• Journal of the Korean Society for Aviation and Aeronautics
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• v.24 no.2
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• pp.59-67
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• 2016

The checklist currently used for Aviation safety inspection performed by ASIs consists of inspection groups and multiple items, it does not have structured hierarchy system which required to efficiently process aviation safety analysis. On this study, through mapping taxonomy of HFACS onto current checklist to secure structured hierarchy system and present a specification on systematic frequency and severity to perform safety risk assessment of detected hazard.

• Journal of the Korean Society of Safety
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• v.27 no.2
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• pp.72-77
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• 2012

There are insufficient models that find problems and solutions for accident prevention through risk assessment and suggest safe work process and work instruction from foundation works to finish work for accident decrease. This paper presents a quantitative risk assessment model by analysis of risk factors in each process such as earth works, drainage works, pavement works, appurtenant works and etc based on accident examples and investigation on actual condition in roads construction work. In addition, the safety management system was developed to perform risk assessment of construction and use it for effective safety training for labor.

• Journal of the Korean Society of Safety
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• v.25 no.5
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• pp.7-14
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• 2010

Ultra high pressure system, which can be generally increased over 1,000bar, needs to have sealing mechanism to protect leakage and selection of the materials used in the intensifier. Components such as pressure vessel, hydraulic hose assembly, accumulator, hydraulic cylinder, hydraulic valve, pipe, etc., are tested under the impulse-pressure conditions. Components need to be tested under 1.5 to 3 times of rated pressure to check the tolerance even though rated pressure range of these components are not ultra high pressure. So, the ultra high pressure system needs to be equiped to test components. In this study, safety assessments of ultra high pressure system which are using failure analysis of components, changing the types of the control system, and finite element analysis with static condition, are investigated.

• Journal of the Korean Society of Safety
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• v.12 no.2
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• pp.70-79
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• 1997

This paper presents a study on the fuzzy linguistic variable based approach for safety assessment of human body in ELF electromagnetic field considering power system states. To cope with the demand in modern industry, the power system becomes larger in scale, higher in voltage. The advent of high voltage system has increased the relative importance of field effects. The analysis of ELF electromagnetic field based on Quasi-Static Method is introduced while the power system is included to model the expected and/or unexpected uncertainty caused by the load fluctuation and parameter changes. In order to analyze the power system, Monte Carlo simulation method and contingency analysis method are adopted in normal state and alert state, respectively. In the safety assessment of human body, the approach based on fuzzy linguistic variable is employed to overcome the shortcomings resulting from a crisp set concept. The suggested scheme is applied to a sample system(modified IEEE 14 bus system) to validate the usefulness.

• Safety and Health at Work
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• v.9 no.2
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• pp.140-143
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• 2018

Background: The Occupational Safety and Health Monitoring and Assessment Tool (OSH-MAT) is a practical instrument that is currently used in the German woodworking and metalworking industries to monitor safety conditions at workplaces. The 12-item scoring system has three subscales rating technical, organizational, and personnel-related conditions in a company. Each item has a rating value ranging from 1 to 9, with higher values indicating higher standard of safety conditions. Methods: The reliability of this instrument was evaluated in a cross-sectional survey among 128 companies and its validity among 30,514 companies. The inter-rater reliability of the instrument was examined independently and simultaneously by two well-trained safety engineers. Agreement between the double ratings was quantified by the intraclass correlation coefficient and absolute agreement of the rating values. The content validity of the OSH-MAT was evaluated by quantifying the association between OSH-MAT values and 5-year average injury rates by Poisson regression analysis adjusted for the size of the companies and industrial sectors. The construct validity of OSH-MAT was examined by principle component factor analysis. Results: Our analysis indicated good to very good inter-rater reliability (intraclass correlation coefficient = 0.64-0.74) of OSH-MAT values with an absolute agreement of between 72% and 81%. Factor analysis identified three component subscales that met exactly the structure theory of this instrument. The Poisson regression analysis demonstrated a statistically significant exposure-response relationship between OSH-MAT values and the 5-year average injury rates. Conclusion: These analyses indicate that OSH-MAT is a valid and reliable instrument that can be used effectively to monitor safety conditions at workplaces.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.2
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• pp.161-172
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• 2017

To evaluate radiological impact from the operation of a low- and intermediate-level radioactive waste disposal facility, a logical presentation and explanation of expected accidental scenarios is essential to the stakeholders of the disposal facility. The logical assessment platform and procedure, including analysis of the safety function of disposal components, operational hazard analysis, operational risk analysis, and preparedness of remedial measures for operational safety, are improved in this study. In the operational risk analysis, both design measures and management measures are suggested to make it possible to connect among design, operation, and safety assessment within the same assessment platform. For the preparedness of logical assessment procedure, classification logic of an operational accident is suggested based on the probability of occurrence and consequences of assessment results. The improved assessment platform and procedure are applied to an operational accident analysis of the Korean low- and intermediate-level radioactive waste disposal facility and partly presented in this paper.

• Journal of Ocean Engineering and Technology
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• v.11 no.3
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• pp.8-19
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• 1997

In this study an adequate type of offshore structure at the Sakhalin region as cold region is proposed and its structural design results are presented based on the reliability analysis. Structural safety assessment has been carried out for the proposed offshore structure at the Sakhalin area as designed by the reliability method. And a rational design procedure is presented based on the reliability analysis. Followings are drawn through the present study : - Four colum TLP structure is proposed as an adequate offshore structure type at the cold region like the Sakhalin region and the reliability-based structural design results are presented. It is seen that the proposed type is a more adequate and economic than the fixed type. - Safety assessment of the proposed structure applying the extended incremental load method is performed. - Referring the allowable safety level for offshore structures it has been found present TLP structure has sufficient structural safety at the system level as well as at the component level.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1997.11a
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• pp.117-122
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• 1997

This paper presents a study on the fuzzy based approach for the safety assessment of human body under ELF electric and magnetic(EM) field considering power system states. The analysis of ELF EM field based on quasi-static method is introduced. UP to the present, the analysis of ELF EM field has been conducted with the consideration of one transmission line, or a power line model only In this paper, however, the power system is included to model the expected and/or unexpected uncertainty caused by the load fluctuation and parameter changes and the states are classified into two types, normal state resulting from normal operation and emergency state from outages. In order to analyze the uncertainty in the normal state, the Monte Carlo Simulation, a statistic approach was introduced and line current and bus voltage distribution are calculated by a contingency analysis method, in the emergency state. To access the safety of human body, the approach based on fuzzy linguistic variable is adopted to overcome the shortcomings of the assessment by a crisp set concept. In order to validate the usefulness of the approach suggested herein, the case study using a sample system with 765(kV) was done. The results are presented and discussed.

• Journal of the Korea Safety Management & Science
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• v.20 no.1
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• pp.1-9
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• 2018

As the chemical industry becomes more advanced, the awareness of chemical accidents is rising, and legal systems for chemical safety management are strengthened. In this study, quantitative risk assessment of liquid chlorine leak was conducted. Risk assessment was performed in the order of frequency analysis, consequence analysis, and risk calculation. The individual risk was presented in the form of contour lines. The social risk was expressed by the FN curve. The risk of day and night was in an unacceptable area, so it was required to mitigate risk. Therefore in-building, which could trap the pool, was selected as a risk mitigation measure. As a result of the cost benefit analysis, it was concluded that this measure should be reasonably implemented.

• Nuclear Engineering and Technology
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• v.53 no.2
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• pp.498-508
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• 2021

Micro reactors are increasingly being considered for utilization as distributed power sources. Hence, the probabilistic safety assessment (PSA) of a direct supercritical-CO₂-cooled fast reactor, called micro modular reactor (MMR), was performed in this study; this reactor was developed using innovative design concepts. It adopted a modular design and passive safety systems to minimize site constraints. As the MMR is in its conceptual design phase, design weaknesses and valuable safety insights could be identified during PSA. Level 1 internal event PSA was carried out involving literature survey, system characterization, identification of initiating events, transient analyses, development of event trees and fault trees, and quantification. The initiating events and scenarios significantly contributing to core damage frequency (CDF) were determined to identify design weaknesses in MMR. The most significant initiating event category contributing to CDF was the transients with the power conversion system initially available category, owing to its relatively high occurrence frequency. Further, an importance analysis revealed that the safety of MMR can be significantly improved by improving the reliability of reactor trip and passive decay heat removal system operation. The findings presented in this paper are expected to contribute toward future applications of PSA for assessing unconventional nuclear reactors in their conceptual design phases.