• Title/Summary/Keyword: Accident Scenarios

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Modeling of Damage Effects Caused by Ammonia Leakage Accidents in Combined Cycle Power Plant (복합화력발전소 내 암모니아 누출 사고에 의한 피해영향 모델링)

  • Eun-Seong Go;Kyeong-Sik Park;Dong-Min Kim;Young-Tai Noh
    • Journal of Korean Society of Disaster and Security
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    • v.16 no.3
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    • pp.1-15
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    • 2023
  • This study focuses on modeling the impact of ammonia leakage from the storage tank in a combined cycle power plant's flue gas denitrification facility. It employs accident impact assessments and diffusion models to determine the optimal scenarios for ammonia storage tank leakage accidents. The study considers the operating conditions of variables as standard conditions for predicting the extent of damage. The Taean combined cycle power plant is chosen as the target area, taking into account seasonal factors such as temperature, humidity, wind speed, atmospheric stability, and wind direction. By utilizing a Gaussian diffusion model, the concentration of ammonia gas at various locations is estimated to assess the potential extent of external damage resulting from a leak. The study reveals that in conditions of high temperature and stable atmosphere within the specified range, lower wind speeds contribute to increased damage to the human body due to ammonia diffusion.

National Disaster Management, Investigation, and Analysis Using RS/GIS Data Fusion (RS/GIS 자료융합을 통한 국가 재난관리 및 조사·분석)

  • Seongsam Kim;Jaewook Suk;Dalgeun Lee;Junwoo Lee
    • Korean Journal of Remote Sensing
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    • v.39 no.5_2
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    • pp.743-754
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    • 2023
  • The global occurrence of myriad natural disasters and incidents, catalyzed by climate change and extreme meteorological conditions, has engendered substantial human and material losses. International organizations such as the International Charter have established an enduring collaborative framework for real-time coordination to provide high-resolution satellite imagery and geospatial information. These resources are instrumental in the management of large-scale disaster scenarios and the expeditious execution of recovery operations. At the national level, the operational deployment of advanced National Earth Observation Satellites, controlled by National Geographic Information Institute, has not only catalyzed the advancement of geospatial data but has also contributed to the provisioning of damage analysis data for significant domestic and international disaster events. This special edition of the National Disaster Management Research Institute delineates the contemporary landscape of major disaster incidents in the year 2023 and elucidates the strategic blueprint of the government's national disaster safety system reform. Additionally, it encapsulates the most recent research accomplishments in the domains of artificial satellite systems, information and communication technology, and spatial information utilization, which are paramount in the institution's disaster situation management and analysis efforts. Furthermore, the publication encompasses the most recent research findings relevant to data collection, processing, and analysis pertaining to disaster cause and damage extent. These findings are especially pertinent to the institute's on-site investigation initiatives and are informed by cutting-edge technologies, including drone-based mapping and LiDAR observation, as evidenced by a case study involving the 2023 landslide damage resulting from concentrated heavy rainfall.

Analysis of Damage Impact Range according to the NG/NH3 Mixing Ratio when applying Ammonia as Fuel for a Combined Cycle Power Plant using an ALOHA Program (ALOHA 프로그램을 활용한 복합화력발전소 내 암모니아 연료 적용 시 NG/NH3 혼소율에 따른 피해영향범위 분석)

  • Yoo Jeong Choi;Hee Kyung Park;Min Chul Lee
    • Journal of the Korean Institute of Gas
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    • v.28 no.1
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    • pp.73-84
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    • 2024
  • In this study, a quantitative risk impact assessment is performed using an ALOHA program to identify the risks when applying ammonia as fuel for combined cycle power plants as one of the solutions of climate change. The worst and the alternative accident scenarios are established for the Sejong combined cycle power plant and the effective ranges are calculated in terms of flammability, thermal radiation, overpressure and toxicity. The analysis results show that the toxic risk is the most critical and the effective distance is highly proportional to the mixing ratio of natural gas and ammonia by showing the Pearson's correlation coefficient over 98% as 0.991, 0.987 and 0.989 for the Level Of Concern(LOC)-1, LOC-2 and LOC-3, respectively. In addition, the coefficients of linearity for LOC-1, LOC-2 and LOC-3 are calculated to 133, 70 and 29, respectively so it can be confirmed that the effective distance increases as the criterion decreases.

Prediction of Damages and Evacuation Strategies for Gas Leaks from Chlorine Transport Vehicles (염소 운송차량 가스누출시 피해예측 및 대피방안)

  • Yang, Yong-Ho;Kong, Ha-Sung
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.2
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    • pp.407-417
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    • 2024
  • The objective of this study is to predict and reduce potential damage caused by chlorine gas leaks, a hazardous material, when vehicles transporting it overturn due to accidents or other incidents. The goal is to forecast the anticipated damages caused by chlorine toxicity levels (ppm) and to design effective response strategies for mitigating them. To predict potential damages, we conducted quantitative assessments using the ALOHA program to calculate the toxic effects (ppm) and damage distances resulting from chlorine leaks, taking into account potential negligence of drivers during transportation. The extent of damage from toxic gas leaks is influenced by various factors, including the amount of the leaked hazardous material and the meteorological conditions at the time of the leak. Therefore, a comprehensive analysis of damage distances was conducted by examining various scenarios that involved variations in the amount of leakage and weather conditions. Under intermediate conditions (leakage quantity: 5 tons, wind speed: 3 m/s, atmospheric stability: D), the estimated distance for exceeding the AEGL-2 level of 2 ppm was calculated to be 9 km. This concentration poses a high risk of respiratory disturbance and potential human casualties, comparable to the toxicity of hydrogen chloride. In particular, leaks in urban areas can lead to significant loss of life. In the event of a leakage incident, we proposed a plan to minimize damage by implementing appropriate response strategies based on the location and amount of the leak when an accident occurs.

Necessity of Quality Control for Aviation Fuel(Jet A-1) to Secure Aviation Safety (항공안전 확보를 위한 항공유(Jet A-1) 품질관리 필요성)

  • Junbeom Heo;Yumi Kang;Heejin Lee
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.30 no.2
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    • pp.194-199
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    • 2024
  • Accidents due to aircraft fuel defects rank in the top 13 of the 34 accident types described by CAST-ICAO Common Taxonomy Team(CICTT). Aircraft accidents occur because of the inflow of moisture or pollutants depending on the distribution process and storage environment. To confirm the change in physical properties of the aircraft oil stored for a long time, we stored JET A-1 aircraft oil in a metal can to observe the change after six months. We confirmed that the aircraft oil stored for a long time satisfied the quality standards, and the stability of the fuel oil was high. However, in scenarios in which aircraft oil is stored separately on ships, onshore storage facilities, oil fields, etc., owing to the nature of missions, such as in marine police aircraft, the inflow of moisture or pollutants may likely occur due to changes in the internal and external environment. In addition, pollutants can be analyzed using existing tests and distillation properties, but for moisture, domestic and international standards and domestic laws determine the moisture separation ability of aircraft oil through the water separation index, but the moisture content is not analyzed. Therefore, aviation safety must be secured by adding quality control standards for moisture content and performing revisions to uniformize domestic and international standards and laws.

Experimental Study on Combined Failure Damage of Bi-directional Prestressed Concrete Panel under Impact-Fire Loading (충돌 후 화재에 대한 이방향 프리스트레스트 콘크리트 패널부재의 복합 파괴손상에 관한 실험적 연구)

  • Yi, Na-Hyun;Lee, Sang-Won;Choi, Seung-Jai;Kim, Jang-Ho Jay
    • Journal of the Korea Concrete Institute
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    • v.26 no.4
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    • pp.429-440
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    • 2014
  • Since the World Trade Center and Pentagon attacks in 2001, terror, military attack, or man-made disaster caused impact, explosion, and fire accident have frequently occured on civil infrastructures. However, structural behavior researches on major Prestressed Concrete (PSC) infrastructures such as bridges, tunnels, Prestressed Concrete Containment Vessel (PCCVs), and LNG tanks under extreme loading are significantly lacking. Especially, researches on possible secondary fire scenarios after terror, bombing, collision of vehicles and vessels on concrete structures have not been performed domestically where most of the past researches related to extreme loadings on structures focused on an independent isolated extreme loading scenario. Due to the outcry of public concerns and anxiety of potential terrorist attacks on major infrastructures and structures, a study is urgently needed at this time. Therefore, in this study, the bi-directional prestressed concrete $1400{\times}1000{\times}300mm$ panels applied with 430 kN prestressing force using unbonded prestressing thread bars were experimentally evaluated under impact, fire, and impact-fire combined loadings. Due to test site restrictions, impact tests were performed with 14 kN impactor with drop heights of 10m and 3.5 m to evaluate impact resistance capacity. Also, fire and impact-fire combined loading were tested using RABT fire loading curve. The measured residual strength capacities of PSC and RC specimens applied with impact, fire, impact-fire combined loadings were compared with the residual strength capacity of undamaged PSC and RC specimens for evaluation. The study results can be used as basic research data for related research areas such as protective design and numerical simulation under extreme loading scenarios.

Evaluation of Countermeasures Effectiveness in a Radioactively Contaminated Urban Area Using METRO-K : The Implementation of Scenarios Designed by the EMRAS II Urban Areas Working Group (METRO-K를 사용한 방사능으로 오염된 도시지역에서 대응행위효과 평가 : EMRAS II 도시오염평가분과 시나리오의 이행)

  • Hwang, Won-Tae;Jeong, Hae-Sun;Jeong, Hyo-Joon;Kim, Eun-Han;Han, Moon-Hee
    • Journal of Radiation Protection and Research
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    • v.37 no.3
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    • pp.108-115
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    • 2012
  • The Urban Areas Working Group within the EMRAS-2 ($\underline{E}$nvironmental $\underline{M}$odelling for $\underline{RA}$diation $\underline{S}$afety, Phase 2), which has been supported by the IAEA (International Atomic Energy Agency), has designed some types of accidental scenarios to test and improve the capabilities of models used for evaluation of radioactive contamination in urban areas. For the comparison of the results predicted from the different models, the absorbed doses in air were analyzed as a function of time following the accident with consideration of countermeasures to be taken. Two kinds of considerations were performed to find the dependency of the predicted results. One is the 'accidental season', i.e. summer and winter, in which an event of radioactive contamination takes place in a specified urban area. Likewise, the 'rainfall intensity' on the day of an event was also considered with the option of 1) no rain, 2) light rain, and 3) heavy rain. The results predicted using a domestic model of METRO-K have been submitted to the Urban Areas Working Group for the intercomparison with those of other models. In this study, as a part of these results using METRO-K, the countermeasures effectiveness in terms of dose reduction was analyzed and presented for the ground floor of a 24-story business building in a specified urban area. As a result, it was found that the countermeasures effectiveness is distinctly dependent on the rainfall intensity on the day of an event, and season when an event takes place. It is related to the different deposition amount of the radionuclides to the surfaces and different behavior on the surfaces following a deposition, and different effectiveness from countermeasures. In conclusion, a selection of appropriate countermeasures with consideration of various environmental conditions may be important to minimize and optimize the socio-economic costs as well as radiation-induced health detriments.

The Development of a Ship Firefighting Drill Simulator (선박소화훈련 시뮬레이터 개발에 관한 연구)

  • Kim, Won-Ouk;Kim, Dae-Hee
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.5
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    • pp.410-416
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    • 2016
  • After the Sewol Ferry accident, the importance of maritime safety has been emphasized in Korea. In particular, educational and experience training are not only being conducted for maritime personnel but also in schools and at maritime-related organizations in order to broadly instill maritime safety awareness. Based on SOLAS regulations, safety education for sailors conducted every 10 days passenger boats, and fire-fighting drills and abandon-ship training should be conducted once a month on merchant ships. After the Sewol Ferry accident, the maximum number of trainees was reduced from 40 to 20 in order to improve the effectiveness of these training sessions by requiring all trainees to participate in the actual training. The current training process consists of two steps: textbook-based theoretical training and actual practice. Current training environment provides limited capability from human and facility recourses which limit the numbers of trainee participated and system operation time. By introducing the simulation training, it will improve the trainee skill and performance prior to the on-site training and allow the more effective and rapid progress on actual practice. Therefore, it will be proposed the three-step training method in order to improve the effectiveness on fire-fighting drill in Maritime Safety Education on this study. This study suggests a three step training method that would increase the efficiency of maritime safety education. An image-training step to enhance individual task awareness and equipment usage via simulation techniques after theoretical training has been added. To implement this simulation, a virtual training session will be conducted before actual training, based on knowledge obtained from theoretical training, which is expected to increase the speed with which trainees can adapt during the practical training session. In addition, due to the characteristics of the simulation, repeated training is possible for reaction drills in emergency circumstances and other various scenarios that are difficult to replicate in actual training. The efficiency of training is expected to improve because trainees will have practiced before practical training takes place, which will decrease the time needed for practical training and increase the number of training sessions that can be executed, increasing the efficiency of training overall. This study considers development methods for fire-fighting drill simulations using virtual reality techniques.

Study on the Consequence Effect Analysis & Process Hazard Review at Gas Release from Hydrogen Fluoride Storage Tank (최근 불산 저장탱크에서의 가스 누출시 공정위험 및 결과영향 분석)

  • Ko, JaeSun
    • Journal of the Society of Disaster Information
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    • v.9 no.4
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    • pp.449-461
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    • 2013
  • As the hydrofluoric acid leak in Gumi-si, Gyeongsangbuk-do or hydrochloric acid leak in Ulsan, Gyeongsangnam-do demonstrated, chemical related accidents are mostly caused by large amounts of volatile toxic substances leaking due to the damages of storage tank or pipe lines of transporter. Safety assessment is the most important concern because such toxic material accidents cause human and material damages to the environment and atmosphere of the surrounding area. Therefore, in this study, a hydrofluoric acid leaked from a storage tank was selected as the study example to simulate the leaked substance diffusing into the atmosphere and result analysis was performed through the numerical Analysis and diffusion simulation of ALOHA(Areal Location of Hazardous Atmospheres). the results of a qualitative evaluation of HAZOP (Hazard Operability)was looked at to find that the flange leak, operation delay due to leakage of the valve and the hose, and toxic gas leak were danger factors. Possibility of fire from temperature, pressure and corrosion, nitrogen supply overpressure and toxic leak from internal corrosion of tank or pipe joints were also found to be high. ALOHA resulting effects were a little different depending on the input data of Dense Gas Model, however, the wind direction and speed, rather than atmospheric stability, played bigger role. Higher wind speed affected the diffusion of contaminant. In term of the diffusion concentration, both liquid and gas leaks resulted in almost the same $LC_{50}$ and ALOHA AEGL-3(Acute Exposure Guidline Level) values. Each scenarios showed almost identical results in ALOHA model. Therefore, a buffer distance of toxic gas can be determined by comparing the numerical analysis and the diffusion concentration to the IDLH(Immediately Dangerous to Life and Health). Such study will help perform the risk assessment of toxic leak more efficiently and be utilized in establishing community emergency response system properly.

Influence of identifiable victim effect on third-party's punishment and compensation judgments (인식 가능한 피해자 효과가 제3자의 처벌 및 보상 판단에 미치는 영향)

  • Choi, InBeom;Kim, ShinWoo;Li, Hyung-Chul O.
    • Korean Journal of Forensic Psychology
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    • v.11 no.2
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    • pp.135-153
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    • 2020
  • Identifiable victim effect refers to the tendency of greater sympathy and helping behavior to identifiable victims than to abstract, unidentifiable ones. This research tested whether this tendency also affects third-party's punishment and compensation judgments in jury context for public's legal judgments. In addition, through the Identifiable victim effect in such legal judgment, we intended to explain the effect of 'the bill named for victim', putting the victim's real name and identity at the forefront, which is aimed at strengthening the punishment of related crimes by gaining public attention and support. To do so, we conducted experiments with hypothetical traffic accident scenarios that controlled legal components while manipulating victim's identifying information. In experiment 1, each participant read a scenario of an anonymous victim (unidentifiable condition) or a nonanonymous victim that included personal information such as name and age (identifiable condition) and made judgments on the degree of punishment and compensation. The results showed no effect of identifiability on third-party's punishment and compensation judgments, but moderation effect of BJW was obtained in the identifiable condition. That is, those with higher BJW showed greater tendency of punishment and compensation for identifiable victims. In Experiment 2, we compared an anonymous victim (unidentifiable condition) against a well-conducted victim (positive condition) and ill-conducted victim (negative condition) to test the effects of victim's characteristics on punishment for offender and compensation for victims. The results showed lower compensation for an ill-conducted victim than for an anonymous one. In addition, across all conditions except for negative condition, participants made punishment and compensation judgments higher than the average judicial precedents of 10-point presented in the rating scale. This research showed that victim's characteristics other than legal components affects third-party's legal decision making. Furthermore, we interpreted third-party's tendency to impose higher punishment and compensation with effect of 'the bill named for victim' and proposed social and legal discussion for and future research.

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