Study on Lightning Protection Design of DCS in a Nuclear Power Plant

DCS （distributed control system） plays a decisive role in the overall operation of a nuclear power plant. If DCS fails, it will seriously affect the normal production of nuclear power plant, causing great losses. So it is very important to take perfect lightning protection measures on DCS of the nuclear power plant. In this paper, according to the actual situation of DCS in a nuclear power plant, by controlling lightning point, securely booting lightning into the ground network, improving low-resistance ground network, eliminating ground loops, determining the safety space, surge protection of power and signal, a set of complete lightning protection design scheme was systematically put forward. Some specific lightning protection measures were highlighted, such as the DCS grounding, equipotential bonds and shields, and some specific considerations were put forward. All of these could offer reference in the practical application.

Development of nuclear power plant real-time engineering simulator

A nuclear power plant real-time engineering simulator was developed based on general-purpose ther- mal-hydraulic system simulation code RELAP5. It mainly consists of three parts:improved thermal-hydraulic system simulation code RELAP5,control and protection system and human-machine interface. A normal transient of CHASHMA nuclear power plant turbine step load change from 100% to 90% of full power,was simulated by the en- gineering simulator as an application example. This paper presents structure and main features of the engineering simulator,and application results are shown and discussed.

Study on Site Specific Design Earthquake Ground Motion of Nuclear Power Plants in China

The main technical backgrounds and requirements are introduced with regard to earthquake ground motion design parameters in several domestic and American standards,codes and guides involved in the seismic analysis and design activities of nuclear power plants in China.Based on the research results from site seismic safety evaluation of domestic nuclear power plant projects in the last years,characteristics and differences of site specific design spectra are analyzed in comparison with standard response spectra,and the suitability of standard response spectra for domestic nuclear power plant projects is discussed.

Probabilistic Approach of Coastal Defense Against Typhoon Attacks for Nuclear Power Plant

With the global warming and sea level rising, it is widely recognized that there is an increasing tendency of typhoon occurrence frequency and intensity. The defenses code against typhoon attacks for nuclear power plant should be calibrated because of the increasing threat of typhoon disaster and severe consequences. This paper discusses the probabilistic approach of definitions about ＂probable maximum typhoon＂ and ＂probable maximum storm surge＂ in nuclear safety regulations of China and has made some design code calibrations by use of a newly proposed Double Layer Nested Mtdti-objective Probability Model （DLNMPM）.

Research on the attribution evaluating methods of dynamic effects of various parameter uncertainties on the in-structure floor response spectra of nuclear power plant

： Consideration of the dynamic effects of the site and structural parameter uncertainty is required by the standards for nuclear power plants （NPPs） in most countries. The anti-seismic standards provide two basic methods to analyze parameter uncertainty. Directly manually dealing with the calculated floor response spectra （FRS） values of deterministic approaches is the first method. The second method is to perform probability statistical analysis of the FRS results on the basis of the Monte Carlo method. The two methods can only reflect the overall effects of the uncertain parameters, and the results cannot be screened for a certain parameter＇s influence and contribution. In this study, based on the dynamic analyses of the floor response spectra of NPPs, a comprehensive index of the assessed impact for various uncertain parameters is presented and recommended, including the correlation coefficient, the regression slope coefficient and Tornado swing. To compensate for the lack of guidance in the NPP seismic standards, the proposed method can effectively be used to evaluate the contributions of various parameters from the aspects ＆sensitivity, acuity and statistical swing correlations. Finally, examples are provided to verify the set of indicators from systematic and intuitive perspectives, such as the uncertainty of the impact of the structure parameters and the contribution to the FRS of NPPs. The index is sensitive to different types of parameters, which provides a new technique for evaluating the anti-seismic parameters required for NPPs.

Preliminary design for inland nuclear power plants completed

The State Nuclear Power Technology Corporation (SNPTC), which is responsible for the development of third-generation nuclear power technology in China, has completed the preliminary designs

核电厂安全级DCS缺省值设置策略研究

针对数字化仪控系统中无效信号的质量位随意蔓延使系统处于一种不确定状态的问题,结合核电厂运行工况和信号特性,对龙鳞平台故障诊断机制和信号质量位标识进行研究。考虑故障安全准则,系统性地提出缺省值设置原则。从信号执行功能和信号边界两个维度进行分析,确认缺省值的设置范围,并详细给出执行保护功能、报警功能、维护和试验功能信号的缺省值设置策略。同时,针对传统的缺省值验证方式无法全面、有效地进行缺省值验证的问题,提出一种利用全范围模拟机和虚拟数字化控制系统(DCS)进行缺省值验证的新方法。利用该方法可有效地对DCS内设置的缺省值进行系统性的验证。所提出的缺省值设置策略和验证方法可为后续核电厂安全级DCS的缺省值分析和设置提供全面的指导。

Ovation DCS控制系统在火电厂自动配煤掺烧中的应用

为增强火电厂自动配煤掺烧效果,提出在火电厂自动配煤掺烧中应用Ovation DCS控制系统。详细介绍了Ovation DCS控制系统的特点和组成,强调其在火电厂自动配煤掺烧中的关键作用,并深入探讨了控制原则以及优先配煤、顺序配煤、余煤配煤3种控制方式,阐述了它们的应用场景和优势。此外,详细描述了自动配煤流程,并进行了火电厂自动配煤控制逻辑设计,包括控制流程设计和控制宏编写,以实现DCS系统的高效运行,并利用时序图方式进行了效果验证,证明了Ovation DCS控制系统在火电厂自动配煤掺烧中的有效性和可行性。

基于ADACS_N平台的DCS二层系统服务器国产化替代与软件移植研究

针对核电厂DCS系统服务器硬件老化与停产共性问题,基于法国ADACS_N平台的DCS二层系统,研究一种服务器国产化替代与软件移植的可行方法,结合系统软硬件架构分析、国产化服务器硬件替代选型策略、源代码移植技术研究、最小化测试平台开发,为延长核电厂DCS系统生命周期、解决进口设备“卡脖子”问题、提升核电厂DCS关键设备自主能力提供一定参考。

The CAD System Development for Power Plants Pipe-Prefabrication

An intelligent design software system for the power station pipe-prefabrication (PPDS) has been developed in the paper,which is taking pipe material database as core and developed on the platform of AutoCAD and Borland C++. Whereas design and construction of power plants in China belong to different deportments,the input and recognition problem of pipeline system disposition chart must be solved firstly for the prefabrication design.Based on AI technology,the model fast building subsystem (MFBS) was established for entering the 3-D pipeline graph data,so that the problems of reconstruction of pipeline digital model and computer identification of original 2-D design data can be solved. The optimization design scheme in the pipe-prefabrication process has been studied and also the corresponding algorithm put forward.The technique and system mentioned can effectively raise the pipe-prefabrication design quality and efficiency in the con- struction of large scale power plants,reduce the period of design and the waste of raw material.PPCADS has still offered the functions such as the construction design for pipeline prefabricated process,the detailing drawing for manufacturing pipe section and automatic generating the technical files for the completed project.

核电DCS网络安全防护技术研究

核电数字化控制系统(DCS)属于国家关键信息基础设施(CII),亟需为其建立综合防御、积极防范、本质安全的网络安全保障体系。基于国家标准法规技术要求,结合核电DCS业务特点、安全现状,对DCS网络安全防护技术进行了深入研究,形成了满足核电DCS业务需求和网络安全等级保护四级技术要求的整体防护技术方案。防护技术方案以“一个中心、三重防护”为设计核心,基于自主研发的网络安全产品,创新应用多项保障DCS业务安全的关键技术,采用安全区域划分、分布控制、集中管控等安全措施构建了网络安全综合防御体系,有效提升了核电DCS防护能力。相关技术已在多个核电工程项目落地,应用效果良好,为其他领域的国家CII系统网络安全建设提供了良好的示范和借鉴。

核电站DcS仪控系统网络信息安全产品的研究与应用

随着国内核电站的不断增多,核电站国产DCS仪控系统的可用性以及可靠性取得了重大进步,近些年来由于工业控制领域的信息安全问题频发,因此对DCS仪控系统的要求也在不断提高。依托北京广利核系统工程有限公司DCS仪控系统,笔者研究并设计了网络信息安全产品-和睦卫士网络安全系统。该网络安全系统已在红沿河核电站5号机组DCS仪控系统中应用,通过测试人员调试验证及现场使用,证明了其能够有效地应对网络战环境下复杂的信息安全威胁,并构建了积极防御、综合防范、本质安全的保障体系,为其他核电站甚至其他控制领域提供了良好的借鉴。

核电站DCS系统数字通信网络的时钟同步研究

随着核电二代加或三代机组中全数字化(DCS)控制系统的应用,以网络交互技术为基础的数据通讯成为DCS系统核心组成。DCS系统时钟网络为数据处理及显示系统、电厂控制系统和汽轮机控制系统等核电站众多仪表设备提供授时服务,因此数字通信网络的时钟同步对电厂安全稳定运行尤为重要。结合某核电站DCS一层时钟跨年跳变导致电站计算机信息和控制系统(KIC)历史曲线记录不更新的事件处理,研究了数字通信网络的同步模式和数字通信中网络时钟滑动。通过研究,探索改进时钟授时系统提高可靠性的方法,对现役核电厂授时系统的改造和新建核电厂授时系统的设计有良好的指导作用。

可用性分配法优化核电厂非安全级DCS系统设计

为核电厂非安全级数字化仪控系统(DCS)系统在设计阶段明确板卡级设备可靠性要求,在产品设计阶段利用可靠性分配方法将可用性指标合理地分配到组成系统的各部件中,可用性分配结果是开展可靠性预计工作目标和设计参考依据,可靠性预计结果是进行可靠性指标分配调整与系统指标验证的基础,二者相辅相成,通过迭代分配和指标验证为实现核电厂非安全级DCS系统设计优化提供参考。

核级DCS系统应用软件第三方评定方法研究

核级DCS系统是核电厂最重要的系统之一,对确保核电厂的安全运行起着至关重要的作用。核级DCS系统的最大特点是通过软件来实现核电厂的安全保护功能。如何保证软件开发过程及最终产品满足预期需求,同时不引入非预期特性,是确保核级DCS系统可靠性和安全性的关键。在最新版核安全导则HAD 102/10中,对于核级DCS系统软件,新增了第三方评定的相关要求。本文遵循相关要求,研究并提出了一种适用于核级DCS系统应用软件第三方评定的方法。该方法已在某核级DCS供货项目中进行了应用,并取得了良好的应用效果。

非安全级DCS控制柜I/O卡件供电及通信设计优化

由于分布式控制系统(DCS)卡件供电及通信方式配置不合理,存在单块输入/输出(I/O)卡件底座故障导致同一列下游卡件同时故障,进而导致机组非计划停堆或面临大瞬态的问题。创新性地对核电厂DCS控制柜I/O卡件供电及通信方式进行了研究。结合硬件属性,全面分析了当前设计下对后续机组安全、稳定运行产生的不利影响,并对同行核电厂不同DCS平台I/O卡件供电及通信设计开展调查。从可靠性和可维护性角度,针对性地提出优化方案,并成功对170台控制柜完成优化改造。该研究有效规避了机组商运后的大量技术改造和验证工作,提高了机组商运后运行的安全性、稳定性和经济性。

基于机器学习的核电厂DCS卡件故障诊断研究

随着核电厂运行时间的累积,数字化仪控设备的老化问题日益凸显。开关电源电路模块是分布式控制系统(DCS)卡件的关键组成部分。该模块的故障会导致卡件失效,甚至可能破坏核电厂的安全经济运行。针对核电厂某DCS卡件开关电源电路模块,开展了基于机器学习的板级故障诊断研究。根据传统机器学习和深度学习,分别开发了粒子群优化(PSO)-支持向量机(SVM)和一维卷积神经网络(1D-CNN)模型。小波包变换用于PSO-SVM模型的电路故障特征提取。基于加速寿命试验获得的电容老化过程数据,通过Saber电路建模仿真采集了开关电源在对应故障模式下的输出电压波形,用于模型的训练和测试。试验结果表明,所开发的故障诊断模型均表现出良好的诊断性能。该研究完成了故障诊断方法的可行性验证,不仅为DCS卡件的预测性维护提供了具有实际工程意义的应用参考,也为后续开展系统级健康管理研究奠定了一定的理论基础。

基于NASPIC的安全级DCS冗余IO设计

在核电站反应堆保护系统的某些特殊应用中,比如极为重要的控制信号、无扰维护、不可运行性限制等场景,需要考虑可靠、稳定、有效的冗余IO设计,在不显著增加设备数量和故障点的前提下提高系统的可靠性和可用性指标。基于NASPIC平台的软件和硬件特征,以某核电站反应堆保护系统数字化升级项目为例,提供一种稳定可靠的冗余IO设计方案,对类似应用需求场景具有适用性,对于华龙一号批量化建设具有一定的借鉴意义。

核电厂国产非安全级DCS应用建议

首先对核电站全厂控制系统的组成进行了介绍;接着结合近年来我国的大型核电建设工程,总结了国产非安全级DCS的发展路径及现状。在此基础上,从常规工业领域DCS的国产化应用、国产DCS的可靠性、国产DCS面向核电站功能需求的二次开发、核电站自主化设计以及建设进度控制等多个维度,较为全面地分析了核电站非安全级DCS全面国产化的可行性及其带来的积极的影响。

核电DCS改造风险评估方案与控制方法探讨

DCS系统是核电机组的重要组成部分,其功能包括传输采集数据、传送控制指令、修改控制逻辑等,直接关系到机组运行安全性和稳定性。针对DCS改造风险问题进行探究,从DCS系统的软硬件结构入手,介绍了核电DCS改造的风险评估方案和控制方法,并结合典型案例进行分析。实践表明:制定完善可行的风险评估方案和控制方法,能降低DCS系统的改造风险,可缩短工期、节约成本,更好地实现预期改造目标。