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One of the major achievements of the OECD Nuclear Energy Agency (NEA) is the knowledge it has helped to generate through the organisation of joint international research projects. Such projects, primarily in the areas of nuclear safety and radioactive waste management, enable interested countries, on a costsharing basis, to pursue research or the sharing of data with respect to particular areas or issues. Over the years, more than 30 joint projects have been conducted with wide participation of member countries.
This report describes the achievements of the OECD/NEA joint projects on nuclear safety research that have been carried out over the past three decades, with a particular focus on thermal-hydraulics, fuel behaviour and severe accidents. It shows that the resolution of specific safety issues in these areas has greatly benefited from the joint projects’ activities and results. It also highlights the added value of international co-operation for maintaining unique experimental infrastructure, preserving skills and generating new knowledge.
Radioactive waste results from many different activities in health care, industry, research, and power production. All such waste must be managed safely, with the protection of human health and the environment as the highest priority. After decades of research, the international scientific community is now confident that placing high-level radioactive waste in deep geological repositories (DGRs) is both safe and effective.
The government of each country has the absolute right and responsibility to implement the energy and environmental policies it believes are best. In the case of the disposal of radioactive waste, it is paramount that these debates should be informed by objective facts. This report therefore aims to provide the general reader with the current state of knowledge with regards to the management of high-level radioactive waste in DGRs.
Large stocks of depleted uranium have arisen as a result of enrichment operations, especially in the United States and the Russian Federation. Countries with depleted uranium stocks are interested in assessing strategies for the use and management of depleted uranium. The choice of strategy depends on several factors, including government and business policy, alternative uses available, the economic value of the material, regulatory aspects and disposal options, and international market developments in the nuclear fuel cycle.
This report presents the results of a depleted uranium study conducted by an expert group organised jointly by the OECD Nuclear Energy Agency and the International Atomic Energy Agency. It contains information on current inventories of depleted uranium, potential future arisings, long-term management alternatives, peaceful use options and country programmes. In addition, it explores ideas for international collaboration and identifies key issues for governments and policy makers to consider.
The NEA Expert Group on Fukushima Waste Management and Decommissioning R&D (EGFWMD) was established in 2014 to offer advice to the authorities in Japan on the management of large quantities of on-site waste with complex properties and to share experiences with the international community and NEA member countries on ongoing work at the Fukushima Daiichi site. The group was formed with specialists from around the world who had gained experience in waste management, radiological contamination or decommissioning and waste management R&D after the Three Mile Island and Chernobyl accidents. This report provides technical opinions and ideas from these experts on post-accident waste management and R&D at the Fukushima Daiichi site, as well as information on decommissioning challenges.
Interest in nuclear energy continues to grow in many countries as a means to ensure security of energy supply and to limit greenhouse gas emissions from the power sector. In this context, recyclable materials constitute an asset for broadening the resource base for nuclear fuel supply, especially in medium- and long-term perspectives.
This report provides an overview of recyclable fissile and fertile materials inventories which can be reused as nuclear fuel. It reviews the options available for managing those materials, through recycling and/or disposal. The potential energetic value of recyclable materials is assessed, taking into account the variability of retrievable energy contents of various materials according to technology and strategy choices made by the owners of the materials.
The analyses contained in this report will be of particular interest to energy policy makers and to nuclear fuel cycle experts.
Also available in this series:
Innovation in Nuclear Energy Technology (2007)
Forty Years of Uranium Resources, Production and Demand in Perspective: The Red Book Retrospective (2006)
Nuclear Power Plant Life Management and Longer-term Operation (2006)
These workshop proceedings discuss different approaches to treating uncertainties in safety cases for radioactive waste management facilities, and more specifically how concepts of risk can be used in both post-closure safety cases and regulatory evaluations. This report includes a synthesis of the plenary presentations and the discussions that took place during the workshop. These proceedings will be of interest to waste repository safety assessors and managers.
Uranium mining and milling has evolved significantly over the years. By comparing currently leading approaches with outdated practices, this report demonstrates how uranium mining can be conducted in a way that protects workers, the public and the environment. Innovative, modern mining practices combined with strictly enforced regulatory standards are geared towards avoiding past mistakes committed primarily during the early history of the industry when maximising uranium production was the principal operating consideration. Today’s leading practices in uranium mining aim at producing uranium in an efficient and safe manner that limits environmental impacts to acceptable standards. As indicated in this report, the collection of baseline environmental data, environmental monitoring and public consultation throughout the life cycle of the mine enables verification that the facility is operating as planned, provides early warning of any potentially adverse impacts on the environment and keeps stakeholders informed of developments. Leading practice also supports planning for mine closure before mine production is licensed to ensure that the mining lease area is returned to an environmentally acceptable condition. The report highlights the importance of mine workers being properly trained and well equipped, as well as that of ensuring that their work environment is well ventilated so as to curtail exposure to radiation and hazardous materials and thereby minimise health impacts.
Nuclear power plants require a wide variety of specialised equipment, materials and services for their construction, operation and fuelling. There has been much consolidation and retrenchment in the nuclear industry since the 1980s, with the emergence of some large global nuclear companies. Electricity market liberalisation in many OECD countries has meanwhile placed nuclear plant operators under increased competitive pressure.
These structural changes in both the producer and consumer sides of the nuclear industry have had implications for the level of competition in the nuclear engineering and fuel cycle markets. With renewed expansion of nuclear power now anticipated, this study examines competition in the major nuclear industry sectors at present, and how this may change with a significant upturn in demand.
The transformative activity of mining has numerous economic, social and environmental impacts that can be both positive and adverse for communities, ecosystems and economies. As the uranium industry begins to address negative perceptions and legacies associated with past activities, environmental, socioeconomic and governance aspects of the uranium mining life cycle are gaining increased attention from investors, communities, regulators and other stakeholders. While environmental and human health and safety concerns often dominate stakeholder engagement programmes and public conversations about uranium operations, less public discussion and analytical research are typically devoted to the socio-economic aspects. This was the basis for this report. Through an examination of case studies from several countries the aim is to clarify how the numerous activities related to uranium mining affect various aspects of socio-economic development – including employment, supply chain investments, exports, taxes and royalties, innovation, infrastructure, education and medical care. This report’s inventory of leading practices is intended to inform public debate on uranium mine development and provide policymakers with a framework of approaches to maximise the social and economic benefits of uranium mining projects.
The nuclear energy sector employs a considerable workforce around the world, and with nuclear power projected to grow in countries with increasing electricity demand, corresponding jobs in the nuclear power sector will also grow. Using the most available macroeconomic model to determine total employment – the “input/output” model – the Nuclear Energy Agency and International Atomic Energy Agency collaborated to measure direct, indirect and induced employment from the nuclear power sector in a national economy. The results indicate that direct employment during site preparation and construction of a single unit 1 000 megawatt-electric advanced light water reactor at any point in time for 10 years is approximately 1 200 professional and construction staff, or about 12 000 labour years. For 50 years of operation, approximately 600 administrative, operation and maintenance, and permanently contracted staff are employed annually, or about 30 000 labour years. For up to 10 years of decommissioning, about 500 people are employed annually, or around 5 000 labour years. Finally, over an approximate period of 40 years, close to 80 employees are managing nuclear waste, totalling around 3 000 labour years. A total of about 50 000 direct labour-years per gigawatt. Direct expenditures on these employees and equipment generate approximately the same number of indirect employment, or about 50 000 labour years; and direct and indirect expenditures generate about the same number of induced employment, or 100 000 labour years. Total employment in the nuclear power sector of a given national economy is therefore roughly 200 000 labour years over the life cycle of a gigawatt of nuclear generating capacity.
National programmes for radioactive waste management require very large amounts of data and information across multiple and disparate disciplines. These programmes tend to run over a period of many decades resulting in a serious risk of data and information loss, which in turn can threaten the production and maintenance of robust safety cases.
Metadata and associated tools and techniques play a crucial role in modern data and information management. The Radioactive Waste Repository Metadata Management (RepMet) initiative has prepared the first international study on the application of metadata to the field of radioactive waste management. This report introduces the concept of metadata, explains how metadata can help to facilitate data management, and gives advice on the issues arising when developing metadata within radioactive waste management programmes. It is aimed at readers looking to obtain a highlevel overview of metadata, and associated tools and techniques, and the strategic importance they can play in Radioactive Waste Management Organisations (RWMOs).
For practical reasons, the consequences of nuclear reactor accidents are often measured in economic terms. Figures currently available, however, show significant discrepancies. For this reason, the NEA created an expert group to investigate the methodologies used in calculating the economic consequences of accidents, and the bases for such methodologies. Calculation methods were assessed according to three end uses: for compensation and liability purposes; for accident preparedness and management purposes; and for making electricity-generation choices. The group concluded that comparing numerical results is very difficult, even for estimates made from the same perspective, as they are strongly dependent on "boundary" conditions (such as the accident scenarios used, plant characteristics and amount of radioactive material released). This book provides a summary of the group’s findings and will be of interest to decision makers, experts and accident-consequence modellers.
It is essential that organisations in the nuclear community maintain a healthy safety culture to achieve common goals regarding the safe operation of nuclear facilities and the safe use of nuclear material. Regulatory bodies are no exception, as a key element of the interconnected system which includes licensees, research institutions, technical support organisations, as well as governmental organisations and other stakeholders. By their very nature, regulatory bodies deeply influence the safety culture and the safety of the organisations they regulate and oversee. Based on their regulatory strategy, the way they carry out their daily oversight work, the type of relationship they cultivate with licensees, the values they convey and the importance they give to safety, regulatory bodies profoundly impact the licensees’ safety culture, their sense of responsibility for safety and, by extension, the safety of their installations.
Regulatory bodies apply a number of methods, practices and approaches to foster and sustain a healthy safety culture. This report provides an overview and practical examples to build the regulatory bodies’ safety culture competence and to perform self-reflection and self-assessment with regard to their own safety culture and its impact on the safety culture of the organisations they oversee. Drawing directly from the experiences from OECD Nuclear Energy Agency member countries, the report discusses effective methods to disseminate safety culture throughout the regulatory body, to build competence in safety culture, and to develop self-reflection and self-assessment activities. Finally, the report presents ten conclusions based on lessons learnt and best practices to inspire managers to continuously develop their regulatory body’s safety culture.
Safety assessment is an interdisciplinary approach that focuses on the scientific understanding and performance assessment of safety functions as well as the hazards associated with a geological disposal facility. It forms a central part of the safety case, and the results of the safety assessments provide evidence to support decision making. The goals of the NEA project on “Methods for Safety Assessment for Geological Disposal Facilities for Radioactive Waste” (MeSA) were to examine and document methods used in safety assessment for radioactive waste disposal facilities, to generate collective views based on the methods’ similarities and differences, and to identify future work. The project reviewed a number of approaches used by various national and international organisations. Following the comprehensive review, a generic safety case with a safety assessment flowchart was developed and is presented herein. The elaboration of the safety concept, the use of safety functions, the implication of uncertainties and the formulation of scenarios are also discussed.
For the past several decades, the Nuclear Energy Agency Salt Club has been supporting and overseeing the characterisation of rock salt as a potential host rock for deep geological repositories. This extensive evaluation of deep geological settings is aimed at determining – through a multidisciplinary approach – whether specific sites are suitable for radioactive waste disposal. Studying the microbiology of granite, basalt, tuff, and clay formations in both Europe and the United States has been an important part of this investigation, and much has been learnt about the potential influence of microorganisms on repository performance, as well as about deep subsurface microbiology in general. Some uncertainty remains, however, around the effects of microorganisms on salt-based repository performance. Using available information on the microbial ecology of hypersaline environments, the bioenergetics of survival under high ionic strength conditions and studies related to repository microbiology, this report summarises the potential role of microorganisms in salt-based radioactive waste repositories.
A modern light water reactor (LWR) of 1 GWe capacity will typically discharge about 20-25 tonnes of irradiated fuel (spent fuel) per year of operation. Despite the low content of about 0.1-0.2% of minor actinides in spent fuel, these actinides can nonetheless contribute significantly to decay heat loading and neutron output, as well as to the overall radiotoxic hazard of spent fuel. For this reason, there has long been an interest in transmuting minor actinides to reduce their impact on the back end of the fuel cycle. Fast reactors are needed to effectively transmute transuranics (TRUs), including minor actinides. However, recent studies have demonstrated that TRU transmutation rates can also be achieved in thermal reactors, although with certain limitations due to the accumulation of transuranics through recycling and their impact on the safety of power plants. The transmutation of TRUs could potentially be implemented in a substantial number of thermal reactors operating today, while waiting for a similar programme in fast reactors to allow for commercial-scale operations in 20 to 30 years or more.
This publication provides an introduction to minor actinide nuclear properties and discusses some of the arguments in favour of minor actinide recycling, as well as the potential role of thermal reactors in this regard. Various technical issues and challenges are examined from the fuel cycle, operations, fuel designs, core management and safety/dynamics responses to safety and economics. The focus of this report is on the general conclusions of recent research that could be applied to thermal reactors. Further research and development needs are also considered, with summaries of findings and recommendations for the direction of future R&D efforts.
Since the accident at Chernobyl in 1986, many countries have intensified their efforts in nuclear emergency planning, preparedness and management. Experience from the NEA nuclear emergency exercises (INEX 1 and INEX 2) indicated a need to improve the international system of communication and information in case of a radiological emergency. To address this need, research was carried out by three NEA working groups, the findings of which are synthesised in the present report.
This report defines emergency monitoring and modelling needs, and proposes strategies which will assist decision makers by improving the selection of data that is transmitted, and the way in which data and information are transmitted and received. Modern communication methods, such as the Internet, are a key part of the strategies described.
Key concepts of radioactive waste management, such as safety, risk, reversibility and retrievability, carry different meanings for the technical community and for non-technical stakeholders. Similarly, socio-economic concepts, including community, landscape and benefit packages, are interpreted differently by diverse societal groups. Opinions and attitudes are not simply a faithful reflection of decision making, actual events and communicated messages; perceptions and interpretations of events and objects also play a role. This report presents key issues and examples in order to build awareness of the importance of symbols and symbolism in communicating about perceptions and interpretations. It adds to the recognition that dialogue amongst stakeholders is shaped by dimensions of meaning that reach beyond dictionary definitions and are grounded in tradition and social conventions. A better understanding of these less obvious or conspicuous realities should help find additional ways of creating constructive relationships amongst stakeholders.
A mature and well-guided multi-stage approach to the validation of nuclear power plant control room designs has the potential to reduce the risks involved in the design process. Such an approach can also increase the effectiveness of, and efficiencies in, the validation process, as well as overall confidence in the results. This relatively new concept of multi-stage validation has yet to be defined in the technical literature, and thus the report describes the approach and the rationale for validating systems through a series of successive, co-ordinated validation activities.
The scope of application of multi-scale validation addressed in the context of this report includes aspects related to both the human factors engineering of new nuclear power plant main control room designs and modifications to existing control room designs. The objective is to provide a common reference for future dialogue, research and development concerning the multi-stage validation approach, and ultimately to support the safe operation of nuclear power plants worldwide.