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Y Ogawa - One of the best experts on this subject based on the ideXlab platform.
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demonstration tokamak Fusion Power plant for early realization of net electric Power generation
Nuclear Fusion, 2005Co-Authors: R Hiwatari, Kunihiko Okano, Y Asaoka, K Shinya, Y OgawaAbstract:A demonstration tokamak Fusion Power plant Demo-CREST is proposed as the device for early realization of net electric Power generation by Fusion energy. The plasma configuration for Demo-CREST is optimized to satisfy the electric breakeven condition (the condition for net electric Power, ) with the plasma performance of the ITER reference operation mode. This optimization method is considered to be suitable for the design of a demonstration Power plant for early realization of net electric Power generation, because the demonstration Power plant has to ensure the net electric generation. Plasma performance should also be more reliably achieved than in past design studies. For the plasma performance planned in the present ITER programme, net electric Power from 0 to 500?MW is possible with Demo-CREST under the following engineering conditions: maximum magnetic field 16?T, thermal efficiency 30%, NBI system efficiency 50% and NBI current drive Power restricted to 200?MW. By replacing the blanket system with one of higher thermal efficiency, a net electric Power of about 1000?MW is also possible so that the performance of the commercial plant with Demo-CREST can also be studied from the economic point of view. The development path from the experimental reactor 'ITER' to the commercial plant 'CREST' through the demonstration Power plant 'Demo-CREST' is proposed as an example of the fast track concept.
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energy analysis and carbon dioxide emission of tokamak Fusion Power reactors
Fusion Engineering and Design, 2000Co-Authors: K Tokimatsu, Kunihiko Okano, Y Ogawa, Hiroki Hondo, Kenji Yamaji, Makoto KatsuraiAbstract:Energy gain and carbon dioxide (CO 2 ) emission of tokamak Fusion Power reactors are evaluated in this study compared with other reactor types, structural materials, and other Japanese energy sources currently in use. The reactors treated in this study are (1) a conventional physics performance international thermonuclear experimental reactor (ITER), like a reactor based upon the ITER engineering design activity (ITER-EDA), (2) a RS (reversed shear) reactor using the reversed shear safety-factor/plasma current profile, and (3) a ST (spherical torus) reactor based upon the final version of the advanced reactor innovative engineering study ST (ARIES-ST). The input energy and CO 2 emission from these reactors are calculated by multiplying the weight or cost of the Fusion reactor components by the energy intensity and/or with the CO 2 intensity data, which are updated as often as possible. The ITER cost estimation is estimated based on the component unit costs. The following results were obtained: (1) The RS and the ST reactor can double the energy gain and reduce CO 2 emission by one-half compared with the ITER-like reactor. (2) Silicon carbide (SiC) used as the structural material of inner vessel components is best for energy gain and CO 2 emission reduction. (3) The ITER-like reactor is slightly superior to a photovoltaic (PV) with regard to CO 2 emission. (4) The energy gain and CO 2 emission intensity of the RS reactor and the ST reactor are as excellent as those of a fission reactor and a hydro-Powered generator. These results indicate that a tokamak Fusion Power reactor can be one of the most effective Power-generating technologies both in high-energy payback gains and reduction of CO 2 .
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evaluation of co2 emissions in the life cycle of tokamak Fusion Power reactors
Nuclear Fusion, 2000Co-Authors: K Tokimatsu, Kunihiko Okano, Y Ogawa, Hiroki Hondo, Kenji Yamaji, Makoto KatsuraiAbstract:Global warming is one of the most serious problems which human beings are currently facing. Carbon dioxide (CO2) from Power plants is considered one of the major causes of global warming. In the present study, CO2 emissions from tokamak Fusion Power plants are compared with those from present Power generating technologies. Plasma parameters are calculated by a systems code that couples the ITER physics, toroidal field coil shape and cost calculation. CO2 emissions from construction and operation are evaluated by multiplying component volume by the CO2 emission intensities of the component materials. The reactor building, balance of plant, etc., are scaled from the ITER reference Power reactor (`ITER-like') by use of the Generomak model. The most important finding is that CO2 emissions from Fusion reactors are less than those from photovoltaic systems and less than double those from fission reactors. The other findings are that: (i) Most CO2 emissions from Fusion reactors are from materials. (ii) CO2 emissions from reactor construction account for almost 60-70% of the total, with the rest coming from reactor operation. (iii) The reversed shear reactor can reduce CO2 emissions by half compared with the ITER-like reactor. It is concluded that tokamak Fusion reactors are excellent for their low CO2 emission intensity, and that they can be one of the effective energy supply technologies to solve global warming.
D J Ward - One of the best experts on this subject based on the ideXlab platform.
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process a systems code for Fusion Power plants part 1 physics
Fusion Engineering and Design, 2014Co-Authors: M Kovari, R Kemp, P Knight, J Morris, D J WardAbstract:Abstract PROCESS is a reactor systems code – it assesses the engineering and economic viability of a hypothetical Fusion Power station using simple models of all parts of a reactor system, from the basic plasma physics to the generation of electricity. It has been used for many years, but details of its operation have not been previously published. This paper describes some of its capabilities. PROCESS is usually used in optimisation mode, in which it finds a set of parameters that maximise (or minimise) a figure of merit chosen by the user, while being consistent with the inputs and the specified constraints. Because the user can apply all the physically relevant constraints, while allowing a large number of parameters to vary, it is in principle only necessary to run the code once to produce a self-consistent, physically plausible reactor model. The scope of PROCESS is very wide and goes well beyond reactor physics, including conversion of heat to electricity, buildings, and costs, but this paper describes only the plasma physics and magnetic field calculations. The capabilities of PROCESS in plasma physics are limited, as its main aim is to combine engineering, physics and economics. A model is described which shows the main plasma features of an inductive ITER scenario. Significant differences between the PROCESS results and the published scenario include the bootstrap current and loop voltage. The PROCESS models for these are being revised. Two new models for DEMO have been obtained. The first, DEMO A, is intended to be “conservative” in that it might be possible to build it using the technology of the near future. For example, since current drive technologies are not yet mature, only 12% of the current is assumed to be due to current drive. Consequently it is a pulsed machine, able to burn for only 1.65 hours at a time. Despite the comparatively large size (major radius is 9 m), the Fusion Power is only 1.95 GW. The assumed gross thermal efficiency is 33%, giving just 465 MW net electric Power. The second, DEMO B, is intended to be “advanced” in that more optimistic assumptions are made. Comparison of DEMO A and B with a reference ITER scenario shows that current drive and bootstrap fraction need the most extrapolation from the perspective of plasma physics.
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analysing the role of Fusion Power in the future global energy system
European Physical Journal Web of Conferences, 2012Co-Authors: Helena Cabal, Yolanda Lechon, U Ciorba, Francesco Gracceva, T Eder, Thomas Hamacher, Antti Lehtila, Markus Biberacher, Poul Erik Grohnheit, D J WardAbstract:This work presents the EFDA Times model (ETM), developed within the European Fusion Development Agreement (EFDA). ETM is an optimization global energy model which aims at providing the optimum energy system composition in terms of social wealth and sustainability including Fusion as an alternative technology in the long term. Two framework scenarios are defined: a Base case scenario with no limits to CO2 emissions, and a 450ppm scenario with a limit of 450ppm in CO2-eq concentrations set by 2100. Previous results showed that in the Base case scenario, with no measures for CO2 emission reductions, Fusion does not enter the energy system. However, when CO2 emission restrictions are imposed, the global energy system composition changes completely. In a 450ppm scenario, coal technologies disappear in a few decades, being mainly replaced by nuclear fission technologies which experience a great increase when constrained only by Uranium resources exhaustion. Fission technologies are then replaced by the Fusion Power plants that start in 2070, with a significant contribution to the global electricity production by 2100. To conclude the work, a sensitivity analysis will be presented on some parameters that may affect the possible role of Fusion in the future global energy system.
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the economic viability of Fusion Power
Symposium On Fusion Technology, 2005Co-Authors: D J Ward, I Cook, Yolanda Lecho, R SaezAbstract:Although Fusion Power is being developed because of its large resource base, low environmental impact and high levels of intrinsic safety, it is important to investigate the economics of a future Fusion Power plant to check that the electricity produced can, in fact, have a market. The direct cost of electricity of a Fusion Power plant and its key dependencies on the physics and technology assumptions, are calculated, as are the materials requirements. The other important aspect of costs, the external costs which can arise from effects such as pollution, accidents and waste are also given. Fusion is found to offer the prospect of a new energy source with acceptable direct costs and very low external costs. This places Fusion in a strong position in a future energy market, especially one in which environmental constraints become increasingly important.
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european Fusion Power plant studies
Fusion Science and Technology, 2005Co-Authors: I Cook, D J Ward, L Giancarli, P Norajitra, D Maisonnier, N P Taylor, P Sardain, L Di Pace, S Hermsmeyer, R A ForrestAbstract:The European Power Plant Conceptual Study (PPCS) reported in the summer of 2004. Several conceptual designs (Models') for commercial Fusion Power plants were developed, spanning a range from relatively near term to more substantial extrapolations. The parameters of the Models were chosen by systems analysis to be economically optimal, given the assigned constraints on plasma and technology performance. The conceptual designs were developed in some detail and analyses were made of their safety, environmental impacts and economic performance. The calculated cost of generating electricity from the Models is in the range of published estimates for the future costs from other sources. Even the near-term Models are economically viable. External costs are very low, for all the Models: similar to wind Power and much less than for fossil fuels. Economic optimization of the designs did not jeopardize their safety and environmental performance. All the Models proved to have the attractive and substantial safety and environmental advantages found in earlier studies, now established with greater confidence.
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implications of Fusion Power plant studies for materials requirements
Plasma Physics and Controlled Fusion, 2002Co-Authors: I Cook, D J Ward, S L DudarevAbstract:This paper addresses the key requirements for Fusion materials, as these have emerged from studies of commercial Fusion Power plants. The objective of the international Fusion programme is the creation of Power stations that will have very attractive safety and environmental features and viable economics. Fusion Power plant studies have shown that these objectives may be achieved without requiring extreme advances in materials. But it is required that existing candidate materials perform at least as well as envisaged in the environment of Fusion neutrons, heat fluxes and particle fluxes. The development of advanced materials would bring further benefits. The work required entails the investigation of many intellectually exciting physics issues of great scientific interest, and of wider application than Fusion. In addition to giving an overview, selected aspects of the science, of particular physics interest, are illustrated.
A E Costley - One of the best experts on this subject based on the ideXlab platform.
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on the Fusion triple product and Fusion Power gain of tokamak pilot plants and reactors
Nuclear Fusion, 2016Co-Authors: A E CostleyAbstract:The energy confinement time of tokamak plasmas scales positively with plasma size and so it is generally expected that the Fusion triple product, nTτ E, will also increase with size, and this has been part of the motivation for building devices of increasing size including ITER. Here n, T, and τ E are the ion density, ion temperature and energy confinement time respectively. However, tokamak plasmas are subject to operational limits and two important limits are a density limit and a beta limit. We show that when these limits are taken into account, nTτ E becomes almost independent of size; rather it depends mainly on the Fusion Power, P fus. In consequence, the Fusion Power gain, Q fus, a parameter closely linked to nTτ E is also independent of size. Hence, P fus and Q fus, two parameters of critical importance in reactor design, are actually tightly coupled. Further, we find that nTτ E is inversely dependent on the normalised beta, β N; an unexpected result that tends to favour lower Power reactors. Our findings imply that the minimum Power to achieve Fusion reactor conditions is driven mainly by physics considerations, especially energy confinement, while the minimum device size is driven by technology and engineering considerations. Through dedicated R&D and parallel developments in other fields, the technology and engineering aspects are evolving in a direction to make smaller devices feasible.
E A Lazarus - One of the best experts on this subject based on the ideXlab platform.
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higher Fusion Power gain with profile control in diii d tokamak plasmas
Nuclear Fusion, 1997Co-Authors: E A Lazarus, G A Navratil, C M Greenfield, E J Strait, M E Austin, K H Burrell, T A Casper, D R Baker, J C DebooAbstract:Strong shaping, favourable for stability and improved energy confinement, together with a significant expansion of the central region of improved confinement in negative central magnetic shear target plasmas, increased the maximum Fusion Power produced in DIII-D by a factor of 3. Using deuterium plasmas, the highest Fusion Power gain, the ratio of Fusion Power to input Power, Q, was 0.0015, corresponding to an equivalent Q of 0.32 in a deuterium-tritium plasma, which is similar to values achieved in tokamaks of larger size and magnetic field. A simple transformation relating Q to the stability parameters is presented
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higher Fusion Power gain with current and pressure profile control in strongly shaped diii d tokamak plasmas
Physical Review Letters, 1996Co-Authors: E A Lazarus, G A Navratil, C M Greenfield, E J Strait, M E Austin, K H Burrell, T A Casper, D R Baker, J C Deboo, E J DoyleAbstract:Author(s): Lazarus, EA; Navratil, GA; Greenfield, CM; Strait, EJ; Austin, ME; Burrell, KH; Casper, TA; Baker, DR; DeBoo, JC; Doyle, EJ; Durst, R; Ferron, JR; Forest, CB; Gohil, P; Groebner, RJ; Heidbrink, WW; Hong, R; Houlberg, WA; Howald, AW; Hsieh, C; Hyatt, AW; Jackson, GL; Kim, J; Lao, LL; Lasnier, CJ; Leonard, AW; Lohr, J; La Haye RJ; Maingi, R; Miller, RL; Murakami, M; Osborne, TH; Perkins, LJ; Petty, CC; Rettig, CL; Rhodes, TL; Rice, BW; Sabbagh, SA; Schissel, DP; Scoville, JT; Snider, RT; Staebler, GM; Stallard, BW; Stambaugh, RD; St John HE; Stockdale, RE; Taylor, PL; Thomas, DM; Turnbull, AD; Wade, MR; Wood, R; Whyte, D | Abstract: Fusion Power has been increased by a factor of 3 in DIII-D by tailoring the pressure profile to avoid the kink instability in H-mode plasmas. The resulting plasmas are found to have neoclassical ion confinement. This reduction in transport losses in beam-heated plasmas with negative central shear is correlated with a dramatic reduction in density fluctuations. Improved magnetohydrodynamic stability is achieved by controlling the plasma pressure profile width. In deuterium plasmas the highest gain Q (the ratio of Fusion Power to input Power), was 0.0015, corresponding to an equivalent Q of 0.32 in a deuterium-tritium plasma. © 1996 The American Physical Society.
N Baluc - One of the best experts on this subject based on the ideXlab platform.
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first principles modeling of tungsten based alloys for Fusion Power plant applications
Key Engineering Materials, 2011Co-Authors: Duc Nguyen Manh, M. Muzyk, K J Kurzydlowski, N Baluc, M Rieth, S L DudarevAbstract:We describe a comprehensive ab initio investigation of phase stability and mechanical properties of W-Ta and W-V alloys, which are candidate materials for Fusion Power plant applications. The ab initio density functional calculations compare enthalpies of mixing for alternative ordered atomic structures of the alloys, corresponding to the same chemical composition. Combining the ab initio data with large-scale lattice Monte-Carlo simulations, we predict several low-energy intermetallic compounds that are expected to dominate alloy microstructures, and hence the low-temperature phase diagrams, for both alloys. Using the predicted ground-state atomic alloy configurations, we investigate the short-range order, point defect (vacancy and self-interstitial atoms) energies, and thermodynamic and mechanical properties of W alloys as functions of their chemical composition. In particular, we evaluate the anisotropic Young modulus for W-Ta and W-V alloys from ab initio elastic constant calculations, with the objective of comparing the predicted values with experimental micro-cantilever measurements. Also, using the calculated Poisson ratios for binary W alloys, which combine tungsten with more than 40 different alloying elements, we investigate if alloying improves the ductility of tungsten-based materials.
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status of r d activities on materials for Fusion Power reactors
Nuclear Fusion, 2007Co-Authors: N Baluc, K Abe, J L Boutard, V M Chernov, E Diegele, S Jitsukawa, Akihiko Kimura, R L Klueh, Akira Kohyama, Richard J KurtzAbstract:Current R&D activities on materials for Fusion Power reactors are mainly focused on plasma facing, structural and tritium breeding materials for plasma facing (first wall, divertor) and breeding blanket components. Most of these activities are being performed in Europe, Japan, the People's Republic of China, Russia and the USA. They relate to the development of new high temperature, radiation resistant materials, the development of coatings that will act as erosion, corrosion, permeation and/or electrical/MHD barriers, characterization of candidate materials in terms of mechanical and physical properties, assessment of irradiation effects, compatibility experiments, development of reliable joints, and development and/or validation of design rules. Priorities defined worldwide in the field of materials for Fusion Power reactors are summarized, as well as the main achievements obtained during the last few years and the near-term perspectives in the different investigation areas.
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materials for Fusion Power reactors
Plasma Physics and Controlled Fusion, 2006Co-Authors: N BalucAbstract:The present paper reviews the status of the knowledge on materials for Fusion Power plants, pointing out that they constitute one of the main key issues on the path to future reactors. Specific issues concerning plasma-facing materials, functional materials and structural materials are successively reviewed. The main candidate materials are presented, with emphasis on the remaining open issues in the field of selection and qualification of materials for Fusion Power reactors.
