Capturing control room simulator data with the HERA System

Reliability Engineering & System Safety, 2014

Lack of appropriate and sufficient human performance data has been identified as a key factor affecting human reliability analysis (HRA) quality especially in the estimation of human error probability (HEP). The Scenario Authoring, Characterization, and Debriefing Application (SACADA) database was developed by the U.S. Nuclear Regulatory Commission (NRC) to address this data need. An agreement between NRC and the South Texas Project Nuclear Operating Company (STPNOC) was established to support the SACADA development with aims to make the SACADA tool suitable for implementation in the nuclear power plants' operator training program to collect operator performance information. The collected data would support the STPNOC's operator training program and be shared with the NRC for improving HRA quality. This paper discusses the SACADA data taxonomy, the theoretical foundation, the prospective data to be generated from the SACADA raw data to inform human reliability and human performance, and the considerations on the use of simulator data for HRA. Each SACADA data point consists of two information segments: context and performance results. Context is a characterization of the performance challenges to task success. The performance results are the results of performing the task. The data taxonomy uses a macrocognitive functions model for the framework. At a high level, information is classified according to the macrocognitive functions of detecting the plant abnormality, understanding the abnormality, deciding the response plan, executing the response plan, and team related aspects (i.e., communication, teamwork, and supervision). The data are expected to be useful for analyzing the relations between context, error modes and error causes in human performance.

CHEMICAL ENGINEERING TRANSACTIONS, 2022

At Olkiluoto nuclear power plant (Finland), Areva and Siemens built a third unit (OL3) as a pressurised water reactor of the EPR construction line. The EPR is a generation III+ reactor and equipped with a fully digital HMI system (Process Information and Control System, PICS). As part of the "Integrated Final Control Room System Validation", a large-scale human factors investigation was conducted. The aim of this study was to review human factors aspects of the 'control room system' in order to ensure that the operating crew is able to safely operate the reactor in all possible operating conditions using the tools available in the control room. For this study, the aspects to be evaluated were first defined based on the human factors requirements. A total of six human factors aspects were identified that were to be investigated. These aspects are task performance (defined performance targets), human errors (number and significance of observed errors), situation awareness (correct understanding of the current and future situation at critical points), communication (correct and sufficient communication), coordination (awareness of colleagues' tasks) and mental workload (Self-assessment of available mental resources). Four operating scenarios were defined which varied in content, difficulty, and complexity and which cover a wide range of conceivable operating conditions (normal to emergency operations). These four scenarios were conducted in the full scope simulator of OL3 with different shift crews. This paper describes the methodology in detail, which generally has proven to be very successful. It highlights the advantages and disadvantages of the methodology developed and provides valuable guidance for future investigations in the context of human performance in control rooms.

During a review of the Advanced Test Reactor safety basis at the Idaho National Laboratory, human factors engineers identified ergonomic and human reliability risks involving the inadvertent exposure of a fuel element to the air during manual fuel movement and inspection in the canal. There were clear indications that these risks increased the probability of human error and possible severe physical outcomes to the operator. In response to this concern, a detailed study was conducted to determine the probability of the inadvertent exposure of a fuel element. Due to practical and safety constraints, the task network analysis technique was employed to study the work procedures at the canal. Discrete-event simulation software was used to model the entire procedure as well as the salient physical attributes of the task environment, such as distances walked, the effect of dropped tools, the effect of hazardous body postures, and physical exertion due to strenuous tool handling. The model also allowed analysis of the effect of cognitive processes such as visual perception demands, auditory information and verbal communication. The model made it possible to obtain reliable predictions of operator performance and workload estimates. It was also found that operator workload as well as the probability of human error in the fuel inspection and transfer task were influenced by the concurrent nature of certain phases of the task and the associated demand on cognitive and physical resources. More importantly, it was possible to determine with reasonable accuracy the stages as well as physical locations in the fuel handling task where operators would be most at risk of losing their balance and falling into the canal. The model also provided sufficient information for a human reliability analysis that indicated that the postulated fuel exposure accident was less than credible.

Applied Ergonomics, 2021

Operators' self-assessment has received limited interest within process control or human-system evaluation. Research on self-assessment has been criticised for poor assessment methodology, and consequently, its status is unclear. This study hypothesised that, given adequate assessment methods (such as task-specific assessment items and scenario replay), we could observe relatively accurate self-assessment results. Eighteen licensed operators and two experts assessed team performance in six nuclear control room scenarios. The results reveal an overall agreement between operators and experts, measured by the intraclass correlation coefficient, ranging from 0.60 to 0.70, which lies close to the intraclass correlation coefficient of 0.75 for the experts. This demonstrates potential for achievement of relatively accurate operator self-assessment for complex work. The agreement varied in a similar manner for both expert agreement and operator-expert agreement across eight performance dimensions. In addition, the operators' self-assessment provided additional information beyond observer assessment in identifying non-acceptable performance items.

Probabilistic Safety Assessment and Management, 2004

This report presents the results of training simulator tests used to support the Probabilistic Safety Assessment Project for Cernavoda Nuclear Power Plant. The test results provided objective data that supported quantification of the non-response contribution to the human error probability following an initiating event. The scenario for evaluating the reliability of main control room operators is in response to an abnormal initiating event. The input data included eight crew responses to each initiating event gathered from exercises performed on the Cernavoda NPP full-scope training simulator The non-response probability is a contributor to the overall non-success of operating crew to achieve a functional objective identified in the PSA package.

Chemical Engineering Transactions, 2012

The performance assessment of industrial operators is a challenge faced by the scientific community in last decades on account of the subjectivity involved, lack of quantitative methods and complex trainertrainee-relation. This paper presents a methodology to evaluate the performance of a control room operator according to operator performance indicators based on relevant human factors, which allows a quantitative and as well as qualitative assessment. The proposed methodology can be used not only for the assessment of operators but also for scheduling training courses, future recruitments, and insurance evaluations.

Data from nuclear power plant (NPP) simulator environments reflect important aspects of human performance and potentially the causes of human error. However, the information collected is constrained by the uniqueness of each particular plant and design of each particular simulator study. Thus, the ability to apply the findings of a given simulator study to other studies of human performance at NPPs is often limited. A well-defined approach to experimental design, a common language or measurement technique for describing and classifying errors and human actions, and an associated theoretical underpinning for the design and resulting statistical analyses are required to allow extrapolation of the results of simulator studies across plant designs, crew make-ups, and scenarios. The purpose of this report is: to propose an approach for collecting human performance data from NPP simulators and employing the reliability engineering (RE) concept of limit state, to describe the process for c...

Displays, 2008

Nuclear power production is a safety-critical process where ultimate execution of process change decisions lie with the operators. Thus it is important to provide the best possible decision support through effective supervisory control operator interfaces. This requires a human factors/ergonomics approach in the modernization of analog instrumentation and control systems of the existing nuclear power plants. In this article, we describe how this approach is being used for modernization of the ANGRA I power plant. Using a cognitive task analysis (CTA) approach, we observed operators working on an advanced control room of a nuclear power plant digital simulator and noted several opportunities for improvement in the human/system interfaces related to the graphics design, alarm systems and procedure integration. A redesigned prototype was constructed as an alternative to the current simulator and hardcopy procedure manuals. The design improves upon the graphical layout of system information and provides better integration of procedures, automation and alarm systems. The design was validated by expert opinion and a scenario-based comparison.

Nuclear Engineering and Design, 2014

• Operator behaviors were analyzed according to Rasmussen's SRK classification.

Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 2000

The Human-System Interface Design Review Guideline (NUREG-0700, Revision 1) was developed by the U.S. Nuclear Regulatory Commission (NRC) to provide human factors guidance as a basis for the review of advanced human-system interface technologies. The guidance consists of three components: design review procedures, human factors engineering guidelines, and a software application to provide design review support called the “Design Review Guideline.” Since it was published in June 1996, Rev. 1 to NUREG-0700 has been used successfully by NRC staff, contractors and nuclear industry organizations, as well as by interested organizations outside the nuclear industry. The NRC has committed to the periodic update and improvement of the guidance to ensure that it remains a state-of-the-art design evaluation tool in the face of emerging and rapidly changing technology. This paper addresses the current research to update of NUREG-0700 based on the substantial work that has taken place since the ...