• Korean Chemical Engineering Research
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• v.57 no.2
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• pp.225-231
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• 2019

In Korea, the minimum separation distance between aboveground high-pressure natural gas pipeline and buildings is regulated by Korea gas safety (KGS) code. In this paper, The technical backgrounds for the revision of the KGS code related to the minimum separation distance was presented. A consequence-based approach was adopted to determine the minimum separation distance by a reasonable accident scenario, which was a jet fire caused by the rupture of one inch branch line attached the gas pipeline. Where, the higher thermal radiation flux threshold was selected for workers in industrial area than for people in non-industrial area, because the workers in industrial area were able to escape in a shorter time than the people in public. As result of consequence analysis for the accident scenario, we suggested the KGS code revision that the minimum separation distances between high-pressure natural gas pipeline installed above ground and buildings should be 30 meter in non-industrial area and 15 meter in industrial area. The revised code was accepted by the committee of the KGS code and now in effect.

• Journal of Korean Institute of Fire Science & Engineering
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• v.1 no.2
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• pp.28-41
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• 2000

Since a few years ago, great disasters have often took place in domestic and abroad, such as Sampoong Department store collapse, Sea-land disaster accident, Incheon Hof fire accidents. Whenever a lot of accidents occurred such as fire, gas explosion, traffic accident, mountain accident, various disease, people required 119 first aid service. As the result, even for the last year, average 2,608 person per day were temporary treated and carried to near hospital by 119 system. But first-aid team or first grade EMT(emergency medical technician) that should provide high quality service and save important lives, might have negatively treated or made their duty only for simple transfer, when they were imminent of emergency case in every kinds of accident spot. Because they worried about medical dispute for "task restriction for EMT" decided by medical laws or rules of first aid. So it was proposed that "task restriction for EMT" should be mitigated or released in the possible range on this occasion.

• Nuclear Engineering and Technology
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• v.45 no.5
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• pp.597-604
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• 2013

Containment Filtered Vent Systems (CFVSs) have been mainly equipped in nuclear power plants in Europe and Canada for the controlled depressurization of the containment atmosphere under severe accident conditions. This is to keep the containment integrity against overpressure during the course of a severe accident, in which the radioactive gas-steam mixture from the containment is discharged into a system designed to remove the radionuclides. In Korea, a CFVS was first introduced in the Wolsong unit-1 nuclear power plant as a mitigation measure to deal with the threat of over pressurization, following post-Fukushima action items. In this paper, the overall features of a CFVS installation such as risk assessments, an evaluation of the performance requirements, and a determination of the optimal operating strategies are analyzed for the Wolsong unit 1 nuclear power plant using a severe accident analysis computer code, ISAAC.

• Nuclear Engineering and Technology
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• v.43 no.6
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• pp.509-522
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• 2011

FRAPCON-3.4a and FRAPTRAN 1.4 are the most recent versions of the U.S. Nuclear Regulatory Commission (NRC) steady-state and transient fuel performance codes, respectively. These codes have been assessed against separate effects data and integral assessment data and have been determined to provide a best estimate calculation of fuel performance. Recent updates included in FRAPCON-3.4a include updated material properties models, models for new fuel and cladding types, cladding finite element analysis capability, and capability to perform uncertainty analyses and calculate upper tolerance limits for important outputs. Recent updates included in FRAPTRAN 1.4 include: material properties models that are consistent with FRAPCON-3.4a, cladding failure models that are applicable for loss-of coolant-accident and reactivity initiated accident modeling, and updated heat transfer models. This paper briefly describes these code updates and data assessments, highlighting the particularly important improvements and data assessments. This paper also discusses areas of improvements that will be addressed in upcoming code versions.

• Transactions of the Korean hydrogen and new energy society
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• v.35 no.1
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• pp.66-74
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• 2024

This study addresses the escalating issue of worldwide hydrogen gas accidents, which has seen a significant increase in occurrences. To comprehensively evaluate the risks associated with hydrogen, a two approach was employed in this study. Firstly, a qualitative risk assessment was conducted using the bow-tie method. Secondly, a quantitative consequence analysis was carried out utilizing the areal locations of hazardous atmospheres (ALOHA) model. The study applied this method to two incidents, the hydrogen explosion accident occurred at the Muskingum River power plant in Ohio, USA, 2007 and the hydrogen storage tank explosion accident occurred at the K Technopark water electrolysis system in Korea, 2019. The results of the risk assessments revealed critical issues such as deterioration of gas pipe, human errors in incident response and the omission of important gas cleaning facility. By analyzing the cause of accidents and assessing risks quantitatively, the effective accident response plans are proposed and the effectiveness is evaluated by comparing the effective distance obtained by ALOHA simulation. Notably, the implementation of these measures led to a significant 54.5% reduction in the risk degree of potential explosions compared to the existing risk levels.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.1
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• pp.1-9
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• 2017

LNG has significant advantages in regard to environmental aspects comparing with conventional fuel oil. In fact, it is estimated that NOx and SOx emission can be reduced by about 90% and 100%, respectively in case of using LNG as a fuel. LNG-fuelled ship has been considered to be the best option both from an environmental and an economic point of view. Along with these trends, some major shipyards and Classification Societies have started to carry out the risk-based system design for LNG-fuelled ship such as passenger ship, platform supply vessel and large container vessel etc. However, new conceptual gas fuelled ship has high risk level compared with vessel using traditional crude oil especially in view of gas explosion accident. Therefore safety area where installed fuel gas supply system is required risk based system design with special considerations. On this paper, the entire process necessary for the quantitative risk analysis was explained to meet the satisfactory safety level of gas fuelled ship.

• Nuclear Engineering and Technology
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• v.47 no.4
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• pp.461-471
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• 2015

Recently, the estimation of the social cost of energy sources has been emphasized as various novel energy options become feasible in addition to conventional ones. In particular, the social cost of introducing measures to protect power-distribution systems from power-source instability and the cost of accident-risk response for various power sources must be investigated. To account for these risk factors, an integrated societal risk assessment framework, based on power-uncertainty analysis and accident-consequence analysis, is proposed. In this study, we applied the proposed framework to nuclear power plants, solar photovoltaic systems, and wind-turbine generators. The required capacity of gas-turbine power plants to be used as backup power facilities to compensate for fluctuations in the power output from the main power source was estimated based on the performance indicators of each power source. The average individual health risk per terawatt-hours (TWh) of electricity produced by each power source was quantitatively estimated by assessing accident frequency and the consequences of specific accident scenarios based on the probabilistic risk assessment methodology. This study is expected to provide insight into integrated societal risk analysis, and can be used to estimate the social cost of various power sources.

• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.118-123
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• 2008

There are many facilities, such as facilities for high pressure gas storage and systems related to high pressure pipes, to handle hazardous materials in energy industries. Because the foundation of the proper risk analysis and management system has not been established, there is the possibility of an accident and Korea has met higher accident rate than developed countries. These accidents in energy facilities could cause great damage to facilities including the surrounding area, We have conducted the present research in order to systematize the emergency response system (ERS) using a lot of information on the degree of damage in an accident by consequence analysis.

• Journal of the Korean Institute of Gas
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• v.24 no.2
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• pp.36-43
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• 2020

Gas system fire extinguishing equipment is a very economically useful facility, but if it is not used for a long period of time after installing the equipment, there is possibility of rupture due to corrosion of containers and operation errors of equipment systems, and this is very dangerous. However, it is impossible to experiment to check whether the equipment is operating normally. If gas is temporarily released into the enclosed space due to rupture and malfunction, it can cause serious human damage due to gas suffocation. In this study, based on the suffocation death accident of gas system fire extinguishing facility, the inflow path of released gas and the possibility of death and time to death were estimated using a 3D scan and FLACS.

• Journal of the Korean Institute of Gas
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• v.24 no.3
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• pp.27-32
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• 2020

For preventing accident, the risk analysis about gas facilities has been more important since many gas facilities be superannuated. Especially, deriving and simulating risk is very important for preventing and corresponding accidents by means of specific analysis method in complex gas facilities. However, many studies have been not enough not yet in order to derive and simulate risk considering various situations. This paper aims to propose deriving and analyzing risk method around limited area of complex gas facilities. Our study proposes total risk analysis that is composed four methods with individual point of view. The risk analysis system based on RiskMAP immediately informs users changes of e risk in zones according to the status, work and surrounding conditions of the facility. The proposed methods in this research are implemented as software algorithm and applied to risk analysis system using RiskMAP in conjunction with IoT and GPS.