• Journal of the Korean Institute of Gas
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• v.10 no.4 s.33
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• pp.47-51
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• 2006

Safety issues for LNG(Liquified Natural Gas) terminal or LNG tank involve various concerns such as production/transportation at cryogenic temperature of $-160^{\circ}C$, large volume of handling, flammability and explosion risk. Hence, in designing an LNG terminal rigid safety criteria and mandatory requirements are unavoidable. Since known cases of LNG related accident are very few, careful study and root cause analysis of them are very important and provide precious information to increase safety level of the LNG terminal. In this paper most key accident cases were gathered and analysed to understand fundamental safety issues of LNG terminal to prevent further accident.

• Journal of the Korean Institute of Gas
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• v.14 no.1
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• pp.28-36
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• 2010

We have garnered 3,593 data of gas accidents reported for 12 years from 1995, and then analyzed the LPG vaporizer accidents according to their types and causes based on the classified database. According to the results the gas rupture has been the most common accident followed by the release, explosion and then fire accidents, the most frequent accident-occurring sub-cause is LPG check floater faults. In addition, we have applied the Poisson Probability Functions to predict the most-likely probabilities of fire, explosion, release and rupture with the LPG vaporizer in the upcoming 5 years. In compliance with Poisson Probability Functions results, in the item which occurs below 3 "LPG-Vaporizer-Fire", in the item which occurs below 5 "LPG-Vaporizer-Products Faults-Check Floater" and the item which occurs below 10 appeared with "LPG-Vaporizer-Products Faults". From this research we have assured the successive database updating will highly improve the anticipating probability accuracy and thus it will play a key role as a significant safety- securing guideline against the gas disasters.

• 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.

• Journal of the Korean Institute of Gas
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• v.4 no.1 s.9
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• pp.69-76
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• 2000

Explosion Quantities and flashing mass resulting from the variation of temperature are calculated by a computer program, BLEVE ESTIMATOR, to carry out the risk assessment of BLEVE. The damages caused by the BLEVE are estimated under the explosion of the simulation condition similar to the Puchun LP gas station accident, and the results are compared with the commercial program SAFER of Dupont CO. Explosion quantities and flashing mass increase exponentially with the increase of explosion temperature. These values for propane are relatively higher than those for n-butane. In conditions of higher vessel temperature, vessel pressure, and liquid ratio of containment, higher overpressures are calculated.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.414-419
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• 2003

In the recent TROI experiments, melts of zirconia and two different compositions of corium were used to observe the occurrence of a steam explosion when it came into contact with water at two different depths. The compositions of the corium were 70 : 30 and 80 : 20 in weight percent of $UO_{2}$ and $ZrO_{2}$, and the mass of the corium was about 10kg. The depth of water in the interaction vessel was 67cm and 130cm. A steam explosion did not occur in the interaction between 80 : 20 corium melt and water at 130cm depth, while steam spikes were observed in the interactions between corium melts of two different compositions and water at 67cm depth. A strong steam explosion occurred in the interaction between 5.43kg of zirconia melt and water at 67cm depth. This fact shows that the explosivity of zirconia is much greater than that of corium.

• Structural Engineering and Mechanics
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• v.60 no.2
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• pp.337-350
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• 2016

Even though extensive researches have been performed for steam explosion due to their complex mechanisms and inherent uncertainties, establishment of severe accident management guidelines and strategies is one of state-of-the arts in nuclear industry. The goal of this research is primarily to examine effects of vessel failure modes and locations on nuclear facilities under typical steam explosion conditions. Both discrete and integrated models were employed from the viewpoint of structural integrity assessment of steel components and evaluation of the cracking and crushing in reinforced concrete structures. Thereafter, comparison of systematic analysis results was performed; despite the vessel failure modes were dominant, resulting maximum stresses at the all steel components were sufficiently lower than the corresponding yield strengths. Two failure criteria for the reinforced concrete structures such as the limiting failure ratio of concrete and the limiting strains for rebar and liner plate were satisfied under steam explosion conditions. Moreover, stresses of steel components and reinforced concrete structures were reduced with maximum difference of 12% when the integrated model was adopted comparing to those of discrete models.

• Journal of the Ergonomics Society of Korea
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• v.20 no.3
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• pp.61-76
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• 2001

This study is for analyzing the explosion accidents in the tunnels, roads, subways, streets and various kinds of building construction area with the use of Fault Tree Analysis(FTA). based on the police Department and Guns & Explosives Safety Technology Association's researching materials. the explosion accidents have been investigated and analyzed between 1988 and 1977. As the result, we can find out that the majority of the explosion accidents in Korea is the accidents by flown stones(45.7%), like in Japan. So we make the research chart which is needed for analyzing the explosion accident, and then analyze these accidents systematically. using the investigation codes of the industrial accidents. After that, the FTA was performed on the accidents by flown stones. They result fromm non-observance of the safety rules, and lees knowledge of the safety and so on. Moreover several causes are combined and then the accidents are apt to happen. So according to the results of this study, for the protection of the explosion accidents, the specialized safety education is badly needed and the enough investigation of the places before the work along with the management for safety in working must be planned.

• Journal of Ocean Engineering and Technology
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• v.37 no.3
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• pp.99-110
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• 2023

When a fire accident accompanied by an explosion occurs, the surrounding firewalls are affected by impact and thermal loads. Damaged firewalls due to accidental loads may not fully perform their essential function. Therefore, this paper proposes an advanced methodology for evaluating the fire resistance performance of firewalls damaged by explosions. The fragments were assumed to be scattered, and fire occurred as a vehicle exploded in a large compartment of a roll-on/roll-off (RO-RO) vessel. The impact velocity of the fragments was calculated based on the TNT equivalent mass corresponding to the explosion pressure. Damage and thermal-structural response analyses of the firewall were performed using Ansys LS-DYNA code. The fire resistance reduction was analyzed in terms of the temperature difference between fire-exposed and unexposed surfaces, temperature increase rate, and reference temperature arrival time. The degree of damage and the fire resistance performance of the firewalls varied significantly depending on impact loads. When naval ships and RO-RO vessels that carry various explosive substances are designed, it is reasonable to predict that the fire resistance performance will be degraded according to the explosion characteristics of the cargo.

• Journal of the Korean Society of Safety
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• v.35 no.6
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• pp.25-31
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• 2020

Boiling Liquid Expanding Vapor Explosion(BLEVE) can cause not only economic damage to the plant but also serious casualties. LPG accidents account for 89.6 percent of all accidents caused by gas leaks in Korea over the past nine years, while casualties from accidents also account for 73 percent of all accidents, according to statistics from the Korea Gas Safety Corporation. In addition, a potential explosion and a fire accident from one LPG storage tank may affect the nearby storage tanks, causing secondary and tertiary damage (domino effect). The safety distance standards for LPG used by LPG workplaces, charging stations, and homes in Korea have become stricter following the explosion of LPG charging stations in Bucheon. The safety distance regulation is divided into regulations based on the distance damage and the risk including frequency. This study suggests two approaches to optimizing the safety distance based on the just consequence and risk including frequencies. Using the Phast 7.2 Risk Assessment software by DNV GL, the explosion overpressure and heat radiation were derived according to the distance caused by BLEVE in the worst-case scenario, and accident and damage probability were derived by considering the probit function and domino effect. In addition, the safety distance between LPG tanks or LPG charging stations was derived to minimize damage effects by utilizing these measures.

• Fire Science and Engineering
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• v.34 no.2
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• pp.86-93
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• 2020

This study aims to maintain the safety of an outdoor storage tank through the fundamental case analysis of explosion and fire accidents in the storage tank. We consider an accident caused by the explosion of fire inside the tank, as a result of the gradual spreading of the residual fire generated by wind lamps flying off a workplace in the storage tank yard. To determine the cause of the accident, atmospheric diffusion conditions were derived through CCTV image analysis, and the wind direction was analyzed using computational fluid dynamics. Additionally, the amount of oil vapor inside the tank when the floating roof was at the lowest position, and the behavior of the vapor inside the tank when the floating roof was at the highest position were investigated. If the cause of the explosion in the storage tank is identified and the level of the storage tank is maintained below the internal floating roof, dangerous liquid fills the storage tank, and the vapor in the space may stagnate on the internal floating roof. We intend to improve the operation procedure such that the level of the storage tank is not under the Pontoon support, as well as provide measures to prevent flames from entering the storage tank by installing a flame arrester in the open vent of the tank.