geological disposal
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2022 ◽  
Vol 64 (1) ◽  
pp. 46-50
Author(s):  
Hiromitsu Saegusa ◽  
Toshiyuki Matsuoka ◽  
Masakazu Niwa ◽  
Eiji Sasao ◽  
Akira Hayano

2021 ◽  
Vol 1 ◽  
pp. 243-244
Author(s):  
Tara Beattie ◽  
Paul Carbol ◽  
Bernd Grambow ◽  
Tobias Knuuti ◽  
Louise Théodon ◽  
...  

Abstract. Knowledge management (KM) is a core activity of the European Joint Programme on Radioactive Waste Management (EURAD), which has driven the development of the EURAD Roadmap, a roadmap for the implementation of radioactive waste management (RWM) leading to geological disposal, using the experiences of advanced national and EU programmes. Because these programmes have been developed over more than 40 years and have adopted different technical and strategic approaches to deep geological repository (DGR) development, the roadmap has been structured to capture largely generic best practice in its presentation of programme Phasing and Thematic goals breakdown structure: 5 Phases of Implementation: Initiation, Site Selection, Site Characterization, Construction, and Operations and Closure. For each phase the roadmap explains how activities and existing knowledge are used to fulfil generic safety and implementation goals common across RWM programmes. 7 themes: Programme Management, Predisposal, Engineered Barrier Systems, Geoscience, Design and Optimisation, Siting and Licensing, and Safety Case. Each theme is further elaborated into sub-themes and domains. The intention of the EURAD roadmap is to provide information and guidance to three primary user groups: Organisations that are developing or updating their national RWM programmes with the objective of moving towards deep geological disposal of some of their wastes and requiring information on the steps involved; Organisations with advanced RWM and DGR programmes that require an informative training tool for new staff and a means of propagating knowledge across the groups involved in diverse activities; All organisations concerned with identifying potential future gaps in capabilities that could hinder implementation of their DGR programmes in decades to come. We recognize that there is not a unique route through the roadmap – like any roadmap, it can be used to stimulate consideration of alternative options and can be adapted by each Member State to suit national priorities. Because of its generic nature, the EURAD roadmap will be populated with content that is common to all programmes, creating a basis and strategy for a long-term project of Knowledge Management and Networking in RWM. The current focus is on signposting to existing content and the generation of new content to fill identified gaps for State of Knowledge, State of the Art, Guidance, Training and active Networks or Communities of Practice.


2021 ◽  
Vol 1 ◽  
pp. 287-288
Author(s):  
Cornelius Holtorf ◽  
Anders Högberg

Abstract. Safe disposal of nuclear waste in deep geological repositories requires secure knowledge transfer or knowledge recovery in time spans of many tens of thousands of years. Never before has any detailed record, knowledge or memory been reliably preserved or recovered over comparable time periods. This challenge has been extensively addressed since the late 1980s, initially during the SANDIA workshops in the USA and more recently in the Nuclear Energy Agency/Organisation for Economic Co-operation and Development (NEA/OECD) project on Preservation of Records, Knowledge and Memory Across Generations (Schröder, 2019). Experts from many disciplines including engineering, the natural sciences, information technology, social studies of science and technology, semiotics, public management, and design as well as artists have contributed to these discussions. Some scholars from the humanities have been involved in working on these issues, especially in recent decades. At the same time, much of the existing work has drawn on assumptions about human history, archaeological monuments and cultural heritage that have been scrutinized and deemed deeply flawed by Joyce (2020). The authors of the present paper are archaeologists and cultural heritage experts. For the past decade, they have been working with the challenge of preserving records, knowledge and memory concerning deep geological disposal sites for nuclear waste (Holtorf and Högberg, 2021). From the perspective of the human sciences, in particular archaeology and heritage studies, the unique task at hand involves not only the previously recognized challenges that require consideration of long-term material durability, linguistic intelligibility, and appropriate sense-making of any communicated information but also two challenges not previously addressed: Human action as informed by cultural and social processes. In designing of various long-term mechanisms, we risk overlooking that what people will do is not going to be governed by mechanics. How human beings learn, reason, value, decide, and act is informed by specific cultural and social processes creating context and meaning. We must avoid ignoring these complexities governing human thinking and agency. This challenge requires more work on understanding how sentient and intelligent beings like humans act in variable contexts across time and space. Our anticipatory assumptions. A proverb states that “nothing ages faster than the future”. In making assumptions about future generations' understandings, meanings, and significances of our nuclear waste we risk “colonizing” the future, fail to embrace variability over time, and miss realizing multiple futures and emerging conditions. We must therefore not foreclose uncertain futures but instead create circumstances favorable for change and transformation of relevant knowledge and memory. This challenge requires more work with processes of translation between generations. The challenges of assessing our anticipatory assumptions and understanding how humans act will also need to be addressed in transmitting records, knowledge and memory for the benefit of future generations.


2021 ◽  
Vol 1 ◽  
pp. 241-242
Author(s):  
Irmgard Niemeyer ◽  
Katharina Aymanns ◽  
Guido Deissmann ◽  
Dirk Bosbach

Abstract. The objectives of international safeguards are the timely detection of diversion of significant quantities of nuclear material from peaceful nuclear activities to the manufacture of nuclear weapons (or for other purposes), and deterrence of such diversion by the risk of early detection for states with comprehensive safeguards agreements with the International Atomic Energy Agency (IAEA). Following these objectives, several studies have focused on the developments of concepts and methods for safeguarding final disposal facilities as well as on identifying the most feasible technologies that could potentially be deployed for verifying final disposal programmes (IAEA, 1998, 2010, 2018). These activities were coordinated through Member State Safeguards Support Programmes, including the joint tasks on the development of “Safeguards for Geological Repositories” (SAGOR, 1994–2004) and on the “Application of Safeguards to Geological Repositories” (ASTOR, 2005–2017). SAGOR performed a diversion path analysis for spent fuel disposal facilities, determined safeguards technical objectives and identified potential safeguards measures to meet those objectives. ASTOR supported the IAEA in assessing how safeguards measures could be effectively implemented and provided recommendations with respect to developing such measures. Specific verification technologies were developed under other Member State Support Programme tasks. A summary report on the progress and status of safeguards for spent fuel encapsulation plants and geological repositories was completed by ASTOR in 2017. ASTOR also identified areas and actions that need to be accomplished to support safeguards implementation in final disposal facilities, such as (1) establish performance requirements for the design of safeguards technologies relevant to geological disposal of spent fuel, (2) determine specific information needs of states and operators regarding safeguards implementation for geological disposal of spent fuel and develop appropriate guidance, (3) determine specific information needs of IAEA inspectors and analysts and develop a guidance document that provides recommendations for implementing safeguards for a geological repository system under the state-level concept and (4) develop and test appropriate safeguards equipment (IAEA, 2017; Moran et al., 2018). While several measures and technologies related to verifying the geological disposal of spent fuel have been used by the IAEA at other facilities or are in development or testing, other technologies still need to be developed and tested. In addition, ASTOR identified the need for approaches to how information about disposed spent fuel and high-level nuclear waste should be managed, handled, organized, archived, read, interpreted and secured for the long term (for centuries after repository closure and beyond), including an international standard for states and facility operators on information management, data-retention methods and timescales for preserving safeguards data for geological repositories. The presentation will introduce the objectives of international nuclear material safeguards for the final disposal of spent nuclear fuel, highlight the current status of developments and discussions in terms of approaches and technologies for safeguarding geological repositories, and give an outlook on implementing safeguards for final disposal in Germany.


2021 ◽  
Vol 1 ◽  
pp. 233-234
Author(s):  
Dirk Bosbach ◽  
Lena Z. Evins

Abstract. Direct disposal of spent nuclear fuel (SNF) in a deep-mined geological repository is foreseen in various countries. Several decades of research (incl. various European projects such as SFS, NF-PRO, MICADO, REDUPP and FIRST-Nuclides) have shown that SNF shows a number of favourable properties as a waste form. Based on this background, the scientific collaborative DISCO project (2017–2021) aims to improve the understanding of the scientific basis of the safety cases for SNF under repository conditions – specifically for modern fuels. It comprises 16 project partners from eight EU countries consisting of large research institutions and small and medium enterprises (SME's), as well as an end-user group. It is supported by the European Union's Horizon 2020 Framework Programme for Research and Innovation with about 4 million euro (EU contribution). The project concept and implementation were initiated via the Exchange Forum of the Implementation of Geological Disposal – Technology Platform (IGD-TP) based on discussions among various actors, namely waste management organisations and the research community. The specific scientific issue of the DISCO project is whether the kinetics of the SNF dissolution process are affected by the composition and characteristics of the SNF itself, with a focus on modern Cr-doped and mixed oxide (MOX) fuels, which have been developed in recent years. The effect of dopants in the fuel matrix with regard to redox reactivity of the irradiated fuel needs to be evaluated, since this may affect the dissolution behaviour of and radionuclide release from these modern fuels. The overall objectives of the DISCO project are (1) to enhance our understanding of SNF matrix dissolution under conditions representative of failed containers in reducing repository environments and (2) to assess whether novel types of fuel (MOX, doped fuels) behave in a similar manner to conventional fuels. Experimental and modelling tasks have been defined to achieve the project objectives. The expected knowledge gain is essential for waste management organisations and will provide new insights into factors affecting their safety cases as fuel systems have evolved.


2021 ◽  
Vol 1 ◽  
pp. 235-236
Author(s):  
Dirk Bosbach ◽  
Crina Bucur ◽  
Christophe Bruggeman

Abstract. The European Joint Programme on Radioactive Waste Management EURAD brings together various research actors, namely waste management organisations (WMO), technical support organisations (TSO) and research entities (RE), to work on a joint strategic research agenda (SRA) focusing on deep geological disposal of radioactive waste. In total, 116 project partners from 23 countries have worked jointly since 2019 in collaborative RD&D work packages, strategic studies and various knowledge management activities. EURAD research is driven by the need for implementation of a deep geological repository and its safety, while aiming for scientific excellence. EURAD has developed a roadmap which is seen as a representation of a generic radioactive waste management (RWM) programme. The content is focused on what knowledge and competencies (including infrastructures) are considered most critical for RWM and implementation of deep geological disposal, in alignment with the EURAD vision. Here, the current SRA update process will be outlined from the perspective of Europe's research entities contributing to EURAD. In this context, the international network of research entities EURADSCIENCE plays a key role. EURADSCIENCE addresses – and will address during decades to come – scientific excellence in (the full lifecycle of) radioactive waste management from cradle to grave. As an independent, cross-disciplinary and inclusive organization, its overarching aim is to ensure scientific excellence and credibility in decision-making on RWM, regardless of national implementation status, waste type or national inventory. To this end, EURADSCIENCE will define and update its own SRA. The approach here is to maintain a holistic view of scientific disciplines and provide scientific excellence to advance progress of national radioactive waste management programmes, and to ensure scientific credibility of waste management concepts as well as addressing fundamental requirements related to knowledge management. More generally speaking, EURADSCIENCE aims to bring forward a vision that assures that scientific excellence and ever-developing scientific advances are integrated at any given time into the multigenerational implementation process of geological disposal. Similarly, the respective WMO and TSO networks, IGD-TP and SITEX, have developed their SRAs based on their specific roles and perspectives. Ultimately, the overlap between these SRAs will define the envelope for future European RD&D activities in the context of RWM. The update process has recently been consolidated after consultations between the three actor groups. Ultimately, the EURAD general assembly will have to approve the SRA update process regarding its alignment with the EURAD roadmap, the development of the seven existing SRA themes, the development of future RD&D activities via an EURAD exchange forum and the focus of RD&D planning for the next 10 years.


2021 ◽  
Vol 1 ◽  
pp. 91-93
Author(s):  
Philip Kegler ◽  
Martina Klinkenberg ◽  
Felix Brandt ◽  
Guido Deissmann ◽  
Dirk Bosbach

Abstract. In Germany it is planned to directly dispose spent nuclear fuel (SNF) from nuclear power plants together with other high-level radioactive wastes (HLW) from former SNF reprocessing (e.g., vitrified waste), in a deep geological repository for heat-generating wastes – the siting process for this repository was started in 2017 and is ongoing. Based on several decades of research, development, and demonstration (RD&D) it is generally accepted at the technical and scientific level that direct disposal of HLW and SNF in deep mined geological repositories is the safest and most sustainable option (CEC, 2011; IAEA, 2004). The current efforts to improve the performance and accident tolerance of fuels in nuclear power generation resulted in an increased utilization of a variety of new types of light-water reactor (LWR) fuels such as fuels doped with Cr, Al, and Si. This doping leads to a significant change of the microstructure of the fuel matrix. The corrosion behavior of these types of fuels under conditions relevant to deep geological disposal has hardly been studied so far; however, this is of crucial importance as the development of a robust safety case for deep geological disposal of SNF requires a solid understanding of its dissolution behavior over very long time scales (up to 1 million years). To fill this knowledge gap, additional systematic studies on modern doped UO2 fuels were needed. Corrosion experiments with SNF cannot entirely unravel all of the various concurring effects of the dissolution mechanism due to the chemical and structural complexity of SNF and its high beta and gamma radiation field during the first 1000 years; moreover, technical restrictions only allow a very limited number of experiments. Therefore, within the EU-DisCo project (https://www.disco-h2020.eu, last access: 11 October 2021), a very ambitious programme of corrosion studies on irradiated Cr and Al/Cr doped fuels was carried out, which was complemented by systematic single-effect dissolution studies (e.g., with respect to doping level, grain size and thermodynamic aspects) performed on carefully prepared and characterized, simplified UO2-based model materials. Here, we present recent results on the dissolution behavior of tailor-made UO2 model materials in accelerated static batch experiments using H2O2 as simulant for radiolytic oxidants, present in long-term disposal scenarios for SNF in failed container conditions due to the alpha irradiation of water. In these dissolution experiments pure UO2 reference pellets exhibiting different densities and grain sizes, as well as Cr-doped UO2 pellets with various Cr-doping levels, produced using different doping methods having different grain sizes, were used. In addition, Nd-doped and industrially produced Cr- and Cr/Nd-doped UO2 pellets were used to determine the influence of these parameters on the dissolution rates. The dissolution experiments were performed under strictly controlled conditions with respect to exclusion of oxygen, temperature control, and exclusion of light. This bottom-up approach was followed to understand how the addition of Cr-oxide into the fuel matrix affects SNF dissolution behavior under repository relevant conditions. The results of the dissolution experiments performed with real SNF and the model materials obtained by the DisCo partners build the basis for numerical simulations on the dissolution behavior of modern SNF. First results of the data evaluation indicate that the addition of dopants and the consequential modification of the fuel matrix does not lead to a significant change of the dissolution behavior of these fuels under repository relevant conditions compared to standard SNF (i.e. dissolution rates agree within an order of magnitude).


2021 ◽  
Vol 1 ◽  
pp. 129-130
Author(s):  
Axel Liebscher ◽  
Heini Reijonen ◽  
Ismo Aaltonen ◽  
Christina Lilja ◽  
Simon Norris ◽  
...  

Abstract. One of the key requirements for the deep geological disposal of high-level nuclear waste is the assessment of its long-term performance and safety (up to 1 Ma). Regarding engineered barrier system materials, such as copper, much of the data available comes from short-term investigations, such as laboratory experiments at different scales. Copper is an important part of many waste packaging and disposal concepts, e.g. KBS-3 developed in Sweden and Finland and Mark II developed in Canada. Natural analogues provide another important way of obtaining understanding on potential repository system behavior. Observations made from the geological systems can be utilized in the safety case, providing information on the assessment time scale. Copper analogue studies (both natural analogues and archaeological analogues) have been reported in the literature and they have been extensively reviewed by various authors (e.g. Miller et al., 2000) and by safety case projects (e.g. Reijonen et al., 2015) within waste management organizations. So far, only a few studies have focussed on the general stability of native copper within its natural media (e.g. Milodowski et al., 2000; Marcos, 2002). Keweenaw native copper occurrences (Lake Superior, USA) have been mentioned as a qualitative source of information (e.g. in Miller et al., 2000); however, data to be used in process-based safety assessments for geological disposal are lacking. These deposits have been mined for a long time and there is a great deal of knowledge related to them as well as samples collected, but no formal review has been made from the geological disposal point of view. The native copper at the Keweenaw area reflects various geological environments from bedrock to sediment and even anthropogenic mine site remnants and geochemical environments (e.g., anoxic vs. oxic, sulphur-free vs. sulphur-bearing). It thus provides a unique complementary data source that will be useful for estimating processes governing behavior of metallic copper. The MICA project phase I systematically collects and reviews the existing literature and data on the Michigan copper analogue sites and available sampling potential. Here, we present the current status of the project.


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