• Safety and Health at Work
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• v.15 no.1
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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.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.6
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• pp.161-170
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• 2020

In this study, develop the seismic acceleration measurement data conversion and signal processing algorithms for improve the operational efficiency of the seismic acceleration measurement system installed for public facilities. Through the analysis of the seismic acceleration time history data, the evaluation methods and criteria and evaluating the safety of buildings were proposed. The system was applied to the test bed building to verify its operation and usability. It is expected to be used as a decision making support data and determining the direction and priority of disaster response in the event of an earthquake.

• Nuclear Engineering and Technology
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• v.52 no.12
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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.

• Journal of Advanced Navigation Technology
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• v.26 no.3
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• pp.125-135
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• 2022

UAM is emerging as the biggest issue in the aviation industry and which is attracting a lot of attention not only domestically but also internationally. In Korea, active research is being conducted centered on the government and industry-university research institutes, such as the establishment of a future K-UAM concept of operation. Therefore, in this study applies the SORA (Specific Operation Risk Assessment) model established by the European JARUS (Joint Authorities for Rulemaking on Unmanned Systems) to apply the K-UAM operation environment and specific corridor for the purpose of cargo transportation that will be operated in the future that the government is promoting. We intend to suggest policy and technical measures for risk mitigation in the initial operating environment by evaluating the level of risk and analyzing the results.

• Journal of the Korea Safety Management & Science
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• v.15 no.4
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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.

• Journal of Energy Engineering
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• v.28 no.4
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• pp.48-60
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• 2019

After the Paris Agreement in 2015, the government has been promoting various policies such as 'Hydrogen-Economy Roadmap(2019)' to supply hydrogen. As part of this, the government announced the goal of building 310 hydrogen refueling stations(HRS) until 2022. To this end, special case standard for the introduction of complex, packaged, and mobile hydrogen refueling stations(MHRS) have been enacted and promulgated. The MHRS has the advantage of being able to supply hydrogen to multiple regions. However, due to the movement and close distance between facilities, it is necessary to secure proper installation standards and operational safety through safety analysis. In this study, the possibility of introduction was investigated by designing a standard model and quantitative risk assessment(QRA). As a result of QRA, personal and social risk were acceptable, and the empirical test direction and implications were derived.

• Journal of the Korean Institute of Gas
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• v.26 no.6
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• pp.52-58
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• 2022

According to the government's roadmap for revitalizing the hydrogen economy, various industries carry out projects using liquefied hydrogen as an energy source. However, safety standards necessary for operational demonstration projects are not prepared in Korea, thus, it is necessary to prepare safety standards as soon as possible. Therefore, in order to secure the safety of liquefied hydrogen instrumentation and handling facilities, it is necessary to prepare safety standards that comprehensively consider the risk of liquefied hydrogen. This study aims to prioritize safety standard items using ETA, FMEA, and AHP, which are risk assessment techniques, to present the feasibility of selecting safety standard items.

• Steel and Composite Structures
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• v.27 no.3
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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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• v.45 no.5
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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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• v.4 no.4
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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.