• Journal of the Korean Institute of Gas
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• v.22 no.1
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• pp.18-25
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• 2018

As the industries become more developed, the amounts of hazardous materials have been increased. Because of that, the possibility of accidents in plants is expected to increase. Especially, the dispersions of toxic materials cause serious effect to human life and environment, So it is very important to confirm safety distance of discharge accident. For this paper, we proposed new algorithms for toxic liquid, such as benzene and acrylonitrile. and using this argorithm, we are going to predict safety distance. The scenario of accidental release was assumed to be the release of entire quantity in 10 minutes is defined as worst-case scenario and Instantaneous release. Also the release from a partial rupture of line is used as an alternative case scenarios as NICS(National Institute of Chemical Safety) guidelines. Using ALOHA program and the algorithm for liquid toxic materials and suggested the graph, as well as correlated equations which can utilize emergency responders.

• Journal of the Korea Safety Management & Science
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• v.25 no.4
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• pp.117-129
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• 2023

This study tested the effect on the toxicity of formaldehyde to select a shelter site due to formaldehyde leakage. As a result of the experiment, the range of ERPG-2 and 3 is between 2.2km and 9.6km, ASET is 6 minutes at 1km, 15 minutes at 3km, 22 minutes at 5km, and the lethality rate is 99.9% at 1km and 9% at 3km. In areas where refuge time is less than 15 minutes or the lethality rate is more than 2%, a shelter is installed. This is because if there are only a few evacuees, the evacuation time may take longer than the pre-movement time of 15 minutes or less specified in PD 7974-6:2004, and the lethality rate with the lowest number of deaths was calculated to be 2%. The shelter must be equipped with a hepa-filter, positive pressure equipment, air purifier, air respirator, goggles, chemical protective clothing type 4 and sufficient parking space must be secured to ensure the safety of evacuees.

• Korean Journal of Hazardous Materials
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• v.6 no.2
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• pp.7-12
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• 2018

Hydrochloric acid is a highly corrosive toxic substance and requires proper safety to minimize damage in case of leakage. Among the various risk-reduction facilities, the dike is a typical safety facility installed to protect the surrounding buildings and facilities by preventing the external spread of hazardous materials from the storage tank. In this study, the KORA program was used to assume leakage accident of hydrochloric acid storage tank. At this time, the extent of the damage effects of ERPG-2 were assessed for each of the three separation distance between the storage tank and the dike. The study found that the smaller the separation distance between the dike and the storage tank, the smaller the extent of damage caused by hydrochloric acid leakage, and the greater the impact of indoor conditions under the same conditions. Through this process, we are going to assist in selecting locations and installing facilities for new and existing businesses.

• Journal of the Korean Society of Safety
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• v.31 no.6
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• pp.32-38
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• 2016

In general, lots of containers including various dangerous materials are transported to the port located in big cities such as Busan where massive residents live. Thus, it's really important how to make the emergency response for the leak accidents of dangerous materials and evaluate the direct or indirect damages to adjacent areas. In this study, in order to make reasonable emergency plans, CA (Consequence Analysis) is employed after selecting a key hazardous and noxious material, hydrogen fluroide. This material accounts for the third largest portion of cargo volume among all dangerous materials and can cause a huge damage in case of leakages. As a case study, Busan North port is selected as a test port since the portion of dangerous materials is higher than that of other ports in Busan. It is assumed that 1 ton of hydrogen fluoride is spilled at Busan North port. CA is performed to assess the impact of this accident. Throughout CA, the ERPG-2 range of a leak accident can be evaluated and this result can be used for decision making tools for mitigating the impact of a leak accident. To mitigate the damage of this accident, suitable a protective equipment and resident evacuation procedures should be prepared. Finally, this study can provide a systematic approach to make the emergency plan for reducing economical and personal losses.

• Journal of the Korean Society of Safety
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• v.38 no.3
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• pp.43-50
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• 2023

Silicone tetrachloride (SiCl₄) leak accidents cause enormous human and environmental damage because it is highly toxic. Some handling facilities use water curtains to reduce the impact range of SiCl₄. Although the water curtain is known as one of the most efficient technologies for post-release mitigation, its effect on reducing SiCl₄ concentration needs to be investigated scientifically and quantitatively. In this study, three-dimensional computational fluid dynamics (CFD) was used to investigate the physical and chemical effects of water curtains as a release-mitigation system for SiCl₄. SiCl₄ is released and dispersed five seconds prior to the operation of the water curtain. Once the water curtain works, the SiCl₄ reacts chemically with the water and its concentration decreases rapidly; it reaches an emergency response planning guidelines level 2 (ERPG-2) of 5 parts per million (ppm) at about 570 m. We observed, however, that the physical effect of water curtains on reducing SiCl₄ concentration is insignificant when the chemical effect is eliminated. These results are crucial since they can be a scientific and quantitative basis for the 'technical guidelines for estimating the accident affected range'. In order to protect the public from chemical accidents, more toxic gas mitigation technologies need to be developed.

• Journal of the Korean Institute of Gas
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• v.22 no.3
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• pp.38-44
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• 2018

Ammonia is used primarily as a refrigerant in refrigeration facility and SCR of a plant, and is frequently involved in leakage accidents. This study was conducted by selecting ammonia, a material with a wide influence range when evaluated, as a material with higher vapor pressure and lighter than air. In this study, the influence ranges were computed using KORA(Korea Off-site Risk Assessment supporting tool) with four different environmental factors : ground roughness, sealing, operating temperature, pressure, and leakage hole size. As a result, the difference in the influence range of ground roughness is approximately 4.62 times, while the ammonia storage tank shows a difference in the reduction rate of 0.64 when sealed. The extent of impact increased with increasing leakage depending on storage temperature and pressure, and when storing higher than the saturation vapor pressure, the impact range showed an average growth rate of 3.45 % per 0.1 Mpa($45^{\circ}C$). The influence ranges based on the size of the leakage holes is shown to be proportional to the area of the leakage zone.

• Journal of the Korean Institute of Gas
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• v.21 no.5
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• pp.95-103
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• 2017

A lot of hazardous materials have been used for product processing and utility plant. Many accidents including toxic release, fire and explosions occur in the ammonia related facility and plant. Various safety and environment management program including PSM, SMS, ORA etc. are being implemented for risk management and accident prevention in the production industry. Also much study and research have been carried about risk assessment of accident scenario in the academic and research area. In this paper, firstly risk level was assessed by using a typically used KORA program and LOPA PFD method for the selected ammonia unloading and storage facility. And then risk reduction measures for the risk assessed facility were studied in 3 aspects and some measures were proposed. Those Risk Reduction measures are including a leak detection and emergency isolation, water spray, dilution tank, dike and trench, scattering protection in hardware impovement aspect, and a applicable risk criteria, conditional modifier for existing LOPA PFD, alternative supporting modeling program in risk estimation methodology aspect, and last RBPS(Risk Based Process Safety) program, re-doing of process hazard analysis, management system compliance audit in managerial activity aspect.