Results 1 - 10 of 132
Results 1 - 10 of 132. Search took: 0.026 seconds
|Sort by: date | relevance|
[en] In the United States, an approach to manage the aging of spent fuel dry storage systems was created by contributions from the regulatory body, storage facility owners, cask vendors, and the engineering community. The U.S. regulations for storing spent fuel beyond the first approved storage term require aging management activities to ensure that materials degradation will not adversely affect the safe storage of the spent fuel. Several guidance documents provide recommendations for complying with this regulation. The U.S. Nuclear Regulatory Commission (NRC) and the Nuclear Energy Institute (NEI) developed NUREG-1927 and NEI 14-03, respectively, to describe methods to identify the components that support a safety function, to evaluate the aging mechanisms could affect safety, and to establish aging management activities. The NEI guidance also introduces a new system to share operating experience through an Institute of Nuclear Power Operations database. The NRC also developed NUREG-2214 to identify the credible materials aging mechanisms for several cask designs used in the United States. NUREG-2214 also provides example aging management programs that may be used to effectively manage aging. Those programs rely, in part, on consensus codes and standards for monitoring and inspection guidelines, such as American Concrete Institute codes and the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code. Finally, to provide oversight of aging management activities, the NRC is developing internal procedures to evaluate, through inspection, the storage facilities’ performance of their aging management programs. Lessons learned from NRC Temporary Instruction TI 2690/011 will inform the development of a new NRC inspection procedure. (author)
[en] As part of its efforts to help resolve the major climate and energy issues facing future generations over the next decades, France is committed to a global energy transition materialised through the Act of 17 August 2015 on the energy transition for green growth (LTECV). This act defines the main objectives for the medium and long term. Among these objectives, it is worth highlighting: — Reduction in greenhouse gas emissions by 40% between 1990 and 2030, and a 4-fold reduction in greenhouse gas emissions between 1990 and 2050; — Development of renewable energy sources to reach 23% of the gross final energy consumption in 2020 and then 32% in 2030; — Reduction in nuclear energy’s contribution to electricity generation to reach 50% by around 2035. To achieve these objectives, the LTECV Act specifies the definition of a French national strategy to lower carbon emissions (SNBC) and a multi-year energy programme (PPE). The first version of this programme covers the periods 2016 to 2018 and 2018 to 2023. It must be reviewed every 5 years over a 10-year period. The main orientations of this PPE programme for the 2019-2028 period were published by the French government within the scope of a project announced in January 2019; they will be open to public consultation before their adoption scheduled for the end of summer. (author)
[en] This publication provides guidance for assessing the sustainability of a nuclear energy system (NES) in the area of nuclear fuel cycle facility (NFCF) safety. It deals with NFCFs that may be potentially involved in the NES such as, mining, milling, refining, conversion, enrichment, fuel fabrication, spent fuel storage, and spent fuel reprocessing facilities. It augments the information presented in the earlier INPRO publications on the methodology for sustainability assessments. The publication is intended for use by organizations involved in the development and deployment of a NES, including planning, design, modification and technical support for NFCFs. INPRO is an international project to help ensure that nuclear energy is available to contribute in a sustainable manner to meeting the energy needs of the 21st century.
[en] With nuclear energy anyhow a necessary part of a sustainable and affordable energy future worldwide, intra-nuclear options to further improve the sustainable performance of nuclear energy have been researched and some developed since the early days of nuclear energy. These especially address the back-end of the nuclear fuel cycle given the management of spent fuel (SF) being a socio-politically sensitive topic translating into technical-economic challenges for many of the back-end fuel cycle options. Especially in those countries with a large legacy of SF from the past decades of nuclear energy use, these SF-inventories become an increasing challenge. For small(er) nuclear power plant (NPP) parks, such a SF-inventory is even more challenging as the prime option to dispose of this SF in geological disposal facility (GDF) may become overly costly. These situations influence the acceptance of nuclear energy as sustainable energy source while nuclear newcomer countries watch which new SF-management options may become available in due time and well before such challenges may also pose to them. Though, SF-management does not have to be a „bottleneck‟ to nuclear energy use now nor in the future. Various SF-management options have been researched, some developed and some even industrialised. There‟s been expectations during the last 30 years that so-called “Generation-IV” systems or even more advanced “Generation-X” (partitioning & transmutation (P&T)) systems would become online by around the 2030s and able to resolve many of the challenges of such SF-management. Today, these expectations largely remain prospects for post-2050 with exception for some countries continuously advancing towards such advanced nuclear energy systems. Though, while the role of nuclear energy and thus its prospects in light of sustainable energy is today high on the agenda and will have to be clarified during the 2020s, a proper solution-oriented and responsible and above-all timely SF-management will need to go along and be realised by mid-century. This paper overviews which back-end fuel cycle strategies may construe such proper solution-oriented SF-management aligned to nuclear energy‟s role within the uncertain prospect to evolve soon towards “Generation-IV” systems. (author)
[en] The work was conducted in the context of the International Atomic Energy Agency’s (IAEA) newly initiated activity on “approaches for nuclear power costs estimation and analysis” (the “Nuclear Cost Basis”, or NCB, project). The NCB provides guidelines and resources for developing consistent cost estimates and analyses covering, basically, all areas of a country’s nuclear power programme; from nuclear infrastructure development; to reactor construction and operation; to management of radioactive waste. The paper focuses on technologically mature, widely used, spent nuclear fuel storage options and technologies. Storage of spent nuclear fuel can be made At-Reactor (AR) or Away-from-Reactor (AFR) ― at Reactor-Site (AFR-RS) or Off-Site (AFR-OS) ―. These options may involve wet (water pools) and dry storage technologies (casks, vaults, silos). For each of these technologies and options, an effort has been made to synthesize existing literature and compile a comprehensive list of key factors affecting costs. This list will be used as a basis for developing standard cost categories and cost breakdown structures for costing purposes. (author)
[en] The various options for the management of spent fuel (SF) from nuclear power reactors is a topic that has been debated from multiple dimensions, being it the socio-political concerns with regard to geological disposal, the technical-economic competitiveness of options such as reprocessing and recycling, as well as from the growing discussion on sustainability and international policy. Many of the discussions relating to SF-management have historically been rather binomial between, on the one hand, the socio-political concerns on the direct disposal of SF and the proliferation concerns regarding reprocessing, and, on the other hand, the uncertain costs of such disposal facilities versus the economics of reprocessing and recycling schemes. Especially since the 1990s, various intergovernmental and national organisations initiated studies on very advanced SF-management schemes such as separation and transmutation also impacting the progress towards a proper solution-oriented and responsible and above-all timely SF-management. After some decades of - generally - indecisiveness on SF-management, and with nuclear energy increasingly in the spotlight in the context of sustainable energy mixes, a more solution-oriented and responsible SF-management becomes necessary, if not urgent. Especially as the uncertain costs and timing for such SF-management become increasingly translated into financial risks for the SF-owners, i.e. utilities. Many discussions on SF-management options were in the past coloured by strategic reflections on Unat availability and pricing, sustainable nuclear fuel cycle options (including Generation-IV systems) and political considerations regarding non-proliferation. Today, there is a growing financial risk presented to utilities which becomes a more compelling trigger towards a decision on various SF-management options. This paper addresses the changing market context for nuclear energy and particularly how SF-management options are increasingly assessed in such uncertain futures. Cost/risk optimising SF-management schemes are crucially important for utilities not to have SF as such remaining a hurdle for the future of nuclear energy’s use. (author)
[en] RTOP code: ➢ Was developed for the direct simulation of coupled physical processes in a fuel rod: in fuel pellets and in cladding. ➢ Thermal behavior of the rod takes into account fuel properties (burnup, porosity, composition), properties and composition of internal initial and fission gases, heat transfer into the coolant, nonuniform spatial distribution of heat generation, etc. ➢ Performs thermo-mechanical calculations for fuel rods taking into account properties of materials, fission gas release, fuel pellet cracking, dimensional instability of cladding and fuel pellets, temperature distribution, etc.
[en] Introduction: Increase the initial enrichment of nuclear fuel result in possible reduce the fuel cycle cost due to lengthening the reactor campaign from 12 to 18 or even 24 months, or due to reduction of fuel batch every year 1/3, 1/4 or 1/5 part of the core Currently, the initial enrichment of fuel is steadily approaching the mark of 5% and average burnup has already exceeded the level of 50 MWd/tU Now an objective of the transition of initial enrichment to the range of 5 -10% and the burn up to 100 MWd/tU becomes on the agenda.
[en] This publication presents the latest update to the INPRO methodology for Nuclear Energy Systems sustainability assessment in the area of waste management and reflects detailed discussions held at an IAEA technical meeting. Waste generated by nuclear energy systems and considered in this publication includes all classes and categories of waste from nuclear power plants and nuclear fuel cycle facilities over the course of normal operations and anticipated operational occurrences. It is anticipated that the information presented in this and other INPRO publications, for example IAEA Nuclear Energy Series No. NG-T-3.12, will assist in the identification of areas for improvement in nuclear energy systems. INPRO is an international project to help ensure that nuclear energy is available to contribute in a sustainable manner to meeting the energy needs of the 21st century.
[en] 45 years since it was first conceived and after reprocessing over 9,300 tonnes of fuel, THORP sheared its last fuel assembly on 9th November 2018. Providing a vital service to UK, European and international reactor operations, the facility will continue to store fuel for at least the next 50 years. This presentation will look back at some of the history, the economics and lessons learnt more than 24 years of successful operation and forward to a new future for the staff and facility. (author)