核电厂主蒸汽管道阻尼减振与抗震分析

增设阻尼器是处理核电厂主蒸汽管道振动与地震冲击问题的主要方法。本文利用Sap2000软件建立核电厂主蒸汽管道的有限元模型,分析出了管道的固有频率、振型等动态特性。分析结果表明,平动是主要的影响振型。本文应用非线性动力时程分析计算蒸汽管道在33 Hz频率下的振动及地震响应,得到了管道加设阻尼器前后的振动位移和振动速度数据,并进行了比较,探讨了阻尼器在管道减振与抗震中的应用效果。结果表明,在不改变管道原有结构、不影响管道正常工作的前提下,安装液体黏滞阻尼器可以对主蒸汽管道产生减振与抗震的效果。     

核电厂阻尼器试验台的设计分析

核电厂主设备阻尼器综合试验台架为核电厂蒸汽发生器、稳压器、主泵等主设备阻尼器实施动态和静态试验,文章对核电厂主设备阻尼器综合试验台架整体方案设计及主要系统进行了介绍,对执行元件和控制元件两类关键设备进行了详细的计算分析和选型。     

核岛管道阻尼器低速摩擦阻力限值分析

核岛管道和设备上常设置液压阻尼器来保护管道或设备免受地震或其他突发震动而损坏,阻尼器的性能参数至关重要,低速摩擦阻力限值是其中的一个重要参数。但由于规范的缺乏,参数的确定无明确的依据,国内外的核电厂采用的数据不一。为了确定低速摩擦阻力限值,从阻尼器的工作原理分析摩擦阻力产生的原因,分析不同参数的阻尼器对管道应力的影响,并调研了国内外核电厂管道阻尼器的实际情况,提出了阻尼器摩擦阻力限值的推荐值和试验注意事项。对设计和运行阶段核电站阻尼器参数的提出具有参考价值。     

核岛主设备支撑用大吨位液压阻尼器密封件延寿可行性研究

基于液压阻尼器密封件的密封压缩回弹原理,通过密封件压缩变形与服役时间的变化关系曲线,对美国麦奎尔核电厂2号机组运行20 a后拆卸的德国Lisega大吨位液压阻尼器密封件的预测寿命进行了计算。计算结果表明,以德国Lisega公司生产的大吨位液压阻尼器为例,无论是外部密封还是内部密封,其密封件预测寿命明显要长于目前在役或在建核电厂中规定的密封件更换周期。     

核电厂常规岛蒸汽系统液压阻尼器漏油原因分析及对策

近年来核电厂常规岛蒸汽系统液压阻尼器液压油泄漏故障多有发生,个别位置液压油泄漏缺陷频发,造成较大的经济损失和设备运维成本.阻尼器液压油泄漏有多方面的原因,本文针对常规岛蒸汽系统高周低幅振动工况下发生的液压油泄漏缺陷阻尼器进行了解体检查,对活塞杆单一位置持续磨损造成液压油密封失效的原因进行了分析.从运行工况、密封部位结构...     

CFD方法在核电厂氢气风险分析中的应用

梳理了核电厂氢气风险分析技术的现状;讨论了CFD方法在核电厂氢气风险分析中的优势及局限;介绍了国际上针对CFD氢气风险分析方法开展的实验项目;以EPR核电厂为例说明了CFD方法在核电厂氢气风险分析中的应用。在以上基础上,展望了核电厂氢气风险分析CFD方法的发展方向。     

基于三维模型的核电厂4D大修信息化平台技术研究

核电厂大修是核电厂运维中的重要工作,由于核电厂属于复杂庞大的资产密集型企业,加上辐照影响和核安全性的要求,使得大修管理的难度较大。探讨研究了核电厂大修的特点、难点和痛点,论述了核电厂大修4D信息化平台技术的必要性和4D大修信息化平台的建立和应用的方法和步骤,并详细介绍了4D大修信息化平台技术在国内应用的案例和实用成效。4D大修信息化平台作为产品生命周期管理(PLM)系统的局部应用,可为核电厂大修提供标准化、可视化、模块化的专业维修管理服务。     

多谱分析法在核级管道抗震分析中的应用

多谱分析法和单谱分析法是核电厂管道抗震分析常用的2种方法.多谱分析法是在管道的各个支承点施加不同的激励,单谱分析法是对管道的支承采用一致激励.多谱分析法考虑了地震激励随空间的变化.本文分别采用多谱分析法和单谱分析法对削减阻尼器后的主蒸汽系统(VVP)管线进行计算,分析2种方法对阻尼器反力的影响.结果表明,2种分析方法的...     

核动力管道抗震完整性试验及分析研究

对于偶发性地震载荷过分保守的处理导致核电厂管道系统使用大量的阻尼器、支吊架而使管道系统刚性过大,使核电厂的制造、安装、在役检查及维修等费用增加。依托主管道先进设计技术和试验验证项目,完成了核动力管道系统的抗震极限承载能力试验。将试验和计算分析结果与现行规范对比,明确了当前管道设计标准的安全裕量,提出了管道系统阻尼比值与应力评价准则等参数的取值建议。     

核电厂退役标准体系建设需求分析

核电的发展必须考虑将来的退役需求和标准体系建设。文章调研了世界主流核电厂退役的法规标准体系、我国现行的核电厂退役政策及标准体系情况;分析了核电厂退役过程中的主要活动,从而明晰核电厂退役所需的标准要求;在此基础上,提出了我国核电厂退役的结构化标准体系框架及标准建设的关注要素。本文研究成果可供我国核电厂退役标准体系建设进行参考和应用。     

核电厂阻尼器的应用及创新

在建筑、桥梁与核电站中应用阻尼器可以很好地在地震来临时保护结构物和构筑物的安全,阻尼器可以视为一种结构保护装置。阻尼器是核电站中管道与机械设备的重要安全保护装置。本文从制造、使用和测试3个方面分别介绍了目前结构保护系统中阻尼器的相关内容,并对比了核电领域与土木工程领域中对抗震阻尼器的不同理解和认知,文中也对核电领域阻尼器的应用的创新和发展提出了建议。     

核电厂通风系统防火阀应用现状及维修优化分析

为了提高核电厂防火阀的可靠性,对多个电厂防火阀的应用现状和故障历史进行了梳理,并采用故障模式及影响分析（FMEA）方法对不同防火阀故障机理和维修策略优化进行了研究。结果表明,对年度外观与动作检查任务进行优化,并增加定期更换熔断元件和电动机构任务,有效降低了防火阀故障率,保证了核电厂的安全稳定运行。      

基于FDS的核电厂主储油罐间防火阀响应控制效用模拟研究

通过应用火灾动力学软件FDS,建立了一套核电厂主储油罐间防火阀响应与失效两种状态下的对比模型,讨论了烟气形态、火焰形态、火源热释放速率及火灾温度场随时间的变化规律。研究表明,防火阀对于核电厂主储油罐间火灾事故的控制效果非常明显,通过火灾封锁法能够有效控制火源热释放速率,降低环境温度,体现了FDS应用在核电厂火灾预防方面的优势。     

Seismic safety of nuclear power plants in eastern Europe

This paper summarizes the work performed by the International Atomic Energy Agency in the areas of safety review and applied research in support of programmes for the assessment and enhancement of seismic safety in Eastern Europe and in particular, WWER type nuclear power plants during the past seven years. Three major topics are discussed; engineering safety review services in relation to external events, technical guidelines for the assessment and upgrading of WWER type nuclear power plants, and the Coordinated Research Programme on "Benchmark study for the seismic analysis and testing of WWER type nuclear power plants". These topics are summarized in a way to provide an overview of the past and present safety situation in selected WWER type plants which are all located in Eastern European countries. The main conclusion of this paper is that even though there is now a thorough understanding of the seismic safety issues in these operating nuclear power plants, the implementation of seismic upgrades to structures, systems and components are lagging behind, particularly for those cases in which re-evaluation indicated the necessity to strengthen the safety related structures or install new safety systems.     

浮动核电站跨界转运的安全和法律问题初步研究

浮动核电站具有模块化、多用途、可移动、运行灵活、适应性强等优势,受到了国际社会的广泛关注,具有广阔的应用前景和发展空间。然而,浮动核电站由于特殊的海外部署场景和可移动特性,不可避免地面临着跨越主权边界转运的安全和法律问题。结合浮动核电站不同的海外部署场景,重点对浮动核电站在不同部署场景下跨界转运可能面临的安全和法律问题进行梳理总结和讨论分析,并从法律、安保和应急层面提出可能的解决方案建议,对浮动核电站跨界转运相关的国际公约和规则制定具有一定参考意义。     

A practical system for isolating nuclear power plants from earthquake attack

The earthquake-generated forces and deformations of the main substructures of a nuclear power plant can be reduced by a factor of about ten times by mounting the power plant building on a recently developed base-isolation system. The very high forces which the ‘resonant appendage’ effect may induce in some critical components (such as fuel elements and control rods) may be reduced by a factor of 40 or more by the isolation system. This system combines recently developed hysteretic dampers with components which support the structure while providing high flexibility for horizontal motion. These dampers utilize the plastic deformation of solid steel beams, while a convenient support system with adequate horizontal flexibility may be provided by laminated rubber bearings of the type frequently used to support bridge decks. The earthquake attack on a nuclear power plant is particularly hazardous since it attacks simultaneously all the plant components, including the control and safety systems. Undetected deterioration of a set of components may further increase the probability of multiple failure during earthquakes. Hence the large reduction in earthquake-induced forces and deformations, which may be achieved with the base-isolation system described, will greatly reduce the likelihood of earthquake-induced accident or damage in those nuclear power plants located in regions of high seismicity.     

浮动核电站设计中的安全准则研究

浮动核电站作为船海工程与核电工程的结合,属于核能工程的新领域,国内尚缺少相应的安全设计准则。结合海洋核动力平台示范工程实际设计需求,基于对陆上压水堆核电厂、海上移动式平台、核动力舰船规范的分析,从浮动核电站总体设计、平台设计以及核安全3个层面分别提出了相应的安全设计准则。研究表明,浮动核电站的安全设计应围绕3项基本安全功能进行;平台设计应考虑布置、结构、辅助系统、电力、通信、消防6个因素;核安全设计应充分考虑其孤岛运行和海洋应用场景对核动力装置系统设备设计、运行的制约影响。      

Experiences from sensor tests and evaluation of sensor performance

Sensors are part of the protection system in a nuclear power plant. They are the first link in the chain with influence to the protection system. It is therefore important that the sensors fulfil the demands of reliability and response time. Dynamic investigations of the sensor systems are possible to perform during operation of the plant with the aid of advanced signal analysis. Correctly performed, such an investigation indicates if any sensor with attached sensing lines deviates from the expected dynamic behaviour. The paper presents results from Ringhals 1 in Sweden where snubbers (pulsations dampers with exchangeable needles) were used in the sensing lines to differential pressure sensors. The dynamic influence of the needles was equivalent to a time constant = 0.55 s. It was clear that the response time was longer than the demanded response time with respect to the sensors task in the safety system. By eliminating the needles the demand on the response time was fulfilled. The deviation lead to a report to the Swedish Nuclear Power Inspectorate (equivalent to a Licensee Event Report) with INES level 1. The title of the report is “Too long response time caused by not correct installed pulsation dampers in swelling transmitters”. The paper proves convincingly that signal analysis of multiple sensor signals is a fruitful way to observe dynamic deviations in measurement systems in nuclear power plants.     

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.