对先进核能系统中U-Pu循环的研究

利用新开发的数据库和程序对加速器驱动的次临界反应堆中的Ｕ－Ｐｕ循环进行了详细的理论研究．通过对反应堆功率、临界系数、γ和中子通量以及裂变核的演化等计算,得到了令人满意的中子学结果.The U-Pu cycle in accelerator driven subcritical reactor is studied by means of new data library and code. The satisfactory neutronics results are obtained by calculating the reactor power, critical value, gamma and neutron flux and evolution of fissioning nuclear density. The detailed analysis is also presented.     

Efficient Power Characteristic Analysis and Multi-Objective Optimization for an Irreversible Simple Closed Gas Turbine Cycle

On the basis of the established irreversible simple closed gas turbine cycle model, this paper optimizes cycle performance further by applying the theory of finite-time thermodynamics. Dimensionless efficient power expression of the cycle is derived. Effects of internal irreversibility (turbine and compressor efficiencies) and heat reservoir temperature ratio on dimensionless efficient power are analyzed. When total heat conductance of two heat exchangers is constant, the double maximum dimensionless efficient power of a cycle can be obtained by optimizing heat-conductance distribution and cycle pressure-ratio. Through the NSGA-II algorithm, multi-objective optimizations are performed on the irreversible closed gas turbine cycle by taking five performance indicators, dimensionless power density, dimensionless ecological function, thermal efficiency, dimensionless efficient power and dimensionless power output, as objective functions, and taking pressure ratio and heat conductance distribution as optimization variables. The Pareto frontiers with the optimal solution set are obtained. The results reflect that heat reservoir temperature ratio and compressor efficiency have greatest influences on dimensionless efficient power, and the deviation indexes obtained by TOPSIS, LINMAP and Shannon Entropy decision-making methods are 0.2921, 0.2921, 0.2284, respectively, for five-objective optimization. The deviation index obtained by Shannon Entropy decision-making method is smaller than other decision-making methods and its result is more ideal.     

Four-Objective Optimizations for an Improved Irreversible Closed Modified Simple Brayton Cycle

An improved irreversible closed modified simple Brayton cycle model with one isothermal heating process is established in this paper by using finite time thermodynamics. The heat reservoirs are variable-temperature ones. The irreversible losses in the compressor, turbine, and heat exchangers are considered. Firstly, the cycle performance is optimized by taking four performance indicators, including the dimensionless power output, thermal efficiency, dimensionless power density, and dimensionless ecological function, as the optimization objectives. The impacts of the irreversible losses on the optimization results are analyzed. The results indicate that four objective functions increase as the compressor and turbine efficiencies increase. The influences of the latter efficiency on the cycle performances are more significant than those of the former efficiency. Then, the NSGA-II algorithm is applied for multi-objective optimization, and three different decision methods are used to select the optimal solution from the Pareto frontier. The results show that the dimensionless power density and dimensionless ecological function compromise dimensionless power output and thermal efficiency. The corresponding deviation index of the Shannon Entropy method is equal to the corresponding deviation index of the maximum ecological function.     

Concept of the Fuel Cycle of the IGNITOR Tokamak

Physics of Atomic Nuclei - In 2015, the development of the conceptual design of IGNITOR, a Russian–Italian experimental thermonuclear tokamak, was completed, and the parameters of all the...     

News and Views: Nuclear Power in Brazil

No energy, whether renewable, clean or known by any other name can possibly be relied upon as the only solution for ensuring a supply of electricity compatible with a nation’s economic and social development. Brazilian consumption and installed capacity of electric power generation per capita indices are still inadequate and below the world average—this crucial fact must be considered. It obliges Brazil to take the most advantage of all resources available to increase its electricity generation capacity as rapidly as possible, thereby enabling consumption to reach levels compatible with the quality of life the Brazilian population aspires to. Planning of a country’s electric system requires efficient management of a diversified portfolio of energy sources. In Brazil, hydroelectricity will continue for many years yet to be the main component of its portfolio of electric power generation sources, but it must be supplemented by thermal sources—uranium, coal, biomass, natural gas, and oil by-products derived from petroleum—in this order of importance, keeping in mind aspects related to local availability, cost, environmental impacts, and use in other applications.     

核动力安全研究动态

本文介绍中国原子能科学研究院在核动力安全研究方面的工作概况．着重论述了８０年代和９０年代初期所进行的、与秦山核电厂设计、建造和审评、以及广东核电站安全审评密切有关的工作．对在热工水力、核燃料、概率安全评估和严重事故研究领域中的主要成果,作了简要小结．简单介绍了计划中即将开展的、与秦山核电厂二期６００ＭＷｅ工程设计有关的工作． In this paper the power reactor safety research activities in ons are briefly reviewed. The research work performed in 1980 s and 1990 s are mainly emphasised, which are closely related to the design, constriction and licensing review of Qinshan Nuclear Power Plant and the safety review of Guandong Nuclear Power Station.Major achievements in the area of thermohydraulics, nuclear fuel,peobabilistic safety assessment and severe accident researches are summarized.The foreseeable research...     

与加速器驱动的核能系统有关的核化学研究

提出了与加速器驱动的洁净核能系统有关的核化学研究课题,研究领域涉及到散裂反应产物与它们的产额分布、长寿命废料的嬗变、中子反应参数测量以及中子的诊断． Some of research scopes on nuclear chemistry, concerning development of clean nuclear power system driven by accelerator have been proposed. The research fields proposed include spallation products and their yield distributions, transmutation of long lived radiowaste, neutron measurement and diagnosis by activation techniques. Advantages of (n, xn) reactions used for transmutation of radiowaste have been discussed.     

Isoscalar and Isovector Giant Resonances in Closed Shells Nuclei and Bulk Properties of Nuclear Matter

Physics of Atomic Nuclei - Centroid energies, $$E_{\textrm{CEN}}$$ , of the isoscalar ( $$T=0$$ ) and isovector ( $$T=1$$ ) giant resonances of multipolarities $$L_{m}=0$$ –3 in...     

世界和我国核电发展形势

核能发电作为一种新型的能源,它将成为世界和我国电力工业的重要支柱．综合世界核电发展的动向和我国核电发展的现状及展望,提出了当前如何充分利用国内外核电市场有利形势,进一步发挥核电设计,制造综合优势,加强国际台作,以及提高设计自主化和设备国产化的能力等． As a kind of new type of energy source, nuclear power will certainly become an important mainstay of the electrical industry in China and the world. The tendency of developing nuclear power in the world and the current situation and prospect of developing nuclear power in China are comprehensively analysed. And basing on these analyses, some proposals about the strategic decision to speed up developing nuclear power in China are put forward, that is, how to make full use of ...     

Nuclear Power System Based on Fission and Fusion Reactors is the Strategic Line of Nuclear Power Industry Development

Physics of Atomic Nuclei - The strategic line of development of a nuclear power system based on fission and fusion reactors which ensures electricity generation on a specified scale, solves the...     

秦山——中国核电将从这里起飞

本文介绍了秦山核电站工艺流程并列出了主设备的有关参数,同时从多方面阐述了秦山核电站的安全性及其相应的安全设施,并指出秦山核电站的建成有着深远的意义. Qin Shah Nuclear Power Plant s (QSNPP) technological process and main equipment srelative parameters are introduced.QSNPP can operate safely,of which,the safety and the relativesafety facilities are mentioned.QSNPP s successful completion indicates the start-up of Chinesenuclear power.     

Dynamic Nuclear Polarization in Solids: The Birth and Development of the Many-Particle Concept

A brief review is presented on historical aspects of the dynamic nuclear polarization (DNP) research in 1960–1970s of the last century. Much attention is given to development of the many-particle approach, from pioneering studies of the 3-spin electron–nuclear cross effect to development of spin-temperature concept and thermal mixing mechanism of DNP in solids. Applicability of different models to modern DNP data is briefly discussed.     

小波分析及神经网络方法在核物理及核工程中的应用

介绍了小波分析和神经网络方法在核物理及核工程领域的应用现状。 分别对小波分析及神经网络方法的基本原理进行了介绍, 详细讨论了小波变换中的多分辨分析方法在γ能谱平滑以及核电站设备监测等方面的应用, 讨论了连续小波变换在γ能谱分析、 粒子种类鉴别以及核反应堆安全监测等领域的应用。 同时, 还详细介绍了神经网络方法在以上各领域的发展现状。 最后, 展望了两种方法在核安全检测、 核辐射防护以及核电站实时监控等领域的发展趋势。 Applications of wavelet analysis and neutral networks in the field of nuclear physics and engineering are reviewed. The principle of these two methods are introduced briefly, and then the applications of multiresolution analysis technique in the smoothing of γ ray spectroscopy, and in nuclear power plant monitoring are discussed in detail. Applications of the continuous wavelet analysis method in γ ray spectroscopy analysis, in particle identification , and in nuclear reactor safety monitoring are also talked over. In addition, the applications of neutral networks in above fields are introduced. Finally, the trends of the future development for these two methods are prospected.     

Nonlinear Control of Beam Halo-Chaos in Accelerator-Driven Clean Nuclear Power System

Beam halo-chaos in high-current accelerators has become a key concerned issue because it can cause excessive radioactivity from the accelerators therefore significantly limits their applications in industry, medicine, and national defense. Some general engineering methods for chaos control have been developed in recent years, but they generally are unsuccessful for beam halo-chaos suppression due to many technical constraints. Beam halo-chaos is essentially a spatiotemporal chaotic motion within a high power proton accelerator. In this paper, some efficient nonlinear control methods, including wavelet function feedback control as a special nonlinear control method, are proposed for controlling beam halo-chaos under five kinds of the initial proton beam distributions (i.e., Kapchinsky-Vladimirsky, full Gauss,3-sigma Gauss, water-bag, and parabola distributions) respectively. Particles-in-cell simulations show that after control of beam halo-chaos, the beam halo strength factor is reduced to zero, and other statistical physical quantities of beam halo-chaos are doubly reduced. The methods we developed is very effective for suppression of proton beam halo-chaos in a periodic focusing channel of accelerator. Some potential application of the beam halo-chaos control in experiments is finally pointed out.     

Efficiency at Maximum Power Output of a Quantum-Mechanical Brayton Cycle

The performance in finite time of a quantum-mechanical Brayton engine cycle is discussed, without intro- duction of temperature. The engine model consists of two quantum isoenergetic and two quantum isobaric processes, and works with a single particle in a harmonic trap. Directly employing the finite-time thermodynamics, the efficiency at maximum power output is determined. Extending the harmonic trap to a power-law trap, we find that the efficiency at max/mum power is independent of any parameter involved in the model, but depends on the confinement of the trapping potential.     

Phase Analysis of Corrosion Products from Nuclear Power Plants

The variability of the properties and the composition of the corrosion products of the stainless CrNi and mild steels in dependence on the conditions (temperature, acidity, etc.) is of such a range that, in practice, it is impossible to determine the properties of the corrosion products for an actual case from the theoretical data only. Since the decontamination processes for the materials of the water-cooled reactor (VVER-440) secondary circuits are in a process of development, it is necessary to draw the needed information by the measurement and analysis of the real specimens [1]. The corrosion layer was separated by scraping the rust off the surface and the powder samples were studied by transmission Mössbauer spectroscopy. It should be noted that the gamma spectroscopic measurements give no evidence of the presence of low-energy gamma radiation emitted from the samples. The scrapped specimen powder was homogenised (using the 50 m sieve) and fixed into the special holder. The ⁵⁷Co in Rh matrix was used as the radioactive Mössbauer source. Measured spectra were fitted using program NORMOS SITE. According to the results obtained from Mössbauer spectra, it is possible to establish that the main component of secondary circuit's corrosion products is magnetite Fe₃O₄. Next components are hematite -Fe₂O₃ and hydroxide akagenite -FeOOH, which is characterised by a significant paramagnetic doublet in the middle of the spectra. The sextets corresponding to base materials (martensite and austenite steels) were identified in all measured spectra.     

铀-钍混合燃料反应堆的可行性分析

分析了以铀为燃料的核电系统的弊端、钍燃料反应堆的理论技术依据和世界范围内钍燃料反应堆的研究状况。提出在我国开发利用钍资源,建立铀．钍混合燃料反应堆具有的独特优势,建议应加大钍资源开发人力物力投入,改变我国核电利用水平落后和钍资源流失之现状。Nuclear energy is a preferred option for electric power generation. The disadvantages of the current uranium-dioxide （UO2 ） fuel in nuclear power were presented and the reactor using the mixed thorium dioxide and uranium dioxide fuel （ ThO2-UO2 ） in the near future was foretold. A proposal to strengthen the research cooperation on the use of the thorium mineral resources in china was put forward.     

Chemical aspects of lifetime extension at Paks Nuclear Power Plant

The review of the water regime used for the Units of Paks Nuclear Power Plant (NPP) was carried out in 2005, after 18–23 years of operation. In order to determine the phase composition of the surface oxide layers primary equipment, samples were measured by Conversion Electron Mössbauer Spectroscopy (CEMS). Due to the absorption of the conversion electrons, information can be obtained from the outermost ～300 nm thick layer of the surface. It was clearly concluded after processing the huge data base of the water regime and CEMS data, that there is nothing to hamper the life time extension of the Units. In 2006, a new water regime was developed that will be applied during the preparation for the life time extension and the extended service life as well. In connection with this work, recommendations were made for some modifications of the previously used water regime. Currently there is no uniform start-up and shutdown water regime for WWER-440 Units. Therefore, special attention was paid to developing of a start-up water regime, which will be applied for the outages as early as 2008. The summarised recommendations for water regime modification will be subject to international expert review in 2008, and the modifications judged to be implemented will be finalised after the review.