摘要:

AbstractThe modular high-temperature reactor (HTR-M) is characterized by the use of standardized reactor, heat transfer, and loop components. One or more primary circuit units make up the nuclear steam-generating system (or heat-generating system) of a HTR-M power plant. The core of the helium-cooled HTR-M consists of a randomly packed bed of spherical fuel elements (pebble bed reactor). The characteristic design of the HTR-M core ensures that permissible core temperatures are not exceeded, even if all cooling systems fail. Today, HTR-M power plants can already be applied in the combined generation of electricity, process steam, and/or district heat. In the near future the HTR-M can be used as a heat source for processing plants in the chemical industry, e.g., for methane cracking, coal gasification and similar chemical processes.

ISSN:0029-5639    

DOI:10.13182/NSE85-4

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractThe possibilities of breeding in liquid-metal fast breeder reactors (LMFBRs) and light water reactors (LWRs) are compared in two ways. The feasibility of breeding has been demonstrated in the Phénix reactor with a measured gain of 0.14. The gain in Superphénix will amount to∼0.20. The studies show that while maintaining the performance of commercial reactors their breeding gain can be further increased either by the concept of heterogeneous cores or by using carbide or nitride fuel (breeding gain∼0.35).Recently, the old idea of breeding in advanced pressurized water reactors (PWRs) has been taken up again with the objective of attaining a gain of 0.05. Unfortunately, these objectives had to be limited to a conversion ratio of 0.9 for safety reasons, and it is not certain whether operation will be rewarding economically.The strategy of substituting PWRs is examined using the French example. By gradually introducing LMFBRs, the cumulated uranium supplies in France can be kept within reasonable limits, which means that they attain three to four times the home resources. This is not possible with advanced LWRs, which can be considered only as a possible backup solution for plutonium recycling into PWRs.

ISSN:0029-5639    

DOI:10.13182/NSE85-A18490

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractThe Wigner-Seitz cell problem is treated by integral transport theory as a superposition of black boundary problems using the volume source and sources equivalent to the two lowest order angular components of the reentrant flux. This treatment sheds light on the convergence properties of iterative integral transport solution methods. The outgoing flux is required to have the lowest order components equal and opposite to those of the reentrant flux. Sample problems with this P11boundary condition give good results. A new approximation to neutron transport theory is also reported. This approximation does not rely on expansion or approximation of the angular flux distribution, but rather on approximating the integral transport kernel by a sum of diffusionlike kernels that preserve spatial moments of the kernel. This might permit transport problems to be treated as a set of coupled diffusion problems in any geometry.

ISSN:0029-5639    

DOI:10.13182/NSE85-A18491

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractResonance ionization spectroscopy is a newly developed technology enabling the counting of single atoms of materials. It is uniquely suited for use as an analytical tool for ultrasensitive elemental analysis. The method is described; typical data illustrating the principal features of the method are shown, and the formation of a spin-off company during the early stages of the U.S. government’s new initiative encouraging technology transfer is described. Alvin M. Weinberg’s contributions to the formation of this enterprise have been significant.

ISSN:0029-5639    

DOI:10.13182/NSE85-A18492

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractFor finite media, a generalized Placzek function is defined, and its asymptotic behavior studied. If the nonasymptotic oscillations of the neutron age are neglected, a Greuling-Goertzel type synthetic slowing down kernel can be derived.

ISSN:0029-5639    

DOI:10.13182/NSE85-A18493

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractThe importance of reliable basic nuclear data, problem-specific neutron spectra, and multidimensional computing models for use in the evaluation of thermal power reactor properties is stressed. Examples are the cycle length, the local distribution of fuel burnup and plutonium buildup, and the void characteristics of an advanced pressurized water reactor with a tight fuel lattice.

ISSN:0029-5639    

DOI:10.13182/NSE85-A18494

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractSurvival curves for men and women dying from cardiovascular disease and similar curves for those dying from cancer in 47 countries were compared with the 1970–1974 per capita incomes of the inhabitants. The data were taken chiefly from 1964 life tables. The steepest survival curves were found in countries with the highest incomes. Comparison of the survival curves in different countries and comparison of cardiovascular survival with cancer survival curves indicate that both groups of diseases are probably diseases of senescence.The differences in survival slopes are interpreted as homeostatic responses in the population to rate of food intake. The response protects the population against long-term effects of changes in food supply by promoting differential reproduction of offspring best suited to the food supply rate from the environment. The response to food supply rate complicates calculation of the effects of protracted exposure to low-level ionizing radiation because the radiation exposure appears to mimic the effect of extra food.

ISSN:0029-5639    

DOI:10.13182/NSE85-A18495

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractThe pattern of global electrification suggests that the global discharge of CO2to the atmosphere is less, and will be increasingly less, than would be the case without the continuing shift toward use of electrical energy.Data show that the world has been moving steadily toward greater electrification. Each year electricity is used to perform a larger number of tasks, and the fraction of energy used in the form of electricity has increased whether in“good times”or in“bad times.”Scenarios that incorporate technological development, and therefore growth in electrification, yield slower growth in emissions of CO2, and consequently slower accumulation in the atmosphere.Increased world electrification slows the growth in CO2for two reasons:electrification may reduce total energy demandelectrification presents opportunities to supply the energy without using CO2-producing fuels.The large potential for slowing atmospheric CO2accumulation by generating electricity with nonfossil technologies is demonstrated by the scenarios presented here.

ISSN:0029-5639    

DOI:10.13182/NSE85-A18496

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractAn increasingly important advantage of nuclear power is its minimal air pollution, in particular the absence of combustion products such as acid rain and carbon dioxide. Developing a consensus about acceptable limits of such pollutants is a slow process that culminates in domestic and international agreements. Therefore, the pace of adoption of new technologies, nuclear power included, is often controlled by the level and intensity of debate, rather than by the technology alone.The state of understanding and consensus about local and long-range transboundary air pollution is therefore germane to the nuclear sector. Progress over the past several decades, mainly between the United States and Canada and within Europe, in developing a more comprehensive and effective international consensus, both informal and formal, is reviewed. There appears to be a trend toward more effective international participation in seeking a less-polluting world, albeit it is punctuated at times by unconcern.

ISSN:0029-5639    

DOI:10.13182/NSE85-A18497

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractSome of the main, general-perspective themes of Dr. Alvin Weinberg’s leadership and long and varied work arethe effect of present and future nuclear energy projects on society, not only in the United States but throughout the worldanalysis, comparison, and combination of various sources of energyextensive multiple use of nuclear energy complexes (so-called NUPLEX, for nuclear complex) for various areas of the worlduse of“Big Technology”and“Big Science”for solving, or helping to solve, political problems.A combined hydro-nuclear-solar project for electric power production is discussed, as well as two other energy-related engineering projects. Some of the projects originated or were inspired by work done at the Oak Ridge National Laboratory under the leadership of Dr. Alvin Weinberg. Also reported are the technical characteristics and interrelationships of the three components of the envisaged hydronuclear-solar project.

ISSN:0029-5639    

DOI:10.13182/NSE85-A18498

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor