核电厂设备状态维修研究及应用

状态维修是一种国际先进的预防性维修策略,也是核电厂维修优化的重要方向,但目前国内核电厂缺少一套有效的技术方法及流程来指导预防性维修策略由定期维修向状态维修的转变,以及状态维修的应用实施;本文介绍了状态维修的基本原理和实施状态维修的优缺点,并结合国内外核电厂状态维修管理和应用现状,研究提出了“范围筛选→大纲建立→数据采集→数据分析→纠正行动”的核电厂设备状态维修实施技术方法及流程,并以实例对方法和流程进行了说明。本文对国内核电厂开展状态维修的研究及应用工作有较好的参考和借鉴价值。     

核电站定期检修项目排程优化

为了提高核电的安全可用率,从维修成本和调和设备可用性的角度探讨了获得最佳维修效率的方法.分别从核电站系统分析和设备类型分析等方面,对核电站定期维修项目排程的风险控制、质量控制和成本控制的方法进行了探讨.最后,以大亚湾及岭澳核电站定期维修项目的信息化、系统化的排程优化为例,对优化方法论和知识积累平台建立的方案进行了阐述.     

核电站设备的维修优化

以核电站设备的维修特征分析为基础,建立了修理性预防维修模型;同时针对核电站设备,对与维修相关的费用和与故障后相关的费用进行了详细的量化研究.最后从故障概率和维修费用出发,讨论了预防维修周期的确定与相应变化,并给出随费用和故障率变化的曲线.     

基于使用可用度的核岛外设备机会维修策略研究

针对核电站事故停机将导致较大经济损失且核岛外设备允许实施并行维修的特点,对核岛外设备机会维修策略进行了研究,提出了一种以设备自身最优维修间隔期为基准的机会维修控制策略.利用蒙特卡罗仿真方法,给出了该策略中以使用可用度最大为目标的最优维修问隔期和机会维修系数的仿真求解算法,并用算例证明了采取机会维修策略能有效提高系统的使用可用度.     

RtCM方法在某核电厂汽水分离再热器系统的应用实践

以可靠性和技术特性为中心的维修(Rt CM)方法是确定资产预防性维修需求、优化维修制度的一种系统工程方法。介绍以Rt CM方法的分析流程和特点,并以某核电厂汽水分离再热器系统为应用试点,详细阐述Rt CM实施过程、设备维修策略优化的效益。实践表明,Rt CM分析方法通过引入故障模板、技术特性分析、设备分级和定量化分析,提高了分析效率,对提高系统设备可靠性发挥了重要作用。     

基于核电厂维修规则实施RCM预维优化的研究

维修规则MR是对核电厂构筑物、系统和设备维修活动进行有效性评价的规则体系,提供了一套系统的SSCs(构筑物、系统及设备)监测和评价优化方法,其目的是通过维修有效性评价来监督核电厂SSCs性能,以促进核电厂能够更安全可靠的运行,并合理平衡核电厂设备的可靠性和可用率;以可靠性为中心的维修RCM是以可靠性为中心的维修优化方法,其目的是通过优化预防性维修工作,以最少的资源投入来保持设备可靠性的固有水平;MR和RCM两者结合,基于维修规则实施RCM预维优化工作,开创了一条使核电厂既满足核安全法规要求所需要的固有安全可靠性,又保持核电厂高运行经济性的优良途径。本文分别介绍了维修规则MR和以可靠性为中心的维修RCM的基本内容和应用效果,并结合核电目前面临的形势,针对基于维修规则实施RCM预维优化工作的可行和必要性进行分析和研究,探索、提出了核电厂基于维修规则实施RCM预防性维修优化的流程和方法。     

核电厂数字化仪控系统维修领域管理实践与创新

介绍了田湾核电站在数字化仪控系统维护过程中对风险分析、设备状态监督、缺陷跟踪、维修管理网络等方面的新思路和新方法的运用情况,描述了企业文化和科技创新对数字化仪控维修工作的促进作用。田湾核电站数字化仪控系统维修领域管理实践与创新手段是科学有效的,可为其他工程项目的数字化仪控维修管理提供借鉴。     

基于GO-FLOW方法的可维修系统可靠性分析

将GO-FLOW方法用于限定维修工和维修优先权的可维修系统的可靠性分析,推导适于GO-FLOW模型计算的可维修系统可靠性参数近似等效模型,并进行模型的验证和误差分析。以冗余泵单元为实际算例,将分析结果与采用GO法的情况进行对比。研究结果表明,在对该类可维修系统进行可靠性定量分析时,与GO法相比,改进后的GO-FLOW算法模型是有效的,并且计算更为简捷。     

反应堆运行阶段的维修策略和方法

描述了反应堆运行阶段的维修策略和维修方法,介绍了以设备可靠性为中心的现代维修理念,提出了在反应堆堆修管理中的各种具体要求以及在维修过程中应正确运用的相应维修策略和维修方法,以满足反应堆安全、可靠、经济和高效运行的原则。     

预测性维修在重水堆设备管理中的应用

秦山重水堆核电厂设备数量多、结构复杂，有些设备故障与运行时间无直接关系，并不能简单通过定期维修来避免这些设备失效。为了提高设备可靠性、增加设备可用率并降低维修成本，对于电厂核安全、机组发电具有重要作用的设备，应开展设备状态监测和预测性维修工作。按照各类型设备特点，采用合适的设备状态监测方法、内容和频度，发现一些设备潜在故障，主动安排这些设备进行预测性维修，优化设备维修管理。     

以可靠性为中心的核电厂厂用水系统维修分析

通过对AP1000核电厂厂用水系统进行故障模式及影响分析(FMEA)以及逻辑决断分析(LTA),深入了解该系统工艺及相关设备的功能故障、故障模式和影响,进而建立优化的维修决策.与现行的维修策略相比,经由可靠性为中心的维修( RCM)优化所得的维修策略对显性故障更多的是选择状态监测/定期维护,而对隐蔽性故障则采用定期试验...     

Decision-Making Support Systems for Reliability-Centered Maintenance

Abstract

A Systematic Reliability Improvement (SRI) program has been developed to support the decision-making processes of preventive maintenance (PM) planning for enhancing plant/system reliability in nuclear power plants. The SRI program is based on improved information-handling methods in the Reliability-Centered Maintenance (RCM) methodology. This program enables us to select a proper PM plan using a computerized system that integrates the following three subsystems which have been developed and is implemented on an engineering work station.

(1) The maintenance management support subsystem can provide statistical parameters which indicate the characteristics of the failure mode for components based on the statistical analysis of field maintenance data.

(2) The FME/CA-database subsystem can manage the system/component failure modes and their characteristics which are estimated by experts at the design stage using 13 types of assessment rankings of the failure mode effects and criticality analysis (FME/CA).

(3) The PM planning support subsystem can support decision-making in determining the priority of PM improvement plans using a new method combining the above FME/CA assessment rankings and interactive logic tree analysis (I-LTA).

The effectiveness of the SRI program and its support systems has been validated through a feasibility study using simulated data on a primary loop recirculation system in BWR plants.     

A genetic algorithm solution for a nuclear power plant risk–cost maintenance model

Reliability Centered Maintenance (RCM) is one of the popular maintenance optimization methods according to certain kinds of priorities. Traditional RCM usually analyzes and optimizes the maintenance strategy from the viewpoint of component instead of the whole maintenance program impact. Research presented in this paper is a pilot study using PSA techniques in RCM. How to reflect the effect on component unavailability by the maintenance activities such as surveillance testing and preventive maintenance in PSA model is discussed firstly. Based on the discussion, a maintenance risk–cost model is established for global maintenance optimization in a nuclear power plant, and a genetic algorithm (GA) is applied to solve such a model to get the global optimized maintenance strategy. Finally, the result got from a simple test case based on a risk–cost model consisting of 10 components is presented.     

以可靠性为中心的维修在核电站维修优化中的应用与创新

以可靠性为中心的维修(简称RCM)是目前国外广泛采用的维修优化方法。本文介绍了RCM分析方法以及该方法在大亚湾核电站的应用情况,并介绍了对RCM决断逻辑进行优化和改进的情况,最后通过实例说明RCM改进后所取得的效果。     

Quantification of unavailability caused by random failures and maintenance human errors in nuclear power plants

Risk analysis of any equipment or system estimates the unavailability of redundant components due to hardware failure, periodic test and repair work, and human errors in maintenance tasks. A model has been developed in this study to estimate the unavailability of a periodically repairable component of a system that considers hardware failure and maintenance errors due to human failure, and which is applicable to estimate system unavailability in nuclear power plants as well as other industries. A sensitivity analysis has been performed based on the newly developed model considering multiple levels of human errors in maintenance tasks to observe the effects of maintenance errors on overall unavailability of a component. The effect of human error on the optimal frequency of periodic maintenance of a device has been analyzed based on the newly developed unavailability quantification model.     

双参数威布尔分布在核电站数据处理中的应用

核电站设备可靠性数据的处理是电站进行以可靠性为中心的维修（RCM）和寿期管理（LCM）的基础。在核电站失效数据的实际处理过程中,常会面临失效样本少、维修导致数据分布不独立等问题。为解决上述问题,本文提出以双参数威布尔分布作为寿命模型、采用贝叶斯方法来处理小样本失效数据的方法,并结合核电站运行数据进行验证。结果表明,本方法在处理样本较少以及存在维修老化问题时,具有更好的适用性和准确度。     

某三代核电机组设备舱门技术特点及维修管理分析

EPR机组的设备舱设计与CPR1000机组有着明显不同,主要由闸门封头、闸门支撑结构、闸门导轨、重型地板组成;设备舱门的提升机构、设备舱门的锁紧方式以及设备舱通道的连接方式较二代机组都是全新的设计,其维修操作方法也就存在差异.为了提高设备可用性,保障设备在机组大修期间能够正常运行,该文通过研究设备舱的基本机构、工作原理...     

Risk-based approaches to ageing and maintenance management

This paper addresses the means of integrating probabilistic assessment (PRA) results into reliability centered maintenance (RCM). Several methods are discussed, including methods derived from a recent American Society of Mechanical Engineers (ASME) report on Risk-Based Inspection and new methods which both identify items for maintenance attention and then calculate the revised risk. Ageing PRA's take into account the changing failure probability with time. Some examples of the application of these techniques to reactor systems are reviewed. Results from PRA's including ageing can also be used on their own to optimise certain aspects of maintenance. An example of optimising test intervals is described. This example indicates that potentially, there could be a considerable reduction in the frequency of testing of some items with no increase in risk.     

核电厂数字化仪控系统状态监测及可靠性预测方法研究

随着我国核电的发展,数字化仪控系统和设备的引入,给核电厂安全性和可靠性带来的风险得到广泛的关注。目前国内外的核电厂数字化仪控系统状态监测仅针对单个设备,具有一定的局限性,忽略了设备间的可靠性关联及设备可靠性趋势对整个系统可靠性的影响。本文提出一种核电厂数字化仪控系统状态监测及可靠性预测方法,以高压安注系统为例,通过监测多个相关设备的状态信息,分析其内在可靠性关联,得到设备当前可靠性趋势对整个系统可靠性状态的影响,建立系统可靠性模型。该模型通过状态信息的更新,实时监测整个系统的可靠性状态,为核电厂系统和设备提供更为全面的预测和可靠性状态监测,为核电厂的系统管理、设备管理及运行维护提供指导。