• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.94-102
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• 2022

Construction workers are engaged in many activities that may expose them to serious hazards, such as falling, unguarded machinery, or being struck by heavy construction equipment. Despite extensive research in building information modeling (BIM) for safety management, current approaches, detecting safety issues after design completion, may limit the opportunities to prevent predictable and potential accidents when decisions of building materials and systems are made. In this respect, this research proposes a proactive approach to detecting safety issues from the early design phase. This research aims to explore accident precursors and integrate them into BIM for tracking safety hazards during the design development process. Accident precursors can be identified from construction incident reports published by OSHA using a text mining technique. Through BIM-integrated accident precursors, construction safety hazards can be identified during the design phase. The results will contribute to supporting a successful transition from the design stage to the construction stage that considers a safe construction workplace. This will advance the body of knowledge about construction safety management by elucidating a hypothesis that safety hazards can be detected during the design phase involving decisions about materials, building elements, and equipment. In addition, the proactive approach will help the Architecture, Engineering and Construction (AEC) industry eliminate occupational safety hazards before near-miss situations appear on construction sites.

• Nuclear Engineering and Technology
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• 제49권2호
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• pp.313-326
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• 2017

The systematic management of plant risk is crucial for enhancing the safety of nuclear power plants and for designing new nuclear power plants. Accident sequence precursor (ASP) analysis may be able to provide risk significance of operational experience by using probabilistic risk assessment to evaluate an operational event quantitatively in terms of its impact on core damage. In this study, an ASP methodology for two operation mode, full power and low power/shutdown operation, has been developed and applied to significant accident precursors that may occur during the operation of nuclear power plants. Two operational events, loss of feedwater and steam generator tube rupture, are identified as ASPs. Therefore, the ASP methodology developed in this study may contribute to identifying plant risk significance as well as to enhancing the safety of nuclear power plants by applying this methodology systematically.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2690-2701
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• 2022

In this paper, we select important fission products for the estimation of the source term during a severe accident of a PWR. The selection is based on the numerical results obtained from depletion calculations for the typical PWR fuel via the in-house code named DEGETION (Depletion, Generation, and Transmutation of Isotopes on Nuclear Application), release fractions of the fission products derived from NUREG-1465, and effective dose conversion coefficients from ICRP 119. Then, for the selected fission products, we obtain the adjoint solutions of the Bateman equations for radioactive decay in order to determine the importance of precursors producing the aforementioned fission products via radioactive decay, which would provide insights into the assumption used in MACCS 2 for a level 3 PSA analysis in which up to six precursors are considered in the calculations of radioactive decays for the fission product after release from the reactor.

• Journal of Advanced Marine Engineering and Technology
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• 제40권8호
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• pp.721-725
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• 2016

This paper reviews the analysis of a given scenario according to the Hybrid Model, and why accident causation models are necessary in casualty investigations. The given scenario has been analyzed according to the Hybrid Model using its main five components, fallible decisions, line management, psychological precursors to unsafe acts, unsafe acts, and inadequate defenses. In addition, the differences between the SHEL and the Hybrid Model, and the importance of a safety barrier during an accident investigation, are shown in this paper. One unit of SHEL can be linked with another unit of SHEL. However, it cannot be used for the analysis of an accident. Therefore, we must use an accident causation model, which can be a Hybrid Model. This can explain the "How" and "Why" of accident, so it is a suitable model for analyzing them. During an accident investigation, the reason we focus on a safety barrier is to create another safety barrier or to change an existing safety barrier if that barrier fails. Hence, the paper shows how a sea accident can be investigated, and we propose a preventive way of avoiding the accident through combining the methods of different models for the future.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1335-1340
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• 2009

In order to establish railway long-tenn safety policy, various railway safety indexes are required. But these indexes are not use efficiently due to the limitation of safety information. Recently m any safety related information have been obtained based on Railway Safety Act 2004. In this study, various safety index, which can be applied both preventive safety activities and safety measure development, are proposed. These safety indexes are based on common safety index in European Railway Agency, but also include special index in Korea. Proposed safety index include accident results, precursors to accident, infrastructure, accident cost and safety management system. These indexes will be applied in railway industry from 2009.

• 한국안전학회지
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• 제31권5호
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• pp.177-186
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• 2016

When an event is occurred in a nuclear power plant (NPP), the NPP operator reports it referred by the regulation on reporting and public announcement of accidents and incidents. Some of the events do not need to be reported because they are not included in the reporting criteria of the regulation. However, it is necessary that they should be managed effectively because the accident can be occurred by the recurrence of a lot of them as precursors. Among the events not included in the reporting criteria of the regulation, near miss is the event that is not occurred but can generate a significant consequence. This can provide the cause of the event which does not result an accident. So, it is able to offer insightful knowledges to prevent higher level events about the function and process of NPP. The objective of this study is to analyze the issues of near miss events, prepare the defence against the risk, and improve the management process of NPP. To achieve it, this study performed to analyze the management structure and status of near miss events as well as the accident reporting system of the domestic and foreign regulation bodies. In case of Korea, the status was analyzed by quantitative data, licensee event reports and procedures. Based on these, we could find the causes that near miss events were not managed effectively. Then, systematic alternatives that reflected the perspective of man, technology and organization were drawn.

• 한국가스학회지
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• 제27권2호
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• pp.79-85
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• 2023

최근 반도체 공정은 대기업을 중심으로 4차산업에 따른 수요 증가로 메모리 반도체에서 파운드리로의 공정변화를 모색하고 있으며 10나노(nm) 공정에서 3 나노(nm)이하 공정으로의 초미세화 공정개발과 같이 산업이 확대되고 있다. 이러한 반도체 칩을 생산하기 위해 사용되는 원료인 특수가스 및 Precursor(전구체) 등의 특성은 유독성, 자연발화성, 인화성, 부식성 물질이다. 이러한 반도체 원료들은 폐쇄시스템으로 운영이 되어 정상 중에는 누출이 되지 않으나 누출 될 경우 가스박스 내부로 확산되고 가스박스 내부에서 적절한 환기가 되지 않는 경우 가스박스 외부로 확산되어 화재, 폭발을 일으키거나 독성 물질의 누출 등 큰 사고로 이어질 수 있다. 최근 반도체 산업에서 원료가 폐쇄시스템으로부터 누출되어 가스박스 내부 및 외부로 확산되는 사고 사례가 발생하고 있으나 가스박스 내부의 적정환기 시스템의 적용 이외에 적절한 예방대책을 제시한 연구 사례를 찾아 볼 수 없었다. 본 연구에서는 반도체 원료 이송배관의 연결부위인 VCR 피팅에서 원료가 누출되어 가스박스 외부로 확산된 사고사례를 바탕으로 이에 대한 예방대책을 제시하고자 한다.