Development Of Reactor Technology Research Articles

Requirements and status of fast neutron cross sections for nuclear fusion

This paper discusses some of the requirements of fast neutron cross sections for the development of tokamak fusion reactor technology and their current status. While considerable progress has been achieved in knowledge of fast neutron scattering and reaction cross sections of fusion reactor materials, much work needs still to be done particularly on double-differential neutron emission and neutron activation cross sections, in particular (n,α) cross sections. Particular consideration has been given to the work of Professor Csikai and co-workers who have rendered essential contributions to the measurement and analysis of 14 MeV neutron cross sections of importance to fusion.

Fusion Nuclear Technology Research and Development in Japan

This paper discusses how basic research in various fields of fusion reactor technology has been undertaken since the mid-1970s in Japan. The major topics in the early years were materials research, superconducting magnet technology, and tritium science and technology. Current fusion nuclear technology research and development activities in Japan come under two administrative frameworks: the Science and Technology Agency (STA) and the universities under the control of the Ministry of Education, Science, and Culture. The long-term plan for fusion nuclear reactor technology development is discussed.

Outcomes of Nuclear Technology Policy: Do Varying Political Styles Make a Difference?

ABSTRACTThe paper looks at the outcomes of nuclear technology policies in five advanced Western industrialised countries which have developed major nuclear construction industries. The genesis, development and dissemination of thermal nuclear reactors is examined and found to be influenced by a range of non-technical factors. Various concepts of ‘political styles’ are explored. Different styles of technological development are identified with reference to the networks of actors relevant to the development of thermal reactor technology, taking particular account of the resources of different actors and their interrelationship. Three distinctive styles are found, associated with three different technological outcomes, two of which are associated with policy success. We conclude that political styles do make a difference, but that their applicability to the explanation of outcomes of technology policy is dependent on the resources of individual actors and the specific demands set by the technological, economic and political context.

Conceptual Design of the Tritium Laboratory of the Karlsruhe Nuclear Research Centre

The Karlsruhe Research Centre (KfK) is engaged in research and development of fusion reactor technology including tritium technology. The planned activities concentrate mainly on the development of compoments of the fuel cycle. The necessary experiments and tests will be performed in a central laboratory. In a first phase, the laboratory will be equipped to handle 10 g of tritium; in a second phase, this amount will be increased to 200 g of tritium. The basic concept of the laboratory is described. Special attention is given to the design of the equipment for storage and handling, including the systems for tritium retention.

INTOR — A European View

This paper discusses INTOR, an international cooperative project which started in 1979. The project demonstrates Tokamak reactor physics and it serves as a test bed for the development of fusion reactor technology. Particular discussion is devoted to the INTOR physics data base and on the strategy of their generation. It is concluded that INTOR offers a chance to go to the next step within a reasonable time during which the data base will be improved. The INTOR design concept is shown to be very useful as a reference system for assessing the impact of innovative concepts.

Uranium resource appraisal: Past trends and outlook for adequacy of supply

As uranium has practically no other industrial uses besides electricity generation, demand is determined by the requirements and stockpiling policies of electric utilities. The uranium market has experienced strong fluctuations and is currently affected by the reductions in nuclear forecasts resulting from the slowdown in electricity demand. Analysing supply/demand indicators proves, however, that in retrospect the development has been relatively smooth and it appears that oversupply is more a consequence of overly optimistic short-term expectations. In the future, especially in the long term, nuclear power policies continue to be concerned with striking a proper balance between increasing production capability and development of new reactor technologies which would be less dependent on the availability of uranium. A bounding scenario approach is applied in this article to the assessment of adequacy of supply under varying assumptions on the total installed nuclear capacity, available resource base and attainable production capability.

Inelastic structural analysis of the mars tandem mirror reactor

The effects of radiation on the structural performance of fusion reactor structures is recognized as a major issue for the development of fusion reactor technology. Neutron irradiation changes the mechanical properties of structural components resulting in a general degradation of these properties. In addition to the mechanical loads (pressure and weight) and the thermal strains, non-uniform inelastic strain fields are induced by radiation swelling and creep in fusion structures. In this paper, we describe a new computer code, STAIRE, for ST ress A nalysis I ncluding R adiation E ffects. This code is based on standard beam theory for pipe-bends. The theory is modified in two areas: (1) consideration of the pipes' cross-section deformation as the radius of curvature changes; and (2) inclusion of inelastic radiation and thermal strains (swelling and creep). An efficient analytical/numerical approach is developed for the solution of indeterminate beam problems. As an application of the method, the stress distribution and deflections of toroidal blanket pipes in the Mirror Advanced Reactor Study (MARS) are evaluated. Swelling strains are identified as a major source of stress and deformation in the proposed blanket design, and possible solutions to the problem are outlined.

Preface: Fast Critical Facilities—Present Status and Future Potential

This article reviews fast critical assembly work conducted by experimental groups in the United States, Japan, England, France, and the Federal Republic of Germany. Topics considered include heterogeneous cores, control rods, the effects of accident-caused core distortions, the central reactivity worth discrepancy in US evaluations, and some methods to extrapolate results found in relatively small critical assemblies to large power reactors. The most important goal of future activities will be to extend as far as possible the reliability of neutronic analysis, which has now been achieved in applications to large reactor systems with their very high sensitivity of the spatial distribution of fluxes, reaction rates, and reactivity worths. It is concluded that given the continued development of fast reactor technology, there is a need for information that can only be provided by fast critical facilities.

An Overview of Inertial Fusion Reactor Design

Recent progress in the conceptual design of inertial fusion reaction chambers and power plants is reviewed. A discussion of expected operating parameters and a brief historical perspective are provided to organize the rich array of chamber and driver concepts. The technical feasibility of several reaction chamber concepts is discussed, along with technical issues that require future analysis, experiment, and development. Where these chambers have been integrated into a power plant design, the characteristics are described. Finally, requirements on the future development of inertial fusion reactor technology are discussed.

Worldwide nuclear-plant performance: Lessons for technology policy

The authors compare the performance of different reactor systems to identify the determinants of plant performance, to examine the evidence of technological maturation, and to discover the principal causes of outage or unavailability. In the light of the findings, they discuss the implications for the UK regarding reactor choice and technology development. They make no judgements about the relative merits of nuclear and fossil-fuel plants, or about safety.

The natural circulation solar heater-models with linear and nonlinear temperature distributions

Nuclear power plants generate heat, which is used to drive turbines connected to a generator that produces electricity. These plants are usually considered to cover base load stations. In this chapter, the main emphasis is on the fundamental aspects of nuclear power plants, covering the core subjects of nuclear engineering. The chapter starts with an introduction and the types of nuclear reactors along with comparative analysis of large to small and medium-sized nuclear reactors. Nowadays, building of large nuclear reactors is not a favorable option, and hence the trend for developing small nuclear reactors is increasing correspondingly. Small-sized nuclear reactors were instrumental during the pioneering days of commercial nuclear power plants to facilitate the development and demonstration of early reactor technologies and to establish operational experience for the fledgling nuclear power industry. This chapter is focused on the design aspects of nuclear power plants, specifically for small reactors, with all the designing features and related parameters. In addition, comparison of large to small reactors with all possible variations has been included with comprehensive explanation. In addition, the operational flexibilities and constructive features have been added considering the role of International Atomic Energy Agency (IAEA). The basic design is mainly concerned with safety, reliability, and passive safety systems. Some of small nuclear reactors (both small and modular types) are included with all possible passive safety system and facilities. A brief review of the design and safety aspects of some small nuclear reactors have been discussed. At the end, some recommendations and challenges are also included for the purpose to play an effective role in the nuclear industry.

Magnetohydrodynamic generators with nonequilibrium ionization

T earliest serious study of the possibility of utilizing nonequilibrium ionization in MHD generators was carried out by Karlowitz and Halasz at the Westinghouse Research Laboratories between 1938 and 1947. It was originally oriented to the development of a generator that could use combustion products at moderate temperatures. The study was terminated when it was realized that recombination rates in molecular gases were too high to permit useful electron densities to be developed. It was concluded, however, that nonequilibrium ionization might be feasible in the atomic working gases that can be used with a nuclear reactor. This work was reviewed by Karlowitz in 1962. With recent developments in nuclear reactor technology, there is now renewed interest in nuclear-powered MHD generators. The temperature range, which is likely to be accessible with reactors and also desirable thermodynamically, is from about 1500° to 2000° K. It seems likely that cycles with over-all efficiencies between 0.50 and 0.60 can be evolved with such maximum temperatures. The requirements of the reactor and the generator together dictate that the pressure in the generator be between 1 and perhaps 10 atm, if the working fluid is argon and the magnetic field is limited to, say, 20,000 gauss. With the development of large superconducting magnets, it may be possible to raise these pressures by a factor of 5. It is likely that the inert gas will be seeded with a fraction of a percent of cesium. Since 1960, considerable effort has been devoted to the study of such plasmas. It began with small-scale studies of the behavior of the plasma, and has only recently advanced to the study of complete generators, the point at which Karlowitz and Halasz left off. The purpose of this article is to review this work and to summarize the current understanding of nonequilibrium ionization, as applied to MHD power generation. This is an important qualification, since the literature of nonequilibrium ionization taken in the broad sense is vast indeed. It includes the literature of gas-discharge physics and low-density plasma physics. As we shall show, however, the nonequilibrium plasmas of interest in MHD power generation are much simpler than those of lower density. The essential point is that the behavior of the high-density plasma is controlled by volumetric phenomena, not by surface phenomena. This distinguishes it particularly from the glow-discharge plasmas so thoroughly studied in the past. There are a number of ways of producing a homogeneous plasma with nonequilibrium ionization. To name a few: there are the methods of photoionization, electron-beam ionization, radio-frequency excitation, radioactive decay, and, finally, nonequilibrium ionization due to (d.c.) Joule heating. It is the last of these methods which will occupy most of the present discussion. Many of the conclusions to be drawn, however, can be extended to the other methods. This follows from the fact, to be demonstrated below, that the general question of the feasibility of producing nonequilibrium ionization can be separated into two fairly distinct parts. There is first the question of the behavior of the nonequilibrium plasma, given that a certain input power is provided to maintain the electrons out of equilibrium with the gas. The question can be posed as follows: 1) What is the connection between the local electrical conductivity of the gas and the local (dissipative) pbwer density? We do not have a detailed theoretical answer to this question, which is very complex, but we do have a completely satisfactory engineering answer, which applies to most of the methods of ionization mentioned previously. The second question is as follows: 2) Can the local (dissipative) power density and gas composition be so chosen in a practical MHD generator configuration as to satisfy the conditions required to produce nonequilibrium ionization? This second question is in many ways more complex and difficult than the first, and the problem is different for each of the ionization schemes mentioned previously. We are certainly farther from having a satisfactory answer, although recent progress in the application of the scheme utilizing the natural d.c. Joule heating of the electrons is encouraging. The following discussion will be divided into two parts, The first, entitled Nonequilibrium Plasma Behavior, will deal with question 1; the second, entitled Generator Characteristics, will deal with question 2. Most of the discussion will apply to alkali-metal seeded noble gases, since these have received the greatest attention. Some work has been done on wet alkali-metal vapors, however, and these results will be mentioned briefly. A serious attempt has been made to ensure that the discussion is correct both historically and technically. The

Review of Solid Core Nuclear Rockets

This paper describes briefly the programs underway to develop solid-core reactor technology for nuclear rockets. Recent successful KIWI and NERVA reactors have shown great progress in the development of graphite reactor technology and provide a sound basis for the ultimate development of nuclear rocket engines for a variety of space missions. In addition to the reactor work, this discussion presents the efforts in the Nuclear Rocket Program for development of nonreactor components, systems studies and research, and full nuclear rocket engine systems tests (to be conducted in the next 2 or 3 years) to provide the overall technology required for application of solid-core nuclear rocket engines to missions.