Results 1 - 10 of 94
Results 1 - 10 of 94. Search took: 0.019 seconds
|Sort by: date | relevance|
[en] The world needs energy to support everyday life and drive human and economic development. In 2019, over 26 000 terawatt-hours of electricity were produced worldwide. This electricity is being produced by a range of energy sources, mostly fossil fuels but also nuclear power and renewables such as solar, hydro and wind. Energy production and use are the largest source of greenhouse gas emissions around the world. As greenhouse gases are a driving force behind climate change, countries worldwide are actively working on a clean energy transition by changing how energy is produced. Here’s a closer look at the clean energy transition and what role nuclear power plays.
[en] The world is far off track when it comes to meeting the Paris Agreement climate goals of limiting the global temperature increase by 1.5°C to 2°C by 2050. Current projections show that fossil fuels will still make up the majority of world energy use by 2050. If we miss the 1.5°C target, this could mean accepting climate impacts, such as millions of people being displaced by sea level rise and millions more being exposed to extreme heatwaves, as well as major biodiversityrelated impacts, including species loss, the elimination of sea ice in the Arctic Ocean, and the loss of virtually all coral reefs. If we miss the 2°C target, half the world’s population could be exposed to summertime ‘deadly heat,’ Antarctic ice sheets could collapse, droughts could increase massively, and the Sahara Desert could begin to expand into southern Europe. World food supplies could be imperilled, driving mass human migration and leading to a growing risk of civilizational collapse. The Clean Energy Ministerial Flexible Nuclear Campaign we co-founded explores the expanded role that nuclear energy can play in de-risking the energy transition. Here, we describe two opportunities to drive deeper decarbonization with nuclear energy. The first is to expand the role of nuclear energy in electricity production through a combination of advanced reactors and thermal energy storage. This is intended to complement renewables in future energy grids. The second is to address the use of oil and gas, which currently accounts for three quarters of energy consumption, by providing large-scale, low-cost hydrogen produced with nuclear power.
[en] Summary: • SMR is an attractive option to enhance energy supply security: - In embarking countries with smaller grids, remote areas and the need of non electric applications; - In expanding nuclear countries for facilitating transition to low carbon energy systems. • Innovative SMR designs and concepts have common impediments to address including regulatory and licensing frameworks; • Studies needed to evaluate potential benefits of deploying SMRs in grid systems that contain large percentages of renewable energy. • Studies needed to: develop Generic User Requirements & Criteria, assess Technology Readiness, address manufacturing aspects, and establish a robust supply chain; • IAEA assists Member States in all aspects of SMR development: infrastructure, safety, safeguards, security, economics, and so forth.
[en] Fast neutron reactors can increase efficiency of nuclear energy and shrink the environmental footprint of radioactive waste. Several countries are looking to these innovative reactors to help ensure a sustainable energy future. Fast reactors use neutrons that are not slowed down by a moderator, such as water, to sustain the fission chain reaction. While only a fraction of natural uranium is used as fuel in existing thermal reactors, fast reactors can use almost all uranium contained in the fuel to extract up to 70 times more energy, reducing the need for new uranium resources.
[en] Specific features of Loviisa VVER-440: – low power density; – large water volumes =► long time delays =► low decay power; –ice condenser =► flooded cavity. Molten pool heat transfer: – Maximum heat loads assumed to occur when a quasi-steady state has been reached (heat losses from RPV match the decay power); –Stratified pool: • oxidic, heat generating pool at the bottom; • metallic layer on top.
[en] Objectives of corium melt pool expertiments: • o reduce uncertainties in the understanding of thermophysical phenomena influencing the melt pool configuration, composition and masses/thicknesses of melt layers and interfacial crusts, relative positions of the layers, heat and mass transfer between the layers and heat fluxes to the melt pool boundaries; • to determine the conditions in the melt pool which are critical for the system behavior, such as layer inversion, mixing and focusing of the heat flux • to develop correlations and validate calculation models for stratified fluid layers; • to predict the heat transfer loadings on the vessel wall for different configurations of the melt pool
[en] Hydrogen is the most abundant chemical element in the universe, but producing it in pure form for a range of industrial processes is energy intensive, with a significant carbon footprint. Hydrogen is used in industrial processes ranging from producing synthetic fuels and petrochemicals to manufacturing semiconductors and powering fuel cell electric vehicles. In order to decrease the environmental impact of the annual production of over 70 million tonnes of hydrogen, some countries are looking to nuclear power. Several countries are now implementing or exploring hydrogen production using nuclear power plants to help decarbonize their energy, industrial and transportation sectors. It is also a way to get more out of a nuclear power plant, which can help to increase its profitability.
[en] Interest in research reactors remains high, with good reason, considering the important role they play in our society. Since the 1950s, hundreds of research reactors around the world have benefited us all in many ways. The 224 research reactors that are in operation now continue to be a cornerstone of the development of nuclear science and technology programmes in 53 countries. Over 30 new research reactor programmes are being planned and developed, some of them in countries with no experience of operating a nuclear installation. Research reactors are key to not only nuclear education and training but also to scientific, industrial, medical and agricultural development. And they can contribute to the development of nuclear power programmes. The sustainability of research reactors depends on several factors, including continuous improvement of safety and security, effective operation management and efficient utilization of the facilities. All research reactor programmes, including those in the planning stages, should be managed in a coordinated manner that involves all stakeholders and provides for effectiveness and sustainability of the programmes.
[en] In this case study a potential impact is assessed by a proposed methodology for estimation of the impact’s magnitude. Also the acceptability of this impact is analysed based on the general requirement that an accident at a Nuclear Energy System will not cause the need for public relocation or evacuation protective actions beyond the site boundary and, on the other hand, based on a risk curve criterion for the public, where acceptability of the dose depends on the probability of release category occurrence.
[en] The DEMO heat transfer and the power conversion systems (PCS) are both part of DEMO Balance of Plant (BOP). Since a tokamak operates in pulsed mode, a concept using an internal thermal energy storage system was elaborated to allow for flexible operation of the power plant also under dwell time conditions. As part of the Power Plant Physics and Technology (PPPT) conducted by the EUROfusion Consortium for the development of fusion energy, the balance of plant develops the necessary systems and interfaces to relevant DEMO systems to allow efficient energy production. This includes design adaptation and safety analyses in order to identify safety provisions to address issues not acceptable to licensing authorities. As an example, the proposed safety provisions for the integrity of the vacuum vessel (VV) are given. An outlook summarizes design development and safety investigations. (author)