• 한국산업보건학회지
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• 제17권2호
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• pp.144-152
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• 2007

Diesel vehicles are a significant source of fine carbon particle emissions including polynuclear aromatic hydrocarbons (PAHs). Urinary 1-hydroxypyrene (1-OHP) is firmly established as a useful biomarker of PAHs uptake in human. To investigate the exposure effect of PAHs in miners according to using diesel truck which was for transportation of ore, we measured urinary 1-OHP as the PAHs exposure biomarker, and analyzed the relationship between urinary 1-OHP concentration and using diesel truck. The study was performed on 118 workers (56 miners in factories using diesel truck, 62 miners in factories non-using diesel truck) and 21 controls. Urine samples were obtained at the end of shift on the survey day. There was no significance in comparison with the mean concentrations on urinary 1-OHP by age, BMI, work duration, smoking, drinking and ventilation type. But significant difference were found among urinary 1-OHP concentrations on factories according to using diesel truck (p=0.000). The urinary 1-OHP mean concentration on underground miners using diesel truck ($0.54{\mu}mol/mol$ creatinine) was higher than those of surface miners using diesel truck ($0.33{\mu}mol/mol$ creatinine, p=0.028), underground miners non-using diesel truck ($0.32{\mu}mol/mol$ creatinine, p=0.001) and controls ($0.22{\mu}mol/mol$ creatinine, p=0.000). In comparison with using status diesel truck, the urinary 1-OHP mean concentration of underground miners using diesel trucks was higher than those of other mine status. The study results would be beneficial to future environmental and biological studies of PAHs exposure to diesel exhaust in mines.

• Nuclear Engineering and Technology
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• 제48권4호
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• pp.881-892
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• 2016

Following the Fukushima accident and its extended station blackout, attention was brought to the importance of the spent fuel pools' (SFPs) behavior in case of a prolonged loss of the cooling system. Since then, many analytical works have been performed to estimate the timing of hypothetical fuel uncovery for various SFP types. Experimentally, however, little was done to investigate issues related to the formation of a flammable gas mixture, distribution, and stratification in the SFP building itself and to some extent assess the capability for the code to correctly predict it. This paper presents the main outcomes of the Experiments on Spent Fuel Pool (ESFP) project carried out under the auspices of Swissnuclear (Framework 2012-2013) in the PANDA facility at the Paul Scherrer Institut in Switzerland. It consists of an experimental investigation focused on hydrogen concentration build-up into a SFP building during a predefined scaled scenario for different venting positions. Tests follow a two-phase scenario. Initially steam is released to mimic the boiling of the pool followed by a helium/steam mixture release to simulate the deterioration of the oxidizing spent fuel. Results shows that while the SFP building would mainly be inerted by the presence of a high concentration of steam, the volume located below the level of the pool in adjacent rooms would maintain a high air content. The interface of the two-gas mixture presents the highest risk of flammability. Additionally, it was observed that the gas mixture could become stagnant leading locally to high hydrogen concentration while steam condenses. Overall, the experiments provide relevant information for the potentially hazardous gas distribution formed in the SFP building and hints on accident management and on eventual retrofitting measures to be implemented in the SFP building.

• 한국대기환경학회지
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• 제32권3호
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• pp.248-255
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• 2016

The leaves of three plant species, such as soybean, raspberry, and kudzu, exposed to hydrogen fluoride was collected in an area surrounding an emission source where the release accident occurred. The ultrasonic-assisted extraction and analysis of fluoride by ion chromatography was carried out. The mean concentration of fluoride in the leaves of three plant species exposed to hydrogen fluoride was $5,409{\pm}1,198mg\;F/kg\;dry\;wt$ and $788{\pm}339mg\;F/kg\;dry\;wt$, respectively. The mean fluoride concentration in ambient air were estimated to be $2.36{\pm}0.65mg/m^3$ ($2.89{\pm}0.79ppm$) and $0.35{\pm}0.15mg/m^3$ ($0.43{\pm}0.19ppm$) in exposed and unexposed sites, respectively. It seems likely that the passive monitoring using plant leaves could identify with respect to plant risk by fluoride in atmosphere.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2008년도 춘계학술 발표회
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• pp.217-222
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• 2008

In the last five years, 45 people died and 104 were wounded because of carbon monoxide poisoning accident. CO poisoning accident is higher than any other gas accident in the rate of deaths/incidents. Most of these CO poisoning accidents were caused by defective exhaust tube in the old gas boiler and multi-use facility. In this study, the spread of CO gas released from leakage hole of exhaust tube was analyzed by concentration measuring test. CO gas leaked form exhaust tube in a building was highest concentrated near the ceiling. Through these experiments, the reasonable installation location of CO alarm was made certain and suggested.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2868-2873
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• 2008

Carbon Monoxide(CO) poisoning accident is higher than any other gas accident in the rate of deaths/incidents. In the last five years, 36 people died and 104 were wounded because of carbon monoxide poisoning accident. Most of these CO poisoning accidents were caused by defective exhaust tube in the old gas boiler and multi-use facility. In this study, the spread of incomplete combustion gas(CO) released from leakage hole of exhaust tube was analyzed by computational flow modeling and concentration measuring test. CO gas leaked form exhaust tube in a building was highest concentrated near the ceiling and formed the circular currents along the walls. Through these experiments and simulation, the reasonable installation location of carbon monoxide alarm was made certain and suggested.

• 한국산업보건학회지
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• 제33권3호
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• pp.346-354
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• 2023

Objectives: Chemical accidents cause extensive human and environmental damage. Therefore, it is important to prepare measures to prevent their recurrence and minimize future damage through accident investigation. To this end, it is necessary to identify the accident occurrence process and analyze the extent of damage. In this study, the development process and damage range of actual chemical leakage accidents were analyzed using CFD. Methods: For application to actual chemical leakage accidents using FLACS codes specialized for chemical dispersion simulation among CFD codes, release rate calculation and 3D geometry were created, and scenarios for simulation were derived. Results: The development process of the accident and the dispersion behavior of materials were analyzed considering the influencing factors at the time of the accident. In addition, to confirm the validity of the results, we compared the results of the actual damage impact investigation and the simulation analysis results. As a result, both showed similar damage impact ranges. Conclusions: The FLACS code allows the detailed analysis of the simulated dispersion process and concentration of substances similar to real ones. Therefore, it is judged that the analysis method using CFD simulation can be usefully applied as a chemical accident investigation technique.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.741-751
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• 2021

There has been a deep interest in trying to find better-performing fuel clad motivated by the desire to decrease the likelihood of the reactor barrier failure like what happened in Fukushima in recent years. In this study, the effect of move towards accident tolerant fuel (ATF) cladding as the most attracting concept for improving reactor safety is investigated for SMART modular reactor. These reactors have less production cost, short construction time, better safety and higher power density. The SiC and FeCrAl materials are considered as the most potential candidate for ATF cladding, and the results are compared with Zircaloy cladding material from reactor physics point of view. In this paper, the calculations are performed by generating PMAX library by DRAGON lattice physics code to be used for further reactor core analysis by PARCS code. The differential and integral worth of control and safety rods, reactivity coefficient, power and temperature distributions, and boric acid concentration during the cycle are analyzed and compared from the conventional fuel cladding. The rod ejection accident (REA) is also performed to study how the power changed in response to presence of the ATF cladding in the reactor core. The key quantitative finding can be summarized as: 20 ℃ (3%) decrease in average fuel temperature, 33 pcm (3%) increase in integral rod worth and cycle length, 1.26 pcm/℃ (50%) and 1.05 pcm/℃ (16%) increase in reactivity coefficient of fuel and moderator, respectively.

• 한국안전학회지
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• 제39권3호
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• pp.20-26
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• 2024

The Chemical Substances Control Act of South Korea mandates submission of transportation plans containing information on the transportation of hazardous chemicals, with over 600,000 submissions recorded annually. In this study, big data analysis was performed on 2,506,985 transportation plans to identify trends and assess their correlation with chemical transportation accidents. The analysis confirmed that despite NaOH accounting for 20.7% of transportation plans, HCl constitutes 40% of chemical transportation accidents, which indicates a correlation of these accidents with the chemical properties of hazardous substances rather than with the number of submitted transportation plans. Furthermore, chemical transportation accidents show a higher probability of occurrence in the 6-8 am and 6-8 pm windows, which is in agreement with higher incidence and fatality rates. The departure points of transportation plans are closely related to the characteristics of local chemical industrial complexes such as Ulsan, Yeosu, and Gunsan, whereas the arrival points are closely related to Pyeongtaek, Hwaseong, and Icheon, which are the locations of semiconductor industries. Ultimately, achievement of safety by consideration of characteristics of transported chemicals, enhancement of driver concentration during specific times, and implementation of preventive measures tailored to local government characteristics are strategies anticipated to contribute to a reduction in chemical transportation accidents.

• 한국산업보건학회지
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• 제16권4호
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• pp.356-363
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• 2006

To investigate the exposure effect of benzene, we measured airborne benzene as external doses, uninary tt-muconic acid as an internal dose of benzene exposure and analyzed the relationship between tt-muconic acid concentration and benzene exposure. The study population of eight businesses included 157 workers(87 workers in field; exposure group, 70 workers in board; control group) who produce or use benzene in petrochemical industry. The concentrations of airborne benzene were evaluated by personal samples and urine was sampled at the pre and end shift. Urinary t,t-muconic acid as internal dose was to analyze the relationship with airborne benzene. The geometric means(GM) of airborne benzene was 0.0231 ppm(range ND-1.0471 ppm) in exposure group and 0.0147 ppm(range ND-0.3162 ppm) in control group. The geometric means(GM) of urinary t,t-muconic acid at end-shift was $196.8{\pm}2.23{\mu}g/g$ creatinine in exposure group and $149.2{\pm}2.08{\mu}g/g$ creatinine in control group. There was significant correlation between the airborne concentration of benzene and the urinary concentration of t,t-muconic acid( r=0.711, p<0.01). From the results of stepwise multiple regression analysis about t,t-muconic acid at end-shift, significant independents was airborne benzene. In this study, there were significant correlation between the urinary concentration of t,t-muconic acid and the airborne concentration of benzene. More extensive studies ruling out healthy worker effect is needed.

• 한국재난정보학회 논문집
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• 제10권1호
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• pp.33-39
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• 2014

화학사고 발생 시 현장 초기대응자들은 사고 원인물질과 농도를 신속하고 손쉽게 확인하기 위한 방식으로, 미국 환경청(EPA) 초기대응팀에서도 널리 사용하고 있는 직독식 탐지장비를 이용하고 있다. 환경부에서는 검지관식 가스 탐지장비를 직독식 탐지장비로 이용하여 사고 발생 시 현장에서 이용하고 있고, 검지관식 가스탐지기는 신속한 원인 물질 확인과 정밀한 분석 전에 전략적으로 대략적인 오염물질의 정량과 정성을 확인할 수 있는 유용한 장비이다. 그러나 현장 초기대응자들의 직독식 탐지장비의 사용방법에 대한 이해 부족과 단순 수치로만 확인하려는 방식으로 인해 탐지결과의 정확성에 대한 의문점을 늘 제기해 왔다. 본 논문에서는 사고 현장에서 정확한 탐지 결과를 얻기 위해 환경부에서 사용하고 있는 검지관식 가스탐지기인 Kitagawa와 Draeger 탐지기의 물질 반응성을 확인하여 초기 대응자들의 현장 탐지결과의 정확성을 높이고자 하였다.