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.     

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 ...     

Closed Thorium-Uranium-Plutonium Cycle Concept in Nuclear Power Engineering

The use of 232Th instead of 238U as a fertile isotope, 233U instead of 239Pu as the main fissile isotope, heavy water instead of light water as a coolant, and its dilution with light water in the VVER reactor campaign make possible self-enrichment of fuel with fissile isotopes, including the time upon achieving the balanced isotopic abundance ratio of actinides, and also provide conditions for closing the Th-U-Pu fuel cycle. This allows increasing the fuel lifetime by around two orders of magnitude, making it much easier to handle radioactive waste, reducing the nuclear hazard of PWE reactors, and providing a technological barrier to prevent the distribution of fissile materials and nuclear technologies.     

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.     

Nuclear Power Unit with Molten Salt Fuel for the Arctic

Physics of Atomic Nuclei - A schematic of a low-power nuclear power unit with circulating fuel based on molten metal fluoride salts is considered. The possibility of creating a virtually...     

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.     

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.     

核电站安全壳缺陷检测系统研究设计

借助于可平稳移动于垂直墙面的负压吸附式爬壁机器人平台,将两台分辨率不同的摄像机固定于机器人前端支架上。通过两组相互独立的无线通信网络,分别实现控制爬壁机器人移动和回传摄像机所拍摄到的安全壳外壁视频信息。无线回传的视频信息在本地上位机监控平台上经过前期处理后进行实时播放显示,同时视频处理软件中的缺陷检测算法模块在后台进行图像缺陷检测,检测到缺陷后,软件平台发送停止信号给机器人,同时视频流切换到高清摄像机进行高清照片拍摄,并将包含缺陷信息的高清照片发送至缺陷测量模块,利用在缺陷测量模块中所开发的测量工具进行安全壳外壁缺陷测量,最终测量所得到的缺陷参数会存入后台数据库进行存储管理,方便后期浏览历史数据,监测安全壳外壁缺陷的动态变化情况。     

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...     

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.     

大亚湾核电站周围大气流场监测数据同化分析

在大亚湾核电站周围大气流场分布模拟计算中,引入了一种简化的同化技术,用以解决观测数据在时间、空间上分布不均匀导致的流场预报误差.测试并分析了该同化技术对计算模式和初始场的影响,结果表明该同化方法对模式误差和初始场误差的抑制是显著的.     

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.     

加速器驱动的核电站──干净现实的核能源

由一台１６００ＭｅＶ的强流质子加速器来辅助驱动一座熔盐核反应堆,从而组建一座新型的核电站．这座电站中裂变核燃料“燃烧”完全,没有长寿命的重锕系与裂片的核废料输出;并可以直接用天然存在的大量钍和贫铀元素作为核燃料来使用．核电站将２０％电能供给加速器运转,８０％电能并入电网．同时电站还可输出十分稀有的稳定同位素和短寿命医用同位素,作为副产品供应市场．这一干净的核能源就是加速器驱动式核反应堆．简称驱动堆;它没有核废料,比自持式核反应堆安全． A new type of nuclear power station can be built by a moltensalt reactor auxiliary driven by a strong neutron source produced by a intensive proton beam with the energy of 1600 MeV from a powerful accelerator. In the power station the nuclear fuels are completely burnt without some long-lived radioactive wastes both of heaVy actinide and fission products. Furthermore the thorium and sub-critical uranium which are massive existence in nature can be used as an available nuclear fuel in...     

Revisiting the Choice of a Nuclear Power Source for the Arctic

Physics of Atomic Nuclei - The possibility of creating a practically maintenance-free reactor facility with a thermoelectric generator or a Stirling engine with a capacity of 1 to 500 kWe and a...     

核磁共振波谱仪用射频功率放大器的设计与实现

介绍了一种应用于核磁共振（Nuclear Magnetic Resonance,NMR）波谱仪的宽频带射频功率放大器的设计与实现,提出了射频功率放大器门控信号的设计,探讨了利用传输线变压器构建功率MOSFET输入输出阻抗匹配网络的方法. 该射频功率放大器采用多级驱动结合功率放大的结构,包含2个工作模块和基于宽频带定向耦合器的辅助电路,支持高带和宽带通道的相关实验. 将该射频功率放大器应用在自主研发的500 MHz高分辨率液体NMR谱仪上,测量射频功放的上升、下降时间及输出线性度,并对比测试¹H和¹³C NMR标样的信噪比,实验结果证明了该设计的可行性.     

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.     

Structural and Parametric Optimization of S–CO2 Nuclear Power Plants

The transition to the use of supercritical carbon dioxide as a working fluid for power generation units will significantly reduce the equipment′s overall dimensions while increasing fuel efficiency and environmental safety. Structural and parametric optimization of S–CO₂ nuclear power plants was carried out to ensure the maximum efficiency of electricity production. Based on the results of mathematical modeling, it was found that the transition to a carbon dioxide working fluid for the nuclear power plant with the BREST–OD–300 reactor leads to an increase of efficiency from 39.8 to 43.1%. Nuclear power plant transition from the Rankine water cycle to the carbon dioxide Brayton cycle with recompression is reasonable at a working fluid temperature above 455 °C due to the carbon dioxide cycle′s more effective regeneration system.     

核电站乏燃料对生物圈的影响及ADS 对策

介绍了核电发展状况和核电产生的乏燃料中的锕系及长寿命裂变产物核素, 在毒性方面评述了这些核素对生物圈的影响, 最后提出用加速器驱动的次临界系统嬗变核废物的对策, 以减轻或消除核废物对生物圈的影响。 The current status of nuclear power development and the actinides and some Long Lived Fission Products (LLFPs) in nuclear power spent fuel have been introduced. The radiation effect of spent fuel on biological circle in the viewpoint of Biological Hazard Potential (BHP) and Annual Limit of Intake were evaluated. The Accelerator Driven Sub critical System （ADS） as a strategy to transmute Minor Actinides (MAs) and LLFPs was recommended in order to reduce or eliminate the radiation effect of spent fuel on biological circle.     

Experimental study of radioactive aerosols in the vicinity of the Chernobyl Nuclear Power Plant

Study of radioactive aerosols in the relocation zone and in the populated areas have been carried out for a number of years. The experiments on modelling resuspension were performed while conducting agricultural work. Nuclear track radiography and alpha spectrometry with radiochemical extraction of plutonium were used as analytical methods for the determination of the transuranium elements contents. The distributions of radioactive particles were obtained as to activity and sizes. Specific activity of “hot particles” increases with decreasing diameter. In aerosols selected at a distance of more than 10 km from the Chernobyl NPP pure fuel particles with sizes of more than 5 μm were not found. The activity of the finely dispersed fraction of aerosols, which is more dangerous when inhaled by the organism, is comparable with a total activity of large particles.