Beam Driven Tokamak Fusion Reactors

The recent successes in neutral beam current drive experiments on large tokamaks prompt us to consider the prospect of a beam driven steady state tokamak fusion reactor. A neo-classical theory on the beam driven current, which fully includes the toroidal effects on the induced ion and electron currents and is the most reliable to date, is reviewed in this article. The prospect of steady state tokamaks predicted by the theory may be somewhat pessimistic if the plasma current is sustained only by the beam driven current, because too much beam power is necessary for the current drive. However, thanks to the bootstrap current which was discovered in many tokamaks in recent years, the feasibility of a continuous tokamak operation will probably be highly improved because several tens of percent of the current will be produced by the bootstrap current. The energy gain Q would attain 30 to 50 in the power reactor and about 10 even for next generation (demonstration size) tokamaks.     

Development of Dust Removal System Using Static Electricity for Fusion Experimental Reactors

Tests to collect and transport metallic and non-metallic dust particles have been conducted using static electricity in a vacuum environment to investigate the applicability of a static electricity dust removal system for fusion experimental reactors. The dust particles are charged by electrostatic induction, floated and collected due to the Coulomb force generated by the AC electric field. They are then transported due to the gradient force induced by the electric curtain of the non-uniform travelling-wave electric field. Using a fully insulated electrode with a single-phase AC voltage up to 15kV, aluminum and carbon dust were successfully collected. The highest collection rates for the aluminum and carbon dust were around 30 and 2g/min, respectively. The linear-type electrodes, using as high as 22kV of the three-phase AC voltage, transported aluminum dust up to an angle of 60°. Applying a guide electrode to the linear-type electrode, the transportation rate was approximately doubled and almost constant at every angle, including a 90° angle. The system transported aluminum dust up to the rate of 13 g/min. The influence of the 0.15 T magnetic field on the dust collection and transportation efficiencies was found to be negligible.     

A Review on the Potential Use of Austenitic Stainless Steels in Nuclear Fusion Reactors

Various engineering materials; austenitic stainless steels, ferritic/martensitic steels, vanadium alloys, refractory metals and composites have been suggested as candidate structural materials for nuclear fusion reactors. Among these structural materials, austenitic steels have an advantage of extensive technological database and lower cost compared to other non-ferrous candidates. Furthermore, they have also advantages of very good mechanical properties and fission operation experience. Moreover, modified austenitic stainless (Ni and Mo free) have relatively low residual radioactivity. Nevertheless, they can’t withstand high neutron wall load which is required to get high power density in fusion reactors. On the other hand, a protective flowing liquid wall between plasma and solid first wall in these reactors can eliminate this restriction. This study presents an overview of austenitic stainless steels considered to be used in fusion reactors.     

Management and Disposal of Waste from Fusion Power Reactors—Comparisons Between Different Blanket Designs

This paper gives results from a waste study performed for future fusion power station designs. The study has been carried out within the European Program on the Safety and Environmental Assessment of fusion power, Long-term (SEAL). Five different blanket designs were compared from the standpoint of waste. Results are given for comparisons regarding primary waste quantities, radiological hazards, chemical hazards, repository volumes required, and doses from repositories. The repository volumes required were compared for a hypothetical German scenario and the doses from repositories were compared for hypothetical French and Swedish scenarios.     

Fusion: Pathways to the Future

Presentations from a Fusion Power Associates (FPA) symposium, Fusion: Pathways to the Future, are summarized. The topics include an overview of the U.S. Department of Energy policies, status and plans for inertial fusion and ITER, and the role of alternate concepts in fusion development. Copies of the presentations are posted at     

Conceptual Designs of Tokamak Fusion Reactors

Tokamak fusion reactor design studies conducted in JAERI with support from national laboratories, universities and industries in the fifteen years since 1973 to the present are described. These studies gave considerable impact on the national and international fusion programs.

From the proposal of He-cooled Li²0 blanket for fusion power reactor in 1973 to the most recent proposal of easily replaceable guard limiter concept to the ITER project, a number of unique proposals that have influenced the world wide fusion reactor design studies are introduced. They are described in the context of major fusion reactor design efforts and design methodology developments of the past fifteen years.     

聚变数据库系统FusionDB研发与应用

聚变研究和设计是一项需国内外广泛合作的系统工程,积累和共享数据是当前重要任务。为了更好地整合聚变数据,FDS团队设计和研发了集聚变数据和数据处理与分析软件于一体的聚变数据库系统FusionDB,系统涵盖了聚变堆设计与安全分析关键数据,是国际上首个包括核数据、材料数据、部件数据、聚变物理实验数据以及核计算仿真和可靠性与概率安全分析等功能的综合型聚变数据库系统。FusionDB已应用于国际热核聚变实验堆ITER、中国科学院FDS系列聚变堆概念设计与研究中。     

Frontiers in Fusion Research

Presentations that were made at a Fusion Power Associates symposium, Frontiers in Fusion Research, are summarized. Discussions include the science frontiers of burning plasma physics, magnetic fusion concepts, inertial fusion concepts, and fusion technology.     

聚变堆第一壁涂层材料

由于使用低Z涂层材料可使传统的结构材料和技术保持不变并能降低等离子体杂质,因而为设计提供了灵活性。低Z涂层可由元素Be,B,C,Al,Ti,V及其化合物中选择。文中介绍了涂层工艺和评价方法。添加约10wt%SiC的热解碳几乎能完全抑制化学溅射。60块C+SiC涂层石墨砖在DoubletⅢ托卡马克的整个照射期间性能令人满意。     

脉冲堆动态引发过程中初始反应性的测量

提出了脉冲堆动态引发过程中初始反应性测量的当量外推方法,由逆动态反应性测量系统、控制棒定位监测系统和裂变脉冲波形测量系统共同获得的数据而得到系统的反应性。此方法在裂变脉冲动态引发实验中成功地得到了应用,获得了初始反应性及其分布。     

External Factors Affecting Fusion Energy Development

A number of external factors affecting the pace and direction of fusion energy development are reviewed and discussed. These include the changing electric utility marketplace environment, the availability of fossil fuels, competing power sources, and environmental issues.     

重水堆钍铀燃料增殖循环方案研究

论文的目的是研究重水堆钍铀燃料增殖循环方案。基于前期设计的技术路线,以CANDU-6堆芯为参考堆芯,研究了钍基堆芯燃料管理策略,分析了中子学特性,并对乏燃料特性进行了评估,包括放射性毒性、衰变热和伽马射线。在此基础上,建立了钍铀燃料增殖循环方案,其在可持续性关键指标方面优于常规天然铀一次通过循环。     

Fusion Power by Magnetic Confinement Program Plan

This report has been available previously only as Volume I of a 5-volume U.S. Energy Research and Development Administration Report ERDA-76/110 (1976). It was the first comprehensive U.S fusion development plan. It treats the technical, schedular and budgetary projections for the development of fusion power using magnetic confinement. It provided the basis for the U. S. fusion facility and funding commitments during the latter half of the 1970's and is published now to archive its historical significance.     

Nonelectric Applications of Fusion

This is the final report of a panel set up by the U.S. Department of Energy (DOE) Fusion Energy Sciences Advisory Committee (FESAC) in response to a charge letter from Dr. James Decker, Acting Director of the DOE Office of Science. In that letter, Dr. Decker asked FESAC to consider whether the Fusion Energy Sciences program should broaden its scope and activities to include non-electric applications of intermediate-term fusion devices. This report, submitted to FESAC July 31, 2003, and subsequently approved by them (Appendix B), presents FESAC's response to that charge.     

Concept of Erbium Doped Uranium Oxide Fuel Cycle in Light Water Reactors

This paper is aimed at the development of a fuel cycle concept for host countries with a lack of nuclear infrastructure. To minimize plutonium proliferation concern the adoption of long-life core with no fuel radiochemical treatment on site is suggested. Current investigation relies upon light water reactor technology and plutonium-free fresh fuel. Erbium doped to uranium oxide (enrichment 19.8%) fuel is selected as the reference. Such a high enrichment is selected in attempt to approach the longest irradiation time in one batch mode. In addition to that, uranium enriched up to 20% does not consider as a nuclear material for direct use in weapon manufacture. A sequence of two irradiation cycles for the same fuel rods in two different light water reactors is the key feature of the advocated approach. It is found that the synergism of PWR and pressure tube graphite reactor offers fuel burnup up to 140GWd/tHM without compromising safety characteristics. Being as large as 8% in the final isotopic vector, fraction of ²³⁸Pu serves as an inherent protective measure against plutonium proliferation.     

Fusion Energy Without Strong Nuclear Radiation

Conventional quantum mechanics calculation shows that fusion energy without strong nuclear radiation is feasible, because this is the nature of sub-barrier nuclear fusion. When the Coulomb barrier is relatively thin and low, the resonant tunneling would select the fusion reaction with strong neutron and Gamma radiation. On the other hand, if the Coulomb barrier is thick and high, the resonant tunneling would select the fusion reaction without strong neutron and Gamma radiation. Thus, fusion energy with lowest radiation is predictable in terms of d + t fusion data. This is the harmony between various approaches towards fusion energy. What we lose is the assumption of compound nucleus model for light nuclei fusion, and what we gain is the fusion energy without strong neutron and Gamma radiation.     

Status and Objectives of Tokamak Systems for Fusion Research

This report had its beginnings at the Third International Symposium on Toroidal Plasma Confinement held in Garching/Munich, Federal Republic of Germany, March 26–30, 1973. The American scientists who attended this conference agreed to assist in preparing a summary of the status of the field. Since that time, the authors of this report have had the opportunity to incorporate progress reported at the VI European Conference on Plasma Physics and Controlled Fusion, held in Moscow, U.S.S.R., from July 29 to August 3, 1973. The report has been available previously only as U.S. Atomic Energy Commission Report WASH-1295 (1974). It was the first comprehensive survey of the status of the tokamak fusion research concept, which was to become the cornerstone of the world fusion effort for the next quarter century. It provided the basis for the rapid buildup of the U.S. tokamak program during the latter half of the 1970's and is published now to archive its historical significance.     

D-T Beam Fusion Reactor

The Beam Fusion Reactor (BFR) is based on a field-reversed configuration and confined ion energies in the range of hundreds of keV. Repetitively pulsed, intense ion beams sustain the ion distributions and provide current drive. In the BFR the ion orbit size is comparable to the dimensions of the confined plasma and the expectation is for classical transport of the particles and energy. Based on technologies that readily exist, or nearly so, a D-T fueled BFR could be assembled in a compact configuration that is scaleable in terms of its output energy as well as to the advanced fuel regime. In the simplest case the mean azimuthal velocities and temperatures of the two ion (fuel) species are equal and the plasma current is unneutralized by electrons; the resulting distribution functions are thermal in a moving frame of reference. Reactor kinetic calculations are based on the Vlasov-Maxwell equation, including a Fokker Planck collision operator and all sources and sinks for energy and particle flow. The quality factor for this system is projected to be: Q P _fusion /P _{bremsstrahlung} = 104.     

Minor Actinide Transmutation Potential of Modified PROMETHEUS Fusion Reactor

This study presents the investigation of the burning and/or transmutation (B/T) of minor actinides (MAs) in the modified PROMETHEUS-H fusion reactor. The calculations were performed for an operation period (OP) of up to 10 years by 75% plant factor () under a neutron wall load (P) of 4.7 MW/m². In order to incinerate and transmute the MAs effectively, the transmutation zone (TZ) containing the mixture of MA nuclides, discharged from the pressured water reactor (PWR)-MOX spent fuel, was located in the modified blanket of the PROMETHEUS-H fusion reactor. Two different blanket modifications were considered, (the Models A and B). The MA mixture was spherically prepared and cladded with SiC to prevent fission products from contaminating coolant and the MAs from contacting coolant. Helium was selected for the nuclear heat transfer in the TZ. The effect of the MA volume fraction in the TZ on the B/T was also investigated. The results bring out that the MAs are converted by the transmutation rather than the incineration. Bothmodels can reduce significantly the effective half-lives of the MA nuclides by burning and/or transmuting these nuclides, and at the same time produce substantial electricity insitu.     

钠沸腾数学模型及其在BE+1上的验证

快堆在发生单个燃料组件瞬间完全堵流事故时,会引起堆芯内的冷却剂沸腾.钠沸腾所形成的压力和物质分布对后期事故的发展有重要影响.为了对事故进行总体性分析,本文选择两流体六方程模型,用子通道的方法进行网格划分,用D. R. Liles等人开发的半隐数值方法进行求解;在法国的BE 1实验中进行了模型验证;根据计算结果,对事故下钠的两相热工水力行为进行了解释.