An accelerated fusion power development plan

Energy for electricity and transportation is a national issue with worldwide environmental and political implications. The world must have energy options for the next century that are not vulnerable to possible disruption for technical, environmental, public confidence, or other reasons. Growing concerns about the greenhouse effect and the safety of transporting oil may lead to reduced burning of coal and other fossil fuels, and the incidents at Three Mile Island and Chernobyl, as well as nuclear waste storage problems, have eroded public acceptance of nuclear fission. Meeting future world energy needs will require improvements in energy efficiency and conservation. However, the world will soon need new central station power plants and increasing amounts of fuel for the transportation sector. The use of fossil fuels, and possibly even fission power, will very likely be restricted because of environmental, safety, and, eventually, supply considerations. Time is running out for policymakers. New energy technologies cannot be brought to the marketplace overnight. Decades are required to bring a new energy production technology from conception to full market penetration. With the added urgency to mitigate deleterious environmental effects of energy use, policymakers must act decisively now to establish and support vigorous energy technology development programs. The U.S. has invested $8 billion over the past 40 years in fusion research and development. If the U.S. fusion program proceeds according to its present strategy, an additional 40 years, and more money, will be expended before fusion will provide commercial electricity. Such an extended schedule is neither cost-effective nor technically necessary. It is time to launch a national venture to construct and operate a fusion power pilot plant. Such a plant could be operational within 15 years of a national commitment to proceed.Prepared Under Contract for the Agency for Advancement of Fusion Power, Inc., George S. Clemens, President.     

Commercial objectives,technology transfer,and systems analysis for fusion power development

Fusion is an essentially inexhaustible source of energy that has the potential for economically attractive commercial applications with excellent safety and environmental characteristics. The primary focus for the fusion-energy development program is the generation of centralstation electricity. Fusion has the potential, however, for many other applications. The fact that a large fraction of the energy released in a DT fusion reaction is carried by high-energy neutrons suggests potentially unique applications. These include breeding of fissile fuels, production of hydrogen and other chemical products, transmutation or burning of various nuclear or chemical wastes, radiation processing of materials, production of radioisotopes, food preservation, medical diagnosis and medical treatment, and space power and space propulsion. In addition, fusion R&D will lead to new products and new markets.Each fusion application must meet certain standards of economic and safety and environmental attractiveness. For this reason, economics on the one hand, and safety and environment and licensing on the other hand, are the two primary criteria for setting long-range commercial fusion objectives. A major function of systems analysis is to evaluate the potential of fusion against these objectives and to help guide the fusion R&D program toward practical applications. The transfer of fusion technology and skills from the national laboratories and universities to industry is the key to achieving the long-range objective of commercial fusion applications.     

冷聚变实验探索

采用电解法和氘气吸附法研究了冷聚变现象。在一次电解实验中,电解开始后约90h,长中子计算器和液体闪烁中子计数器中都同时观察到一个持续时间达4h、峰值强度为400聚变/s的中子讯号。长中子计数器和液体闪烁计数器的计数均比本底高15倍,液体闪烁计数器同时记录了2.45MeV中子的反冲质子能谱。     

Nuclear fission power for 21st century needs: Enabling technologies for large-scale, low-risk, affordable nuclear electricity

We examine the principal concerns regarding provision of a large fraction of human energy needs with nuclear fission reactor-derived electricity, and offer robust physics and engineering responses to each of them. We then propose a representative system-level integration of these solutions to the longstanding problems that have confronted nuclear fission-based power. This integration obviates all fuel supply issues, including the entire set of isotopic enrichment ones, while rendering comparably useful as nuclear fuels all of the actinide elements and isotopes. It entirely avoids transport and reprocessing and the full set of ad hoc waste disposal issues, and completely precludes all those involving proliferation/diversion of fissile isotopes into weapons' programs. It offers high-grade heat in pressurized helium gas for thermodynamically efficient, economically appealing, environmentally attractive combined-cycle conversion to electricity while robustly avoiding prospects of internal overheating of any portion of the reactor's core or fuel. It provides highly redundant means of any desired statistical reliability for prevention of core meltdown in LOCA circumstances. It provides zero biospheric hazard in event of either natural or man-made catastrophe. It requires – indeed, admits of – no operator control actions, other than initial start-up and final shutdown commands, so that operator errors are entirely precluded; during the half-century of potentially full-power operational life in between these two commands, it thermostatically regulates in an entirely automatic manner its own nuclear power generation to match the heat removed from its core in a time-varying fashion. The thorium-burning variant of this new class of reactors involves no long-lived actinide isotopes, thereby obviating a present-day keystone issue of long-term reactor waste storage and disposal. Each of these novel features is technologically separable, so that these new reactor design concepts may be applied piecewise to enhance prospects of nuclear reactor-centered power generation in many different utilization circumstances. However, synergisms arising from their full integration seem likely to be compellingly attractive in most situations, for a constellation of economic and safety reasons. We therefore project a bright future for cheap electricity safely obtained in >10 TWe quantities from nuclear power reactors of this new type, moreover over multi-century time frames. We observe that pertinent aspects of neutron physics and modern technology together offer a far richer spectrum of possibilities for nuclear power reactors than has been significantly explored through the present; the present architecture is merely exemplary.     

Connections between physics and economics for Tokamak fusion power plants

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 ( = 2.5) and low-safety-factor (q =2.3) plasma with =0.1 and efficient (I 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 coefficient B a/I 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, =nI 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, =nI 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 (=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.     

聚变电站中工程能量增益与质量功率密度对发电成本的影响

从经济弹性角度详细分析了聚变电站中工程能量增益与堆体质量功率密度对发电成本的影响。由发电成本对工程能量增益与堆体质量功率密度的函数关系,导出了发电成本对工程能量增益与堆体质量功率密度的“弹性系数”,并由此进行发电成本对工程能量增益与堆体质量功率密度的敏感性分析。分析表明,工程能量增益或堆体质量功率密度越大,发电成本对它们的敏感性越差。     

The ARIES-AT advanced tokamak,Advanced technology fusion power plant

The ARIES-AT study was initiated to assess the potential of high-performance tokamak plasmas together with advanced technology in a fusion power plant and to identifying physics and technology areas with the highest leverage for achieving attractive and competitive fusion power in order to guide fusion R&D. The 1000-MWe ARIES-AT design has a major radius of 5.2 m, a minor radius of 1.3 m, a toroidal β of 9.2% (β_N = 5.4) and an on-axis field of 5.6 T. The plasma current is 13 MA and the current-drive power is 35 MW. The ARIES-AT design uses the same physics basis as ARIES-RS, a reversed-shear plasma. A distinct difference between ARIES-RS and ARIES-AT plasmas is the higher plasma elongation of ARIES-AT (κ_x = 2.2) which is the result of a “thinner” blanket leading to a large increase in plasma β to 9.2% (compared to 5% for ARIES-RS) with only a slightly higher β_N. ARIES-AT blanket is a simple, low-pressure design consisting of SiC composite boxes with a SiC insert for flow distribution that does not carry any structural load. The breeding coolant (Pb–17Li) enters the fusion core from the bottom, and cools the first wall while traveling in the poloidal direction to the top of the blanket module. The coolant then returns through the blanket channel at a low speed and is superheated to ∼1100 °C. As most of the fusion power is deposited directly into the breeding coolant, this method leads to a high coolant outlet temperature while keeping the temperature of the SiC structure as well as interface between SiC structure and Pb–17Li to about 1000 °C. This blanket is well matched to an advanced Brayton power cycle, leading to an overall thermal efficiency of ∼59%. The very low afterheat in SiC composites results in exceptional safety and waste disposal characteristics. All of the fusion core components qualify for shallow land burial under U.S. regulations (furthermore, ∼90% of components qualify as Class-A waste, the lowest level). The ARIES-AT study shows that the combination of advanced tokamak modes and advanced technology leads to an attractive fusion power plant with excellent safety and environmental characteristics and with a cost of electricity (4.7 ¢/kWh), which is competitive with those projected for other sources of energy.     

Cold fusion—Engineering perspectives

Considerable heat was liberated from a palladium-deuterium (Pd-D) system and this was attributed to cold nuclear fusion of deuterium within the palladium lattice.¹ The primary source of heat in cold fusion was proposed to be the work-of-fracture of cracks in the Pd electrodes, and the mechanism for crack initiation and propagation was identified as deuterium or hydrogen embrittlement.² In this paper, comparable characteristics of cold fusion and embrittlement are established, relevant aspects of the extensive engineering database on hydrogen and deuterium embrittlement are reviewed, some areas of study and applications of the cold fusion process are identified, and parameters for controlling the ignition and heat release from metals are specified.This and related works have been fully sponsored by the author.     

聚变发电反应堆概念设计研究

在广泛分析聚变能相关领域研究发展状况和国际热核聚变实验堆(ITER)物理与技术基础上,提出了一个考虑了技术可行性的聚变发电反应堆概念(称之为FDS Ⅱ)。这个概念具有ITER参数适量外推的等离子体物理与技术水平的聚变堆芯和具有发展潜力的液态锂铅氚增殖包层,在对这个概念进行中子学、热工水力学、力学、安全与环境影响和经济学等一系列计算分析的基础上,给出了初步的概念设计和进一步设计优化的共性原则。     

Physics basis for the advanced tokamak fusion power plant, ARIES-AT

The advanced tokamak is considered as the basis for a fusion power plant. The ARIES-AT design has an aspect ratio of A≡R/a=4.0, an elongation and triangularity of κ=2.20,δ=0.90 (evaluated at the separatrix surface), a toroidal beta of β=9.1% (normalized to the vacuum toroidal field at the plasma center), which corresponds to a normalized beta of β_N≡100×β/(I_P(MA)/a(m)B(T))=5.4. These beta values are chosen to be 10% below the ideal MHD stability limit. The bootstrap-current fraction is f_BS≡I_BS/I_P=0.91. This leads to a design with total plasma current I_P=12.8  MA, and toroidal field of 11.1 T (at the coil edge) and 5.8 T (at the plasma center). The major and minor radii are 5.2 and 1.3 m. The effects of H-mode edge gradients and the stability of this configuration to non-ideal modes is analyzed. The current drive system consists of ICRF/FW for on-axis current drive and a Lower Hybrid system for off-axis. Transport projections are presented using the drift-wave based GLF23 model. The approach to power and particle exhaust using both plasma core and scrape-off-layer radiation is presented.     

Feasibility studies of D—^3He fusion power in China

The systematic study on D-3He advanced fuel fusion in China has been performed.Comparisons between D-3He and D-T fuel cycles in physics,engineering,environmental safety and so on have been made.D-3He fusion offers significant adavantages for reducing the neutron yield by a factor of 10-60,The 3He resource and mining possibility are investigated.The energy payback factor of 97 for mining lunar 3He resource is calculated.The operating parameter scope for D-3He fueled Tokamak reactor is analyzed.The prompt energy broadening for fusion products is calculated and results are consistent with those obtained by Lehner using a different method.Centrally peaked current drive with high efficiency is studied utilizing plasma synchrotron radiation.Centrally peaked current drive with gigh efficiency is studied utilizing plasma synchrotron radiation.More than 80% of plasma current required can be driven passively.A D-^3He fueled Tokamak commercial reactor-Mooncity was designed.Neutronics calculations show that the radioactivity,afterheat,BHP value for Mooncity are 10-60 times less than those for D-T fusion.     

Cold fusion — The heat mechanism

The assumption that deuterium, and not palladium, is the fuel in the Pons-Fleischmann experiments led to high expectations of cold nuclear fusion. The conversion of mechanical energy to heat was neglected in studying the phenomenon. Considerable strain energy is stored in metals when processed from the ore. The initiation, growth, and propagation of cracks in the bulk disturb the energy balance within the metal. Deuterium induces and propagates cracks in metals and alloys, including palladium. The sudden discharge of fracture energy during crack propagation generates considerable heat. The abundance of deuterium in cracked palladium will not continue the heat-generation process. The confident figures-of-merit of cold fusion have been based on the small energy input to the electrolytic cells and do not consider the substantial energy required to process (by melting) the palladium from the ore, or to recycle the cracked electrode samples. In this paper, the work-of-fracture is shown to be the likely mechanism responsible for the excess heat in cold fusion.This and related work have been fully sponsored by the author; Technical Consultant, 2868 Spring Chapel Court, Herndon, Virginia 22071.     

Design issues and implications for structural integrity of fusion power plant components

The criteria and implications for successful design, licensing and power plant operation are assessed, and imposed constraints and limitations are examined. The design of a reliable fusion power plant is dependent on the availability of licensed nuclear materials and the structural-thermal loading conditions during normal and abnormal events. Various conditions in a tokamak lead to structural damage and possible failure. Taking into consideration all the possible structural failure mechanisms, the most likely are combinations of fatigue and creep. Issues encountered in the fusion environment are the significant amount of irradiation creep, the large ratio of helium production to displacement damage, and the degradation of fatigue strength and ductility, effects which are even encountered at low temperatures. Design codes distinguish between failure criteria under steady and transient loads, and lay down rules for failure prediction under combined creep-fatigue conditions. Currently, there are no established fusion specific licensing processes or component design codes. Any limits imposed on designs or performance are taken from existing design codes developed by the fission industry. There is a need to initiate the process of defining and developing tools for the design and licensing of fusion components and facilities to ensure nuclear safety.     

An investigation of energy balances in palladium cathode electrolysis experiments

A series of experiments was performed at the Idaho National Engineering Laboratory (INEL) to investigate mechanisms that may contribute to energy flows in electrolysis cells like those of Fleischmann and Pons. Ordinary water (H₂O), heavy water (D₂O), and a mixture of the two were used in the INEL experiments. Cathodes used include a 51-m Pd foil and 1-mm diameter extruded wire Pd rods in straight and coiled configurations. Energy balances in these experiments revealed no significant net gain or net loss of energy. Cell overpotential curves were fit well with a Tafel equation, with parameters dependent on electrode configuration, electrolyte composition, and temperature. Water evaporation and interactions of hydrogen isotopes with the Pd cathode were evaluated and found not to be significant to energy balances. No ionizing radiation, tritium production, or other evidence of fusion reactions was observed in the INEL experiments.Work supported by U.S. Department of Energy, Director of Energy Research, under DOE Contract no. DE-AC07-76ID01570.     

An overview of the development of the first wall and other principal components of a laser fusion power plant

This paper introduces the JNM Special Issue on the development of a first wall for the reaction chamber in a laser fusion power plant. In this approach to fusion energy a spherical target is injected into a large chamber and heated to fusion burn by an array of lasers. The target emissions are absorbed by the wall and encapsulating blanket, and the resulting heat converted into electricity. The bulk of the energy deposited in the first wall is in the form of X-rays (1.0-100 keV) and ions (0.1-4 MeV). In order to have a practical power plant, the first wall must be resistant to these emissions and suffer virtually no erosion on each shot. A wall candidate based on tungsten armor bonded to a low activation ferritic steel substrate has been chosen as the initial system to be studied. The choice was based on the vast experience with these materials in a nuclear environment and the ability to address most of the key remaining issues with existing facilities. This overview paper is divided into three parts. The first part summarizes the current state of the development of laser fusion energy. The second part introduces the tungsten armored ferritic steel concept, the three critical development issues (thermo-mechanical fatigue, helium retention, and bonding) and the research to address them. Based on progress to date the latter two appear to be resolvable, but the former remains a challenge. Complete details are presented in the companion papers in this JNM Special Issue. The third part discusses other factors that must be considered in the design of the first wall, including compatibility with blanket concepts, radiological concerns, and structural considerations.     

Fusion News: 2005

This paper summarizes key 2005 news events in the development of fusion energy. Highlights include evolution and resolution of ITER siting decision, progress on construction of NIF, and passage of U.S. fusion budget for Fiscal Year 2006.     

Report of the FEAC Inertial Fusion Energy Review Panel: July 1996

This report presents the results and recommendations of the U. S. Department of Energy Fusion Energy Advisory Committee (FEAC) review of its Inertial Fusion Energy (IFE) program. The subpanel charged with the review was chaired by John Sheffield of Oak Ridge National Laboratory. The FEAC, to which the subpanel reported, was chaired by Robert Conn of the University of California at San Diego.     

Fusion News: 2006

This paper summarizes key 2006 news events in the development of fusion energy. Highlights include status of ITER project, progress on construction of NIF, and status of US fusion budget for Fiscal Year 2007.