• 대한안전경영과학회지
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• 제11권3호
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• pp.49-56
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• 2009

The quantity of the fuel gas consumed is trending upwards because it can be easily delivered but isn't deteriorated and doesn't have any environmental pollution. Though there are many advantages to use the fuel gas, it can be hesitated to consume more gas because of its explosiveness and combustibility. So paying more attentions to prevent the fuel gas accidents is required. In this paper, we examine the present situation data about the fuel gas accidents and analyze them statistically using ANOVA. we confirm that there is an acceptable difference between the mean values of accidents classified by the kind of gas, the cause, the type and the place but isn't by month. It is expected that our result can be applied as preliminary data when mapping out a strategy for preventing the fuel gas accidents.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2009년도 춘계학술대회
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• pp.193-202
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• 2009

The quantity of the fuel gas consumed are trending upwards because it can be easily delivered but isn't deteriorated and doesn't have any environmental pollution. Though there are many advantages to use the fuel gas, because of its explosiveness and combustibility, it can be hesitate to consume more gas. So paying more attentions to prevent the fuel gas accidents is required. In this paper, we examine the present situation data about the fuel gas accidents and analyze those statistically using ANOVA. we confirm that there is an acceptable difference between the mean values of accidents classified by the kind of gas, the cause, the type and the place but isn't by month. It is expected that our result can be applied as preliminary data when mapping out a strategy for preventing the fuel gas accidents.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2010년도 춘계학술대회
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• pp.81-95
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• 2010

Gas turbines generating power operate in high temperature condition and use natural gas as fuel. For that reason, there are many cases where damage is done to the hot gas parts caused by the high temperature and many accidents occur like gas explosions, then various efforts are needed to maintain the hot gas parts and prevent accidents. It is difficult to find the root causes of damage to the hot gas parts from the gas explosion caused by gas leakage through rotor cooling air line from fuel gas heat exchanger during the shut down. To prevent gas turbine from damage, removal of gas leakage inside of gas turbine is required by purging the turbine before firing, improving the fuel gas heating system and installing alarm systems for detecting gas leakage from stop valve to turbine while the gas turbine has shut down.

• 한국가스학회지
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• 제4권3호
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• pp.1-8
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• 2000

연료가스의 사용이 늘어나고 고압가스를 사용하는 공정이 날로 대형화$\cdot$복잡화됨에 따라 가스사고도 대형화되는 둥 이를 적절하게 관리할 필요성이 증대되고 있다. '95${\~}$'98년 동안 발생했던 사고를 체계적으로 분류$\cdot$분석하여서 사고 발생에 영향을 미치는 주된 요인을 찾아내었다. 그 결과 사고감소분야에 대해서는 기존의 사고관리정책을 견지하도록 하며 사고가 소폭 감소하거나 증가하는 분야에 대해서는 감소 대책을 제시하였다. '95${\~}$'98년 가스사고는 총 2,027건이며 띨6년 이후 연평균 $12\%$ 감소하는 것으로 나타났다. 가스종류별로는 LPG(Liquefied petroleum gas), 도시가스 등 연료가스사고가 $96\%$로서 대부분이며 사용처별로는 주택, 요식업소 등 사용시설에서 주로 사고가 발생했다. 원인별로는 가스의 종류 및 시설에 따라 그 특징이 다르나 시설미비, 제품불량, 및 사용자 취급부주의에 의한 사고가 대부분을 차지하였다. 연료가스에 의한 고의사고는 311건으로 전체가스사고 중 $15\%$를 차지하며 연평균 $38\%$ 증가하는 추세이나 그 발생 매커니즘이 다르므로 향후 좀더 체계적인 분석을 할 필요가 있으며 이번 분석에서 제외하였다.

• 한국가스학회지
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• 제4권2호
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• pp.46-51
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• 2000

연료가스의 사용이 늘어남에 따라 이로 인한 가스사고를 적절하게 관리할 필요성이 증대되고 있다. 최근 4년 동안 발생했던 사고를 체계적으로 분석하여 사고 발생에 영향을 미치는 주된 요인을 찾아내고 이를 사고감소 대책을 제시하는데 활용한다. 해빙기는 연평균 치보다 사고발생비율이 높아 상대적으로 취약한 기간으로 분석되었다. 동 기간동안 LPG(Liquefied petroleum gas) 사고는 연 평균치와 비슷하나 전체적으로 차지하는 비중이 높으며 원인별로는 사용자취급부주의에 의한 사고와 제품불량 혹은 시설미비에 의한 사고가 많아 이에 대한 대책이 시급한 것으로 나타났다. 동 기간동안 도시가스사고는 연 평균치보다 높아 전반적으로 주의 깊게 관리할 필요가 있으며 특히 원인별로 시설미비로 인한 사고 및 타공사로 인한 사고가 비중이 높았다. 비중이 높은 사고나 연 평균치보다 사고비율이 높은 사고에 대해 이를 저감할 수 있는 대책을 제안하였다.

• 대한안전경영과학회지
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• 제12권2호
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• pp.75-82
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• 2010

Gas turbines for power generating operate in a very high temperature condition and use natural gas for fuel. For this reason, many cases of damage happen at hot gas parts which are severely affected by high temperature gas and many cases of explosion occur by fuel gas. So a lot of efforts should be made to prevent hot gas parts damage and gas explosion accidents. Though there are many damage cases and explosion accidents, it is very difficult to find out the root causes of hot gas parts damage caused by gas explosion due to gas leakage in the heat exchanger for air cooling and gas heating. To prevent gas turbine from damage caused by gas explosion, removal of leakage gas from gas turbine is inevitably required before firing the gas turbine and installing alarm systems is also required for detecting gas leakage at stop valve to turbine while shut down.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.973-979
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• 2024

In the framework of the Generation IV research and development project, in which the French Commission of Alternative and Atomic Energies (CEA) is involved, a main objective for the design of Sodium-cooled Fast Reactor (SFR) is to meet the safety goals for severe accidents. Among the severe ones, the Unprotected Transient OverPower (UTOP) accidents can lead very quickly to a global melting of the core. UTOP accidents can be considered either as slow during a Control Rod Withdrawal (CRW) or as fast. The paper focuses on fast UTOP accidents, which occur in a few milliseconds, and three different scenarios are considered: rupture of the core support plate, uncontrolled passage of a gas bubble inside the core and core mechanical distortion such as a core flowering/compaction during an earthquake. Several levels and rates of reactivity insertions are also considered and the thermal-mechanical behavior of an ASTRID fuel pin from the ASTRID CFV core is simulated with the GERMINAL code. Two types of fuel pins are simulated, inner and outer core pins, and three different burn-up are considered. Moreover, the feedback from the CABRI programs on these type of transients is used in order to evaluate the failure mechanism in terms of kinetics of energy injection and fuel melting. The CABRI experiments complete the analysis made with GERMINAL calculations and have shown that three dominant mechanisms can be considered as responsible for pin failure or onset of pin degradation during ULOF/UTOP accident: molten cavity pressure loading, fuel-cladding mechanical interaction (FCMI) and fuel break-up. The study is one of the first step in fast UTOP accidents modelling with GERMINAL and it has shown that the code can already succeed in modelling these type of scenarios up to the sodium boiling point. The modeling of the radial propagation of the melting front, validated by comparison with CABRI tests, is already very efficient.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.293-294
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• 2014

In Korea, only butane gas could be used as fuel gas of the outdoor gas stove. However, butane is not vaporized well at low temperatures. For this reason, in the field, nozzle of the portable butane gas stove is converted illegally to use propane gas. Because vapor pressure of propane gas is higher than that of butane gas at same temperature, gas accidents such as gas leakage could be occurred. To prevent gas accidents and use portable propane gas stoves safely, international standards need to be analyzed and verification tests need to be performed with prototype stove. This study could suggest to revise standard for safety improvement with portable propane gas stoves.

• Corrosion Science and Technology
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• 제3권6호
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• pp.257-261
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• 2004

Leaking of fuel gas in a building creates flammable atmosphere and gives rise to explosion. Observations from accidents suggest that some explosions are caused by quantity of gas significantly less than the lower explosion limit amount required to fill the whole confined space, which might be attributed to inhomogeneous mixing of the leaked gas. The minimum amount of leaked gas for explosion is highly dependent on the degree of mixing in the building. This paper proposes a method for estimating minimum amount of flammable gas for explosion assuming Gaussian distribution of flammable gas.

• Nuclear Engineering and Technology
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• 제45권5호
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• pp.581-588
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• 2013

This paper deals with the Safety Analysis for $CANDU^{(R)}$ 6 nuclear reactors as affected by main Heat Transport System (HTS) aging. Operational and aging related changes of the HTS throughout its lifetime may lead to restrictions in certain safety system settings and hence some restriction in performance under certain conditions. A step in confirming safe reactor operation is the tracking of relevant data and their corresponding interpretation by the use of appropriate thermal-hydraulic analytic models. Safety analyses ranging from the assessment of safety limits associated with the prevention of intermittent fuel sheath dryout for a slow Loss of Regulation (LOR) analysis and fission gas release after a fuel failure are summarized. Specifically for fission gas release, the thermal-hydraulic analysis for a fresh core and an 11 Effective Full Power Years (EFPY) aged core was summarized, leading to the most severe stagnation break sizes for the inlet feeder break and the channel failure time. Associated coolant conditions provide the input data for fuel analyses. Based on the thermal-hydraulic data, the fission product inventory under normal operating conditions may be calculated for both fresh and aged cores, and the fission gas release may be evaluated during the transient. This analysis plays a major role in determining possible radiation doses to the public after postulated accidents have occurred.