• 한국수소및신에너지학회논문집
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• 제31권5호
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• pp.459-466
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• 2020

As the hydrogen industry grows, expansion of infrastructure for hydrogen supply is required, but the safety of hydrogen facilities is concerned due to the recent accidents at the Gangneung hydrogen tank and the Norwegian hydrogen fueling station. In this study, the damage range and impact analysis on the on-site hydrogen fueling station was conducted using Hy-KoRAM. This is a domestically developed program that adds functions based on HyRAM. Through this risk assessment, it was evaluated whether the on-site hydrogen fueling station meets international standards and suggested ways to improve safety.

• 융합정보논문지
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• 제10권8호
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• pp.127-136
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• 2020

화학물질을 이용한 화학테러·사고는 국내·외에서 지속해서 발생, 시도되는 추세이다. 국내의 경우, 환경부 화학물질안전원에서 CARIS(Ver. 2018)를 화학테러·사고 발생지역의 피해 영향 범위 평가 용도로 제공하여 현장 대응에 활용하고 있다. 하지만 현행 CARIS는 실내, 지하 등과 같은 폐쇄된 공간에 대한 영향을 고려하지 못하여 현장에서 요구하는 정밀한 피해 영향 범위 평가 결과를 제공하는데 어려우며 제공되는 정보도 제한적이다. 본 연구에서는 CARIS(Ver. 2018)를 구동하여 획득한 피해 영향 범위 평가 결과와 국내·외 문헌 자료를 비교, 검토하여 제한사항과 개선 방향을 제시하였다. 또한 지하, 실내 등 특수 지점, 지역에 대한 구동 모델 구축의 필요성과 현장 대응 요원 등 포함한 주민에게 제공되는 정보의 방향성을 제안하였다. CARIS의 보완과 수정에 있어 본 연구에서 제안한 방법이 반영된다면 더욱 진보된 화학테러·사고 현장 대응 역량 체계 구축이 될 것으로 기대한다.

• Journal of Advanced Research in Ocean Engineering
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• 제1권4호
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• pp.198-210
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• 2015

This paper presents the damage assessment of a free-fall dropped object on the seabed. The damage to a dropped object totally depends on the relationship between the impact energy and the soil strength at the mudline. In this study, unexpected dropping scenarios were first assumed by varying the relevant range of the impact velocity, structure geometry at the moment of impact, and soil strength profile along the penetration depth. Theoretical damage assessments were then undertaken for a free-fall dropping event with a fixed final embedment depth for the structure. This paper also describes the results of a three-dimensional large deformation finite element analysis undertaken for the purpose of validation. The analyses were carried out using the coupled Eulerian-Lagrangian approach, modifying the simple elastic-perfectly plastic Tresca soil model. The validation exercises for each dropping scenario showed good agreement, and the present numerical approach was capable of predicting the behavior of a free-fall dropped object.

• 환경영향평가
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• 제17권6호
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• pp.381-391
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• 2008

The instances of the damage to livestock are increasing with frequent environmental disputes on the noise and vibration. This study analyzed 134 open cases dealing with the environmental disputes on livestock damaged by noise and vibration, and being intervened by National Environmental Dispute Resolution Commission. The environmental disputes on the noise and vibration account for 86% of all the disputes, and cases of the consequent damages to livestock have increased. As shown in the 134 cases, pig is the most lethal livestock attacked by the noise and vibration. During last 10 years, 89% of the noise damages hurting the livestock resulted from the noises pertaining to construction and 58% was due to the noise damages from the road constructions. The noise levels in the range of 70~80 dB(A) and the vibration levels of 70~75 dB(V) caused most of the disputes. The average rate of reimbursement for the livestock damages for the last 10 years was higher than the average rate of reimbursement of the total disputes intervened by National Dispute Resolution Commission.

• 환경영향평가
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• 제21권6호
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• pp.941-949
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• 2012

The various plants including power plants have been increased near downtown in accordance with the policy objective of rising the power feed rate and development projects. As a result of these various plants near residential area, noise damage complaints has been raised very often. The power plant is included with the range of environmental impact assessment project. Nevertheless, environmental noise issues regarding construction of these power plants have arisen. Accordingly it is time to consider the environmental and social issues of plants noise in accordance with the government's policy objectives of increased power production. In this study, we reviewed the current noise impact assessment and we also sought solutions to these issues. In order to minimize the problem of noise impact on neighborhood and residents, we intended to propose alternative method of 3D simulation in dealing with these issues.

• 한국안전학회지
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• 제33권5호
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• pp.150-156
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• 2018

As the types and usage of chemical increase, modern countries should protect their health and environment from the risk of hazardous chemical. Chemical accidents not only affect humans but also cause huge losses to the environment. Moreover, since its effects do not end in a short period of time, it is necessary to identify the extent of the damage and establish a prevention and response system in advance. In 2015, the Chemical Substances Management Act provided a system for assessing the impact on the people and the environment around the workplace. However, it is difficult to quantitatively evaluate the impact on environmental factors such as vegetation and aquatic, with the current hazard assessment methods. The purpose of this study is to analyze the quantitative risk of environmental receptors. This study improved the existing risk assessment formula by using the environmental vulnerability index and established the end point concentration criterion which can estimate the damage range to environmental media. To verify the results of the study, a virtual accident scenario was selected and a case study was conducted. As a result, the extent of impact on the environmental medium can be calculated, and the degree of environmental risk of the zone can be quantified through the risk analysis considering the environmental vulnerability. This study is expected to increase the reliability of the reliability of the existing risk anaylsis method beacause it is a risk analysis method that can be applied when the environmental factors are absolutely necessary and when the residents and environment are complex.

• 한국가스학회지
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• 제24권5호
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• pp.20-28
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• 2020

불산 누출사고 발생 시 피해영향범위 예측을 수계산, 영향평가 시뮬레이션, CFD 시뮬레이션을 활용하여서 예측하고 실제 환경영향보고서와 비교·분석하였다. 수계산은 누출원모델과 확산모델을 활용하여서 계산하였으며 영향평가 시뮬레이션은 우리나라 환경부에서 제공하는 KORA, 미국 환경부의 ALOHA, 상용화 프로그램 중 비교적 널리 사용 중인 PHAST를 사용하였고, CFD 시뮬레이션은 STAR-CMM+ 프로그램을 활용하였다. 사용자 입장에서 편리성, 신속성, 수용성, 경제성 등을 고려할 때 불산 누출사고 영향예측에 가장 적절하게 사용할 수 있는 프로그램은 ALOHA와 KORA 이었다. 아울러, 본 연구결과는 정부의 정책개발과 기업의 안전부서에서 피해영향범위 프레임워크를 선정하고 불필요한 규제, 불필요한 안전투자를 최적화하여 정부 또는 기업의 제한된 자원을 효율적으로 활용하는 데 도움이 될 것으로 기대된다.

• Smart Structures and Systems
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• 제31권2호
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• pp.101-111
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• 2023

Structural health monitoring (SHM) covers a range of damage detection strategies for buildings. In real-time, SHM provides a basis for rapid decision making to optimise the speed and economic efficiency of post-event response. Previous work introduced an SHM method based on identifying structural nonlinear hysteretic parameters and their evolution from structural force-deformation hysteresis loops in real-time. This research extends and generalises this method to investigate the impact of a wide range of flag-shaped or pinching shape nonlinear hysteretic response and its impact on the SHM accuracy. A particular focus is plastic stiffness (K_p), where accurate identification of this parameter enables accurate identification of net and total plastic deformation and plastic energy dissipated, all of which are directly related to damage and infrequently assessed in SHM. A sensitivity study using a realistic seismic case study with known ground truth values investigates the impact of hysteresis loop shape, as well as added noise, on SHM accuracy using a suite of 20 ground motions from the PEER database. Monte Carlo analysis over 22,000 simulations with different hysteresis loops and added noise resulted in absolute percentage identification error (median, (IQR)) in K_p of 1.88% (0.79, 4.94)%. Errors were larger where five events (Earthquakes #1, 6, 9, 14) have very large errors over 100% for resulted K_p as an almost entirely linear response yielded only negligible plastic response, increasing identification error. The sensitivity analysis shows accuracy is reduces to within 3% when plastic drift is induced. This method shows clear potential to provide accurate, real-time metrics of non-linear stiffness and deformation to assist rapid damage assessment and decision making, utilising algorithms significantly simpler than previous non-linear structural model-based parameter identification SHM methods.

• 한국안전학회지
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• 제38권3호
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• pp.43-50
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• 2023

Silicone tetrachloride (SiCl₄) leak accidents cause enormous human and environmental damage because it is highly toxic. Some handling facilities use water curtains to reduce the impact range of SiCl₄. Although the water curtain is known as one of the most efficient technologies for post-release mitigation, its effect on reducing SiCl₄ concentration needs to be investigated scientifically and quantitatively. In this study, three-dimensional computational fluid dynamics (CFD) was used to investigate the physical and chemical effects of water curtains as a release-mitigation system for SiCl₄. SiCl₄ is released and dispersed five seconds prior to the operation of the water curtain. Once the water curtain works, the SiCl₄ reacts chemically with the water and its concentration decreases rapidly; it reaches an emergency response planning guidelines level 2 (ERPG-2) of 5 parts per million (ppm) at about 570 m. We observed, however, that the physical effect of water curtains on reducing SiCl₄ concentration is insignificant when the chemical effect is eliminated. These results are crucial since they can be a scientific and quantitative basis for the 'technical guidelines for estimating the accident affected range'. In order to protect the public from chemical accidents, more toxic gas mitigation technologies need to be developed.

• 한국가스학회지
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• 제28권1호
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• pp.73-84
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• 2024

본 연구에서는 기후변화 해결책 중 하나인 천연가스 복합화력발전소를 암모니아로 연료 전환 시 위험성을 파악하기 위해 ALOHA 전산 해석 프로그램을 이용하여 정량적 사고피해영향평가를 실시하였다. 국내 세종복합화력발전소를 대상으로 최악 및 대안의 사고 시나리오를 수립하고, 인화성, 복사열, 과압, 독성의 위험 요인에 대해 영향 범위를 산출한 결과, 암모니아 확산에 의한 독성 위험성이 가장 크게 나타났다. 특히, 천연가스-암모니아 혼소율에 따른 사고피해영향평가 분석 결과, 암모니아 저장 및 이송시스템으로부터 누출로 인한 독성의 피해 영향은 선형적 비례의 관계에 있음을 확인하였다. 정량적으로는 피어슨 상관계수가 LOC-1, LOC-2, LOC-3이 각각 0.991, 0.987, 0.989로 98% 이상의 높은 값을 나타냈으며, 선형계수는 LOC-1, LOC-2, LOC-3이 각각 133, 70, 29로 낮은 농도 기준일수록 암모니아 혼합 비율에 따른 피해 영향이 증가함을 확인하였다.