and critical approach in organizational structures, and what special features must be considered with regard to similar large-scale projects abroad.

While safety culture describes the interaction between the actors and all employees within them, safety management addresses organizational control (VDI EE, 2024). Management systems are designed as learning processes (Mayer, 2015). From the perspective of human reliability, the feedback loops of learning are often particularly critical, primarily for two reasons (Sträter, 2019):

• Critical information within an organization is known to the workforce, but is not passed on through the organizational hierarchical levels.
• Conflicting information within the organization is not adequately resolved or is resolved in such a way that safety concerns are not adequately addressed.

The reasons for this include heterogeneous goals between internal and external actors, as well as individual or group-specific preferences (biases) in organizational management (Dierig, 2014; Englisch, 2024; Fritsch, 2025; Geffers, 2016). For effective organizational design, appropriate structures must be created within the organization (Seidel, 2024).

This presentation will examine and discuss the resilient structure of a management system required by the Site Selection Act:                                         

• The "drift into failure" concept and the psychological effects and human/organizational factors that an organization must manage
• The structure of a resilient organizational control system and its differences from traditional organizational control systems

Advantages of an organizational control system for sustainable and long-term safety performance, as well as for accelerating the site selection process

How to cite: Straeter, O., Seidel, L., Schmidt, N., and Fritsch, F.: Designing management systems in accordance with the StandAG, Third interdisciplinary research symposium on the safety of nuclear disposal practices, Berlin, Germany, 17–19 Sep 2025, safeND2025-20, https://doi.org/10.5194/safend2025-20, 2025.

The German selection process for a site for a deep geological repository for high-level radioactive waste was due to conclude in 2031. In recent years, the responsible organizations have independently published their doubts on this ambitious target, postponing the date for a site selection back by several decades, now ranging from 2046 to 2074 (BGE 2022; Krohn et al. 2024). With this procedural delay come not only organizational but also financial questions relating to the provision of sufficient funds until the closure of the repository itself which is now, if the site is selected on the second half of the 21^st century, not expected to happen within the next century. German nuclear waste management activities are funded via the external segregated fund KENFO whose purpose is to generate sufficient returns on investments to fund the whole waste management process, from interim to final waste storage of high-level wastes, but also the storage of low- and intermediate level wastes (von Hirschhausen and Wimmers 2023). Recent market turbulences and the procedural delays place doubt on KENFO’s ability to fulfil its purpose over the coming decades. This work aims to assess the risks of KENFO’s funds running short by applying a stochastic approach to long-term funding in nuclear waste management in Germany. We determine that to ensure sufficient funding and avoid future taxpayers having to provide funding for German waste management activities, KENFO must either achieve sufficiently high returns on the investments made, or the current fund volume must be increased with a lump sum cash injection. Using a Monte Carlo simulation to determine the scenario ranges of site selection dates, we estimate the minimum returns that KENFO must achieve to consistently exceed the current target return of 3.7% by several percentage points (see Figure 1). We also find that even if the site selection process went as plans, would are unlikely to suffice, necessitating a cash injection of at least €31.07 billion at 3.7% average returns. The assessment is limited by two main components. First, the uncertainty regarding the development of investment returns, cost developments, and other relevant parameters, such as inflation, is substantial over the long time period of several decades. Second, nuclear waste management costs are largely unknown. The cost assessments used in this work depend on a 2015 costing study which in turn relied on the utilities’ provisions (WKGT 2015), and since then, there has been no independent cost study of nuclear waste management (Irrek 2023). Consequently, policymakers must address the looming challenge of funding shortfalls for German nuclear waste management. They can either address the “costs” of nuclear waste management by accelerating the site selection process, improving efficiencies, and learning from other countries’ approaches, after approximating the expected costs, or they can address KENFO’s investments and fund strategy by, .e.g, aiming for higher returns from potentially riskier investments.

References (left our due to word limit but available upon request)

How to cite: Wimmers, A., Awawda, M., and von Hirschhausen, C.: Assessing the Long-Term Funding Adequacy and Generational Equity of State Funds under Uncertainty: A Stochastic Model for the German Nuclear Waste Fund KENFO, Third interdisciplinary research symposium on the safety of nuclear disposal practices, Berlin, Germany, 17–19 Sep 2025, safeND2025-142, https://doi.org/10.5194/safend2025-142, 2025.

The safe disposal of radioactive waste represents one of the most demanding and long-term challenges faced by modern society, that requires an in-depth understanding of complex technical, geological and safety-related processes. There is a significant risk of knowledge loss over long time periods, especially when institutions dissolve, are restructured or when documentation is not adequately maintained or managed. Ensuring the continuity of knowledge transfer across generations is crucial to maintaining safety and security by considering past experiences and historical data. Artificial intelligence (AI) and its applications, which are currently at the forefront of technological discussions and solutions, could offer innovative tools to overcome these Knowledge Management (KM) challenges.

The application of AI in RWMO knowledge management requires a structured approach to meet the special requirements of nuclear safety: all knowledge must meet the highest standards of accuracy, reliability and validation. AI systems must be equipped with mechanisms that check data against authorized sources and prevent the generation of false or falsified information. Transparency and traceability are crucial to ensure that users can understand how results are generated and that decisions are based on validated and trustworthy information. RWMO knowledge management systems need to be dynamic and able to integrate new information as it becomes available.

In this regard, AI applications like Large Language Models (LLMs) can provide valuable support to RWMO knowledge management, but face significant challenges such as hallucinations, outdated training data, probabilistic outputs, and high resource requirements for training and operation. Therefore, pure LLMs like Generative Pre-trained Transformers (GPT) alone cannot meet the necessary requirements. Corresponding AI solutions should be based on a reliable and secure knowledge pool, which is built upon a solid foundation of high-quality data that is well structured, comprehensible and accessible to realize the full potential. This includes the use of ontologies to represent relationships between concepts, decision trees, and structured documents such as “lessons learned”, “set of essential records” or “regulations”.

GRS research in corresponding projects like KISS (FKZ 15S9448B, funded by BMBF) shows that the implementation of the knowledge pool in a so-called Graph RAG scenario seems to be appropriate for such a system. Here a LLM-Chatbot serves mainly as a communicating interface, while the data is provided by a separate knowledge pool.

The knowledge pool is based on a multi-layered architecture designed to provide contextual information efficiently. It consists of four layers: Content layer, metadata layer, semantic layer and access layer. The Content Layer stores raw data, including documents, and multimedia, as the foundation. The Metadata Layer enriches this data with attributes like tags, categories, and versioning for better organization and retrieval. The Semantic Layer transforms content into meaningful structures using ontologies, knowledge graphs, and embeddings.

This system architecture enhances LLM performance and ensures scalability and flexibility. Since the system understands the context and the relationships, more meaningful results can be obtained.

This approach is also applicable to other applications when knowledge, information and data are strongly interconnected. E.g. competence databases, systems for data management or systems to trace regulatory decisions.

How to cite: Seher, H., Dierschow, F., Mönig, H., Herb, J., Giorio, L., and Britz, S.: Use of innovative technologies to support RWMO knowledge management, the GRS approach, Third interdisciplinary research symposium on the safety of nuclear disposal practices, Berlin, Germany, 17–19 Sep 2025, safeND2025-10, https://doi.org/10.5194/safend2025-10, 2025.

Due to the long periods of time involved in nuclear waste management, effective knowledge management is essential to promote the transfer of knowledge between different generations and to strengthen the innovative capacity of organisations. In the following, lessons learned are highlighted as one of the key aspects of intergenerational knowledge management at BGE.

Lessons learned are an important part of knowledge management as they provide valuable insights from past projects and experiences. By systematically documenting and analysing these lessons, it is possible not only to avoid mistakes, but also to identify best practices that can be passed on across generations and projects. This promotes not only knowledge transfer, but also a culture of continuous learning.

At BGE, lessons learned projects are captured through workshops and interviews with knowledge holders. For this purpose, a guideline is being developed to facilitate the collection of lessons learned. Once the lessons learned have been documented, knowledge management takes over the task of analysing and processing them in the form of micro-articles.

The unique selling point of micro-articles is the transferability of project-related experience to other contexts. It is important to bear in mind that a change of perspective is required to ensure this general applicability. A fixed structure and a concise form of no more than one DIN A4 page provide for a transparent presentation of issues with a varying degree of complexity. 

Additionally, enrichening the articles by adding metadata makes possible a system-independent retrieval. Furthermore, it is used to create a clustering that facilitates finding the appropriate recommendations for action at the start of a new project, thus minimising the risk of repeating errors.

The micro-articles are made available to colleagues at a central fileshare. BGE’s own intelligent search engine, named iFinder, will assist in the distribution of said articles, enabling this approach to knowledge transfer in the BGE, both in terms of documented knowledge and personal knowledge.

While a theoretical approach is essential to analysing and understanding the field of knowledge transfer, practical steps must be taken to integrate a sustainable knowledge culture into everyday working life, thus promoting exchange and collaboration between generations.

How to cite: Feuker, P., Färber, A., Wanka, S., and Wellmann, P.: Lessons learned as one of the key aspects of intergenerational knowledge management at BGE, Third interdisciplinary research symposium on the safety of nuclear disposal practices, Berlin, Germany, 17–19 Sep 2025, safeND2025-131, https://doi.org/10.5194/safend2025-131, 2025.

With regard to the interim and final storage of radioactive waste and the requirements of long-term documentation, the long-term durability of digital storage media poses a particular challenge. According to § 38 StandAG, it is the task of the Federal Office for the Safety of Nuclear Waste Management (BASE) to permanently store data and documents that are or may become important for the final and interim storage of radioactive waste. Permanent integrity must be guaranteed for this so-called storage data.

In accordance with § 26 StandAG, selected data and documents must be preserved for a period of at least 500 years after closure of the repository in order to enable the retrieval of the emplaced waste if necessary. The aim of the ‘Labest Digital’ research project commissioned by BASE is to clarify which digital storage media strategy is most suitable from a long-term perspective and what options exist for optimising individual storage media.

The ‘Labest Digital’ project will be presented in compact form as part of the lecture. The latest findings from the ageing tests on a variety of digital storage media will take centre stage. The test results for DVD, SSD and HDD, which are considered typical standard storage media, will be discussed in detail. In addition, the results of microfilm, M-Disc and NanoFiche, which are regarded as representatives of durable and resistant storage media, are placed in a comparative discourse. This comparison provides valuable insights into the long-term reliability and optimisation potential of the individual digital storage media. It therefore forms a solid basis for the development of concepts for the sustainable preservation of digital data.

How to cite: Melzer, C., Staben, B., and Kuhn, T.: Evaluation and optimisation of the long-term durability of digital storage media - current results from the ‘Labest Digital’ research project, Third interdisciplinary research symposium on the safety of nuclear disposal practices, Berlin, Germany, 17–19 Sep 2025, safeND2025-92, https://doi.org/10.5194/safend2025-92, 2025.