A Versatile Fail-Safe Trip Circuit for Reactor Safety Systems

A transistorized trip circuit is described which employs a simple self-testing technique to achieve a high degree of fail-safeness with a minimum number of components. It operates with d-c input currents in the range from 10 to 100 microamperes and can control up to 100 watts of load power. The trip differential for a load change from full power to zero power is less than 0.1 microampere; and the temperature stability of the trip point is better than 0.02 a/°C. This trip circuit may be used with either relay or solid-state logic and power switching circuits.     

Some Aspect of Protective Systems in Nuclear Power Plants

Protective systems for nuclear power reactors have assumed a high degree of development. The primary motive has been the emphasis given to making reactors safe and more recently the desire to offset the site distance requirement through engineered safeguards. Increased reactor operating experience and improved safety analyses have contributed to a better definition of the events and conditions requiring protective systems. The judicious use of such philosophies as redundancy and coincidence in system designs has led to both greater safety and reactor operating continuity. Reliability of protective systems has been enhanced by parallel efforts in system and individual component design. Techniques and procedures for checking and testing protective systems have been developed and adopted at many installations to offset the inherent difficulty of assessing reliability of systems which experience little or no use under actual stressed conditions. Design practices have been effected to provide greater assurance that systems are independent although this remains as one of the outstanding problems. Protective systems in the context of monitoring devices are being developed by the application of noise analyses, digital computer control and the use of transistorized or solid state circuitry. Finally, the actual performance of protective systems is being manifested through analysis of existing operating records.     

A Transistorized Fail-Safe High-Low Trip

The paper describes a novel transistorized trip circuit which was designed according to A.C. fail safe principles, the circuit trips being on high and low levels, thus indicating off normal input conditions. Both levels are detected by a single regenerative comparator. The output decays within 3 msec after a trip condition, independent of input signal slope or level. The circuit posseses an inherent static trip state lock.     

核反应堆诊断专家系统

本文介绍了专家系统的基本原理,评述了多种核反应堆诊断专家系统,探讨了核反应堆诊断专家系统实用化的知识工程结构。     

A Fail-Safe Reactor Safety System

A highly reliable solid state reactor safety system operated in dynamic mode is described. Direct current signals from detectors for reactor control are converted to pulse signals, which are continuously generated by the circuit until some abnormal condition occurs.

The design and construction of several kinds of logic circuits used for reactor control are explained in detail. The fail-safe property of the circuits have been ascertained by tests, and effects due to temperature variation are negligible in a range 10°~50°C.

Results of reliability analysis show that the reactor safety system described, with redundant dynamic logic circuits, has the necessary qualities to assure highly reliable and safe operation of reactor plants.     

Development Status of Liquid Systems for Stopping Nuclear Reactors

A classification scheme based on the most important indicators, including structural, is proposed for liquid systems for stopping a reactor. The development status of liquid stopping systems (systems which have been built and which are now being designed) for different types of reactors in our country and abroad is presented. The basic parameters and structural features of the systems are presented. Recent directions in the development of liquid stopping systems are noted: reliability of actuation, passive insertion of the absorber, simplification of the construction, integration of the emergency cooling and emergency absorber insertion systems, improvement of mixing, and prevention of the absorber from entering the reactor.The main directions of experimental research on liquid systems and the experimental results on propagation (mixing) of the liquid absorber introduced into the reactor volume and the circulation loop are presented.     

Innovative Nuclear Energy Systems and the Future of Nuclear Power

There is a renewed interest in nuclear power worldwide. The interest is sparked by concerns about global warming and security of energy supplies. In addition to the growing interest in building more reactors in countries that already have nuclear power, future demands for nuclear power are likely to include applications in countries that do not presently use nuclear power and applications beyond large-scale electricity generation. This paper will discuss some of the characteristics that future reactors will need to have to meet such demands, as well as other measures required to facilitate a nuclear renaissance. In addition, the emergence of new international nuclear initiatives and their potential roles will be described.     

Advanced Nuclear Power Systems with Micropelleted Fuel for Nuclear-Powered Ships

The possibilities of using high-temperature reactors operating together with a gas turbine are determined for nuclear-powered icebreakers. The advantages of such systems over previously used nuclear-powered systems and diesel-electric propeller systems are examined. The possibilities of using the MARS-S reactor and gas-turbogenerators, utilizing the heat from the exhaust gases, in nuclear-powered icebreakers are studied. The characteristics of the MARS-S and propeller electric system of a nuclear-powered icebreaker with drive-shaft power up to 90 MW are presented. The possibility of using such systems in floating electric power plants utilizing heat for driving a counterpressure turbine is examined. A version of a single-reactor ship power plant for a lighter and an icebreaker, such as Taimir, is presented. __________ Translated from Atomnaya Energiya, Vol. 99, No. 1, pp. 3–8, July 2005.     

核动力系统多目标优化设计方法研究

为提高核动力系统多目标优化设计结果的精确性,提出一种改进的多目标自适应差分进化算法,并通过测试函数对算法性能进行了验证。基于改进的多目标自适应差分进化算法开发了一种核动力系统多目标优化设计方法;以AP1000核电厂非能动余热排出热交换器为对象,采用开发的核动力系统多目标优化设计方法对其进行了优化设计,计算结果证明该方法是有效可行的。      

Paradigm for Expert Display Systems in Nuclear Plant and Elsewhere

L. Beltracchi has recently published work on a Rankine cycle display of operation for a nuclear power station. Discovery of the display was lengthy and difficult. This paper discusses similar CRT displays of plant operation from the point of view of knowledge representation and presents an abstraction describing a wide class of such displays. It is suggested that this abstraction is a useful tool for discovery of good safety displays. An example for an idealized, very simple plant is given to explain the concept.     

压水堆核动力系统瞬态热工水力特性分析仿真软件

采用点堆中子动力学模型、两相漂移流蒸汽发生器模型、三区不平衡稳压器模型、主循环泵四象限特性模型和非能动应急余热导出系统模型,并利用Compaq Visual Fortran 6.0语言开发了微机型压水反应堆瞬态热工水力特性分析程序,并利用Microsoft Visual Studio.NET语言实现输入参数的可视化、输出结果的实时处理和动态显示。利用RELAP5程序对本瞬态安全分析软件进行了可靠性验证,结果表明,本软件求解精度较高、速度快、界面新颖、功能完善、可操作性强。此外,利用本软件对秦山核电站事故瞬态工况下的热工水力特性进行了分析,得出了一些具有工程价值的结论。     

Electronuclear Systems – a New Generation of Nuclear Power Systems

The possibility of using electronuclear systems as a new generation of safe nuclear power systems is examined. Since the reliability of the linear accelerator is a basic safety element of an electronuclear system, novel methods for increasing accelerator reliability, which were developed at the Institute of Theoretical and Experimental Physics, are proposed.The special features of electronuclear systems as compared with conventional critical reactors are demonstrated by comparing the characteristics of the TVR research reactor at the Institute for Theoretical and Experimental Physics to those of an electronuclear neutron generator based on the TVR and the ISTRA-36 linear proton accelerator. It is shown that the generator is much safer than the TVR reactor.