人的可靠性分析中不确定性的影响、来源以及处理

概率安全分析 (PSA)在管理决策中的作用不断增加 ,要求尽量减少PSA的不确定性。人的可靠性分析 (HRA)作为PSA的一部分 ,是PSA结果不确定性的一个重要来源。调查分析了核电站PSA结果中HRA不确定性的影响。通过分析所应用的HRA模型、数据和实施过程 ,讨论了HRA不确定性的可能来源 ,以及减少这些不确定性的一些方法和措施。考虑到HRA不确定性存在的必然性 ,讨论了在PSA中处理HRA不确定性的方法。     

认知失误定量分析方法及其在PSA中的应用

认知可靠性和失误分析方法(CREAM)是第二代人的可靠性分析方法中的代表方法之一.以CREAM的核心思想为基础,对定量分析方法进行了改进,给出了共同绩效条件(CPC)对人的可靠性影响的量化指数.提出了用环境影响指数来定量计算情景环境迫使人的认知失误的发生概率,给出了概率安全评价(PSA)中人误概率的分析方法,并用于诊断核电站蒸汽发生器传热管破裂和蒸汽发生器隔离时的人误概率分析.     

基于网络的核电站PSA数据库管理系统设计研究

核电站PSA数据库管理系统是进行核电站安全评估的手段之一.按照数据库规范设计法,设计了基于网络的核电站PSA数据库管理系统NDMS,NDMS能为PSA提供方便而充分的数据.根据核电站实际情况,NDMS采用了网络化设计,并设计了用户管理机制及智能编码规则管理机制.目前NDMS已作为PSA分析软件RiskA的数据库平台得到了较好的应用.     

人的认知失误事件定量分析法的进展及应用

认知可靠性与人误分析法(即认知失误分析法,CREAM)是具有代表性的第2代可靠性分析(HRA)方法,它可从回顾式和预测式进行班组人误事件概率的定量分析.本工作除描述了通用的CREAM方法外,还建立了用环境影响指数β与共同绩效条件(CPC)因子关系的人误事件概率简化的定量化公式,可用于计算核电厂人误事故中班组的人误事件概率.并假想以秦山一期蒸汽发生器传热管破裂(SGTR)事故为例,说明人的认知失误事件概率的计算过程及结果,为核电厂概率安全评价(PSA)的班组人因分析提供了另一种有效的途径,使核电厂的风险的概率估计值更为客观、更有参考价值.     

法国的核电站概率安全评价技术

法马通公司发现,概率安全评价技术(PSA)使其现有核电站得到了很大的改进,PSA技术将用作今后反应堆设计的一种手段,和确保进一步提高其运行性能的方法。法马通公司使用PSA技术进行核电站设计,差不多有20年了。最近,该公司还参加了比利时的多伊尔3号堆和蒂昂热2号堆的PSA工作。希望下一代核电站进一步有改进的重要方面是,降低堆芯损坏概率。PSA可用来分析     

HTR-10常规岛热力系统中特殊子系统的运行可靠性分析

在利用事件树和故障树相结合的方法对核电站进行概率安全评价（PSA）分析中,其备用系统和可修复系统的运行可靠性分析是一个难点。本文利用故障树分析的技术和可靠性工程数学的分析方法,对10MW高温气冷堆（HTR－10）常规中的上述子系统的运行可靠性进行了深入的分析和研究,可供PSA分析人员参考。     

WANO人因事件统计及分析

对世界核电厂营运者联合会1993～2002年940份运行事件分析报告进行分析．发现有551件与人因相关．人因失误仍然是核电站事故最主要的诱因之一运用统计技术和数据挖掘技术对这551件人因事件进行分析．获得如下结论：①维修、调试,试验活动中所产生的人误导致系统潜在失效而最终诱发系统事故已成为人因事故最重要的原因;②反应堆启动阶段和停堆阶段人误概率较高,且易诱发严重事故;③人因事件发生概率与反应堆类型没有必然的联系;④对事故征兆或事故判断失误和操作失误是人误的最主要表现形式．也是导致人因事故的最主要原因,造成严重电站瞬态和安全系统的故障或者不恰当投运的事故的可能性较大;⑤理论知识欠缺、基本操作能力较差、组织管理缺陷、规程不足以及粗心大意、缺乏相互检查是导致人因失误最主要的根原因.     

2 大型自主化核电厂PSA分析软件PSAP 1．0

概率安全分析（PSA）是核电站安全分析的一种有效方法，在核电站的安全评价、运行、维修及为安全管理部门的决策提供技术支持等方面具有重要的作用。PSA方法已广泛应用于在役核电厂的运行管理、系统及部件的维修以及核电厂的风险监控之中，取得了很好的经济效益与社会效益。长期以来，我国有关PSA的工作主要是在核电厂的应用方面，在PSA方法学研究及PSA技术研发方面做得工作很少。没有开发自己的PSA分析软件，因而，在开展核电厂PSA工作时，采用的都是国外的PSA软件。     

电源失效率计算

由于核电站的断电率直接影响反应堆安全,因此,在核电站安全分析,尤其是概率安全分析中需要掌握大量的电源失效率数据。我国还没有核电站,PSA 工作刚起步,但已有二十多年实验堆运行经验。我们的目的就是要利用国内堆运行累积数据,参考国外 PSA 分析数据,处理一部分适于我国 PSA 分析的数据,为建立国内数据库做些工作。设想从堆的运行中统计出一批数据,原则上说,数据处理之前要分析它的物理过程,确定模型。事实     

核电站严重事故后果概率安全评价方法研究

核电站严重事故后果概率安全评价(PSA)是采用概率论的方法对核电站放射性后果进行分析,并定量给出放射性物质对核电站周围公众的健康效应影响。以国内某压水堆核电站为参考厂址,建立合适的场外后果分析模型。采用分层抽样方法对参考厂址1a的气象数据进行抽样,源项和释放特征等数据取自二级PSA的研究结果。利用事故后果评价程序对核电站严重事故后果进行计算,并用概率论方法对结果进行评估。通过计算将各事故和事故谱的场外个人剂量表示为CCDF曲线和总频率-剂量曲线,再用概率论方法得到不同距离处个人剂量超过指定剂量的条件概率;也可用此方法对确定烟羽应急计划区的安全准则中所描述的"大多数严重事故序列"进行量化。     

Nuclear Power Plant Operator Performance Analysis Using Training Simulators

This paper deals with a research on human factors performed by the Japanese BWR group, focusing mainly on the work done in Phase I (1984–86) of the research project. As a first simulator study of operator performance during accidents in the nuclear field in Japan, it was necessary to develop analysis methods to identify and quantify operator errors.

The performance of operators under plant abnormal conditions was analyzed using full-scale BWR plant simulators. By utilizing on-line plant data collection systems and audio/video devices, data were gathered from actual plant operators in the retraining courses on two full-scale simulators at the BWR operator training center in Japan. More than a hundred cases of operator performance data were analyzed to identify human errors and to classify the types of errors.

For application to probabilistic safety assessment (PAS), error probabilities were estimated and compared with existing data. Quantification of cognitive errors was also performed based on the Time-Reliability Correlation. An assessment of the effects of human factors in PSA suggested the importance of errors in the operators' cognitive processes, which accounted for the major effects of errors in tasks of high safety significance.

The results of the analysis esrve as a basis for building a data bank to be utilized for multiple purposes of PSA, man-machine interface improvement and operator training.     

Application of thermal comfort theory in probabilistic safety assessment of a nuclear power plant

Human factor errors in probabilistic safety assessment(PSA) of a nuclear power plant(NPP) can be prevented using thermal comfort analysis.In this paper,the THERP+HCR model is modified by using PMV (Predicted Mean Vote) and PPD(Predicted Percentage Dissatisfied) index system,so as to obtain the operator cognitive reliability,and to reflect and analyze human perception,thermal comfort status,and cognitive ability in a specific NPP environment.The mechanism of human factors in the PSA is analyzed by operators of skill,rule and knowledge types.The THERP+HCR model modified by thermal comfort theory can reflect the conditions in actual environment,and optimize reliability analysis of human factors.Improving human thermal comfort for different types of operators reduces adverse factors due to human errors,and provides a safe and optimum decision-making for NPPs.     

Human error probability estimation by coupling simulator data and deterministic analysis

Operator error in diagnosis and execution of task have significant impact on Nuclear Power Plant (NPP) safety. These human errors are classified as mistakes (rule base and knowledge based errors), slip (skill based) and lapses (skill based). Depending on the time of occurrence, human errors have been categorized as i) Category ‘A’ (Pre-Initiators): actions during routine maintenance and testing wherein errors can cause equipment malfunction ii) Category ‘B’ (Initiators): actions contributing to initiating events or plant transients iii) Category ‘C’ (Post-Initiators): actions involved in operator response to an accident. There have been accidents in NPPs because of human error in an operator's diagnosis and execution of an event. These underline the need to appropriately estimate HEP in risk analysis. There are several methods that are being practiced in Probabilistic Safety Assessment (PSA) studies for quantification of human error probability. However, there is no consensus on a single method that should be used. In this paper a method for estimating HEP is proposed which is based on simulator data for a particular accident scenario. For accident scenarios, the data from real NPP control room is very sparsely available. In the absence of real data, simulator based data can be used. Simulator data is expected to provide a glimpse of probable human behavior in real accident situation even though simulator data is not a substitute for real data. The proposed methodology considers the variation in crew performance time in simulator exercise and in available time from deterministic analysis, and couples them through their respective probability distributions to obtain HEP. The emphasis is on suitability of the methodology rather than particulars of the cited example.     

二级PSA中人员可靠性分析方法研究

在概率安全分析(PSA)中,人员可靠性分析(HRA)是必不可少的组成部分。国内在一级PSA中的HRA做了大量的研究工作,已有良好的基础和工程实践,但由于核电厂严重事故下人员响应的复杂性,有关二级PSA的HRA还处于摸索阶段。通过研究二级PSA中人员响应特点,调研国内外在二级PSA中采用的HRA方法,最后以我国某三代压水堆核电厂严重事故下一回路快速卸压为例,采用THERP、HCR+THERP以及SPAR-H三种方法,分别进行了HRA,并给出相应的结论和建议。     

An approach to the construction of a one top fire event PSA model

An internal fire event probabilistic safety assessment (PSA) model has been generally quantified by modifications of a pre-developed internal events PSA model. New accident sequence logics not covered in the internal events PSA model are separately developed to incorporate them into the fire PSA model. Previous studies on the changes of the one top internal event PSA model for the one top fire event PSA model have been limited to the equipment failures affected by the fire. In addition, they assumed that the probabilities of basic events associated with equipment or cables impacted by the fire are one. However, the probabilities of spurious operation events and human failure events affected by the fire might not be estimated as one. In this study, new modification rules were proposed for the construction of a one top PSA model for fire events by using a one top internal event PSA model. The proposed new modification rules can be applied to all the fire damage events for the fire-induced equipment failure events and spurious operation events, human error events impacted by a fire, regardless of whether they are estimated as one or not. Applications of the proposed modification rules to the compartment and scenario-level fires for the hypothetical plants were performed for demonstrating their appropriateness to the changes of the one top internal event PSA model to the one top fire event PSA model. In addition, quantification procedure with the one top fire event PSA model was presented and discussed.     

核电厂地震PSA中HRA方法研究

在调研外部事件人员可靠性分析（HRA）的发展历史及方法缺陷的基础上，研究了当前国内外外部事件HRA技术标准，并以某核电厂地震概率安全评价（PSA）中的人因事件为研究对象开展方法研究，说明了地震场景HRA与内部事件HRA的不同点，明确地震人员响应的流程，阐述地震场景下HRA方法，使其得到的分析结果更加接近外部事件的实际情况，并可为外部事件PSA的开发提供技术依据。      

火灾情景下的人员可靠性分析

国内外各核电厂火灾概率安全评价（PSA）表明,人员操作对火灾情景下的电厂风险有重要影响,因此,有必要采用系统的人员可靠性分析（HRA）方法来评价火灾情景下的人员失误概率。本文阐述了HCR/ORE和CBDTM模型的基本理论和在火灾情景下的特殊考虑。将HCR/ORE和CBDTM方法与THERP方法相结合应用于火灾情景下的人员可靠性分析,并进行了实例分析。为建立更符合工程实际的火灾PSA模型奠定了基础。     

百万千瓦级核电厂停堆工况下的概率安全评价

对百万千瓦级核电厂停堆运行事故进行内部事件1级概率安全评价(PSA),根据不同的停堆进程分别建立停堆PSA模型,分析经历余热排出系统(RRA)低运行区间(LOI-RRA)水位对电厂风险水平构成的影响;同时采用事故系列先兆标准电厂风险分析模型人员可靠性分析(SPAR-H)方法进行人员可靠性分析,评价其定量化结果的适用性。分析结果表明,停堆工况下的电厂风险不可忽视,在停堆工况下的事故规程有待完善之处,冷停堆工况下由LOI-RRA水位导致堆芯损坏频率明显增加,人因失误是造成停堆高风险的关键因素。     

Assessment methodology for confidence in safety margin for large break loss of coolant accident sequences

Deterministic Safety Analysis and Probabilistic Safety Assessment (PSA) analyses are used to assess the Nuclear Power Plant (NPP) safety. The conventional deterministic analysis is conservative. The best estimate plus uncertainty analysis (BEPU) is increasingly being used for deterministic calculation in NPPs. The PSA methodology integrates information about the postulated accident, plant design, operating practices, component reliability and human behavior. The deterministic and probabilistic methodologies are combined by analyzing the accident sequences within design basis in the event trees of a postulated initiating event (PIE) by BEPU. The peak clad temperature (PCT) distribution provides an insight into the confidence in safety margin for an initiating event.     

核电厂传统人员可靠性分析方法中引入班组因素的研究

在核电厂等大型复杂系统中,人员干预行为通常以班组的协作来完成,而目前核电厂概率安全评价（PSA）采用的以人的失误率预测技术（THERP）和人的认知可靠性（HCR）方法为代表的人员可靠性分析（HRA）方法主要关注对个人绩效的影响,它们在评估核电厂主控室班组绩效时存在一定局限。本文定义一种新的绩效形成因子“班组绩效形成因子（TPSF）”,并将其合理地引入THERP和HCR方法的定量化体系中,使它们可在一定程度上体现班组环境对人员绩效的影响。文章提出了TPSF等级的评价方法及将其引入THERP和HCR方法的定性实施框架。结果证明,合理地将班组因素引入传统HRA方法能改进它们对班组环境下人员绩效模化的合理性。