HUMAN ERRORS DURING THE SIMULATIONS OF AN SGTR SCENARIO: APPLICATION OF THE HERA SYSTEM

WONDEA JUNG,APRIL M. WHALEY,BRUCE P. HALLBERT 한국원자력학회 2009 Nuclear Engineering and Technology Vol.41 No.10

Due to the need of data for a Human Reliability Analysis (HRA), a number of data collection efforts have been undertaken in several different organizations. As a part of this effort, a human error analysis that focused on a set of simulator records on a Steam Generator Tube Rupture (SGTR) scenario was performed by using the Human Event Repository and Analysis (HERA) system. This paper summarizes the process and results of the HERA analysis, including discussions about the usability of the HERA system for a human error analysis of simulator data. Five simulated records of an SGTR scenario were analyzed with the HERA analysis process in order to scrutinize the causes and mechanisms of the human related events. From this study, the authors confirmed that the HERA was a serviceable system that can analyze human performance qualitatively from simulator data. It was possible to identify the human related events in the simulator data that affected the system safety not only negatively but also positively. It was also possible to scrutinize the Performance Shaping Factors (PSFs) and the relevant contributory factors with regard to each identified human event.

ESTIMATING THE OPERATOR’S PERFORMANCE TIME OF EMERGENCY PROCEDURAL TASKS BASED ON A TASK COMPLEXITY MEASURE

WONDEA JUNG,JINKYUN PARK 한국원자력학회 2012 Nuclear Engineering and Technology Vol.44 No.4

It is important to understand the amount of time required to execute an emergency procedural task in a high-stress situation for managing human performance under emergencies in a nuclear power plant. However, the time to execute an emergency procedural task is highly dependent upon expert judgment due to the lack of actual data. This paper proposes an analytical method to estimate the operator’s performance time (OPT) of a procedural task, which is based on a measure of the task complexity (TACOM). The proposed method for estimating an OPT is an equation that uses the TACOM as a variable,and the OPT of a procedural task can be calculated if its relevant TACOM score is available. The validity of the proposed equation is demonstrated by comparing the estimated OPTs with the observed OPTs for emergency procedural tasks in a steam generator tube rupture scenario

Analysis of an Operators' Performance Time and Its Application to a Human Reliability Analysis in Nuclear Power Plants

Jung, Wondea,Park, Jinkyun,Kim, Jaewhan,Ha, Jaejoo IEEE 2007 IEEE transactions on nuclear science Vol.54 No.5

<P> With a scarcity of empirical data, much of the input regarding a human reliability analysis (HRA) is dependent on an analysts' subjective judgment, which is one of the major causes of a high uncertainty in the results of an HRA. When considering that risk-informed activities require the probabilistic safety assessment (PSA) quality to be as high as possible, an HRA should be performed by using a systematic method with realistic plant specific data to meet the established requirements for risk-informed applications. In order to obtain more objective HRA results, data extracted from real experiences or simulators is essential. This paper presents a human performance analysis of the emergency tasks for nuclear power plants (NPPs) to support an HRA. Using the full-scope simulator of a reference plant, more than 110 simulator records with six emergency scenarios were gathered and analyzed to generate an operators' performance time such as the time taken to diagnose what event has occurred, and the time to execute a procedural step or a task. A sensitivity analysis for an HRA has also been performed by using an operators' performance time. </P>

원자력발전소 위험도 평가를 위한 인간신뢰도분석

정원대(Wondea Jung),김재환(Jaewhan Kim) 대한인간공학회 2011 大韓人間工學會誌 Vol.30 No.1

Objective: The aim of this paper is to introduce the activities and research trends of human reliability analysis including brief summary about contents and methods of the analysis. Background: Various approaches and methods have been suggested and used to assess human reliability in field of risk assessment of nuclear power plants. However, it has noticed that there is high uncertainty in human reliability analysis which results in a major bottleneck for risk-informed activities of nuclear power plants. Method: First and second generation methods of human reliability analysis are reviewed and a few representative methods are discussed from the risk assessment perspective. The strength and weakness of each method is also examined from the viewpoint of reliability analyst as a user. In addition, new research trends in this field are briefly summarized. Results: Human reliability analysis has become an important tool to support not only risk assessment but also system design of a centralized complex system. Conclusion: Human reliability analysis should be improved by active cooperation with researchers in field of human factors. Application: The trends of human reliability analysis explained in this paper will help researchers to find interest topics to which they could contribute.

철도와 타 산업에서의 인적오류 보고 및 분석 체계 비교 분석

정원대(Jung Wondea),고종현(Ko Jong Hyun),곽상록(Kwak Sang Log) 한국철도학회 2006 한국철도학회 학술발표대회논문집 Vol.- No.-

Human factors still plays a significant part in many railway accidents. The accidents often resulted from multiple causes of hardware failures and human errors. So to ensure the safety of railway operations, human error should be prevented effectively. In order to reduce the potential of human error, a systematic error analysis should be undertaken in advance for identifying the root causes of the error. In this paper, we reviewed the present state of the reporting and investigation of human error in railway industries, and compared it to ones of other industries such as aviation and nuclear power.

NASA-TLX 방법에 의한 KTX 운전 직무부하 분석

정원대(Jung Wondea),고종현(Ko Jong-Hyun),박진균(Park Jinkyun),곽상록(Kwak Sang-Log),임승수(Lim Seoung-Su) 한국철도학회 2006 한국철도학회 학술발표대회논문집 Vol.- No.-

Human factors still plays a significant role in railway accidents. The accidents often resulted from multiple causes of hardware failures and human errors. So to ensure the safety of railway operations, human error should be effectively prevented and managed. Among several factors influencing human performance, task load (or task complexity) is well known as a major contributor to human error. In order to reduce the potential of human error, a systematic analysis should be undertaken to evaluate task load and to reduce it by modifying task process and/or education&training. In this paper, we proposed a systematic framework for railway industry to perform task analysis and to evaluate task load, and applied it to KTX operational tasks. According to the application study, we identified 14 generic task types of KTX operation. And also this paper shows the quantitative task load of those generic tasks which were analyzed by NASA-TLX method.

New Procedural Path for F&B Operation and Its Risk Impact on a Nuclear Power Plant

Informa UK (TaylorFrancis) 2018 Nuclear technology Vol. No.

Inter-relationships between performance shaping factors for human reliability analysis of nuclear power plants

Park, Jooyoung,Jung, Wondea,Kim, Jonghyun Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.1

Performance shaping factors (PSFs) in a human reliability analysis (HRA) are one that may influence human performance in a task. Most currently applicable HRA methods for nuclear power plants (NPPs) use PSFs to highlight human error contributors and to adjust basic human error probabilities (HEPs) that assume nominal conditions of NPPs. Thus far, the effects of PSFs have been treated independently. However, many studies in the fields of psychology and human factors revealed that there may be relationships between PSFs. Therefore, the inter-relationships between PSFs need to be studied to better reflect their effects on operator errors. This study investigates these inter-relationships using two data sources and also suggests a context-based approach to treat the inter-relationships between PSFs. Correlation and factor analyses are performed to investigate the relationship between PSFs. The data sources are event reports of unexpected reactor trips in Korea and an experiment conducted in a simulator featuring a digital control room. Thereafter, context-based approaches based on the result of factor analysis are suggested and the feasibility of the grouped PSFs being treated as a new factor to estimate HEPs is examined using the experimental data.

A Study on the Revision of the TACOM Measure

Park, Jinkyun,Jung, Wondea Professional Technical Group on Nuclear Science 2007 IEEE transactions on nuclear science Vol.54 No.6

<P> It is well known that the performance of human operators, which is one of the predominant factors affecting the safety of any human-involved systems, is largely attributable to the complexity of tasks. From this regard, in order to evaluate the complexity of tasks stipulated in procedures, Park <etal/> developed the TACOM measure that consists of five sub-measures. In this study, in order to unravel a potential problem observed in the course of validation studies about the TACOM measure, the revised TACOM (R-TACOM) measure was suggested based on the theory of a task complexity. Although more detailed studies are necessary, the result of this study indicates that the R-TACOM measure is a more proper measure than the TACOM measure in quantifying the complexity of tasks stipulated in procedures. </P>

A Study on the Validity of a Task Complexity Measure for Emergency Operating Procedures of Nuclear Power Plants—Comparing With a Subjective Workload

Jinkyun Park,Wondea Jung IEEE 2006 IEEE transactions on nuclear science Vol.53 No.5

<P>In this study, the appropriateness of the task complexity (TACOM) measure that can quantify the complexity of emergency tasks was investigated by comparing subjective workload scores with the associated TACOM scores. To this end, based on the NASA-TLX (task load index) technique, 18 operators were asked to subjectively estimate perceived workload for 23 emergency tasks that were specified in the emergency operating procedures of the reference nuclear power plants. As the result of comparisons, it was observed that subjective workload scores increase in proportion to the increase of TACOM scores. Therefore, it is expect that the TACOM measure can be used as a serviceable method to quantify the complexity of emergency tasks</P>