Possibilities and distinctive details of the application of shape-memory alloys in nuclear technology

Conclusions To increase the reliability and safety of nuclear power plants, increase the compactness of parts, and decrease the irradiation of personnel, it is important to employ nonstandard technical devices, including shape-memory devices. At the present time, there is a definite scientific-technical potential for using shape-memory devices in nuclear power plants: utilization strategy, experimenal—commercial technology for fabricating different intermediate products, collection of alloys with different actuating temperatures, fundamental and construction solutions, theoretical foundations, experimental research base, experimental characteristics, verification of and experience in operation (in part, under reactor conditions), program of improvement in the direction of increasing resistance to irradiation, high speed of operation, and corrosion resistance. Of the diverse shape-memory devices the following will apparently be primarily used: stationary thermomechanical connections, gaskets, plugs, fasteners, and so on, self-operating bipositional counteraccident devices which act on the main process of the system and on the flow rate of the medium, electrically controlled driving mechanisms for closing fixtures, and small instruments. To accelerate the adoption of such devices in nuclear technology a catalog of shape-memory devices which are currently available must be compiled, a dictionary on application of shape-memory alloys must be developed, the stages of research and development must be separate, the technical conditions must be formulated, shape-memory alloys and devices must be certified, engineering methods of construction and calculation of devices must be developed, including methods for rapid heating and cooling and calculation of the speed of operation. NIKIéT. Translated from Atomnaya énergiya, Vol. 82, No. 5, pp. 392–396, May, 1997.     

Electroless nickel-plating for the PWSCC mitigation of nickel-base alloys in nuclear power plants

The feasibility study has been performed as an effort to apply the electroless nickel-plating method for a proposed countermeasure to mitigate primary water stress corrosion cracking (PWSCC) of nickel-base alloys in nuclear power plants. In order to understand the corrosion behavior of nickel-plating at high temperature water, the electrochemical properties of electroless nickel-plated alloy 600 specimens exposed to simulated pressurized water reactor (PWR) primary water were experimentally characterized in high temperature and high pressure water condition. And, the resistance to the flow accelerated corrosion (FAC) test was investigated to check the durability of plated layers in high-velocity water-flowing environment at high temperature. The plated surfaces were examined by using both scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) after exposures to the condition. From this study, it is found that the corrosion resistance of electroless nickel-plated Alloy 600 is higher than that of electrolytic plating in 290 °C water.     

Application of the leak-before-break concept in nuclear power plant safety analysis

NIKIÉT. Translated from Atomnaya Énergiya, Vol. 75, No. 6, pp. 426-430, December, 1993.     

加快核电标准建设 促进核电健康发展

论述了尽快建立和完善我国核电标准体系的重要意义,分析了我国核电标准建设取得的成绩和存在的问题,提出了积极推进我国核电标准建设的建议,表明了中国核工业集团公司将进一步加强标准化工作,加强与核电标准相关行业的协调配合,共同促进我国核电标准建设。     

Safety prediction in nuclear power

The practical operational safety of nuclear objects is of fundamental importance for assessing the future prospects under discussion and selecting a strategy for the development of nuclear power. It is shown that the methods currently being used for making safety predictions do not contain an analysis of the unavoidable errors and uncertainties of the models used or the initial and boundary conditions under which the physical processes that develop into serious accidents arise and develop. It is proposed that the method of quantile estimates of the uncertainties, which is free of the drawbacks of the Monte Carlo method and which increases the reliability of safety predictions in nuclear power, be used. __________ Translated from Atomnaya énergiya, Vol. 102, No. 2, pp. 80–86, February, 2007.     

Application of concentrated ozone for decontamination of equipment in a nuclear power plant

The destruction of chromium oxides on the surface of 12Kh18N10T steel by concentrated ozone at different temperatures is investigated. The optimal temperature of the process in water is found to be 95°C. The oxidation time of the surface layer of chromium oxides is 5–10 min. Subsequent ozone treatment of a steel surface for a 20-fold longer time did not show any substantive destruction of the surface of corrosionresistant steel. Ozone diffusion through the surface of a bubble to the metal surface plays a decisive role in the oxidation of chromium.     

人工神经网络理论在核动力领域的应用与展望

对人工神经网络(ANN)在核动力领域的应用研究进行了评述。重点阐述了人工神经网络在核动力控制系统、核电厂监测与瞬态辨识、设备故障监测与诊断、核燃料管理、核参数预测等方面的应用与研究进展。就人工神经网络在核动力领域的实际应用问题提出了作者的看法。     

A review of refractory metal alloys and mechanically alloyed-oxide dispersion strengthened steels for space nuclear power systems

Mechanical and thermo-physical properties of refractory metal alloys and mechanically alloyed (MA)-oxide dispersion strengthened (ODS) steels are reviewed and their potential for use in space nuclear reactors is examined. Preferable refractory alloys for use in liquid metal and gas-cooled space reactors include Nb-1%Zr, PWC-11, Mo-TZM, Mo-xRe where x varies from 7% to 44.5%, T-111 and ASTAR-811C. These alloys are heavy, difficult to fabricate, and are not readily available. The advantages of the MA-ODS alloys are: (a) their strength at high temperatures (>1000 K), which decreases slower with temperature than those of niobium and molybdenum alloys; (b) relatively lightweight and less expensive; (c) low swelling and no embrittlement with exposure to high-energy neutrons (>0.1 MeV) up to 10²⁷ n/m²; and (d) high resistance to oxidation and nitration. The few data available on compatibility of MA-ODS alloys with alkali liquid metals up to 1100 K are encouraging, however, additional tests at typical temperatures (1000-1400 K) in space nuclear reactors are needed. The anisotropy of MA-ODS alloys when cold worked, and particularly rolled into tubes, should not hinder their use in space nuclear power systems, in which operation pressure is either near atmospheric or as high as 2 MPa, but joints weldability is an issue.     

世界核电国家的发展战略历程与我国核电发展

概述了世界上主要发展核电的国家的技术路线、发展战略历程及其经验与教训;当前国际上核电发展的动向及前景;我国核电中长期发展规划的目标任务;我国核电自主化取得的成绩、具备的能力以及为赶上国际先进水平所做的努力;我国核能开发利用的前景展望。     

Application of neural networks to multiple alarm processing anddiagnosis in nuclear power plants

A feasibility study of multiple alarm processing and diagnosis using neural networks is presented. The backpropagation network (BPN) algorithm is applied to the training of multiple alarm patterns for the identification of faults in a reactor coolant pump (RCP) system. The general mapping capability of the neural network makes it possible to identify a fault easily. A number of case studies are performed, with emphasis on the applicability of the neural network to the pattern recognition of multiple alarms. Based on the case studies, the neural network can identify the cause of multiple alarms well, although untrained, incomplete/sensor-failed or time-varying alarm symptoms are given. Also, multiple faults are easily identified with a given alarm pattern     

世界核电国家的发展战略历程与我国核电发展

概述世界上主要发展核电的国家的技术路线、发展战略历程及其经验与教训;当前国际上核电发展的动向及前景;我国核电中长期发展规划的目标任务;我国核电自主化取得的成绩、具备的能力以及为赶上国际先进水平所做的努力;我国核能开发利用的前景展望。     

Offshore nuclear power plants

Offshore Power Systems, a joint enterprise of Westinghouse and Tenneco, has been formed to manufacture floating nuclear power plants. Commitments for the first two offshore plants have been received from the Public Service Electric and Gas Company. This paper describes the floating nuclear plant concept with special reference to its advantages and its novel features. The novel features are a consequence of the floating aspect and include the design of the platform, the safety analysis and also the analysis and specification of plant motions due to environmental effects such as wind, waves and earthquakes. Site-related aspects such as the breakwater and mooring systems are discussed. The nuclear power plants will be manufactured in a central facility and this manufacturing concept is described.     

核电站三维模型在进度计划管理中的应用

三维技术在被广泛用于设计的同时,设计成果三维模型也包含了大量可用于施工的信息。通过可视化的界面,三维模型可被用于工程施工的各个方面。通过将三维模型与工程进度计划关联,生成四维模型的方法,可实现工程进度计划的可视化管理。