Quality assurance for a nuclear power plant simulator by applying standards for safety-critical software

Nuclear power plant simulators are playing a more important role in nuclear power plant lifecycle analysis, and the quality of the simulators should be verified to ensure the safety of nuclear power plants. Currently, there is no systematic quality assurance method for nuclear power plant simulators. In this paper, a systematic quality assurance method for nuclear power plant simulators is proposed basing on experiences with safety-critical software. Key aspects of the method are discussed. In addition, application of this method to a real project is also described as a practical reference.     

A framework for nuclear power plant emergency response system

<正>The purpose of this study is to establish an intelligent expert system for nuclear power plant emergency response.A new framework of environmental risk management methodology by the concept of pattern recognition was introduced in this paper.A knowledge-based decision support system for emergency response and risk management of nuclear power plant was also discussed.The mathematical pattern relationship of accidental release effects on neighboring area and the corresponding response measures were presented in this paper.With this decision system,the decision maker can specify the procedure and minimize their human error in the decision process.The improvement of risk response and the quality of management system could be upgraded by this system.Besides,the methodology can also be served as a basis for the future development of environmental risk response system design.     

核动力装置运行过程可靠性研究现状与发展

核动力装置运行过程的可靠性研究是保障装置安全，提高装置效能的重要基础，本文从运行过程可靠性问题的背景出发，研究了可靠性分析方法的适应性，并论述了问题研究的技术途径。     

核电机组电气设计分析

近年来,我国核电事业得到快速发展,一大批核电项目陆续开工建设,其中大部分为引进技术的二代改进型和三代核电机组。由于技术输出国的标准规范与我国现有的核电设计标准不一致,以及考虑厂址适应性等问题,我国对引进的核电机组存在逐步消化、吸收并改进的过程。本文对核电机组的电气设计进行探讨,希望对今后同类工程具有参考作用。     

Physics basis for the advanced tokamak fusion power plant, ARIES-AT

The advanced tokamak is considered as the basis for a fusion power plant. The ARIES-AT design has an aspect ratio of A≡R/a=4.0, an elongation and triangularity of κ=2.20,δ=0.90 (evaluated at the separatrix surface), a toroidal beta of β=9.1% (normalized to the vacuum toroidal field at the plasma center), which corresponds to a normalized beta of β_N≡100×β/(I_P(MA)/a(m)B(T))=5.4. These beta values are chosen to be 10% below the ideal MHD stability limit. The bootstrap-current fraction is f_BS≡I_BS/I_P=0.91. This leads to a design with total plasma current I_P=12.8  MA, and toroidal field of 11.1 T (at the coil edge) and 5.8 T (at the plasma center). The major and minor radii are 5.2 and 1.3 m. The effects of H-mode edge gradients and the stability of this configuration to non-ideal modes is analyzed. The current drive system consists of ICRF/FW for on-axis current drive and a Lower Hybrid system for off-axis. Transport projections are presented using the drift-wave based GLF23 model. The approach to power and particle exhaust using both plasma core and scrape-off-layer radiation is presented.     

核电站仪控系统数字化开发仿真测试技术研究

在核电站应用数字化仪表与控制 (I&C)取代模拟 I&C 系统,已成为必然的发展趋势。本文分析了核电站全范围模拟机的蒸汽发生器数学模型,研制开发独立的核电站蒸汽发生器实时仿真系统,并与控制系统形成能够相互作用的闭环系统,用于数字化仪控系统改造提供仿真对象及进一步控制方案研究。在仿真过程中,除了仿真模型之外,其他的硬件和软件由真实的控制系统构成。不但为核电站仪表与控制 (I&C)系统数字化开发提供理论分析,也为今后现场调试工作创造有利条件。     

从大亚湾三环路到秦山二期两环路看我国核电站自主设计能力

秦山核电二期工程与大亚湾核电站相比,反应堆功率下降,冷却剂系统三环路变为两环路。因此,重新设计了有关系统,并进行了相应的试验研究与工程验证。初步运行结果表明,设计是成功的。本文介绍部分系统的设计变化与特点以及相关的试验研究,反映设计与试验研究的成功结合,展现我国自主发展核电、自主设计大中型商用核电站的能力。     

Structural integrity analysis of an Ignalina nuclear power plant building subjected to an airplane crash

Recent terrorist attacks using commandeered commercial airliners on civil structures have raised the issue of the ability of nuclear power plants to survive the consequences of an airliner crash. The structural integrity analysis due to the effects of an aircraft crash on an Ignalina nuclear power plant (INPP) accident localization system (ALS) building is the subject of this paper. A combination of the finite element method and empirical relationships were used for the analysis. A global structural integrity analysis was performed for a portion of the ALS building using the dynamic loading from an aircraft crash impact model. The local effects caused by impact of the aircraft's engine on the building wall were evaluated independently by using an empirical formula.The results from the crash analysis of a twin engine commercial aircraft show that the impacted reinforced concrete wall of the ALS building will not have through-the-wall concrete failure, and the reinforcement will not fail. Strain-rate effects were found to delay the onset of cracking. Therefore, the structural integrity of the impacted wall of the INPP ALS building will be maintained during the crash event studied.     

田湾核电站堆芯装换料管理子系统设计

田湾核电站机组堆芯采用堆内倒换换料技术,装换料管理子系统是燃料管理系统的子系统之一,它以直观的图形操作方式协助管理人员完成核燃料堆芯装卸料的步序设计和优化工作.该子系统为纯B/S结构,采用ASP.NET平台、矢量绘图、暗通道提交、图片缓存等技术.本文介绍了该子系统的设计思路,重点阐述了图形交互技术的实现方法.     

Optimization of a dynamic uncertain causality graph for fault diagnosis in nuclear power plant

Fault diagnostics is important for safe operation of nuclear power plants (NPPs).In recent years,data-driven approaches have been proposed and implemented to tackle the problem,e.g.,neural networks,fuzzy and neurofuzzy approaches,support vector machine,K-nearest neighbor classifiers and inference methodologies.Among these methods,dynamic uncertain causality graph (DUCG)has been proved effective in many practical cases.However,the causal graph construction behind the DUCG is complicate and,in many cases,results redundant on the symptoms needed to correctly classify the fault.In this paper,we propose a method to simplify causal graph construction in an automatic way.The method consists in transforming the expert knowledge-based DCUG into a fuzzy decision tree (FDT) by extracting from the DUCG a fuzzy rule base that resumes the used symptoms at the basis of the FDT.Genetic algorithm (GA) is,then,used for the optimization of the FDT,by performing a wrapper search around the FDT:the set of symptoms selected during the iterative search are taken as the best set of symptoms for the diagnosis of the faults that can occur in the system.The effectiveness of the approach is shown with respect to a DUCG model initially built to diagnose 23 faults originally using 262 symptoms of Unit-1 in the Ningde NPP of the China Guangdong Nuclear Power Corporation.The results show that the FDT,with GA-optimized symptoms and diagnosis strategy,can drive the construction of DUCG and lower the computational burden without loss of accuracy in diagnosis.     

Optimization of a dynamic uncertain causality graph for fault diagnosis in nuclear power plant

Fault diagnostics is important for safe operation of nuclear power plants (NPPs).In recent years,data-driven approaches have been proposed and implemented to tackle the problem,e.g.,neural networks,fuzzy and neurofuzzy approaches,support vector machine,K-nearest neighbor classifiers and inference methodologies.Among these methods,dynamic uncertain causality graph (DUCG) has been proved effective in many practical cases.However,the causal graph construction behind the DUCG is complicate and,in many cases,results redundant on the symptoms needed to correctly classify the fault.In this paper,we propose a method to simplify causal graph construction in an automatic way.The method consists in transforming the expert knowledge-based DCUG into a fuzzy decision tree (FDT) by extracting from the DUCG a fuzzy rule base that resumes the used symptoms at the basis of the FDT.Genetic algorithm (GA) is,then,used for the optimization of the FDT,by performing a wrapper search around the FDT:the set of symptoms selected during the iterative search are taken as the best set of symptoms for the diagnosis of the faults that can occur in the system.The effectiveness of the approach is shown with respect to a DUCG model initially built to diagnose 23 faults originally using 262 symptoms of Unit-1 in the Ningde NPP of the China Guangdong Nuclear Power Corporation.The results show that the FDT,with GA-optimized symptoms and diagnosis strategy,can drive the construction of DUCG and lower the computational burden without loss of accuracy in diagnosis.     

核电站设备三维模型设计的基本准则和应用实践

详细介绍了三维设备模型设计在核电站中的实际应用,概括了建模准则的制定、程序编制、模型建立、项目实践的全过程。阐述了作为数字核电站的重要组成部分——三维设备模型设计的基本准则和应用实践,从而进一步验证了数字电厂主要结构体系和程序配置的合理性、有效性,对核电站全寿期管理概念的具体实践进行了有益的尝试,并取得了良好的应用成果。为三维设备模型更深入地应用于大亚湾、岭澳核电站的运行、维修模拟以及岭澳二期、广三核项目的工程设计管理,奠定了可靠的工作基础。     

自主化1000MW级压水堆核电站核蒸汽供应系统概念设计

本文简介介绍了我国百万千瓦级压水堆核电站（ＣＮＰ１０００）核蒸汽供应系统的概念设计,主要内容为主要技术参数、堆芯设计、反应堆冷却剂主回路系统及其主要设备设计、安注系统、辅助给水系统和数字化仪表与控制系统设计。     

核电厂厂址选择阶段的总图运输设计

简要地介绍了核电厂厂址选择阶段的总图运输设计的基本任务、规则设计，并讨论了建设子项的确定、主厂区平面设计、竖向布置和防设计基准共水位等技术问题。     

A cascade intelligent fault diagnostic technique for nuclear power plants

Safe operation of nuclear power plant is one of the most important tasks in nuclear power development. This justifies the variety of methods that have been proposed to support the operators in the task of plant condition monitoring, fault detection, and diagnosis. A number of hybrid fault detection and diagnosis methods have also been proposed, with their attendant weaknesses. This work proposes the hybrid of principal component analysis (PCA), signed directed graph (SDG), and Elman Neural Network (ENN) for fault detection, fault isolation, and severity estimation, respectively. The proposed hybrid method is verified with the data derived from Personal Computer Transient Analyzer (PCTRAN) simulation. The verification result shows that the PCA-based fault detection methodology realized timely detection of anomaly in the simulated nuclear power plants system, the SDG-based fault recognition method was able to isolate the system abnormality and identify the root causes, and the ENN-based fault severity estimation method presents the failure fraction of fault, representing the severity. With this integrated hybrid method, more fault information is provided for the operators, which serves as a good foundation for further decision-making and interventions.     

An interface redesign for the feed-water system of the advanced boiling water reactor in a nuclear power plant in Taiwan

A well-designed human-computer interface for the visual display unit in the control room of a complex environment can enhance operator efficiency and, thus, environmental safety. In fact, a cognitive gap often exists between an interface designer and an interface user. Therefore, the issue of the cognitive gap of interface design needs more improvement and investigation. This is an empirical study that presents the application of an ecological interface design (EID) using three cases and demonstrates that an EID framework can support operators in various complex situations. Specifically, it analyzes different levels of automation and emergency condition response at the Lungmen Nuclear Power Plant in Taiwan. A simulated feed-water system was developed involving two interface styles. This study uses the NASA Task Load Index to objectively evaluate the mental workload of the human operators and the Situation Awareness Rating Technique to subjectively assess operator understanding and response, and is a pilot study investigating EID display format use at nuclear power plants in Taiwan. Results suggest the EID-based interface has a remarkable advantage over the original interface in supporting operator performance in the areas of response time and accuracy rate under both normal and emergency situations and provide supporting evidence that an EID-based interface can effectively enhance monitoring tasks in a complex environment.     

结构材料常规疲劳数据库开发

开发了反应堆结构材料常规疲劳数据库管理系统，库中包含了常规疲劳设计分析曲线参量，即应力－寿命、概率－应力－寿命、应变－寿命、概率－应变－寿命、循环应力－应变及概率－循环应力－应变曲线参量，以及相关材料和试验条件信息。可通过材料名称或机械性能区间指标查询。根据查询结果，可进行常规疲劳设计分析与评价或常规疲劳可靠性设计分析与评价。     

Fuzzy probability on reliability study of nuclear power plant probabilistic safety assessment: A review

Fault tree analysis (FTA) is a graphical model which has been widely used as a deductive tool for nuclear power plant (NPP) probabilistic safety assessment (PSA). The conventional one assumes that basic events of fault trees always have precise failure probabilities or failure rates. However, in real-world applications, this assumption is still arguable. For example, there is a case where an extremely hazardous accident has never happened or occurs infrequently. Therefore, reasonable historical failure data are unavailable or insufficient to be used for statistically estimating the reliability characteristics of their components. To deal with this problem, fuzzy probability approaches have been proposed and implemented. However, those existing approaches still have limitations, such as lack of fuzzy gate representations and incapability to generate probabilities greater than 1.0E-3. Therefore, a review on the current implementations of fuzzy probabilities in the NPP PSA is necessary. This study has categorized two types of fuzzy probability approaches, i.e. fuzzy based FTA and fuzzy hybrid FTA. This study also confirms that the fuzzy based FTA should be used when the uncertainties are the main focus of the FTA. Meanwhile, the fuzzy hybrid FTA should be used when the reliability of basic events of fault trees can only be expressed by qualitative linguistic terms rather than numerical values.     

Applications of fault detection and diagnosis methods in nuclear power plants: A review

Nuclear power industries have increasing interest in using fault detection and diagnosis (FDD) methods to improve safety, reliability, and availability of nuclear power plants (NPP). A brief overview of FDD methods is presented in this paper. FDD methods are classified into model-based methods, data-driven methods, and signal-based methods. While practical applications of model-based methods are very limited, various data-driven methods and signal-based methods have been applied for monitoring key subsystems in NPPs. In this paper, six areas of such applications are considered. They are: instrument calibration monitoring, instrumentation channel dynamic performance monitoring, equipment monitoring, reactor core monitoring, loose part monitoring, and transient identification. The principles of using FDD methods in these applications are explained and recent studies of advanced FDD methods are examined. Popularity of FDD applications in NPPs will continuously increase as FDD theories advance and the safety and reliability requirement for NPP tightens     

核电厂流程整理和优化试点项目的实施

为使江苏核电有限公司(以下简称"JNPC")的质量管理体系的适用性、操作性得到进一步提升,从扩建工程的程序体系入手,引入跨行业的先进经验和在程序管理领域的良好实践,JNPC组织实施了流程整理和优化项目的规划及试点工作。希望通过项目的开展,能够实现业务过程端到端的管理,减少不增值流程。