The research on extracting the information of human errors in the main control room of nuclear power plants by using Performance Evaluation Matrix

Digitalized nuclear instruments and control systems have been the main stream design for the main control room (MCR) of advanced nuclear power plants (NPPs) nowadays. Digitalization of human–system interface (HSI) could improve human performance and, on the other hand, could reduce operators’ situation awareness as well. It might cause that humans make wrong decision during an emergency unintentionally. Besides, digital HSI relies on computers to integrate system information automatically instead of human operation. It has changed the operator’s role from mainly relating operational activity to mainly relating monitoring. However, if the operators omit or misjudge the information on the video display units and wide display panel, the error of omission and error of commission may occur. This study applies Content Category Analysis (CCA) and Performance Evaluation Matrix (PEM) methods to explore the potential problems in the MCR of advanced NPPs which are caused by human errors. The results show that the potential problems that would probably contribute to the human performance of MCR in the advanced NPPs are multiple accidents, pressure level, number of operators, and other factors such as working environmental. The conclusions of this research may be considered to avoid and prevent human errors in the human factor related researches especially in the nuclear safety field.     

The implementation of a human factors engineering checklist for human–system interfaces upgrade in nuclear power plants

The primary purpose of this paper is to provide a human factors engineering (HFE) checklist for human–system interfaces (HSIs) upgrades in nuclear power plants (NPPs). The HFE checklist is used to review the HSIs design submittals prepared by licensees or applicants for a license or design certification of a HSI upgrade. NUREG-series regulation documents are used to develop the main frame of the initial HFE checklist. The contents of the HFE checklist are constructed by the theories and principles governing human factors. Then, verification and validation (V&V) of the HFE checklist is accomplished by validity and reliability evaluation. The results show that the HFE checklist has sufficient validity and reliability for the review of HSI upgrades in NPPs.     

Evaluation and comparison of alarm reset modes in advanced control room of nuclear power plants

An automation function has been widely applied in main control room of nuclear power plants (NPPs). The alarm system of fourth nuclear power plant (FNPP) in Taiwan is also going to be developed with automatic technology that is expected to support the operators’ performance and reduce the number of alarms. In this study, an experiment with a training simulator as an advanced alarm system was conducted to compare the effects of different alarm reset modes on performance and subjective ratings. The objective was to evaluate the practicability of alarm system with only auto-reset function in FNPP. Results revealed that, using the auto-reset mode, participants had lower task load index (TLX) on effort in the first test trial and was more satisfied under multi-task condition. In contrast, using manual reset mode, participants were more satisfied on alarm handling, monitoring, and decision making. In other words, both reset modes are necessary to assist the operator in different aspects, but with only single reset mode is insufficient. The reset function in advanced alarm system therefore should be very flexible.     

Predicting work performance in nuclear power plants

Diagnosis and monitoring are the major tasks of an operator in main control room of nuclear power plants (NPPs). The operator’s mental workload influences his/her performance, and furthermore, affects the system safety and operations. This study investigated the operator’s mental workload and work performance of the NPP in Taiwan. An experiment including primary and secondary tasks was designed to simulate the reactor shutdown procedure of the fourth nuclear power plant (FNPP). The performance of the secondary tasks (error rate), subjective mental workload (NASA Task Load Index, NASA-TLX) as well as seven physiological indices were assessed and measured. The group method of data handling (GMDH) was applied to integrate these physiological indices to develop a work performance predictive model. The validity of the proposed model is very well with R² = 0.84 and its prediction capability is high (95% confidence interval). The proposed model is expected to provide control room operators a reference value of their work performance by giving physiological indices. Besides NPPs, the proposed model can be applied to many other fields, e.g. aviation, air transportation control, driving and radar vigilance, etc.     

核电站中处理人的行为问题的系统方法

引发事件的失误原因或者作为行为趋向的一部分统称为人的行为问题.总结出了核电站中处理人的行为问题的系统方法,即从问题的识别与描述、事件调研、原因分析到开发纠正行动这样一个过程.结合核电站实际,着重介绍了人误原因的识别,如根原因分析技术和起因树.     

The impact of job security,satisfaction and stress on performance assessment and optimization of generation companies

In this study, performances of Iranian thermal power plants have been assessed with respect to human factors such as job stress, satisfaction and security through data envelopment analysis (DEA). In the first step performance of power plants (DMUs) have been evaluated considering traditional production factors including installed capacity, internal consumption and fuel consumption as inputs and gross production as output (model 1). In the next step, model 1 is expanded to include three above mentioned human factors (model 2). Power plants have been ranked based on their relative efficiency scores in both models. Pearson and Spearman correlation coefficients between relative efficiency scores and rankings of power plants in two models have been calculated. The results show that efficiency scores and rankings of power plants in two models are quite different indicating that mentioned human factors have direct impact on overall performance of generation companies and that if we were to use just traditional factors it would not reflect the optimum efficiency of the DMUs. Finally, job security has been found as the most effective human factor in Iranian power plants. This is the first study that presents an integrated approach for assessment of electric power plants considering job stress, security and satisfaction. And it is shown that these human factors play important role in overall performance of generation companies.     

核电厂主控室人机界面评价实验研究

基于以人为中心的人机交互设计和评估的思想,结合国内核电厂的实际情况,确定一些重要的核电厂主控室人机界面评估因素,并划分核电厂主控室人机界面各组成部分的评价指标与评价层次,建立了客观的评价指标体系,为核电厂主控室人机界面综合评价奠定了基础。运用模糊数学的方法,建立核电厂主控室人机界面定量评价模型,对核电厂主控室人机界面进行较为客观的综合评价。通过对核电厂操纵员问卷调查的形式进行实验验证,从而实现了定性评价与定量评价的一致性。研究表明,该方法应用于核电厂主控室人机界面评价是一种有效的方法。     

Job requirements for control room jobs in nuclear power plants

Together with other variables, human factors play a central role in the safety of highly complex technical systems such as nuclear power plants. However, despite the unquestionable importance of human factors, little information is available about relevant ability requirements for control room jobs in nuclear power plants. The purpose of this study was to close this gap, to provide specific information about ability requirements for such jobs, and to evaluate how several hypothesized factors (ability domain, type of job, and operating condition) contribute to ability requirements. We found that high levels of cognitive as well as social/interpersonal abilities are needed for control room jobs, and that ability requirements increase with the hierarchical job level for these two domains but decrease for psychomotor/physical abilities and for sensory/perceptual abilities. Furthermore, specifically concerning jobs with a leadership function, we found some differences between incidents and normal operations regarding requirements for social/interpersonal abilities, indicating that the former require a different leadership style than the latter.     

Power system planning with emission constraints: Effects of CCS retrofitting

Today, the world's energy needs are still supplied mainly from fossil fuel based resources. This is true for electricity generation as well, thus making the power sector responsible for 45% of greenhouse gas emissions. The present climate crisis has made it necessary to minimise emissions in power generation, with low-carbon energy sources taking on greater significance in recent years. However, most low-carbon sources have inherent problems, like intermittency and high capital expenditure. A suitable alternative is carbon capture and storage (CCS) technology which allows continued fossil fuel-based electricity generation at much lower rates of emission. Two approaches are possible in the deployment of CCS technology. The first is to introduce new power plants equipped for carbon dioxide (CO₂) capture, while systematically shutting down existing coal power plants. Another is to retrofit existing power plants for CO₂ capture. These approaches are compared in this work. The study shows that allowing CCS retrofitting of existing power plants can reduce the overall cost requirement significantly. In addition, a sensitivity analysis is also done to study the effect of nuclear energy on the overall energy mix.     

人员可靠性与系统安全

论述了人员可靠性对系统安全的影响，分析了它的特点和应采用的研究方法，介绍了笔者近年来在核电站人员可靠性基础研究方面的情况，并对研究的发展趋势进行了展望。     

Team crystallization (SIO2): Dynamic model of team effectiveness evaluation under the dynamic and tactical environment at nuclear installation

Accident management activities at nuclear power plants require concurrent communication, information sharing, team based decision-making and collective actions under tactical and dynamic environments. Team effectiveness under such environments can be characterized as the performance of team situation awareness with hierarchically distributed information and knowledge susceptible to organizational characteristics and communication quality. This paper proposes a team performance model, called a team crystallization model comprising of four elements: state, information, organization, and orientation and its quantification method using a communication process model based on a receding horizon control approach. The team crystallization model is a holistic approach for evaluating team effectiveness in conjunction with team situation awareness considering physical system dynamics and team behavioural dynamics for a tactical and dynamic task at a nuclear power plant. This model provides a systematic measure to evaluate time-dependent team effectiveness or performance affected by multi-agents such as plant states, communication quality in terms of transferring situation-specific information and strategies for achieving the team task goal at a given time, and organizational factors. To demonstrate the applicability of the proposed model and its quantification method, a case study was carried out using the data obtained from a full-scope power plant simulator for 1000 MW(e) pressurized water reactors with four on-the-job operating groups and one expert group who knew accident sequences.     

基于层次分析方法的核电火灾风险评估研究

核电火灾是现代消防安全的重要部分。依据核电厂的实际组成构造对其进行了层次划分,建立了由堆本体、一次冷却系统、化容控式系统堆安全系统、汽轮发电机组和燃料操作系统为中间层的核电火灾危险性评价指标体系。结合收集到的相关核电事故数据资料,运用层次分析法对核电厂各系统部位引发火灾造成的核电安全风险进行了评估,确定了各组分的统计权重,得到了针对核电厂各构造部位的火灾危险性层次评价模型。并利用评价打分的方法对核电厂进行调查模拟评价,计算出核电厂各组成部分消防安全状况的危险指数,所得结果比较符合核电火灾实际统计。     

An integrated framework to the predictive error analysis in emergency situation

This paper introduces an analysis framework and procedure to predictively analyze human errors in performing emergency tasks, which are mostly composed of cognitive activities, in nuclear power plants. The framework focuses on the cognitive errors and provides a new perspective in the utilization of context factors into cognitive error prediction. The basic viewpoint on the occurrence of cognitive error taken in this paper is that the cognitive function failures occur from the mismatch between operator's cognitive capability and the requirements of a given task and situational condition. In accordance with this viewpoint, performance influencing factors that influence the occurrence of human errors are classified into three groups, i.e. Performance Assisting Factors (PAF), Task Characteristic Factors (TCF), and Situational Factors (SF). This classification helps analysts view the overall task context in an integrative way by considering the level of PAF with the requirements of TCF and SF to predict the possibility of cognitive function failures. Further, it enables analysts to draw specific error reduction strategies. The framework suggested was applied to the analysis of cognitive error potential for the bleed and feed operation of emergency tasks in nuclear power plants.     

自动抢接止回阀装置液压系统设计及仿真分析

利用井口自动化装置进行石油钻井过程中溢流、井喷时的关井作业是目前井控作业的热点。为了有效减少工作人员操作时间,保证装置的可靠性。提出了1种自动抢接止回阀装置,并将装置的控制系统设计成全液压系统。基于AMEsim对设计的液压系统进行建模以及模拟仿真分析,得到了执行元件（3个液压马达和1个伸缩液压缸）的输出特性曲线,然后与理论计算、设计及选型的执行元件的参数进行对比。研究结果表明:设计的液压回路可以确保自动抢接止回阀装置的整个工作过程正常、稳定的进行。设计的自动抢接止回阀装置的性能基本满足使用要求,具有一定的实用价值。     

Teaching older drivers to navigate GPS technology

Background and objectives: New technologies are being implemented in motor vehicles. One key technology is the electronic navigation system (ENS) that assists the driver in wayfinding, or actually guides the vehicle in higher level automation vehicles. It is unclear how older adults interact with ENSs and the best approach to train older adults to use the devices. The objectives of this study were to explore how older drivers interacted with an ENS while driving on live roadways and how various training approaches impacted older drivers’ ability to accurately enter destinations into the ENS. Research design and methods: In Experiment 1, 80 older drivers navigated unfamiliar routes using an ENS or paper directions and completed a series of ENS destination entry tasks. In Experiment 2, 60 older drivers completed one of three training conditions (ENS video only, ENS video with hands-on training, placebo) to examine the impacts of training on destination entry performance. Results and discussion: Driving performance was aided by the use of the ENS, but many older drivers had difficulty entering destinations into the device (Experiment 1). The combined video with hands-on ENS training resulted in the best overall destination entry performance (Experiment 2). Practical applications: The results suggest older drivers may experience problems entering destinations into ENSs, but training can improve performance. These performance issues may be especially important as more vehicle features require interaction with computer systems to select destinations or other automation related features. Further research is needed to determine how to prepare the next generation of older drivers who will interact with technologies aimed at increasing mobility.     

Optimization of test interval for ageing equipment: A multi-objective genetic algorithm approach

Reducing the unavailability of safety systems at nuclear power plants, by utilizing the probabilistic safety assessment (PSA) methodology, is one of the prime goals in the nuclear industry. In that sense, optimization of test and maintenance activities, which are defined within the technical specifications, represents quite popular and interesting domain. Obtaining optimal test and maintenance schedule is of great significance for improving system availability and performance as well as plant availability in general.On the other side, equipment aging has gradually become a major concern in the nuclear industry since the number of safety systems components, that are approaching their wear-out stage, is rising fast. Nuclear power plants life management programs, considering safety components aging, are being developed and employed. The immense uncertainty associated to the available component aging rates databases poses significant difficulties in the process of incorporation and quantification of the aging effect within the PSA and, subsequently, in the decision-making process.In this paper, an approach for optimization of surveillance test interval of standby equipment with highly uncertain aging parameters, based on genetic algorithm technique and PSA, is presented. A standard standby safety system in nuclear power plant is selected as a case study. A Monte Carlo simulation-based approach is used to assess uncertainty propagation on system level. Optimal test interval is derived on the basis of minimal system unavailability and minimal impact of components aging parameters uncertainty. The results obtained in this application indicate the fact that risk-informed surveillance requirements differ from existing ones in technical specifications as well as show the importance of considering aging data uncertainties in component aging modeling.     

A taxonomy of performance influencing factors for human reliability analysis of emergency tasks

This paper introduces the process for, and the result of, the selection of performance influencing factors (PIFs) for the use in human reliability analysis (HRA) of emergency tasks in nuclear power plants. The approach taken in this study largely consists of three steps. First, a full-set PIF system is constructed from the collection and review of existing PIF taxonomies. Secondly, PIF candidates are selected from the full-set PIF system, considering the major characteristics of emergency situations and the basic criteria of PIF for use in HRA. Finally, a set of PIFs is established by structuring representative PIFs and their detailed subitems from the candidates. As a result, a set of PIFs comprised of the 11 representative PIFs and 39 subitems was developed.     

污水处理厂自动化监控系统

自动化技术在能源、电力、机械、环境等行业的应用越来越广泛，也促使了自动化水平的不断提高。由于Synall2000强大的网络化功能，为将来系统在子网级和企业级实施基于Synall2000网络化数据监控系统打下了坚实、可靠的基础。在全面实施单个站点自动化监控的基础上，可方便地实现子网级的网络化数据自动采集与监控系统。     

Age-related differences in effects of non-driving related tasks on takeover performance in automated driving

Introduction: During SAE level 3 automated driving, the driver’s role changes from active driver to fallback-ready driver. Drowsiness is one of the factors that may degrade driver’s takeover performance. This study aimed to investigate effects of non-driving related tasks (NDRTs) to counter driver’s drowsiness with a Level 3 system activated and to improve successive takeover performance in a critical situation. A special focus was placed on age-related differences in the effects. Method: Participants of three age groups (younger, middle-aged, older) drove the Level 3 system implemented in a high-fidelity motion-based driving simulator for about 30 min under three experiment conditions: without NDRT, while watching a video clip, and while switching between watching a video clip and playing a game. The Karolinska Sleepiness Scale and eyeblink duration measured driver drowsiness. At the end of the drive, the drivers had to take over control of the vehicle and manually change the lane to avoid a collision. Reaction time and steering angle variability were measured to evaluate the two aspects of driving performance. Results: For younger drivers, both single and multiple NDRT engagements countered the development of driver drowsiness during automated driving, and their takeover performance was equivalent to or better than their performance without NDRT engagement. For older drivers, NDRT engagement did not affect the development of drowsiness but degraded takeover performance especially under the multiple NDRT engagement condition. The results for middle-aged drivers fell at an intermediate level between those for younger and older drivers. Practical Applications: The present findings do not support general recommendations of NDRT engagement to counter drowsiness during automated driving. This study is especially relevant to the automotive industry’s search for options that will ensure the safest interfaces between human drivers and automation systems.     

Ergodynamics and Hybrid Intelligence Systems in the Reliability of Power Plant Operators

Based on ergodynamics and the hybrid intelligence theory, an analysis of the nuclear power plant operator’s performance is given at the levels of strategies, tactics, and actions. Special attention is paid to the strategies used in the course of severe accidents at nuclear power plants. Data from Ukrainian and Russian power plants and training centres and from accidents around the world were collected and processed. It is shown that in an emergency it is essential for the human operator to be flexible. This flexibility includes two main training and personal factors: a large set of strategies and tactics the operator manages to use, and quick transformations between the strategies (tactics). It was also found that some emergency tasks are too complicated: They require simultaneous use of different strategies, with time strictly limited by nuclear power plant dynamics. Those tasks cannot be successfully solved by any individual operator. Hybrid intelligence systems involving different specialists should be used in those cases in order to avoid failures in emergency problem solving.