• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.19 no.4
• /
• pp.381-389
• /
• 2009

Confined spaces are inherently dangerous workplace and many fatal and nonfatal accidents have been reported. Even though these accidents occur in various kinds of confined spaces, there has rarely been reported on the health hazard agent, i.e., the types of gases and their concentration ranges. Therefore in this study, we evaluated several toxic and asphyxiating gas concentrations in various confined spaces. We surveyed 57 manholes, 3 sewage treatment plants, 2 yellow radish manufacturing companies and 7 barges to measure the concentrations of oxygen($O_2$), hydrogen sulfide($H_2S$), carbon monoxide(CO), ammonia($NH_3$). Lower Explosion Limits(LEL) and Volatile Organic Compounds (VOCs). Those four types of confined spaces occupies 56% of accidents during last 9 years in Korea. In 57 manholes, the concentration varied according to the types of manholes; rainfall and sewage, and by location; residential and industrial areas. Sewage manhole in industrial area was evaluated as the most hazardous than other types of manhole like rainfall manholes, residential sewage manholes. The highest $H_2S$ concentration and the lowest $O_2$ concentration at sewage manhole in industrial area were 300 ppm, 8.7% respectively. In 3 sewage treatment plants, $H_2S$ and $NH_3$ concentrations were reached up to the 500 ppm and 200 ppm respectively. Two yellow radish manufacturing companies showed the concentrations of 316 ppm, 505.2 ppm, 90 ppm and 15.7% for $H_2S$, CO, VOCs and $O_2$, respectively. Seven barges showed 15.9%~20.9% oxygen concentration. Gas species and concentration ranges varied by the types and location of confined spaces; CO, $H_2S$, $O_2$ could be hazardous in manhole, especially manhole connected to sewage plants. CO, $H_2S$, LEL, $O_2$, $NH_3$ should be controlled in sludge silo and sluge pumping confined spaces in sewage treatment plant. The activity of lifting out radish from the storage tank was evaluated more hazardous rather than the other activities in yellow radish manufacturing industry. The employers must conduct the survey to identify all possible confined spaces in their local workplace prior to performing the tasks. At the national level to reduce the accidents in the confined spaces, we suggest that systemic approach and active education program including possible hazards, standard operation procedures, ventilation plan, and personal protective equipment in confined spaces should be implemented.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.1829-1834
• /
• 2010

In order to prepare for the commercialization of Korean tilting train, this study was made on the pre-analysis of risk factors that can happen during operation, and emergency measures for safe operation of tilting train. The purpose of the study of emergency measures is to help to make tilting train run safely by making counteraction procedures for unusual situations such as train breakdown or accidents during the operation of a tilting train so that the engineer can quickly take care of each situation. Based on the items of emergency measures for EMU operated by Korean Railroad(or Korail), possible breakdown items during operation were selected and prioritized considering the occurring frequency and emergency level of each breakdown. In addition to these items, by adding items to represent tilting train's typicalfunctions such as tilting function error, tilting storage battery's electric pressure drop, etc, a total of62 emergency items were finally selected and measures for each item was made.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2006.05a
• /
• pp.177-180
• /
• 2006

The accidents of oil leakage is increasing in the Underground Concrete structures for Oil Storege. In the result, the waterproofing in the underground structures is melt down and cannot fulfil its Performance. This study shows an experimental study in the effects of the oil leakage to on the performance of Waterproofing Materials. In order to investigate the actual condition and the problems, a comparative analyses were conducted considering the various types of leakage. Utilizing the obtained results at the basic data for test methods and the standard of quality, we intended to propose a strategy to develop an innovated waterproofing Materials and improve the clean environment of underground structures.

• Proceedings of the KIPE Conference
• /
• 2013.07a
• /
• pp.471-472
• /
• 2013

When ESS(Energy Storage System) is under normal operation, island situation can be occur because of grid accidents. When island operation occur, the system mode switches in to UPS(Uninterruptible Power Supply) mode to supply stabled load power. To decide island operation, checking grid magnitude or frequency is general. But regulation for sag and swell is required. In this paper, it proposes grid connection error detection algorithm for UPS operation when sag and swell occurs in grid, and analyzed by simulation.

• Journal of Hydrogen and New Energy
• /
• v.33 no.3
• /
• pp.232-239
• /
• 2022

This study performed qualitative and quantitative risk assessment of equipment for evaluating the protocol of hydrogen refueling stations and suggested measures to improve safety. Hazard and operability study was performed for qualitative risk assessment, and Hy-KoRAM was used for quantitative risk assessment. Through a qualitative risk assessment, additional ventilation devices were installed, simultaneous venting of the storage container was prohibited, and the number of repeated refilling of the evaluation equipment was identified to manage the number of fillings of the container. Through quantitative risk assessment, the area around the device was set as a restricted area when evaluating the station, and measures were suggested to reduce the frequency of accidents.

• International conference on construction engineering and project management
• /
• 2015.10a
• /
• pp.693-694
• /
• 2015

While urban regeneration projects are currently under active execution in several old cities in Korea, there are few projects to improve the quality of life of rural communities. Considering the decline of the SOC system, deterioration of housing, and degeneration of economic feasibility, the purpose of this study is to provide solutions to realize an improved economic and social environment of rural communities through an integrated management system for traffic safety and water management systems. Therefore, this research used an Entity-Relationship Diagram to construct an integrated system for traffic safety and water management systems for Chungcheong rural communities. The ERD is prepared by depicting 7 relationships for 13 entities, including traffic accidents and agricultural products, and 26 attributes, including soil moisture and underflow storage. Consequently, it will be possible to set up a decision-making support system that can analyze and evaluate the regeneration index, technology, and management of the systems for Chungcheong rural communities, based on supplier and user perspectives

• Journal of the Korean Institute of Gas
• /
• v.5 no.4 s.16
• /
• pp.1-7
• /
• 2001

This paper presents a 'consequence analysis' for vapor cloud explosions caused by heavy gas leakages from commercially used storage tanks at petrochemical plants. Particularly, this paper emphasizes on evaluating the results of various vapor cloud explosion accidents from Butane storage tanks. Also this paper analyses the impact of variables on the accidents in order to acquire the optimum conditions for variables. $SuperChems^{TM}$ Professional Edition was applied to analyse the impact (If atmospheric and other variables in the situation where vapor cloud continuously disperses from the ground level. Under the assumption that practical operating conditions are selected as a standard condition, and Butane leaks from the storage tank for 15 minutes, the results show that the maximum distance of LFL (Lower Flammable Limit) was 52 meters and overpressure by the vapor cloud explosion was 1 psi at 128.2 meters. It is observed that the impact of the variables on accidental Butane storage tank leakage mainly varied upon atmospheric stability, wind velocity, pipe line size, visible length, etc., and changes in the simulation result occurred as the variables varied. The maximum distance of the LFL (Lower Flammable Limit) increased as the visible length became shorter, the size of the leak became larger, the wind velocity was decreased, and the climatic conditions became more stable. Thus, by analysing the variables that influence the simulation results of explosions of Butane storage tanks containing heavy gases, I am presenting the most appropriate method for 'consequence analysis' and the selection of standards for suitable values of variables, to obtain the most optimal conditions for the best results.

• Journal of the Korean Institute of Gas
• /
• v.13 no.1
• /
• pp.61-67
• /
• 2009

There are lots of energy facilities using gas(storage facility, compressed gas pipe, station, tank lorry) on the domestic. These major gas facilities cause major accidents associated with fire, explosion, toxic and etc. With the increased interest in reducing air pollution, supply of natural gas for gas vehicles is increasing. Thus, the number of establishments of LNG (Liquefied Natural Gas) and CNG(Compressed Natural Gas) stations is increasing as well. However, due to major gas accidents such as the fire and explosion accident of a Buchen LPG (Liquefied Petroleum Gas) station, it is difficult to establish a new station. In this research, we present quantitative risk assessment for LCNG;LNG multi-station and compare it result against individual risk criteria of HSE.

• Journal of the Korean Society of Safety
• /
• v.32 no.4
• /
• pp.129-136
• /
• 2017

This study investigated the probability of possible accident through qualitative and quantitative analysis of the pressure safety valve types installed in facilities using high pressure gas to compare the installation domestic and foreign pressure safety valve standards sought the safety characteristics and safety improvement direction accordingly. The three types are the case where the shut-off valve is not installed at the front of the PSV (Case A), If a shut-off valve is installed at the front of the PSV for inspection (Case B) and If a shut-off valve is installed in front of PSV (C.S.O), PSV is installed in parallel (Case C). Three types of cases were compared with FTA and HAZOP. The results of study of the possible accidents due to over-pressure safety valve installation type, used in a high-pressure gas facilities was shows in the following order Case B > Case A > Case C. The results of analysis through FTA was in order to protect the reservoir for the possible occurring of accident the safety valve installation is depend on its type. In the FTA analysis, defects in the device itself which attached to the storage tank as a substitute for analysis of the probability of operator mistakes was Case B with as high as $2.01{\times}10^{-6}$. Depending on the type of installation analysis of Case B in order to ensure safety is prohibited to install shut-off valve and believes that mandatory regulations are needed. Rationally installing of pressure safety valve in the high pressure using facilities will be expected to improve the industrial safety from severe accidents such as high-pressure gas fire explosion.

• Journal of the Society of Disaster Information
• /
• v.3 no.1
• /
• pp.55-68
• /
• 2007

Recently, people in cities of developed countries are exposed to unfortified damages of crime and disaster due to urbanization, industrialization and information-oriented era caused by congestion of population in terms of hardware and various social pathology phenomena and frequent and large scale of disaster caused by crime and disorder, which occur in the course of going through nuclear family, a gap between rich and poor and aging society in terms of software. In this regard, demand for security upon individual life and property has been increased but the police that are responsible for the public security does not effectively reduce damage in life and property because their activities are mainly oriented in coping with security accidents more than prevention. Shortage of manpower and budget, retarded equipment, and heavy overwork are the reasons. In order to confront with this kind of situation, we should utilize CCTV system with the purpose of declining possible chances of crime, not for eliminating cause of crime as crime prevention activities to predict danger in advance as a way of prevention and we may expect a role of damage prevention by installing CCTV in places where security accident may possibly happen. In conclusion, there are invasion of privacy, misuse of the system, insufficiency of overall monitoring office management, lack of citizens' understanding and economical allotment of the system installation costs in installation of CCTV system. However. it is necessary to install the CCTV system for effective prevention of crime and prevention activities of security accidents and accurate PR of purposes of installing CCTV to local residents, establishing relevant laws about system misuse, allotment of equipment costs and fees by R&D of the system machinery, cost reduction method of storage, management and replacement, saving costs from co-operative attitude of government, and local autonomous entities and local residents should be involved.