• Journal of the Korean Professional Engineers Association
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• v.45 no.6
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• pp.20-27
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• 2012

World has become interested in the development of new dean energy because of oil prices rise and global warming due to carbon dioxide emissions. This study evaluated the safety of the refueling infrastructure for hydrogen, CNG and HCNG(hydrogen blended natural gas) which recently take center stage as a clean fuel. The risk of fuel was evaluated by 3D computational fluid dynamics program for gas dispersion and explosion. Hydrogen is higher than the CNG explosion overpressure and shows rapid spread. On the other hand, CNG and 30% HCNG showed quite similar characteristics. HCNG slightly rises in risk than the CNG, but HCNG is safe compared to hydrogen.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.167-173
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• 2014

Hydrogen energy is expanding in range for civil use together with development of pollution-free power sources recently, and it is judged that the use of hydrogen will increase more as a part of carbon dioxide reduction measures according to the Climatic Change Convention. Especially, it is thought that the securement of safety of the used dispenser will be the biggest obstacle in the use of high-pressure hydrogen because the hydrogen station is operated in a high pressure. This study found risks in the process and problems on operation by making use of HAZOP(6 kinds), a qualitative safety evaluation technique, and FMEA(5 kinds), a fault mode effect analysis, for the hydrogen charging system at a hydrogen gas station, derived 6 risk factors from HAZOP and 5 risk factors from FMEA, and prepared measures for it.

• Journal of Auto-vehicle Safety Association
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• v.13 no.4
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• pp.73-80
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• 2021

Recently, Korea has established a plan for the supply of hydrogen vehicles and is promoting the expansion of the supply. Risk factors for hydrogen vehicles are hydrogen leakage, jet fire, and explosion. Therefore Safety measures are necessary for this hazard. In addition, risks in semi-closed spaces such as tunnels, underground roads, and underground parking lots should be analyzed. In this study, an explosion experiment was conducted on a hydrogen tank used in a hydrogen vehicle to analyze the risk of a hydrogen vehicle explosion accident that may occur in a semi-closed space. As results, the effect on the structure and the human body was analyzed using the overpressure and impulse values for each distance generated during the explosion.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.113-113
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• 2014

This study has been conducted for evaluation of qualitative/quantitative risk of HCNG filling station. In case of fire explosion occurred because of hydrogen, CNG, and HCNG leaking on same conditions, maximum overpressure was measured as 30kPa for hydrogen, 3.5kPa for HCNG, and 0.4kPa for CNG. The overpressure of HCNG was measured 7.75 times higher than that of CNG, but it was only 11.7% compared with hydrogen. When the 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. As the explosion occurred with the same sized container that had 350bar for hydrogen and 250bar of CNG and HCNG, 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.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.2
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• pp.158-163
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• 2022

The test method on the Type II high-pressure hydrogen storage tanks made of the metal wire hoop winding is a complex and high risk. Also closeup on the tank being test is difficult. In this study, we studied a mechanical test method for a high-pressure hydrogen tanks. This method must be simple, risk-free and possible to observe the change in microscopic behavior of a metal wire on a liner. As the results, it was possible to observe the microscopic behavior on the metal wire by the mechanical test method. Also, a simple and risk-free test was possible compared to the conventional test method for high pressure hydrogen tanks.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.4
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• pp.381-387
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• 2023

The risk assessment (safety assessment) must be performed to verify the risks during operation and installation of the hydrogen system and to ensure safe design and operation. Among them, hazard and operability study (HAZOP), a qualitative risk assessment, is most often used to discover risk factors and secure safety. However, in HAZOP performance, there is a difference in the level of evaluation results depending on the level and experience of the evaluator, and there is a high possibility that subjective results will be derived. This study aims to develop a risk factor library that can list and provide information on potential risk factors in order to solve these problems when performing HAZOP, reduce risk factors that are omitted or overlooked.

• Journal of the Korean Institute of Gas
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• v.25 no.6
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• pp.80-84
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• 2021

As the Hydrogen law was enacted, 4 types of hydrogen appliances were designated as inspection products. The types of hydrogen appliances are water electrolysis equipment, hydrogen extraction equipment, stationary fuel cells, and mobile fuel cells. The establishment fo safety standards for hydrogen appliance inspection defines risk factors for each hydrogen appliance and stipulates safety standards to prevent risk factors. The main safety standards for each hydrogen appliance are hydrogen quality and safety control for water electrolysis, toxic substances emission prevention and carbon monoxide emission prevention for hydrogen extraction facilities, vibration safety for mobile fuel cells.

• Nuclear Engineering and Technology
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• v.47 no.1
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• pp.26-32
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• 2015

During the course of a severe accident in a light water nuclear reactor, large amounts of hydrogen can be generated and released into the containment during reactor core degradation. Additional burnable gases [hydrogen ($H_2$) and carbon monoxide (CO)] may be released into the containment in the corium/concrete interaction. This could subsequently raise a combustion hazard. As the Fukushima accidents revealed, hydrogen combustion can cause high pressure spikes that could challenge the reactor buildings and lead to failure of the surrounding buildings. To prevent the gas explosion hazard, most mitigation strategies adopted by European countries are based on the implementation of passive autocatalytic recombiners (PARs). Studies of representative accident sequences indicate that, despite the installation of PARs, it is difficult to prevent at all times and locations, the formation of a combustible mixture that potentially leads to local flame acceleration. Complementary research and development (R&D) projects were recently launched to understand better the phenomena associated with the combustion hazard and to address the issues highlighted after the Fukushima Daiichi events such as explosion hazard in the venting system and the potential flammable mixture migration into spaces beyond the primary containment. The expected results will be used to improve the modeling tools and methodology for hydrogen risk assessment and severe accident management guidelines. The present paper aims to present the methodology adopted by Institut de Radioprotection et de $S{\hat{u}}ret{\acute{e}}$ $Nucl{\acute{e}}aire$ to assess hydrogen risk in nuclear power plants, in particular French nuclear power plants, the open issues, and the ongoing R&D programs related to hydrogen distribution, mitigation, and combustion.

• Journal of Energy Engineering
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• v.28 no.4
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• pp.48-60
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• 2019

After the Paris Agreement in 2015, the government has been promoting various policies such as 'Hydrogen-Economy Roadmap(2019)' to supply hydrogen. As part of this, the government announced the goal of building 310 hydrogen refueling stations(HRS) until 2022. To this end, special case standard for the introduction of complex, packaged, and mobile hydrogen refueling stations(MHRS) have been enacted and promulgated. The MHRS has the advantage of being able to supply hydrogen to multiple regions. However, due to the movement and close distance between facilities, it is necessary to secure proper installation standards and operational safety through safety analysis. In this study, the possibility of introduction was investigated by designing a standard model and quantitative risk assessment(QRA). As a result of QRA, personal and social risk were acceptable, and the empirical test direction and implications were derived.

• Journal of the Korean Institute of Gas
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• v.23 no.6
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• pp.33-38
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• 2019

In order to invigoration the hydrogen economy, production of hydrogen needed for hydrogen charging stations and hydrogen fuel cells is needed. Generally, it is reforming used to coal fuel or natural gas. Other technologies include water electrolysis using pure water. Among these water electrolysis technologies, development is mainly carried out using PEM(Polymer Electrolyte Membrane electrolysis). In this study, the company aims to identify potential harmful hazards to PEM electrolysis hydrogen stations in the development stage among hydrogen charging stations. In order to find the hazardous factors in the facilities of the electrolysis and hydrogen charging stations, we were analyzed by Failure Mode & Effect Analysis(FMEA).