• Safety and Health at Work
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• 제15권1호
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• pp.87-95
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• 2024

Background: This study focuses on assessing occupational risk for the health hazards encountered during maintenance works (MW) in semiconductor fabrication (FAB) facilities. Objectives: The objectives of this study include: 1) identifying the primary health hazards during MW in semiconductor FAB facilities; 2) reviewing the methods used in evaluating the likelihood and severity of health hazards through occupational health risk assessment (OHRA); and 3) suggesting variables for the categorization of likelihood of exposures to health hazards and the severity of health effects associated with MW in FAB facilities. Methods: A literature review was undertaken on OHRA methodology and health hazards resulting from MW in FAB facilities. Based on this review, approaches for categorizing the exposure to health hazards and the severity of health effects related to MW were recommended. Results: Maintenance workers in FAB facilities face exposure to hazards such as debris, machinery entanglement, and airborne particles laden with various chemical components. The level of engineering and administrative control measures is suggested to assess the likelihood of simultaneous chemical and dust exposure. Qualitative key factors for mixed exposure estimation during MW include the presence of safe operational protocols, the use of air-jet machines, the presence and effectiveness of local exhaust ventilation system, chamber post-purge and cooling, and proper respirator use. Using the risk (R) and hazard (H) codes of the Globally Harmonized System alongside carcinogenic, mutagenic, or reprotoxic classifications aid in categorizing health effect severity for OHRA. Conclusion: Further research is needed to apply our proposed variables in OHRA for MW in FAB facilities and subsequently validate the findings.

• 한국구조물진단유지관리공학회 논문집
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• 제24권6호
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• pp.161-170
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• 2020

본 연구에서는 공공 시설물을 대상으로 설치된 지진가속도 계측 시스템의 운영 효율성 개선을 위하여 지진 이벤트 신호 변환 및 처리 알고리즘을 개발하였다. 더불어 처리된 지진 가속도 시간이력의 분석을 통해 건축물의 안전성을 평가할 수 있는 평가 방법과 평가 기준을 제안하였으며, 테스트베드 건축물에 적용하여 그 작동과 활용성을 검증하였다. 이를 통해 지진 이벤트 계측자료의 분석 정확성을 확보하고, 지진재해 상황에서 재난 대응의 방향과 우선순위 판단을 위한 의사결정 지원자료로 활용할 수 있을 것으로 판단된다.

• Nuclear Engineering and Technology
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• 제52권12호
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• pp.2812-2820
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• 2020

House load operation (HLO) occurs when the generator supplies power to the house load without triggering reactor trips during grid disturbances. In Korea, the HLO capability of optimized power reactor 1000 (OPR1000) plants has prevented several reactor trips. Operational experiences demonstrate the difference in the reactor trip incidence due to grid disturbances between OPR1000 plants and Westinghouse plants in Korea, attributable to the availability of the HLO capability. However, probabilistic safety assessments (PSAs) for OPR1000 plants have not considered their specific design features in the initiating event analyses. In an at-power PSA, the HLO capability can affect the initiating event frequencies of general transients (GTRN) and loss of offsite power (LOOP), resulting from transients within the grid system. The initiating event frequencies of GTRN and LOOP for an OPR1000 plant are reduced by 17.7% and 78.7%, respectively, compared to the Korean industry-average initiating event frequencies, and its core damage frequency from internal events is reduced by 15.2%. The explicit consideration of the HLO capability in initiating event analyses makes significant changes in the risk contributions of the initiating events. Consequently, for more realistic at-power PSAs in Korea, we recommend incorporating plant-specific HLO-related design features when estimating initiating event frequencies.

• 한국항행학회논문지
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• 제26권3호
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• pp.125-135
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• 2022

최근 항공산업 분야의 최대 이슈로 부각되고 있는 UAM(Urban Air Mobility)은 국내 뿐아니라 국제적으로 많은 관심이 집중되고 있다. 현재 우리나라는 미래 K-UAM 운용개념서 제정 등 정부 및 산학연을 중심으로 활발한 연구가 진행되고 있으나 아직까지 비행안전의 핵심 요소인 K-UAM 운용 환경에 대한 위험도 평가 방안은 마련되어 있지 않다. 따라서 본 논문에서는 유럽 JARUS(Joint Authorities for Rulemaking on Unmanned Systems)에서 제정한 SORA(Specific Operation Risk Assessment) 모델을 적용하여 정부가 추진하고 있는 화물 운송 목적의 K-UAM 운용 환경 및 특정 회랑을 대상으로 위험도를 평가하고 그에 따른 결과 분석을 통해 위험도 완화를 위한 정책 및 기술적 방안을 제시하고자 한다.

• 대한안전경영과학회지
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• 제15권4호
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• pp.25-35
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• 2013

Recently, national leisure activities have increased in proportional to having time and money to spare for living on. Especially, camping activities are positioned as a new leisure type for middle class families, so that it is expected that camping facilities are also rapidly increased. However, there is no institutional measures for safe camping activity. It is urgently requested that camping activities including designing and operating campsite are regulated within the legal system. In this study, the status of camping activities and its legal system are investigated. The strategic policy directions for safe camping activity are suggested in the view of legal system, operational guidelines, and institutional supports; (1) the legal basis for camping activities should be prepared. (2) the supervision of campsite management should be improved based on informational services. (3) the self-operation guidelines for campsite owners should be developed and provided. (4) the criteria of safety assessment for design and operating campsite should be prepared. (5) the safety information of campsite should be published and shared among camping communities.

• 에너지공학
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• 제28권4호
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• pp.48-60
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• 2019

정부는 2015년 파리협정 이후, 미세먼지 종합관리 대책(2017), 수소경제 활성화 로드맵(2019) 등을 통해 수소 보급을 위한 다양한 정책을 추진하고 있다. 그 일환으로 2022년까지 수소공급을 위한 충전소 310개소의 구축 목표를 발표하였다. 이를 위해 융·복합, 패키지형, 이동식 수소충전소의 도입을 위한 특례를 제정·공포하였다. 이동식 수소충전소는 여러 지역에 수소를 공급가능한 장점이 있는 반면, 설비의 이동과 집약적 설치로 인해 적정한 설치기준과 운영안전성 확보가 필요하다. 본 연구에서는 이동식 수소충전소 표준모델 설계와 정량적 위험성 평가(QRA)를 실시하여 도입 가능성을 검토하였다. QRA 결과, 개인적, 사회적 위험도는 가용한 것으로 나타났으며, 도입에 대한 실증방향과 시사점을 도출하였다.

• 한국가스학회지
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• 제26권6호
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• pp.52-58
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• 2022

정부의 수소 경제 활성화 로드맵에 따라 다양한 산업 분야에서 액화수소를 에너지원으로 하는 사업을 진행하고 있고, 액화수소 설비 및 취급시설의 제작 및 운영 실증 사업 또한 수행되고 있다. 그러나 운영 실증사업에 필요한 안전기준이 국내에는 마련되지 않아 실증 사업의 걸림돌로 작용하고 있어 조속한 안전기준 마련이 필요한 실정이다. 따라서 액화수소 설비 및 취급시설의 안전성 확보를 위하여 액화수소의 위험성을 종합적으로 고려한 안전기준의 마련이 반드시 필요하다고 본다. 본 연구에서는 일반적인 방법과 같이 국외사고 사례 분석 및 유사 분야의 안전기준을 참고로 도출한 선박용 액화수소 사용 시설 안전기준을 위험성 평가기법인 ETA, FMEA와 의사 결정방법인 AHP를 활용해 안전기준 항목의 우선순위 도출하여 안전기준 항목 선정에 타당성을 제시하고자 한다.

• Steel and Composite Structures
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• 제27권3호
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• pp.327-335
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• 2018

This paper presents structural assessment of a steel railway bridge for current condition using modal parameter to upgrade finite element modeling in order to gather accurate result. An adequate monitoring, such as acceleration, displacement, strain monitoring, is important tool to understand behavior and to assess structural performance of the structure under surround vibration by means of the dynamic analysis. Evaluation of conditions of an existing steel railway bridge consist of 4 decks, three of them are 14 m, one of them is 9.7 m, was performed with a numerical analysis and a series of dynamic tests. Numerical analysis was performed implementing finite element model of the bridge using SAP2000 software. Dynamic tests were performed by collecting acceleration data caused by surrounding vibrations and dynamic analysis is performed by Operational Modal Analysis (OMA) using collected acceleration data. The acceleration response of the steel bridge is assumed to be governing response quantity for structural assessment and provide valuable information about the current statute of the structure. Modal identification determined based on response of the structure play significant role for upgrading finite element model of the structure and helping structural evaluation. Numerical and experimental dynamic properties are compared and finite element model of the bridge is updated by changing of material properties to reduce the differences between the results. In this paper, an existing steel railway bridge with four spans is evaluated by finite element model improved using operational modal analysis. Structural analysis performed for the bridge both for original and calibrated models, and results are compared. It is demonstrated that differences in natural frequencies are reduced between 0.2% to 5% by calibrating finite element modeling and stiffness properties.

• Nuclear Engineering and Technology
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• 제45권5호
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• pp.581-588
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• 2013

This paper deals with the Safety Analysis for $CANDU^{(R)}$ 6 nuclear reactors as affected by main Heat Transport System (HTS) aging. Operational and aging related changes of the HTS throughout its lifetime may lead to restrictions in certain safety system settings and hence some restriction in performance under certain conditions. A step in confirming safe reactor operation is the tracking of relevant data and their corresponding interpretation by the use of appropriate thermal-hydraulic analytic models. Safety analyses ranging from the assessment of safety limits associated with the prevention of intermittent fuel sheath dryout for a slow Loss of Regulation (LOR) analysis and fission gas release after a fuel failure are summarized. Specifically for fission gas release, the thermal-hydraulic analysis for a fresh core and an 11 Effective Full Power Years (EFPY) aged core was summarized, leading to the most severe stagnation break sizes for the inlet feeder break and the channel failure time. Associated coolant conditions provide the input data for fuel analyses. Based on the thermal-hydraulic data, the fission product inventory under normal operating conditions may be calculated for both fresh and aged cores, and the fission gas release may be evaluated during the transient. This analysis plays a major role in determining possible radiation doses to the public after postulated accidents have occurred.

• International Journal of Reliability and Applications
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• 제4권4호
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• pp.183-190
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• 2003

Rail breaks and derailments can cause a huge loss to rail players due to loss of service, revenue, property or even life. Maintenance has huge impact on reliability and safety of railroads. It is important to identify factors behind rail degradation and their risks associated with rail breaks and derailments. Development of mathematical models is essential for prediction and prevention of risks due to rail and wheel set damages, rail breaks and derailments. This paper addresses identification of hazard modes, estimation of probability of those hazards under operating, curve and environmental condition, probability of detection of potential hazards before happening and severity of those hazards for informed strategic decisions. Emphasis is put on optimal maintenance and operational decisions. Real life data is used for illustration.