• Journal of the Korea Safety Management & Science
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• v.4 no.1
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• pp.49-56
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• 2002

In this case study, results of the explosion accident at MEK-PO factory were analysed by using the consequence analysis of quantitative hazard assessment and the explosion energy, the burst pressure of vessel, and overpressures at the explosion center and at 300m distance from the explosion center were estimated, respectively. As a result, we found that a cause of accident was the runaway reaction of product(MEK-PO) because of the molecular expansion in vessel and that the possibility of the runaway reaction was classified the mechanical failure(the obstacle of refrigerator or the shutdown valve), design error, and operating error by lack of thermochemical knowledge. Also, the evasive action to prevent accident was suggested.

• Nuclear Engineering and Technology
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• v.48 no.1
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• pp.72-86
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• 2016

A steam explosion may occur during a severe accident, when the molten core comes into contact with water. The pressurized water reactor and boiling water reactor ex-vessel steam explosion study, which was carried out with the multicomponent three-dimensional Eulerian fuel-coolant interaction code under the conditions of the Organisation for Economic Co-operation and Development (OECD) Steam Explosion Resolution for Nuclear Applications project reactor exercise, is presented and discussed. In reactor calculations, the largest uncertainties in the prediction of the steam explosion strength are expected to be caused by the large uncertainties related to the jet breakup. To obtain some insight into these uncertainties, premixing simulations were performed with both available jet breakup models, i.e., the global and the local models. The simulations revealed that weaker explosions are predicted by the local model, compared to the global model, due to the predicted smaller melt droplet size, resulting in increased melt solidification and increased void buildup, both reducing the explosion strength. Despite the lower active melt mass predicted for the pressurized water reactor case, pressure loads at the cavity walls are typically higher than that for the boiling water reactor case. This is because of the significantly larger boiling water reactor cavity, where the explosion pressure wave originating from the premixture in the center of the cavity has already been significantly weakened on reaching the distant cavity wall.

• Journal of the Korean Society of Safety
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• v.3 no.2
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• pp.5-16
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• 1988

This study is conducted to evaluate the explosion of tolune storage tank in the petrochemical plant by Fault Tree Analysis. The conclusions are as follows; 1) Fault Tree diagram and the required computer program for evaluation of explosion accident is developed. 2) The probability of the top event, explosion accident, is $1.5\;{\times}\;10^{-8}$ per year, so there is almost no possibility of explosion during the life cycle of tank. However, the probability of Gate 6 and Gate 7 is 8.8 per month, therefore, attention should be paid to them for accident prevention. 3) The number of minimal cut sets is 67 sets which are not calculated the probability of each set, because of the lack of computer capacity. All the minimal cut sets should be examined case by case. However, it is necessary to be paid attention to COM1, 126, 131, and COM4 in minimal cut sets, because the number of appearance is so high. 4) The number path sets is 70 sets which are not calculated the probability of each set, because of the lack of computer capacity. It is very useful to prepare safety checklist by using this minimal path sets. Also, the events which appear many times, 123, COM5, 139, 127 and 128, are very high in reliability.

• Journal of Energy Engineering
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• v.23 no.4
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• pp.223-229
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• 2014

This study investigated the explosion characteristics of HCNG fuel using a simulation tool. The damage caused by the storage container explosion and vapor cloud explosion in a gas station was predicted. In case of an vapor cloud explosion in the HCNG station, 50~200kPa explosion pressure was predicted inside the station. When the cylinder explosion was occurred, in case of hydrogen, the measured influential distance of overpressure was 59m and radiant heat was 75m. In case of CNG, influential distance of overpressure was 89m and radiant heat was 144m would be estimated. In case of 30% HCNG that was blended with hydrogen and CNG, influential distance of overpressure was 81m and radiant heat was 130m were measured. The damage distance that explosive overpressure and radiant heat influenced CNG was seen as the highest. HCNG that was placed between CNG and hydrogen tended to be seen as more similar with CNG.

• Journal of the Korean Society of Combustion
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• v.20 no.1
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• pp.1-5
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• 2015

Fire and explosion analysis are performed for the quantitative risk assessment on the LNG test plant. From the analysis for a case of fire due to large leakage of LNG from the tank, it is obtained that loss of lives can be occurred within the radius of 60 m from the fire origin. Specially, wind can extend the extent of damage. Because the LNG test plant is not enclosed, the explosion overpressure is less than 6 kPa and the explosion has little effect on the integrity of the LNG test plant.

• Journal of the Korean Institute of Gas
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• v.20 no.3
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• pp.38-45
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• 2016

In this study, we found that the release and dispersion of ammonia can create hazardous atmospheres using FLACS software. In General, ventilation or gas detector installations are recommended as preventive measures to control explosion incidents. However, the ventilation installations cannot be applicable to the refrigeration facility that uses ammonia as refrigerating medium, because the freezing room should be sealed. From the accident investigation of the explosion case, we suggested that all electronic devices were needed to be switched by explosion proof devices, and communication facility was also needed to be installed to announce to all employees within a building in case alert condition like ammonia releases occurred.

• Fire Science and Engineering
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• v.31 no.4
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• pp.119-127
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• 2017

This study analyzed the cause of car explosion that occurred in the riverside park. The car carrying a male driver and a female passenger was parked in the park and explosion occurred inside the car. After the explosion, the driver and the passenger got burned. When they went to the hospital by the 119 Rescue Service, they stated that the car was sprayed with thinner before they had a quarrel and the explosion occurred during their quarrel. However, after several days, they changed their statement. They said that gasoline in the plastic bottle was poured and ran into the cigarette lighter. They tried to pull the cigarette lighter but pushed it by mistake. Then explosion occurred. Because only the explosion by mistake could receive car insurance, whether the cause of explosion was intentional or not became an issue. The car exploded was carefully investigated and analyzed. The statement of the driver and passenger was analyzed in the aspect of fire science. As a result, it was demonstrated that this car explosion occurred by driver's intention.

• Journal of the Korean Institute of Gas
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• v.3 no.1
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• pp.21-26
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• 1999

Chemical plant's fire and explosion does not only damage to the chemical plants themselves but also damage to people in or near of the accident spot and the neighborhood of chemical plant. For that reason, Chemical process safety management has become important. One of safety management methods is called 'the quantitative analysis', which is used to reduce and prevent the accident. The results of the quantitative analysis could be used to arrange the equipments, evaluate the minimum safety distance, prepare the safety equipments. In this study we make the computer program to make easy to do Quantitative analysis of the accident. The output of the computer program is the magnitude of fire(pool fire and fireball) and explosion(UVCE and BLEVE) effects. We used the thermal radiation as a measure of fire magnitude and used the overpressure as a measure of explosion magnitude. In case of BLEVE, the fly distance of fragment can be evaluated. Also probit analysis was done in every case. As the case study, Buchun LPG explosion accident in Korea was analysed by the program developed. The simulation results showed that the permissible distance was 800m and probit analysis showed that 1st degree bum, 2nd degree burn, and death distances are 450, 280, 260m, respectively the simulation results showed the good agreement with the results from SAFER PROGRAM made by Dupont.

• Journal of the Korean Society of Safety
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• v.35 no.1
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• pp.1-11
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• 2020

Article 325 (Prevention of Fire Explosion due to Electrostatic) of the Rule for Occupational Safety and Health Standard specifies that in order to prevent the risk of disasters caused by static electricity, fire, explosion and static electricity in the production process, However, in order to do this, it is absolutely necessary to use a pre-detection technology and a detector for antistatic discharge prediction, which is a precautionary measure by static electricity in a fire / explosion hazard place, but in Korea, And there is no technical standard for the application of the technology of the explosion proof structure of the related equipment. Research methods include domestic and overseas electrostatic discharge detection technology and literature investigation of related equipment explosion proofing technology, domestic and foreign electrostatic discharge detection device production and use situation investigation, advanced foreign technology data analysis and benchmarking. In particular, we sought to verify the results of empirical experiments using electrostatic discharge detection technology through sample purchase and analysis of related major products, development of optimization technology through prototype production, evaluation, and supplementation, and expert knowledge through expert consultation. The results of this study were developed and fabricated two prototypes of electrostatic discharge detector based on the technology / standard related to electrostatic discharge detection technology in Korea and abroad through development of electrostatic discharge detection technology and development and production of detector. In addition, based on the development of electrostatic discharge detection technology, we developed an intrinsic safety explosion proof ib class explosion proof technology applicable to the process of using and handling flammable gas and flammable liquid vapor and combustible dust. In the case of the over voltage and minimum voltage are supplied to the explosion-proof structure ESD detector, check the state of the circuit and the transient and transient currents generated by the coil and capacitor elements during the input and standby of the signal pulse voltage. Explosion-proof equipment-Part 11: Intrinsically safe explosion proof structure The comparative evaluation with the reference curve in Annex A of "i" confirms that the characteristics of the intrinsically safe explosion protection structure are met.

• Journal of the Korean Institute of Gas
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• v.4 no.3 s.11
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• pp.9-18
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• 2000

Accident analysis are useful in the design stage of chemical plants and their surrounding structures. Also, analysis results are required for safety management of existing plants. In this paper, the fire and explosion effect by BTX released was evaluated. The computer program was prepared for accident analysis and adopted for evaluating the magnitude of fire (pool fire) and explosion (UVCE) effect. The thermal radiation was used as a measure of fire magnitude and the overpressure as a measure of explosion magnitude. And probit analysis was made for each case. As a case study, benzene tank model was used. The simulation results of explosion of benzene showed that the damage within 20 meters from the accident spot was severe and the damage beyond 60 meters was negligible. The simulation results of fire of benzene showed that the damage in summer is bigger than that in winter. And the damage of city located inland seems to be bigger than that of city in seaside. And thermal radiation effects was negligible beyond 40 meters-distance from the accident spot.