ISSN:
1572-9591
Keywords:
systems
;
fusion reactor
;
economics
;
tokamak
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
Notes:
Abstract A simplified physics, engineering, and costing model of a tokamak fusion reactor is used to examine quantitatively the connection between physics performance and power-plant economics. The material contained herein was generated as part of a broader study of the economic, safety, and environmental impact of fusion based on a range of confinement schemes, fusion fuels, blanket/shield configurations, power-conversion schemes, and commercial end products. Only a DT-fuelled tokamak reactor that produces electricity through an intermediate heat exchange and a conventional thermal-electric conversion cycle is considered; a self-cooled lithium-metal blanket with vanadium-alloy structure, steel shield, and superconducting magnets is used for all cases studied. An optimistic extension of Troyon scaling is applied to a high-elongation (κ = 2.5) and low-safety-factor (q ψ =2.3) plasma with β=0.1 and efficient (I φ P CD =0.2 A/W) current drive. This 1200-MWe (net) power plant provides an economically competitive base case with which to compare other approaches to tokamak fusion power. The base case chosen for comparisons represents an optimistic extrapolation of present tokamak physics and technology. Troyon scaling with a coefficientβ B φ a/I φ equal to 0.04 is applied; the impact of an ad hoc but pessimistic scaling that diminished the Troyon coefficient with plasma elongation was also examined. Additionally, a constant current-drive efficiency, ϒ=nI φ R T /P CD =0.2 A/W, atT=10 keV plasma temperature is assumed; although representing an aggressive R&D target relative to present experience, the realization of bootstrap currents for the basecase, and especially for the second-stability-region tokamak, can significantly reduce this problem. The impact and reoptimization for a constant normalized current-drive efficiency, ϒ=nI φ R T/P CD, was also examined. Although the focus of this study has been the optimistic basecase tokamak, comparisons are made with tokamaks based on (a) operation in the second-stability region (β=0.2, increased aspect ratio, reduced elongation), (b) super high-field but low-beta operation, (c) very low aspect ratio and highly elongated spherical torus, and (d) a direct application of the present database using a long-pulsed, low-beta tokamak. The economic impact of a range of base-case parameters and operating variables is examined, including current-drive efficiency, beta, stability limits, advanced magnets, economy of scale, blanket/shield lifetime, blanket thickness, and plant lead time. It is found that a range of tokamak options, relative to the optimistic base case selected for this study, may provide economically competitive power plants. Areas where physics and technology advances are needed to achieve this attractive end product are quantitively elucidated for all tokamak options considered.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01108258
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