Summary and Objectives

The ENTRUST project is coordinated by Amphos 21 Consulting S.L. located in Barcelona, Spain, in collaboration with Stanford University’s Center for International Security and Cooperation (CISAC) in California, USA. It examines the general question of how to manage in the long term the growing stocks of spent nuclear fuel and high-level radioactive waste produced at commercial power plants in a context of uncertain transitions and persisting societal concerns over nuclear energy technologies. The project comprises scientific and training objectives. The main scientific objective is to develop an analytical framework for the holistic assessment of nuclear waste management (NWM) scenarios and policies with the objective of building and maintaining public trust.

Our aims are to:

  • Define a theory for the holistic study of nuclear waste management (NWM) systems aimed at building public trust;
  • Develop an analytical framework as a methodological body for the participatory quantitative story telling of NWM strategies and policies and test it as part of CISAC’s “Reset of U.S. Nuclear Waste Management Policy” initiative; and
  • Complete an integrated analysis of NWM policies in the United States (US) and selected European Union (EU) countries, and subsequently develop a strategy at EU level.

Project information


  • European Commission’s Marie Sklodowska-Curie Fellowship (H2020-MSCA-IF-GF-2016) (2017–2020)
  • Stanford University’s CISAC Nuclear Security Fellowship (2017–2019)

Coordinator: Amphos 21 Consulting S.L., Spain

Partner: Stanford University, California, United States

Start date: 1 August 2017

End date: 31 July 2020

CORDIS webpage:


Dealing with the safe long-term NWM has become one of the world’s largest problems as it conveys technical and societal challenges. Main technical challenges reside in the inevitable uncertainties in the models and data used for these analyses of long-term solutions due to the extraordinarily long time scales that must be explicitly considered. Main sources of uncertainties concern the behavior of the waste materials and packages and of the environmental and geologic conditions. Yet, the biggest challenges to NWM are social. Difficulties in achieving public support have been seriously underestimated in the past, and opportunities to increase public involvement and to gain public trust have been missed. Worldwide, nearly one-third of the historical attempts to site geologic repositories for HLW and SNF were prematurely and permanently terminated because of public opposition. For this reason, most countries have made major changes in their approach to waste disposition to address the recognized social challenges.

A new approach has been developed that brings two academically separated but intellectually related and complementary research strands for the holistic study of nuclear waste management systems, strategies and policies: integrated assessment and science for governance.
The use of integrated assessment (IA) tools seeks a holistic approach to the study of systems. Even if the field of IA is not entirely new, its methodological body still needs further development to effectively integrate environmental, economic and societal dimensions of analysis. Currently, the two main areas of development in the field consist in increasing: i) the heterogeneity of representation by accounting for several scales of analysis; and ii) the degree of integration by extending the system boundaries to address interlinkages between elements. In turn, IA entails practical implications on the process of generation of quantitative information. For instance, given NWM systems and policies are governed by complex relations across different scales and domains, it is evident that the generation and use of scientific information for their integrated assessment require interfacing quantitative approaches with qualitative principles.
In parallel to the development of IA methods, epistemological discussions over the use of science in the governance of technologies started to emerge in the 1970s. The field of Science for Governance (or Operational Research), intends to respond to the increasing difficulties in the quality control of science and the failure of the paradigm of evidence-based policy relying on illusory precision of models and indicators. Maintaining the public’s trust in science calls for an urgent evaluation of its dysfunctions and responsible use of quantitative information. To address this issue, an innovative approach called quantitative story telling (QST) has been proposed. QST involves a participative and deliberative analysis of the quality of policies and narratives on governance. It can address social concerns based on a careful use of quantitative information for addressing technical issues. QST is particularly relevant for assessing science-related policy challenges, such as NWM.


Principal investigator
Principal investigator

François Diaz-Maurin

European Commission’s Marie Sklodowska-Curie Fellow, Amphos 21 Consulting SL. Affiliate, Center for International Security and Cooperation (CISAC), Stanford University.

François Diaz-Maurin is a scientist and engineer trained in nuclear waste management (Stanford University, 2017–2019), environmental science and technology (Ph.D., Universitat Autònoma de Barcelona, 2013, summa cum laude), and civil engineering (B.Sc./M.Sc., University of Rennes 1, 2004/2007, both with distinction).

Prior to joining academia in February 2011, he worked 4 years as a structural and mechanical engineer on various major R&D projects in the nuclear industry in Paris, France (2007-2008) and in Boston, United States (2009-2010).

François’ research deals with issues related to the radioactive waste materials produced at commercial and military facilities in a context of uncertain energy transitions and persisting social concerns over nuclear energy technologies. It covers the theoretical, methodological and empirical aspects of the back-end of the nuclear fuel cycle integrating knowledge from various disciplines in the science, engineering and social sciences areas.

He is the author or co-author of over 40 scientific publications mainly on multi-scale integrated analysis applied to nuclear energy systems, natural resources management and sustainability assessment.


Rodney C. Ewing

Frank Stanton Professor in Nuclear Security and Co-Director of the Center for International Security and Cooperation (CISAC) in the Freeman Spogli Institute for International Studies (FSI).

Rod Ewing is also Professor in the Department of Geological Sciences in the School of Earth, Energy and Environmental Sciences at Stanford University.

He is the author or co-author of over 750 research publications and the editor or co-editor of 18 monographs, proceedings volumes or special issues of journals. He has published widely in mineralogy, geochemistry, materials science, nuclear materials, physics and chemistry in over 100 different ISI journals. He has been granted a patent for the development of a highly durable material for the immobilization of excess weapons plutonium.

Professor Ewing has served on thirteen National Research Council committees and board for the National Academy of Sciences, Engineering and Medicine that have reviewed issues related to nuclear waste and nuclear weapons. In 2012, he was appointed by President Obama to serve as the Chair of the Nuclear Waste Technical Review Board, which is responsible for ongoing and integrated technical review of DOE activities related to transporting, packaging, storing and disposing of spent nuclear fuel and high-level radioactive waste; he stepped down from the Board in 2017.

Jordi Bruno

CEO and Chairman of the Board of Amphos 21 Group.

Jordi Bruno is an international expert on Sustainability and Environmental Strategies, including Circular Economy. He has worked for more than 30 years for the safe disposal of radioactive and industrial wastes. Author of more than 130 papers, five books and countless reports.

He has directed several PhD theses and he is member of a number of scientific and strategic councils. Jordi Bruno holds a PhD in Inorganic Chemistry by the Royal Institute of Technology (KTH) in Stockholm (Sweden), an MBA by the Stockholm School of Economics and an Executive MBA for Smaller Technology Companies from Stanford.

Research assistants
Research assistants

Hilary C. Sun

Hilary is a graduate student at Stanford University pursuing a M.S. in Computer Science (Class of 2019). She completed a B.S. in Computer Science also from Stanford University with minors in Statistics and History. In ENTRUST, Hilary contributed as a data scientist and programmer with the support of the VPUE Department and Faculty Grants program from Stanford’s Office of the Vice Provost for Undergraduate Education (2017-2018).

Jerold Yu

Jerold is a graduate student at Stanford University pursuing a M.S. in Statistics (Class of 2020). He completed a B.S. in Mathematical and Computational Science also at Stanford University. In ENTRUST, Jerold contributed as a data scientist and programmer with the support of the VPUE Department and Faculty Grants program from Stanford’s Office of the Vice Provost for Undergraduate Education (2018-2020).

Juan Morganti

Juan is a graduate student at Stanford University pursuing a M.A. in International Policy Studies (Class of 2019). In ENTRUST, Juan contributed as a research assistant working on the political and legal history of the U.S. nuclear waste management program with the support of the MIP Research Assistant Funding Program from Stanford's Freeman Spogli Institute (FSI) for International Studies (2018-2019).


We designed and developed several analytical tools supporting the integrated assessment of NWM strategies: (1) a comprehensive bibliometric analytical tool to study the scholarly and scientific literature about nuclear waste since 1940; (2) a multi-criteria evaluation tool for the comparison of long-term SNF storage options; (3) a calculation and data visualization tool to evaluate possible locations of interim storage and disposal facilities for SNF; and (4) a multi-criteria evaluation tool used to compare different spent fuel management and disposal strategies by comparing the relative performance of sites at the level of their geological environment properties. The approach is part of recent efforts toward the integration of the back-end of the nuclear fuel cycle. The back-end integration accounts for the various processes of NWM—onsite storage, consolidated storage, transport and geological disposal. These processes must be fully coupled so that benefits and impacts can be assessed at the level of the whole fuel cycle and for the different social actors. The tools developed during this project support that aim by allowing the evaluation of NWM systems at any point in the system (storage, transport, disposal). The tools have been initially developed in the context of the U.S. NWM program during the outgoing phase and then were applied to the EU context, especially on clay-based disposal systems.

To support the scientific objectives of the project, the Principal Investigator went through an extensive training program on the technical and scientific basis of NWM. The training program consisted in auditing classes, reviewing the scientific literature, participating to workshops/conferences, and interviewing experts in the many fields relevant to the technical and social aspects of NWM.

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Research papers
Book chapter
Conference papers
Conference posters
Research paper
Socio-Technical Multi-Criteria Evaluation for Spent Fuel Management: The Case of San Onofre, California. With J. Yu & R.C. Ewing. In preparation.
Research paper
A GUI tool for multi-criteria evaluation and conflict analysis in nuclear waste management. With J. Yu & R.C. Ewing. In preparation.
Research paper
A socio-technical multi-criteria evaluation method for nuclear waste management. With J. Yu & R.C. Ewing. Submitted.
Conference poster
Diaz-Maurin, F., Bruno, J., & Ewing, R. C. (Accepted). Towards an Integrated Approach to Performance Assessment of Clay-based Disposal Systems. 8th Clay International Conference, 14–17 June 2021, Nancy, France.
Clay materials exhibit favorable physical and chemical properties for radioactive waste geological disposal. They can prevent and delay the water access to waste materials, control the local geochemical environment, and retard the migration of mobilized radionuclides by swelling and diffusion-limited processes and a high sorption capacity due to a very high specific area of clay minerals. These favorable properties make clay materials therefore attractive both as a natural barrier when used as a host rock and as an engineered barrier when used as buffer, backfill or sealing materials. Yet, these properties can be modified by the repository construction due to the stress redistribution around the excavated void spaces. Clay materials are also affected by the waste emplacement due to the temperature-induced effects caused by heat-generating radioactive waste in the repository that enhance the thermal, hydrological, mechanical, and chemical (THMC) coupled processes. At the same time, different clay materials will respond differently to perturbations due to their different physical and chemical properties resulting from different structure and composition of clay minerals. This complexity requires a vast amount of experimental and modeling efforts to achieve a techno-scientific understanding of the overall behavior of clay-based disposal systems. Yet, because the processes involved can be coupled and activated across different spatial and temporal scales, this makes such understanding incredibly challenging which, in turn, makes it difficult to develop a meaningful safety case argument. Using a multi-scale integrated analysis approach, we seek to face this challenge by developing an integrated performance assessment to clay-based disposal systems. Multi-scale integrated analysis methods have been applied to energy supply systems, natural resources management and sustainability assessment [1–3] and, more recently, also to geological disposal systems [4,5]. In this paper, we will first review past and ongoing performance assessments of clay-based disposal systems focusing on the French repository project in a Callovian-Oxfordian clay formation. Focusing on the key parameters affecting the repository behavior, we will connect the geological disposal system components, THMC processes, and safety functions across temporal and spatial scales. This integrated view seeks to improve the understanding of the overall repository behavior across scales in support of the safety case review process.
Book chapter
Bruno, J., Duro, L., & Diaz-Maurin, F. (2020). 13—Spent nuclear fuel and disposal. In M. H. A. Piro (Ed.), Advances in Nuclear Fuel Chemistry (pp. 527–553). Woodhead Publishing.
Spent nuclear fuel (SNF) constitutes the largest portion of high-level nuclear waste for those countries that have adopted the open nuclear fuel cycle strategy. The radioactivity content of SNF decays so that it reaches comparable levels of the natural uranium mined to manufacture fresh fuel only after some 100,000 years. There is a need to provide isolation of these radioactive materials from the biosphere during this period. This is presently done by implementing a strategy that consists of a storage period to cool down the fuel elements after fission in the reactor followed by their deep geological disposal. In this chapter we first describe the different types of SNF, the various storage practices, and the most advanced geological disposal programs (Finland, Sweden, and France). We then discuss the various processes that can affect the integrity of SNF during the extended storage period prior to geological disposal. Finally, we present an outlook of the key remaining issues, particularly in light of continuously delayed SNF management decisions.
Conference paper (peer-reviewed)
Open access
Diaz-Maurin, F., & Ewing, R. C. (2020). Integration of the Back-end of the Nuclear Fuel Cycle: An Overview. MRS Advances, 5(5–6), 253–264.
Recent efforts have been made toward the integration of the back-end of the nuclear fuel cycle in the United States. The back-end integration seeks to address several management challenges: 1) current storage practices are not optimized for transport and disposal; 2) the impact of interim storage on the disposal strategy needs to be evaluated; and 3) the back-end is affected by—and affects—nuclear fuel cycle and energy policy choices. The back-end integration accounts for the various processes of nuclear waste management—onsite storage, consolidated storage, transport and geological disposal. Ideally, these processes should be fully coupled so that benefits and impacts can be assessed at the level of the full fuel cycle. The paper summarizes the causes and consequences of the absence of integration at the back-end of the nuclear fuel cycle in the U.S., critically reviews ongoing integration efforts, and suggests a framework that would support the back-end integration.
Conference poster
Open access
Diaz-Maurin, F., & Ewing, R. C. (2019). Multi-scale, multi-criteria evaluation of nuclear waste repositories in different geologic settings. Goldschmidt Conference Abstracts, 798.

The isolation of radioactive waste in a deep geological repository depends on engineered and geologic barriers. The geologic barriers depend most on low hydraulic conductivity and geochemical constraints that limit solubility and increase sorption. However, there is a difference between selecting sites of similar geologies vs. sites where the geology is different. In the former case, the same geochemical factors can be used to analyze the performance of different sites—as in Sweden and Finland [1]. In other countries, the choice can be among sites with very different geologic settings—as may be the case in the U.S. and Germany. Yet, sites that are in different host rocks will not necessarily rely on the same retardation concepts. The difficulty is that host-rock-specific criteria do not allow the direct comparison of the technical suitability of sites with different geologic settings. We present an approach for the multi-scale, multi-criteria evaluation of sites by focusing on the geohemical factors contributing to retardation. A multi-scale representation of disposal systems allows the comparison of host-rock-specific repository designs at the level of their main components and processes (e.g., geological barriers, geochemical processes); whereas, their technical suitability is determined for a specific set of indicators and criteria [2]. The multi-criteria evaluation seeks to rank all potential sites according to their level of fulfilment of safety functions [3]. This approach does not search for a technically optimal solution because the selected site will necessarily be a combination of technical suitability and social acceptance.

Open access
Diaz-Maurin, F. (2019). RE: A fresh look at nuclear energy Science eLetters (not indexed), 10 March 2019.
Conference paper (peer-reviewed)
Open access
Diaz-Maurin, F., & Ewing, R. C. (2019). Probabilistic Performance Assessment vs. the Safety Case Approach. MRS Advances, 4 (17–18), 987–992.
The “safety case” approach has been developed to address the issue of evaluating the performance of a geologic repository in the face of the large uncertainty that results for evaluations that extend over hundreds of thousands of years. This paper reviews the concept of the safety case as it has been defined by the international community. We contrast the safety case approach with that presently used in the U.S. repository program. Especially, we focus on the role of uncertainty quantification. There are inconsistencies between the initial proposal to dealing with uncertainties in a safety case and current U.S. practice. The paper seeks to better define the safety case concept so that it can be usefully applied to the regulatory framework of the U.S. repository program.
Conference paper (peer-reviewed)
Open access
Diaz-Maurin, F., Sun, H. C., Yu, J., & Ewing, R. C. (2019). Evolution and Structure of the Scientific Basis for Nuclear Waste Management. MRS Advances, 4 (17–18), 959–964.
The final disposal of nuclear waste is at the interface between the technologies of the nuclear fuel cycle that produce the waste and the natural hydrologic and geochemical cycles of geologic repositories. Despite this broad interdisciplinary scope, nuclear waste management, as practiced, remains “balkanized” among the relevant disciplines. The individual subdisciplines continue to work in relative isolation from one another: materials science dealing with the immobilization of nuclear waste; engineering science dealing with the design, construction and operation of the repository; geoscience dealing with the long-term behavior of host rocks and the hydrology; health science dealing with the effects of radiation; social sciences dealing with the issues of trust, risk and ethics. Understanding how these very different disciplines interact is fundamental to creating and managing a nuclear waste organization. Based on a comprehensive review of the scholarly and scientific literature of waste management, we have analyzed the evolution and structure of research in nuclear waste management between 1979 and 2017. Focusing on materials science, we show that some research themes have been isolated from the most central themes of nuclear waste management. Moreover, we observed a relative decline of the fundamental research in materials science. This decline was evidenced by a drop in the number of articles published in the proceedings of the MRS symposia “Scientific Basis for Nuclear Waste Management” since 2000. We argue for the need to more precisely and inclusively define the field of nuclear waste management.
Research paper
Open access
Diaz-Maurin, F., & Ewing, R. C. (2018). Mission Impossible? Socio-technical Integration of Nuclear Waste Geological Disposal Systems. Sustainability, 10(12): 4390.
We present a new perspective on geological disposal systems for nuclear waste. Geological disposal systems encompass all the processes required for the permanent isolation of highly-radioactive materials from humans and the biosphere. Radioactive materials requiring geological disposal are created by commercial nuclear power plants, research reactors, and defense-related nuclear activities, such as spent nuclear fuel from commercial reactors and high-level waste from reprocessing to reclaim fissile material for weapons. We show that disposal systems are so complex that new methods of representation are required. Despite the common call for a systems approach, a broader perspective is needed to obtain an integrated view of disposal systems. We introduce a conceptual formalism of geological disposal systems based on a multi-scale integrated analysis approach. This ‘metabolic’ representation allows one to account for the technical complexity of disposal systems in relation to their broader societal context. Although the paper is conceptual, the integrated formalism can improve the understanding of the complexity of disposal systems and their policy requirements by connecting technical solutions with societal constraints. However, the paper also reveals the limits to efforts to integrate technical and social dimensions of geological disposal systems into a single formalism.
Research paper
Open access
Diaz-Maurin F. (2018). Chronic long-term risk of low-level radiation exposure: Bridging the lay/expert divide. Bulletin of the Atomic Scientists, 74(5): 335–339.
The failure of experts and lay people to understand each other has been fueling conflict around the environmental clean-up of the many sites in the United States that are contaminated by the nuclear weapons program. This mutual distrust was exacerbated by the culture of secrecy surrounding the atomic weapons program during World War II, and later by the innate culture of bureaucracy in the federal agencies that have sprung up since then. A prime example of this problem can be found in the regulation of chronic long-term risk from low-level radiation exposure affecting communities in Missouri’s North St. Louis County. This case study illuminates this divide, and illustrates opportunities to close it.
Open access
Diaz-Maurin, F. (2018). Atomic Homefront: a film about struggling to live with Manhattan Project radioactive waste. Bulletin of the Atomic Scientists, 11 June 2018.
Conference paper
Diaz-Maurin F. (2018). Trust and the Ethical Imperative of the U.S. Nuclear Waste Management Program. 59th Annual Convention of the International Studies Association (ISA), 4-7 April 2018, San Francisco, CA. pp. 36.

Datasets & codes

Multi-criteria evaluation of spent fuel management scenarios at San Onofre, California
  • under review
Citation network analysis on radioactive waste materials (1940-2017)
  • available soon
Open access
Attributes of Nuclear Waste Disposal Systems through collapsible tree diagram
  • Last update: Oct 30, 2018
  • DOI: pending
Open access
Bibliographic analysis of transuranic (TRU) waste and defense high-level waste (DHLW) based on the OSTI database on U.S. scientific and technical literature (1950-2017)
  • Last update: Apr 25, 2018
  • DOI: pending
Other data-sets related to publications available upon request.

Discover our spin-off company!

Decidia Research & Consulting is a young Spain-based company specialized in integrated analysis and methods for decision support. Its cross-disciplinary methods help to better manage uncertainty, reduce conflict, improve models’ integration, and increase institutional trust in the context of decision. Decidia operates on a broad spectrum of areas ranging from radioactive waste management to decommissioning of nuclear facilities, environmental remediation, natural resource management, energy systems and large infrastructures.


The research leading to this website was supported by the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Individual Fellowship program (grant agreement no. 739850) and the MacArthur Foundation under CISAC’s Nuclear Security Fellowship program (2017-2019).

© 2020 François Diaz-Maurin.