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Approaches to radiological protection have been evolving, particularly over the past several years. This has been driven by the emergence of modern concepts of and approaches to risk governance, and by calls from within the radiological protection community for the simplification and clarification of the existing system of protection, as based on the Recommendations of the International Commission on Radiological Protection (ICRP).
The NEA Committee on Radiation Protection and Public Health (CRPPH) has been very active in developing its own suggestions as to how the system of radiological protection should evolve to better meet the needs of policy makers, regulators and practitioners. One of those suggestions is that a generic concept of “regulatory authorisation” of certain levels and types of exposure to radiation should replace the current and somewhat complicated concepts of exclusion, exemption and clearance. It has also been suggested that by characterising emerging sources and exposures in a screening process leading into the authorisation process, regulatory authorities could develop a better feeling for the type and scale of stakeholder involvement that would be necessary to reach a widely accepted approach to radiological protection.
In order to verify that these suggestions would make the system of radiological protection more understandable, easy to apply, and acceptable, independent consultants have “road tested” the CRPPH concepts of authorisation and characterisation. Their findings, which show that applying these concepts would represent significant improvement, are reproduced herein. Specific approaches for the application of the new CRPPH ideas are also illustrated in this report.
With an electricity system defined by high shares of hydropower, large capacity for interconnection with its neighbours and low carbon intensity, Switzerland is well positioned to attain its objective of net zero carbon emissions by 2050. However, the exact pathway remains the subject of discussion. First, what should the shares of nuclear energy and variable renewable energies such as solar PV and wind be in the energy mix? Second, what degree of electricity trade should Switzerland have with its European neighbours?
New system modelling of different energy policy choices with the Nuclear Energy Agency’s POSY model shows that all considered scenarios are technically feasible. However, relying on variable renewables alone or decoupling Switzerland from neighbouring countries could increase total system costs by up to 250%. Instead, continuing to operate Switzerland’s newest nuclear power plants alongside existing hydropower resources, while maintaining interconnection capacity at current levels, emerges as the most cost-effective option to achieve net zero emissions in 2050. Ample data and technical documentation of a least-cost mixed integer (MILP) modelling with hourly resolution are also provided in order to allow replication, extension and discussion of this study’s findings
In order to provide experts with a forum to present and discuss developments in the field of partitioning and transmutation (P&T), the OECD Nuclear Energy Agency (NEA) has been organising, since 1990, a series of biennial information exchange meetings on actinide and fission product P&T. These proceedings contain all the technical papers presented at the 11th Information Exchange Meeting, which was held on 1-4 November 2010 in San Francisco, California, USA. The meeting covered national programmes on P&T; fuel cycle strategies and transition scenarios; waste forms and geological disposal; transmutation fuels and targets; pyro and aqueous processes; transmutation physics and materials; and transmutation system design, performance and safety.
The cost estimation process of decommissioning nuclear facilities has continued to evolve in recent years, with a general trend towards demonstrating greater levels of detail in the estimate and more explicit consideration of uncertainties, the latter of which may have an impact on decommissioning project costs. The 2012 report on the International Structure for Decommissioning Costing (ISDC) of Nuclear Installations, a joint recommendation by the Nuclear Energy Agency (NEA), the International Atomic Energy Agency (IAEA) and the European Commission, proposes a standardised structure of cost items for decommissioning projects that can be used either directly for the production of cost estimates or for mapping of cost items for benchmarking purposes. The ISDC, however, provides only limited guidance on the treatment of uncertainty when preparing cost estimates. Addressing Uncertainties in Cost Estimates for Decommissioning Nuclear Facilities, prepared jointly by the NEA and IAEA, is intended to complement the ISDC, assisting cost estimators and reviewers in systematically addressing uncertainties in decommissioning cost estimates. Based on experiences gained in participating countries and projects, the report describes how uncertainty and risks can be analysed and incorporated in decommissioning cost estimates, while presenting the outcomes in a transparent manner.
This study analyses a range of advanced nuclear fuel cycle options from the perspective of their effect on radioactive waste management policies. It presents various fuel cycle options which illustrate differences between alternative technologies, but does not purport to cover all foreseeable future fuel cycles. The analysis extends the work carried out in previous studies, assesses the fuel cycles as a whole, including all radioactive waste generated at each step of the cycles, and covers high-level waste repository performance for the different fuel cycles considered.
New nuclear reactor designs are expected to have a higher level of safety than current designs. As part of the efforts to achieve this, important safety issues related to the new designs need to be identified at an early stage, and research required for problem resolution defined.
These proceedings bring together the papers presented at the OECD/NEA Workshop on Advanced Nuclear Reactor Safety Issues and Research Needs. Conclusions of the workshop discussions are offered at the end of the book, which will be of particular interest to all those involved in planning and designing the next generation of nuclear reactors.
Energy markets will be significantly different in the future. The electricity generation system is becoming more diverse with the development of energy-related technologies including renewable energy sources, storage technologies and demand-side management. Beyond the electricity sector, various low-carbon energy technologies are being developed to respond to the need to decarbonise hard-to-abate sectors such as heavy industry and long-distance transportation.
In this report the NEA investigates the changing needs of energy markets and the potential role of nuclear technologies as low-carbon energy sources. Focusing on the technical characteristics of advanced nuclear reactor systems, including Generation III/III+ reactors, small modular reactors and
Generation IV reactors, it explores the ways these advanced nuclear technologies could address the future energy market needs. The conclusion is that advanced nuclear reactor systems, while complying with the flexibility requirements of the electricity grid and supporting system reliability, have a large potential as alternative low-carbon energy sources for residential and industrial heat supply and hydrogen production.
A new generation of nuclear reactor designs is being developed in order to meet the needs of the 21st century. In the short term, the most important objective is to improve competitiveness in the deregulated market. For this purpose evolutionary light water reactors are being developed and promoted actively. In the longer term, other requirements related to long-term sustainability will emerge, including the need to minimise the environmental burden passed on to future generations, the need to establish sustainability of the fuel and the need to minimise stocks of separated plutonium and their accessibility.
At this workshop, information on R&D activities for advanced reactor systems was exchanged and research areas in which international co-operation could be strengthened were identified, in particular the roles that could be played by existing experimental facilities and the possible needs for new infrastructure.
Plutonium and minor actinide burning or recycling in thermal and fast reactors is being studied in many countries with the aim of maintaining and developing fuel cycle options which can be adjusted to changing demands and constraints. The challenge is to move towards an economically and socially sustainable nuclear energy system based on advanced reactors - advanced water-cooled reactors, fast reactors and perhaps accelerator-based, hybrid reactors - and new types of fuel cycles which help to minimise the waste arising. An additional issue concerns the availability of resources for the long-term future. This workshop introduced new ideas on R&D activities and identified areas and research tasks relevant for the deployment of new systems and in which international co-operation can be strengthened. The roles played by existing experimental facilities as well as possible needs for new ones are discussed. The conclusions of the technical sessions are synthesised and the results of a round table discussion on international co-operation are presented.
Experience from decommissioning projects suggests that the decommissioning of nuclear power plants could be made easier if it received greater consideration at the design stage and during the operation of the plants. Better forward planning for decommissioning results in lower worker doses and reduced costs. When appropriate design measures are not taken at an early stage, their introduction later in the project becomes increasingly difficult. Hence, their early consideration may lead to smoother and more effective decommissioning.
It is now common practice to provide a preliminary decommissioning plan as part of the application for a licence to operate a nuclear facility. This means, in turn, that decommissioning issues are being considered during the design process. Although many design provisions aiming at improved operation and maintenance will be beneficial for decommissioning as well, designers also need to consider issues that are specific to decommissioning, such as developing sequential dismantling sequences and providing adequate egress routes. These issues and more are discussed in this report.
Irrespective of current views on the future of nuclear power programmes, concerns are arising with respect to the long-term ability to preserve safety competence because student enrolments in nuclear engineering are decreasing rapidly and experienced staff are reaching retirement age. "Assuring Nuclear Safety Competence into the 21st Century" was discussed in depth by workshop participants. The need for a long-term strategic view was emphasised, and policy recommendations were made. These proceedings will be of particular interest to those playing a policy role in the nuclear industry, regulatory bodies and the education sector.