• Journal of the Korea Academia-Industrial cooperation Society
• /
• 제18권4호
• /
• pp.599-607
• /
• 2017

Since 2015, small and medium domestic enterprises that treat more than a certain quantity of chemical substances in accordance with the Chemical Substance Control Act are obliged to submit an off-site impact assessment and risk management plan. In order to reduce the administrative and economic burden of the risk assessment, its impact was determined. Toxic leaks of nitric acid, methanol, and acetic acid were estimated and the correlations (between them?) were calculated. In addition, the correlations of this study were used to compare the KORA results according to the accident scenarios of the actual workplace and the extent of the damage as a function of distance in the case of toxic leaks. In this study, the correlation formula of the materials can be used to quickly determine the damage distance in the event of the accidental leakage of materials in the road or workplace, and to prepare emergency plans and respond to emergencies more quickly.

• Journal of the Korean Institute of Gas
• /
• 제1권1호
• /
• pp.73-80
• /
• 1997

This study was performed to develop the dispersion modeling methodology for quantitative prediction of the hazard distance or toxic buffer distance by comparing 10-min average, 30-min average, and 1-hr average maximum ground-level concentration with $Cl_2$ regultaion concentration, IDLH and ERPG-3 concentration for hazardous toxic gas, $Cl_2$ releases from the storage tank of the chemical plant facilities. For this dispersion modeling, the source term model, dispersion model, meteorological and topographical data are incorporated into the SuperChems model, and then the effects of the atmospheric stability, wind speed, and surface roughness length changes on the maxum ground-level concentration were estimated.

• The Journal of the Convergence on Culture Technology
• /
• 제10권2호
• /
• pp.407-417
• /
• 2024

The objective of this study is to predict and reduce potential damage caused by chlorine gas leaks, a hazardous material, when vehicles transporting it overturn due to accidents or other incidents. The goal is to forecast the anticipated damages caused by chlorine toxicity levels (ppm) and to design effective response strategies for mitigating them. To predict potential damages, we conducted quantitative assessments using the ALOHA program to calculate the toxic effects (ppm) and damage distances resulting from chlorine leaks, taking into account potential negligence of drivers during transportation. The extent of damage from toxic gas leaks is influenced by various factors, including the amount of the leaked hazardous material and the meteorological conditions at the time of the leak. Therefore, a comprehensive analysis of damage distances was conducted by examining various scenarios that involved variations in the amount of leakage and weather conditions. Under intermediate conditions (leakage quantity: 5 tons, wind speed: 3 m/s, atmospheric stability: D), the estimated distance for exceeding the AEGL-2 level of 2 ppm was calculated to be 9 km. This concentration poses a high risk of respiratory disturbance and potential human casualties, comparable to the toxicity of hydrogen chloride. In particular, leaks in urban areas can lead to significant loss of life. In the event of a leakage incident, we proposed a plan to minimize damage by implementing appropriate response strategies based on the location and amount of the leak when an accident occurs.

• Journal of the Korean Institute of Gas
• /
• 제22권4호
• /
• pp.55-62
• /
• 2018

There is growing interest in solar power generation due to global warming. As a result, demand for polysilicon, which is the core material for solar cells, is increasing day by day. As the market grows, large and small accidents occurred in the production process. In 2013, hydrochloric acid leaked from the polysilicon manufacturing plant in SangJu. In 2014, a fire occurred at a polysilicon manufacturing plant in Yeosu, and in 2015, STC(Silicon Tetrachloride) leaked at a polysilicon manufacturing plant in Gunsan City. Leakage of chemicals in the polysilicon manufacturing process can affect not only the workplace but also the surrounding area. Therefore, in this study, we identified the hazardous materials used in the polysilicon manufacturing process and quantitatively estimate the amount of leakage and extent of damage when the worst case scenario is applied. As a result, the damage distance by explosion was estimated to be 726 m, and the damage distance to toxicity was estimated to be 4,500 m. And, if TCS(Trichlorosilane), STC(Silicon Tetrachloride), DCS(Dichlorosilane) leaks into the air and reacts with water to generate HCl, the damage distance is predicted to 5.7 km.

• Applied Chemistry for Engineering
• /
• 제9권7호
• /
• pp.1023-1029
• /
• 1998

Small water leak experiment was carried out for the 5Cr-1Mo steel specimen in sodium atmosphere. Perfect re-open time for the leak path of a specimen, by micro leak, was 129 minutes, and its size observed about 2 mm diameter at sodium side. The halos phenomena appeared around of leak spot before the leak path has re-opened, and the size of halos observed was different from the real re-open size of a specimen. Also, the corrosion of a specimen initiated from sodium side, but it did not occur at steam side. In AES analysis, the segregation phenomena of Cr in the specimen was found much more than those of other elements. And also, the sodium compounds formed by sodium-water reaction and deposited onto the leak site of specimen were observed by EPMA analysis and SEM photograph. It is postulated that the corrosion products could be precipitated to form mixed Na Fe Cr compounds.

• Journal of the Korean Institute of Gas
• /
• 제28권1호
• /
• pp.11-18
• /
• 2024

If flammable liquid leaks, vapor evaporated from the pool can cause poisoning or suffocation to workers, leading to secondary accidents such as fires and explosions. To prevent such damage, ventilation facilities shall be installed when designing indoor workplaces. At this time, the behavior varies depending on the characteristics of the leaked chemical, so it is necessary to select a suitable vent location according to the material. Therefore, 3D CFD simulations were introduced to derive optimal vent position and ventilation efficiency was quantitatively evaluated by vent position. At this time, assuming a situation in which flammable liquids leak at indoor workplaces to form pools, the concentration of vapor evaporated from pools was compared to derive the optimal vent position. As a result of research on toluene with high vapor density, ventilation efficiency was confirmed to be the highest at the upper supply-lower exhaust, and it is judged that introducing it can achieve about 3.7 times ventilation effect at the same maintenance cost. Through this study, it is expected that the workplace will be able to secure workers' safety by applying simulation results and installing ventilation ports.

• Fire Science and Engineering
• /
• 제31권1호
• /
• pp.81-88
• /
• 2017

This study analyzed chemical accidents each year according to the status, type of accident, accident place, business size, and chemical substance. The results of the chemical accident investigation were 16 cases in 2013, 27 cases in 2014, 46 cases in 2015, and 23 cases in 2016. According to the type of chemical accident, number of accidents, and casualty accidents, leakage was found to be the major cause. As a result of accidents and casualties caused by chemical accidents, workplaces had the highest numbers in all survey items. An examination of the top 10 accident materials revealed 9 substances to be hazardous chemicals. These materials were accident preparedness substances, and toxic substances.

• Fire Science and Engineering
• /
• 제33권4호
• /
• pp.97-104
• /
• 2019

Behind the growth of the chemical industry which is a cornerstone of the Korean economy, dozens of hazardous and noxious chemical accidents occur every year, resulting in enormous casualties and environmental damages. Many cases among chemical accidents are caused by the carelessness of workers in handling facilities such as hydrochloric acid and hydrofluoric acid, and the aging of handling facilities. In order to mitigate the damage by such chemical accidents, a safety system for preventing atmospheric diffusion of hazardous and xoxious chemicals in dike was proposed. The atmospheric diffusion prevention safety system consists of leak detection phase, alarm and measurement phase, suppression and blocking phase. Through the proposed the atmospheric diffusion prevention safety system, the need for 2nd chemical accident prevention such as atmospheric diffusion in dike can be posed.

• Journal of Chest Surgery
• /
• 제39권10호
• /
• pp.770-774
• /
• 2006

Background: Continuous air leakage through chest tube after lung surgery may increase pt's hospital stay and lead to many complications including empyema etc. Chemical pleurodesis has frequently been used for prevention of air leakage. Therefore, we performed chemical pleurodesis using diluted fibrin glue in patients with continuous air leak-age and observed the effects and efficiency of treatment. Material and Method: From September, 2001 to August, 2005, 16 patients whose continuous air leakage lasted more than 7 days underwent chemical pleurodesis with diluted fibrin glue. The effects of treatment, complications and recurrences were reviewed. Dissolved fibrinogen 1.0 g and aprotinin 500,000 KIU were mixed in a 50 cc syringe (Mixed solution A). And dissolved thrombin 5,000 IU and Calcium chloride 600 mg were mixed in a 50 cc syringe (Mixed solution B). Cefazolin 1.0 g was mixed in a 50 cc syringe (Mixed solution C). Rubber tube was inserted between the chest tube and the collecting bottle. An inserted rubber tube was positioned 60cm above the patient and forming a loop appearance was done. Mixed solutions A, B and C were injected into the highest rubber tube. Results: Continuous air leakages disappeared in all f6 patients at next day. Chest tubes were removed after 3 days in all patients. Complications were chest pain in 12 patients (75%), leukocytosis in 14 patients (88%), fever and chill in 14 patients (88%). All complications were transient and disappeared without specific treatment. Conclusion: Our findings demonstrated that diluted fibrin glue chemical pleurodesis was effective in patients with continuous air leakage lasting more than 7 days. Diluted fibrin glue chemical pleurodesis had good results with acceptable complications. long term follow-up is necessary to evaluate the accurate effects of treatment and recurrence in a large number of patients.

• Journal of the Korean Institute of Gas
• /
• 제26권2호
• /
• pp.39-48
• /
• 2022

The domestic gas detector installation standards applied to gas detectors, which are one of the facilities that can prevent accidents such as fire, explosion, and leakage that can cause serious industrial accidents, do not take into account the behavioral characteristics of hazardous chemicals in the atmosphere. It can be seen that the technical basis is insufficient because the standard is applied. Therefore, in this study, the size of the leak hole for each facility mainly used in chemical plants and the diffusion distance according to the concentration of interest of hazardous chemicals were analyzed, and based on this, the optimal installation distance for gas detectors for each material was suggested. Using the method presented in this study, more economical and effective gas detector installation can be expected, and furthermore, it can be expected to help prevent serious industrial accidents.