• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2918-2927
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• 2020

This paper proposes a simplified elastic-plastic analysis procedure using the penalty factors presented in the Code Case N-779 for strain-based fatigue assessment of nuclear safety class 1 components under severe seismic loads such as safety shutdown earthquake and beyond design-basis earthquake. First, a simplified elastic-plastic analysis procedure for strain-based fatigue assessment of nuclear safety class 1 components under the severe seismic loads was proposed based on the analysis result for the simplified elastic-plastic analysis procedure in the Code Case N-779 and the stress categories corresponding to normal operation and seismic loads. Second, total strain amplitude was calculated directly by performing finite element cyclic elastic-plastic seismic analysis for a hot leg nozzle in pressurizer surge line subject to combined loading including deadweight, pressure, seismic inertia load, and seismic anchor motion, as well as was derived indirectly by applying the proposed analysis procedure to the finite element elastic stress analysis result for each load. Third, strain-based fatigue assessment was implemented by applying the strain-based fatigue acceptance criteria in the ASME B&PV Code, Sec. III, Subsec. NB, Article NB-3200 and by using the total strain amplitude values calculated. Last, the total strain amplitude and the fatigue assessment result corresponding to the simplified elastic-plastic analysis were compared with those using the finite element elastic-plastic seismic analysis results. As a result of the comparison, it was identified that the proposed analysis procedure can derive reasonable and conservative results.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.870-877
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• 2006

Recently, failures of equipments are linked directly to extensive damages of human lives or financial losses from the increasing uses of train control equipments utilizing computers. Then safety activities have to progress for guaranteeing safety during the system life-cycle. In this paper, we examine the methods for risk analysis and assessment of safety activities and propose optimized one method for risk assessment. There are original risk assessment methods; risk graph and risk matrix method under the qualitative analysis, IRF(Individual Risk Formula) calculations and statistical calculations method under the quantitative analysis. Best-Practice(BP) risk analysis method is proposed for combining advantages of the qualitative and the quantitative analysis. In the comparison of risk graph and risk matrix method for safety estimation, BP method has no applications published up to now, but we can expect that this method will be utilized widely for the risk assessment due to various strong points.

• Journal of the Korea Safety Management & Science
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• v.19 no.4
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• pp.133-140
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• 2017

The Ministry of Science, ICT and Future Planning made law for Pre-Hazard Risk Analysis in December 31, 2014 to protect researchers from continuing accidents in laboratory. Conducted before an experiment, Pre-Hazard Risk Analysis finds hazards of the experiment and rules to manage the hazards.So the Pre-Hazard Risk Analysis can support laboratory safety system by prevent accidents in laboratory. Pre-Hazards Risk Analysis is newly created system so that executors need Guidelines to perform this analysis properly. This study is to develop guide tool for Pre-Hazard Risk Analysis by analyzing other risk assessment systems; PSM, Off-site Consequence Assessment, laboratory safety system. Also, this study suggested how to establish database for Pre-Hazard Risk Assessment by analyse KRAS.

• International Journal of Safety
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• v.6 no.2
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• pp.38-42
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• 2007

As railway signaling system is computerized, the significance on safety demonstration and assessment has been increased. Therefore, railway signaling system should reflect the needs for safety assessment technique. Various studies on safety assessment technique for railway signaling have been made in Europe and standardization of the requirements for safety acceptance has been initiated by IEC. In order to develop and establish the safety assessment techniques for railway signaling in Korea, we try to review safety assessment activities for signaling system via reviewing relevant case studies and consulting with experts. And also we propose the safety assessment activity/methodology for Korean railway signaling system.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.727-728
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• 2005

• Proceedings of the Safety Management and Science Conference
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• 2013.04a
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• pp.445-456
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• 2013

According to Department of labor guideline "2012-104 (2012.9.26.)" This study is to suggest the basic information and the improvement for the application of risk assessment on a construction site by group interview & survey of construction worker who is the practice of the subject and then numerical analysis about awareness and action plan of Safety and health. The result of group interview and survey of construction worker, most of construction worker feel the danger during the work. Then construction worker analysis results that risk assessment helps to change & raise awareness of safety and reduce an industrial disaster. Easy Safety management activity such as TBM & safety education active will be necessary for safe worksite and then I suggest the TBT(tool box talk) active which combines TBM & safety education.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.75-75
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• 2017

• Journal of the Korean Society of Safety
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• v.25 no.3
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• pp.91-99
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• 2010

In this study, the advanced numerical algorithm is developed which can performed the static and dynamic stochastic finite element analysis by considering the effect of uncertainties included in the member stiffness of steel cable-stayed bridges and seismic load. After conducting the linear and nonlinear initial shape analysis, the advanced numerical algorithm is the assessment tool which can performed structural the response analysis considering the static linearity and non-linearity of before or after induced intial tensile force, and examined the reliability assessment more efficiently. The verification of the developed numerical algorithm is evaluated by analyzing the regression analysis and coefficient of correlation using the direct monte carlo simulation. Also, the dynamic response characteristic and coefficient of variation of the steel cable-stayed bridge is calculated by considering the uncertainty of random variables using the developed numerical algorithm. In addition, the quantitative structural safety of the steel cable-stayed bridges is evaluated by conducting the reliability assessment based upon the dynamic stochastic finite element analysis result.

• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.98-103
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• 2003

Based on ASME probabilistic risk assessment (PRA) and NEI PRA peer review guidance, we evaluate a human reliability analysis (HRA) in probabilistic safety assessment (PSA) for Korea standard nuclear power plants, Ulchin Unit 3&4, to improve it performed at under design. The HRA for Ulchin Unit 3&4 is assessed as higher than Grade I based on ASME PRA standard and as higher than Grade 2 based on NEI PRA peer review guidance. The major items to be improved identified through the evaluation process are the documentation, the systematic human reliability analysis, the participitation of operators in the works and review of HRA. We suggest the guidance on the identification and qualitative screening analysis for pre-accident human errors and solve some items to be improved using the suggested guidance.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1997.11a
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• pp.151-156
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• 1997

In this thesis, the safety assessment of the steel box girder bridge were studied. From the structural analysis results of the steel box girder bridge, bending moment and shear force were calculated, and these element force was applied to the safety assessment of the steel box girder bridge.