• Nuclear Engineering and Technology
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• 제44권4호
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• pp.379-386
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• 2012

A symptom-based procedure with a critical safety function monitoring system has been established to reduce the operator's diagnosis and cognitive burden since the Three-Mile Island (TMI) accident. However, it has been reported that a symptom-based procedure also requires an operator's cognitive efforts to cope with off-normal events. This can be caused by mismatches between a static model, an emergency operating procedure (EOP), and a dynamic process, the nature of an ongoing situation. The purpose of this study is to share the evidence of mismatches that may result in an excessive cognitive burden in conducting EOPs. For this purpose, we analyzed simulated emergency operation records and observed some operator behaviors during the EOP operation: continuous steps, improper description, parameter check at a fixed time, decision by information previously obtained, execution complexity, operation by the operator's knowledge, notes and cautions, and a foldout page. Since observations in this study are comparable to the results of an existing study, it is expected that the operational behaviors observed in this study are generic features of operators who have to cope with a dynamic situation using a static procedure.

• Nuclear Engineering and Technology
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• 제37권1호
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• pp.118-126
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• 2005

While emergency operating procedures (EOPs) occupy an important role in the management of various abnormal situations in nuclear power plants (NPPs), current technology for the validation of EOPs still largely depends on manual review. A validation method for EOPs of NPPs is thus proposed based on dynamic multi-level flow modeling (MFM). The MFM modeling procedure and the EOP validation procedure are developed and provided in the paper. Application of the proposed method to EOPs of an actual NPP shows that the proposed method provides an efficient means of validating EOPs. It is also found that the information on state transitions in MFM models during the management of abnormal situations is also useful for further analysis on EOPs including their optimization.

• 대한인간공학회지
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• 제29권1호
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• pp.129-138
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• 2010

Gori-I nuclear power plant has been examining the effectiveness and efficiency of the current emergency operation procedures from human factors viewpoint. Previous study showed that some mistakes that the procedures did not comply with the writers' guidelines. Reviewing the current writers' guidelines for emergency operating procedures revealed that they lack of some important human factors rules such as enumeration of switching conditions and detailed action requirements, definite expression for setup points, description for anticipated results, and recommendation for use of present tense, affirmative sentence and active voice. This study suggested a new classification system for the writers' guideline contents supplementing the deficiencies of the current emergency operation procedure text.

• Nuclear Engineering and Technology
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• 제35권5호
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• pp.412-425
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• 2003

According to the results of related studies, one of the typical factors related to procedure related human errors is the complexity of procedures. This means that comparing the change of the operators' behavior with respect to the complexity of procedures may be meaningful in clarifying the reasons for the operators' non-compliance behavior. In this study, to obtain data related to the operators' non-compliance behavior, emergency training records were collected using a full scope simulator. And three types of the operators' behavior (such as strict adherence, skipping redundant actions and modifying action sequences) observed from the collected emergency training records were compared with the complexity of the procedural steps. As the results, two remarkable relationships are obtained. They are: 1) the operators seem to frequently adopt non-compliance behavior to conduct the procedural steps that have an intermediate procedural complexity, 2) the operators seems to accommodate their non-compliance behavior to the complexity of the procedural steps. Therefore, it is expected that these relationships can be used as meaningful clues not only to scrutinize the reason for non-compliance behavior but also to suggest appropriate remedies for the reduction of non-compliance behavior that can result in procedure related human error.

• Nuclear Engineering and Technology
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• 제44권8호
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• pp.929-938
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• 2012

The Computerized Procedure System (CPS) is one of the primary operating support systems in the digital Main Control Room. The CPS displays procedure on the computer screen in the form of a flow chart, and displays plant operating information along with procedure instructions. It also supports operator decision making by providing a system decision. A procedure flow should be correct and reliable, as an error would lead to operator misjudgment and inadequate control. In this paper we present a modeling for the CPS that enables formal verification based on Petri nets. The proposed State Token Petri Nets (STPN) also support modeling of a procedure flow that has various interruptions by the operator, according to the plant condition. STPN modeling is compared with Coloured Petri net when they are applied to Emergency Operating Computerized Procedure. A converting program for Computerized Procedure (CP) to STPN has been also developed. The formal verification and validation methods of CP with STPN increase the safety of a nuclear power plant and provide digital quality assurance means that are needed when the role and function of the CPS is increasing.

• 한국융합학회논문지
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• 제8권10호
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• pp.105-114
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• 2017

본 연구는 구급대원으로 활동하는 응급구조사의 표준작전절차에 대한 융복합적인 인지도와 수행도를 알고자 하는데 그 목적이 있다. 이러한 목적을 달성하기 위하여 본 연구에서는 구급대원으로 활동하는 응급구조사 400명을 연구대상으로 표집하여 SPSS 20.0 Version을 사용하여 분석하였다. 연구 결과는 다음과 같다. 첫째, 연구대상자의 융복합적인 인지도는 호흡기 감염예방 부분이 가장 높았고, 손위생이 가장 낮았으며, 수행도는 치료장비 및 직원의 안전 부분이 가장 높았고, 손위생이 가장 낮았다. 인지도가 전체적으로 수행도 보다 높았다. 둘째, 일반적 특성에 따라 인지도는 연령, 성별, 상처 경험에 따라 통계적으로 유의한 차이가 있었으며, 수행도는 근무경력만이 유의한 차이를 보였다. 응급구조사의 융복합적인 인지도와 수행도 간에 정적 상관관계를 보이는 것으로 나타났다. 이 같은 결과로 구급대원으로 활동하는 응급구조사의 표준작전절차에 관한 인지도와 수행도를 복합적으로 높이기 위해 인지도를 선행으로 한 프로그램을 지속적으로 반복 교육 시 수행도를 증가시킬 수 있을 것으로 사료된다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2001년도 추계학술발표회요약집
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• pp.163.2-163
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• 2001

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2002년도 추계학술발표회요약집
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• pp.180.1-180
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• 2002

• 산업공학
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• 제24권4호
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• pp.274-280
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• 2011

Delayed access to surgery may lead to deterioration in the patient condition, poor clinical outcomes, increase in the probability of emergency admission, or even death. The purpose of this work is to decide the number of patients selected from a waiting list and to schedule them in accordance with the operating room capacity in the next period. We formulate the problem as an infinite horizon Markov Decision Process (MDP), which attempts to strike a balance between the patient waiting times and overtime works. Structural properties of the proposed model are investigated to facilitate the solution procedure. The proposed procedure modifies the conventional value iteration method along with the binary search technique. An example of the optimal policy is provided, and computational results are given to show that the proposed procedure improves computational efficiency.

• Nuclear Engineering and Technology
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• 제52권9호
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• pp.2009-2016
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• 2020

A nuclear power plant is a large complex system with tens of thousands of components. To ensure plant safety, the early and accurate diagnosis of abnormal situations is an important factor. To prevent misdiagnosis, operating procedures provide the anticipated symptoms of abnormal situations. While the more severe emergency situations total less than ten cases and can be diagnosed by dozens of key plant parameters, abnormal situations on the other hand include hundreds of cases and a multitude of parameters that should be considered for diagnosis. The tasks required of operators to select the appropriate operating procedure by monitoring large amounts of information within a limited amount of time can burden operators. This paper aims to develop a system that can, in a short time and with high accuracy, select the appropriate operating procedure and sub-procedure in an abnormal situation. Correspondingly, the proposed model has two levels of prediction to determine the procedure level and the detailed cause of an event. Simulations were conducted to evaluate the developed model, with results demonstrating high levels of performance. The model is expected to reduce the workload of operators in abnormal situations by providing the appropriate procedure to ultimately improve plant safety.