• Title/Summary/Keyword: National Safety Assessment

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Total Mercury Contents of Antarctic Toothfish Dissostichus mawsoni Caught in the Antarctic Sea

  • Son, Kwang-Tae;Kwon, Ji-Young;Jo, Mi-Ra;Yoon, Minchul;Song, Ki-Cheol;Choi, Woo-Seok;Yeon, In-Ja;Kim, Ji-Hoe;Lee, Tae Seek
    • Fisheries and Aquatic Sciences
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    • v.17 no.4
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    • pp.427-431
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    • 2014
  • Mercury is an element of special concern for human health. Measurements of total mercury levels in fish have been taken into consideration to assess risk. In this study, the Antarctic toothfish Dissostichus mawsoni was evaluated as a potential safe food source through measurement of total mercury contents. Total mercury concentrations in Antarctic toothfish ranged from $0.101{\pm}0.047mg/kg$ to $0.139{\pm}0.075mg/kg$. The total mercury concentration was significantly correlated with macroscopic values including total fish length, weight, gonadosomatic index, and maturity (P < 0.01 or 0.05). Furthermore, according to the risk assessment, the total mercury body exposure rate from Antarctic toothfish ranged from 2.125% to 2.847% of the Provisional Tolerable Weekly Intake. Therefore, the Antarctic toothfish could be used as a potential safe seafood source.

Damage Assessment of Reinforced Concrete Beams Under Flexural Failure Mode Using Acoustic Emission Testing (음향방출 기술을 이용한 철근콘크리트 보의 휨 파괴 손상평가)

  • David Kim;Seonglo Lee;Wonsuk Park
    • Journal of the Korean Society of Safety
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    • v.38 no.2
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    • pp.36-43
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    • 2023
  • In this study, a four-point bending test was conducted to assess and detect the damage to reinforced concrete structures using the acoustic emission (AE) technique. Based on the crack investigation results, flexural failure was classified into four stages and compared with the characteristic analysis results of AE parameters. The parametric characterization indicated that the activity of the primary AE signal was high in the early stage, and that of the second signal increased after the flexural cracks stabilized. Because the secondary AE signal included noise generated by friction, parameter-based analysis for damage assessment was performed using the primary signal; the secondary signal was used as complement. The activity analyses of the primary and secondary signals effectively classified crack propagation; however, determining the macrocracks and yielding of reinforcing bars had certain limitations. Nevertheless, applying the damage index with cumulative AE energy is a complementary technique for detecting and assessing structure damage that well detects the occurrence of macrocracks.

Advanced Korean Industrial Safety and Health Policy with Risk Assessment

  • Kwon, Hyuck-Myun;Cho, Jae-Hyun;Moon, Il;Choi, Jae-Wook;Park, Doo-Yong;Lee, Young-Soon
    • Safety and Health at Work
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    • v.1 no.1
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    • pp.29-36
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    • 2010
  • This article describes a systematic roadmap master plan for advanced industrial safety and health policy in Korea, with an emphasis on. Since Korean industries had first emergence of industrial safety and health policy in 1953, enormous efforts have been made on upgrading the relevant laws in order to reflect real situation of industrial work environment in accordance with rapid changes of Korean and global business over three decades. Nevertheless, current policy has major defects; too much techniques-based articles, diverged contents in less organization, combined enforcement and punishments and finally enforcing regulations full of commands and control. These deficiencies have make it difficult to accommodate changes of social, industrial and employment environment in customized fashion. The approach to the solution must be generic at the level of paradigm-shift rather than local modifications and enhancement. The basic idea is to establish a new system integrated with a risk assessment scheme, which encourages employers to apply to their work environment under comprehensive responsibility. The risk assessment scheme is designed to enable to inspect employers' compliances afterwards. A project comprises four yearly phases based on applying zones; initially designating and operating a specified risk zone, gradually expanding the special zones during a period of 3 years (2010-2012) and the final zone expanded to entire nation. In each phase, the intermediate version of the system is updated through a process of precise and unbiased validation in terms of its operability, feasibility and sustainability with building relevant infrastructures as needed.

Risk Analysis of Off-site Risk Assessment using Vulnerability by Environmental Medium (환경매체별 취약성을 반영한 장외영향평가 위험도 분석)

  • Choi, Woo Soo;Back, Jong Bae
    • Journal of the Korean Society of Safety
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    • v.33 no.5
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    • pp.150-156
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    • 2018
  • As the types and usage of chemical increase, modern countries should protect their health and environment from the risk of hazardous chemical. Chemical accidents not only affect humans but also cause huge losses to the environment. Moreover, since its effects do not end in a short period of time, it is necessary to identify the extent of the damage and establish a prevention and response system in advance. In 2015, the Chemical Substances Management Act provided a system for assessing the impact on the people and the environment around the workplace. However, it is difficult to quantitatively evaluate the impact on environmental factors such as vegetation and aquatic, with the current hazard assessment methods. The purpose of this study is to analyze the quantitative risk of environmental receptors. This study improved the existing risk assessment formula by using the environmental vulnerability index and established the end point concentration criterion which can estimate the damage range to environmental media. To verify the results of the study, a virtual accident scenario was selected and a case study was conducted. As a result, the extent of impact on the environmental medium can be calculated, and the degree of environmental risk of the zone can be quantified through the risk analysis considering the environmental vulnerability. This study is expected to increase the reliability of the reliability of the existing risk anaylsis method beacause it is a risk analysis method that can be applied when the environmental factors are absolutely necessary and when the residents and environment are complex.

Numerical investigation on the hydraulic loss correlation of ring-type spacer grids

  • Ryu, Kyung Ha;Shin, Yong-Hoon;Cho, Jaehyun;Hur, Jungho;Lee, Tae Hyun;Park, Jong-Won;Park, Jaeyeong;Kang, Bosik
    • Nuclear Engineering and Technology
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    • v.54 no.3
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    • pp.860-866
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    • 2022
  • An accurate prediction of the pressure drop along the flow paths is crucial in the design of advanced passive systems cooled by heavy liquid metal coolants. To date, a generic pressure drop correlation over spacer grids by Rehme has been applied extensively, which was obtained from substantial experimental data with multiple types of components. However, a few experimental studies have reported that the correlation may give large discrepancies. To provide a more reliable correlation for ring-type spacer grids, the current numerical study aims at figuring out the most critical factor among four hypothetical parameters, namely the flow area blockage ratio, number of fuel rods, type of fluid, and thickness of the spacer grid in the flow direction. Through a set of computational fluid dynamics simulations, we observed that the flow area blockage ratio dominantly influences the pressure loss characteristics, and thus its dependence should be more emphasized, whereas the other parameters have little impact. Hence, we suggest a new correlation for the drag coefficient as CB = Cν,m2.7, where Cν,m is formulated by a nonlinear fit of simulation data such that Cν,m = -11.33 ln(0.02 ln(Reb)).

A Study on the Risk Assessment and Improvement of Musculoskeletal Burden Works in the Semiconductor Manufacturer (반도체 제조회사의 근골격계부담작업 유해요인조사 실태와 개선방안)

  • Jeong, Yeyoung;Park, Jae Hee
    • Journal of the Korean Society of Safety
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    • v.37 no.1
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    • pp.49-54
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    • 2022
  • In Korea, companies which have work-related musculoskeletal burden works should have conducted legal risk assessments every three years from 2004 onwards. However, due to problems with the legal definition of work-related musculoskeletal burden works, some companies may have been exempted from the risk assessment even though their workers still experience work-related musculoskeletal pain. For example, the manufacturing process used by a particular semiconductor manufacturing company involved a great deal of legal musculoskeletal bueden works. However, this company eliminated the musculoskeletal burden works by continuously introducing automated processes, and finally, in 2016, all work which was legally defined as musculoskeletal burden work were removed from the company's manufacturing process. Nevertheless, in a 2016 survey, 9.6% of the company's workers still complained of musculoskeletal pain, and in a 2019 survey this proportion actually increased to 15.7%. This incident demonstrates the limitations and problems of the current legal risk assessment of work-related musculoskeletal burden work. Therefore, this study proposes two improvements to solve these problems. Firstly, it is necessary to broaden the current legal definition of work-related musculoskeletal burden works. For example, vibration risk factors and push/pull tasks that are currently missing from the definition should be included. Secondly, it is proposed that a survey on musculoskeletal pain should be conducted for all workers, regardless of whether they are engaged in musculoskeletal burden works. The results of this study could be used to improve the legal risk assessment of work-related musculoskeletal burden works.

Application of Dynamic Probabilistic Safety Assessment Approach for Accident Sequence Precursor Analysis: Case Study for Steam Generator Tube Rupture

  • Lee, Hansul;Kim, Taewan;Heo, Gyunyoung
    • Nuclear Engineering and Technology
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    • v.49 no.2
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    • pp.306-312
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    • 2017
  • The purpose of this research is to introduce the technical standard of accident sequence precursor (ASP) analysis, and to propose a case study using the dynamic-probabilistic safety assessment (D-PSA) approach. The D-PSA approach can aid in the determination of high-risk/low-frequency accident scenarios from all potential scenarios. It can also be used to investigate the dynamic interaction between the physical state and the actions of the operator in an accident situation for risk quantification. This approach lends significant potential for safety analysis. Furthermore, the D-PSA approach provides a more realistic risk assessment by minimizing assumptions used in the conventional PSA model so-called the static-PSA model, which are relatively static in comparison. We performed risk quantification of a steam generator tube rupture (SGTR) accident using the dynamic event tree (DET) methodology, which is the most widely used methodology in D-PSA. The risk quantification results of D-PSA and S-PSA are compared and evaluated. Suggestions and recommendations for using D-PSA are described in order to provide a technical perspective.

A study on the application of water safety plans for the hazard risk management of tap water (수돗물 위해요소 리스크 관리를 위한 물안전계획 적용 연구)

  • Kim, Jinkeun;Kim, Dooil
    • Journal of Korean Society of Water and Wastewater
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    • v.33 no.4
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    • pp.259-268
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    • 2019
  • One of the most effective methods to consistently ensure the safety of a tap water supply can be achieved by application of a comprehensive risk assessment and risk management approach for drinking water supply systems. This approach can be termed water safety plans(WSP) which recommended by WHO(world health organization) and IWA(international water association). For the introduction of WSP into Korea, 150 hazards were identified all steps in drinking water supply from catchment to consumer and risk assessment tool based on frequency and consequence of hazards were developed. Then, developed risk assessment tool by this research was implemented at a water treatment plant($Q=25,000m^3/d$) to verify its applicability, and several amendments were recommended; classification of water source should be changed from groundwater to stream to strengthen water quality monitoring contaminants and frequencies; installation of aquarium to monitor intrusion of toxic substances into raw water; relocation or new installation on-line water quality analyzers for efficient water quality monitoring; change of chlorination chemical from solid phase($Ca(OCl)_2$) to liquid phase(NaOCl) to improve soundness of chlorination. It was also meaningful to propose hazards and risk assessment tool appropriate for Korea drinking water supply systems through this research which has been inconsistent among water treatment authorities.

Probabilistic optimal safety valuation based on stochastic finite element analysis of steel cable-stayed bridges

  • Han, Sung-Ho;Bang, Myung-Seok
    • Smart Structures and Systems
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    • v.10 no.2
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    • pp.89-110
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    • 2012
  • This study was intended to efficiently perform the probabilistic optimal safety assessment of steel cable-stayed bridges (SCS bridges) using stochastic finite element analysis (SFEA) and expected life-cycle cost (LCC) concept. To that end, advanced probabilistic finite element algorithm (APFEA) which enables to execute the static and dynamic SFEA considering aleatory uncertainties contained in random variable was developed. APFEA is the useful analytical means enabling to conduct the reliability assessment (RA) in a systematic way by considering the result of SFEA based on linearity and nonlinearity of before or after introducing initial tensile force. The appropriateness of APFEA was verified in such a way of comparing the result of SFEA and that of Monte Carlo Simulation (MCS). The probabilistic method was set taking into account of analytical parameters. The dynamic response characteristic by probabilistic method was evaluated using ASFEA, and RA was carried out using analysis results, thereby quantitatively calculating the probabilistic safety. The optimal design was determined based on the expected LCC according to the results of SFEA and RA of alternative designs. Moreover, given the potential epistemic uncertainty contained in safety index, failure probability and minimum LCC, the sensitivity analysis was conducted and as a result, a critical distribution phase was illustrated using a cumulative-percentile.