• Journal of the Korean GEO-environmental Society
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• v.21 no.5
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• pp.23-33
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• 2020

As the scale of the economy expands, the number of cases of damage in enclosed spaces such as tunnels is increasing due to the accident of transportation vehicles of dangerous substances such as explosive flammable materials that have increased rapidly. In the case of road tunnels in particular, in the aspect of protection against the long-winding trend and the environment in the downtown area, the number of cases of passing through the downtown area increases, and securing the safety of structures against unexpected extreme disasters such as explosions during tunnel passage is very urgent. For this reason, developed countries are already conducting a review of internal bombardment, but there are almost no evaluation and countermeasures for explosion risk in Korea. Therefore, in this study, in order to evaluate the explosion safety of road tunnels, a boiling liquid explosive explosion (BLEVE), which is considered to have the greatest explosion load among vehicles driving on the road, is set as a reference explosion source, and the equivalent TNT explosion load is used for simulation of the explosion. A method of conversion was presented. In addition, by applying the derived explosion load, dynamic behavior simulation was performed by assuming various variables for the tunnel, and the explosion safety of the tunnel was analyzed.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.1
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• pp.73-79
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• 2009

Hazardous materials (HazMats) are substances that are flammable, explosive, toxic, or harmful, if released into the environment. Since the transportation of HazMats increases in many developed countries, HazMat transportation has the key function in the process of HazMat usage to trace information of production, storage, shipment, usage, and waste disposal. The Korean Ministry of Environment (KMOE) and the National Emergency Management Agency (NEMA) have developed many laws, regulations, and standards for hazardous materials. However, the Korean HazMat laws, regulations, and standards do not guarantee accurate information of HazMat origin-destination (O-D) shipments, though the HazMat O-D movement is the critical information in safety and security of HazMat transportation. The objectives of this research are: (1) to investigate emerging and recurrent issues in Korean HazMat transportation, and (2) to develop the estimation method of O-D matrices for hazardous materials under limited data sets. The sodium hydroxide waste shipment among forty candidate HazMats is selected as the sample research case. The growth-factor method is applied to estimate the 2005 O-D matrix of sodium-hydroxide waste shipment. The column-and-row factoring process is used to calibrate the estimated sodium-hydroxide O-D matrix. The result shows the applicability of the O-D estimation process for hazardous materials. The Sodium Hydroxide Waste Origin-Destination Matrix is obtained to trace routes and paths of the Sodium Hydroxide transportation.

• Korean Chemical Engineering Research
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• v.61 no.1
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• pp.62-67
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• 2023

Due to the prolonged impact of COVID-19, the demand for Information Technology (IT) products is increasing, and their production facilities are expanded. Consequently, the use of harmful and dangerous chemicals are increased, the risk of fire(s) and explosion(s) is also elevated. In order to mitigate these risks, the government sets standards, such as KS C IEC 60079-10-1, and manages explosion-prone hazardous facilities where flammable substances are manufactured, used, and handled. However, using the standards of KS, it is difficult to predict the actual possibility of an explosion in a facility, because ventilation (an important factor) is not considered when setting up a hazardous work environment. In this study, the SEMI S6, Tracer Gas Test was applied to the chemical vapor deposition (CVD) facility, a major part of the display industry, to evaluate ventilation performance and to confirm the possibility of creating a less explosive environment. Based on the results, it was confirmed that the ventilation performance in the assumed scenarios met the standards stipulated in SEMI S6, along with supporting the possibility of creating a less explosive working condition. Therefore, it is recommended to use the prediction tool using engineering techniques, as well as KS standards, in such hazardous environments to prevent accidents and/or reduce economic burden following accidents.

• Korean Journal of Hazardous Materials
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• v.2 no.1
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• pp.18-26
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• 2014

We analyzed the demand of competent authorities requiring adequate technical information for initial investigation of chemical accidents. Reflecting technical reports on chemical accident response by environmental agencies in the U.S. and Canada, we presented information on environmental diffusion and toxic effects available for the first chemical accident response. Hydrogen fluoride may have the risk potential to corrode metals and cause serious burns and eye damages. In case of inhalation or intake, it could have severe health effects. The substance itself is inflammable, but once heated, it decomposes producing corrosive and toxic fume. In case of contact with water, it can produce toxic, corrosive, flammable or explosive gases and its solution, a strong acid, may react fiercely with a base. In case of hydrogen fluoride leak, the preventive measures are to decrease steam generation in exposed sites, prevent the transfer of vapor cloud and promptly respond using inflammable substances including calcium carbonate, sodium bicarbonate, ground limestone, dried soil, dry sand, vermiculite, fly ash and powder cement. The method for fire fighting is to suppress fire with manless hose stanchions or monitor nozzles by wearing the whole body protective clothing equipped with over-pressure self-contained breathing apparatus from distance. In case of transport accident accompanied with fire, evacuation distance is 1,600m radius. In cae of fire, fire suppression needs to be performed using dry chemicals, CO₂, water spray, water fog, and alcohol-resistance foam, etc. The major symptoms by exposure route are dyspnoea, bronchitis, chemical pneumonia and pulmonary edema for respiration, skin laceration, dermatitis, burn, frostbite and erythema for eyes, and nausea, diarrhea, stomachache, and tissue destruction for digestive organs. In atmosphere, its persistency is low, and its bioaccumulation in aquatic organism is also low.

• Journal of the Korean Society of Safety
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• v.38 no.5
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• pp.8-14
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• 2023

Lithium ions can induce the thermal runaway phenomenon and lead to reignition due to electrical, mechanical, and environmental factors such as high temperature, smoke generation, explosions, or flames, which is extremely likely to create safety concerns. Therefore, one of the ways to improve the flame retardancy of the electrolyte is to use a flame-retardant additive. Comparing the associated characteristic value of existing substances with the required experimental value, it was found that these values were either considerably different or were not documented. It is vital to know a substance's combustion characteristic values, flash point, explosion limit, and autoignition temperature (AIT) as well as its combustion characteristics before using it. In this research, the flash point and AIT of materials were measured by mixing a highly volatile and flammable substance, diethyl carbonate (DEC), with flame-retardant dimethyl methylphosphonate (DMMP). The flash point of DEC, which is a pure substance, was 29℃, and that for DMMP was 65℃. Further, the lower explosion limit calculated using the measured flash point of DEC was 1.79 Vol.%, while that for DMMP was 0.79 Vol.%. The AIT was 410℃ and 390℃ for DEC and DMMP, respectively. In particular, since the AIT of DMMP has not been discussed in any previous study, it is necessary to ensure safety through experimental values. In this study, the experimental and regression analysis revealed that the average absolute deviation (ADD) for the flash point of the DEC+DMMP DEC+DMMP system is 0.58 sec and that the flash point tends to increase according to changes in the composition employed. It also revealed that the AAD for the AIT of the mixture was 3.17 sec and that the AIT tended to decrease and then increase based on changes in the composition.