• The Korean Journal of Emergency Medical Services
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• v.3 no.1
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• pp.7-19
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• 1999

Background : We are in the edge of some human made disasters such as hazardous materials and air pollution, for example, the world news reported that the city of Bhopal, India had serious victims related with a leaking out of the chemical materials, Methyl Isocyanate and many people in India were killed by. These situations many people who live in this world are world are worrying about are not others, but just ours and people consider about that kind of the disasters are the possible situation to happen to all the people. Therefore, we performed this basic study to recognize the risk of Methyl Isocyanate leak accident and to prepare local disaster plan with EMS system. Method : Trace 8.0, a simulation software made by the U.S. company Safer System was used as a tool to estimate the diffusion distance, area and its victims at the concentrations of 0.02ppm, 0.2ppm 5ppm respectively for an assumed B-city of 2 hundred thousands population count in which was presumed 500kg Methyl Isocyanate gas to leak out. Results : 1. During 1 hour, maximum diffusion distances of 0.02ppm 0.2ppm and 5ppm were 5.41km, 1.61km and 0.29km respectively on the plume impact. 2. Maximum population counts influenced by Methyl Isocyanate gas at the concentrations of 0.02ppm 0.2ppm and 5ppm were 40838, 4346 and 222 on the plume impact, while those were 138238, 17261 and 1588 on the vulnerability impact, respectively. 3. Therefore, 17261 persons must put on respiratory device and 138283 persons must be evacuated to safety place within 1 hour. Conclusions : Only small amount leak of Methyl Isocyanate may cause tremendous chemical disaster in urban area, so its disaster plan must be prepared with an accident simulation program and Material Safety Data Sheets(MSDS). Especially, nearby emergency center of an industrial complex must have a strong position about preparation of chemical disaster plan and perform a disaster dill of hazardous material accident annually.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.843-850
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• 2020

The purpose of this study is to evaluate the structural risk and weakness of a railway tank car through nonlinear collision analysis according to overseas collision safety standards. The goal is to propose a crash safety design guideline for railway tank cars for transporting dangerous goods in Korea. We analyzed the buffer impact test procedure of railway freight cars prescribed in EN 12663-2 and the tank puncture test criteria prescribed in 49CFR179. A nonlinear finite element model according to each standard was modeled using LS-DYNA, a commercial finite element analysis solver. As a result of the buffing impact test simulation, it was predicted that plastic deformation would not occur at a collision speed of 6 km/h or less. However, plastic deformation was detected at the rear of the center sill and at the tank center supporting the structure at a collision speed of 8 km/h or more. As a result of a head-on test simulation of tank puncture, the outer tank shell was destroyed at the corner of the tank head when 4% of the kinetic energy of the impacter was absorbed. The tank shell was destroyed in the area of contact with the impacter in the test mode analysis of tank shell puncture when the kinetic energy of the moving vehicle was reduced by 30%. Therefore, the simulation results of the puncture test show that fracture at the tank shell and leakage of the internal material is expected. Consequently, protection and structural design reinforcement are required on railway tank cars in Korea.

• Journal of the Korean Institute of Gas
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• v.19 no.4
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• pp.29-34
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• 2015

Accidents in laboratory dealing with chemicals have constantly occurred. In the case of a gas explosion or an accident related to leakage of chemical materials, the damage is much greater, thereby leading to a serious accident. Especially, the safety of laboratory in University is important because students build up knowledge and skills and accumulate experience as the main researchers. In this paper, 5 gases(CO, $NH_3$, $H_2$, $CH_4$, $N_2$) are selected to model since they are often used in university laboratories. From the scenarios where the gases are released, the diffusion process is estimated and analyzed to predict damage degree by PHAST v.6.7. Internal diffusion process is modeled through FLUENT which is Computational Fluid Dynamics(CFD) tool. Also, we compare indoor damage with outdoor one when discharged to the outside through the laboratory's window. In the modeling results, the outdoor damages for accident scenarios in the results are far less than then of real plants since the vessel usually used in laboratory(i.e. the capacity of the cylinder; 47 L or less) is significantly less than workplace's one(using ton measure). However as shown in the results small amount can have high consequences for indoor accidents.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.14 no.2
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• pp.113-121
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• 2014

A subsea oil production system must be safely operated for 20-30 years after being installed. Because of the severe conditions of the subsea environment, such as extreme high pressure, low visibility, the possibility of unexpected impact by any object, and corrosion by seawater, subsea oil production systems should be monitored by subsea data logger systems and remotely operated vehicles to check for abnormal vibration and leakage to prevent a catastrophic accident. Because of the severity of subsea environmental conditions and the dominance of a few companies in the market, many people have thought that it would be difficult to develop a subsea data logger system. The primary objectives of the study described in this paper were to analyze existing subsea data logger systems to establish the requirements for a subsea data logger system, implement a prototype subsea data logger system, and conduct a test of the prototype subsea data logger system.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.5
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• pp.453-456
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• 2016

The major causes of electrical fire in low-voltage distribution lines are classified into short-circuit fault, overload fault, electric leakage, and electric contact failure. The special principal factor of the fire is electric arc or spark accompanied with such electric faults. This paper studies the development of an electric fire prevention system with detection and alarm of that in case of parallel arc fault occurrence in low-voltage distribution lines. The proposed system is designed on algorithm sensing the instantaneous voltage drop of line voltage at arc fault occurrence. The proposed detector has characteristics of high-speed operation responsibility and superior system reliability from composition using a large number of semiconductor devices. A new sensing control method that shows the detection of parallel arc fault is sensed to ripple voltage drop through a diode bridge full-wave rectifier at electrical accident occurrence. Some experimental tests of the proposed system also confirm the practicality and validity of the analytical results.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.6
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• pp.545-554
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• 2014

In general, odorant was added to fuel gases, such as LPG, LNG and city gas, to prevent gas poisoning, ignition, explosion, or other accident caused by fuel gases, and to enable immediate and easy detection of fuel-gas leakage by emitting an offensive smell. This study describes a study on the exhaust emissions characteristics and fuel economy of liquefied petroleum gas (LPG) vehicle using LPG fuel with new sulfur free odorant. New sulfur free odorant was added to LPG to reduce sulfur content of the LPG. Its performance and exhaust emission were compared to those of LPG with sulfur containing odorant (EM, ethyl mercaptan). Engine performance using LPG with sulfur free odorant was similar to that with sulfur-containing odorant. Exhaust emissions from the LPG vehicle with LPG including sulfur free odorant were also similar to those with LPG including sulfur containing odorant in the FTP 75 and NEDC mode. There experimental results suggest that the sulfur free odorant may substitute for the sulfur containing odorant in LPG fuel.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.1
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• pp.1-6
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• 2017

Surge pressure is created by rapid change of flow rate due to operation of hydraulic component or accident of pipeline. Proper control of surge pressure in distribution system is important because it can damage pipeline and may have the potential to degrade water quality by pipe leakage due to surge pressure. Surge relief valve(SRV) is one of the most widely used devices and it is important to determine proper parameters for SRV's installation and operation. In this research, determining optimum parameters affecting performance of the SRV were investigated. We proposed the methodology for finding combination of parameters for best performance of the SRV. Therefore, the objective function for evaluate fitness of candidate parameters and surge pressure simulation software was developed to validate proposed parameters for SRV. The developed software was integrated into genetic algorithm(GA) to find best combination of parameters.

• Journal of the Korean Institute of Gas
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• v.14 no.2
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• pp.15-21
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• 2010

The demand of gas as an eco-friendly energy source has being increased. With increasing the LPG demand, the number of LPG filling station. In this work, the influence on over-pressure caused by Vapor Cloud Explosion in gas station was calculated by using the Hopkinson's scaling law and injury effect by the accident to a human body was estimated by applying the probit model. As a result of the injury estimation conducted by using the probit model for leakage 10% of 20ton storage tank. The distances from LPG station for death and tympanum rupture are 36.5 and 290 meters, respectively.

• Journal of the Korean Institute of Gas
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• v.11 no.1 s.34
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• pp.18-22
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• 2007

The fault current through the earth originated from a power line ground fault might cause arcing through the soil to an adjacent pipeline, which might bring about not only a catastrophic accident such as gas explosion and oil leakage but also a hazard to the safety of workers responsible for the maintenance and repair of the pipeline. In this paper we investigated the arcing phenomena through soil between a power line tower and a pipeline and outlined the standards for the separation distance of a buried pipeline adjacent to the power line tower.

• Journal of the Korean Society of Safety
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• v.31 no.5
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• pp.54-60
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• 2016

In this study, tank truck incidents of road transport of hazardous materials to experimental investigated the potential fire hazard. Real scale fire was to perform experiments for on this qualitative and quantitative data collection and analysis. Particularly affected by radiant heat from the flames caused and damage estimates range investigated accordingly. Flame temperature, internal temperature of tank and emitted radiation from the flames was investigated. The flame of light oil spill caused a fire at a temperature of about $300^{\circ}C$ high in comparison with the methanol by combustion of diesel and methanol, according to the difference, the flame duration changes varies depending on the Burning rate. Depending on spill rate(30, 60, 90 and $120{\ell}/min$) and the longer the duration of the flame important factors for the internal temperature of tank lorry rise was found. Road accident in a fire caused by leakage of hazardous was could the higher the damaged. Therefor, Fire suppression activities should be required in particular to be around.