Fault Tree를 활용한 항공기 격납고 소화시스템의 화재 안전성 분석

이종국 한국화재소방학회 2017 한국화재소방학회논문지 Vol.31 No.6

An aircraft maintenance hangar is a building that stores, maintains, and inspects expensive aircraft. The frequency of fireoccurrence is low, but the resulting human and material damage can be very serious. Therefore, in this study, we conducteda qualitative analysis of the fire safety of the currently operating fire suppression systems for aircraft maintenance hangarsusing the Fault Tree method, and then performed a quantitative analysis using the failure rate data for the derived basic eventsand analyzed the importance of the minimal cut sets. As a result of the qualitative analysis by the minimal cut set, it wasfound that there were 14 accident paths that could be expanded to a large fire, due to the fire control failure of the aircrafthangar fire suppression system. The quantitative analysis revealed that, the probability of the fire expanding into a large oneis 2.08 × E-05 /day. The analysis of the importance of the minimal cut set shows that four minimal cut sets, namely the firedetector and foam head action according to the zone and blocking of the foam by the aircraft wing and the fire plume, hadthe same likelihood of causing the fire to develop into a large one, viz. 24.95% each, which together forms the majorityof the likelihood. It was confirmed for the first time by fault tree method that the fire suppression system of aircraftmaintenance hangars is not suitable for fires under the aircraft wings and needs to be improved. 항공기 정비 격납고는 고가의 항공기를 보관하거나 정비, 점검등을 하는 건축물로 화재발생 빈도는 낮지만 화재발생 시 인적, 물적 피해가 매우 클 수 있다. 따라서 본 연구에서는 Fault tree를 이용하여 현재 운용중인 항공기 정비격납고 소화시스템의 화재 안전성에 대한 정성적 분석을 시행하고, 도출된 기본사상에 대한 고장률 자료를 활용하여정량적 분석을 실시한 후 정상사상의 발생 확률에 대한 Minimal cut set의 중요도를 분석하였다. Minimal cut set에의한 정성적 분석결과 항공기 격납고 포헤드 소화시스템의 화재제어 실패로 대형화재로 확대될 수 있는 사고경로는14개라는 것을 알 수 있었다. 또한 정량적인 분석 결과 대형화재로 확대될 확률은 2.08×E-05/day이며, Minimal cutset의 중요도 분석 결과 화재 발생 시 4개의 Minimal cut set 즉, 구역별 화재 감지기 및 포헤드 동작과 항공기 날개및 Fire plume에 의한 소화약제 차단이 동일하게 24.95%로 대형화재로 확대될 가능성의 대부분을 차지하였으며, 항공기 정비 격납고의 포헤드 소화시스템은 항공기 날개 하부화재에 대한 적응성이 없어 개선이 필요한 것으로 Faulttree를 이용하여 처음 확인하였다.

Fuzzy event tree analysis for quantified risk assessment due to oil and gas leakage in offshore installations

Cheliyan, A.S.,Bhattacharyya, S.K. Techno-Press 2018 Ocean systems engineering Vol.8 No.1

Accidental oil and gas leak is a critical concern for the offshore industry because it can lead to severe consequences and as a result, it is imperative to evaluate the probabilities of occurrence of the consequences of the leakage in order to assess the risk. Event Tree Analysis (ETA) is a technique to identify the consequences that can result from the occurrence of a hazardous event. The probability of occurrence of the consequences is evaluated by the ETA, based on the failure probabilities of the sequential events. Conventional ETA deals with events with crisp failure probabilities. In offshore applications, it is often difficult to arrive at a single probability measure due to lack of data or imprecision in data. In such a scenario, fuzzy set theory can be applied to handle imprecision and data uncertainty. This paper presents fuzzy ETA (FETA) methodology to compute the probability of the outcomes initiated due to oil/gas leak in an actual offshore-onshore installation. Post FETA, sensitivity analysis by Fuzzy Weighted Index (FWI) method is performed to find the event that has the maximum contribution to the severe sequences. It is found that events of 'ignition', spreading of fire to 'equipment' and 'other areas' are the highest contributors to the severe consequences, followed by failure of 'leak detection' and 'fire detection' and 'fire water not being effective'. It is also found that the frequency of severe consequences that are catastrophic in nature obtained by ETA is one order less than that obtained by FETA, thereby implying that in ETA, the uncertainty does not propagate through the event tree. The ranking of severe sequences based on their probability, however, are identical in both ETA and FETA.

Subsea X-mas Tree에서의 Blockage 처리 실패에 대한 위험도 저감 방안 분석

유원우(Won-Woo Yoo),박민선(Min-Sun Park),양영순(Young-Soon Yang) 한국해양공학회 2013 韓國海洋工學會誌 Vol.27 No.2

A subsea chemical injection system treats blockage problems in a subsea production system. It is important to treat problems quickly, because production delays cause fatal profit losses in a subsea production system. Therefore, the subsea industry requires a relatively higher reliability level for a production system compared to other industries. In this study, a subsea chemical injection system (linked to a control system) to inject chemicals into a subsea X?mas tree was analyzed. By using FSA (Formal Safety Assessment), the risk factors were defined and a quantitative risk analysis utilizing FTA (Fault Tree Analysis) and ETA (Event Tree Analysis) was performed. As a result, the effectiveness of a risk reduction option was evaluated.

내진성능확보를 위한 교량의 최적유지보수계획법

고현무,이선영,박관순,김동석 한국지진공학회 2002 한국지진공학회논문집 Vol.6 No.5

교량의 내진성능확보를 위한 유지보수계획을 수립하는데 있어서, 전체 생애주기비용의 최소화를 통하여 최적의 검사 및 수리회수의 결정방법을 제시한다. 생애주기 비용에는 초기비용, 파괴비용 뿐만 아니라, 검사 및 보수비용이 포함된다. 시간에 따른 내진성능저하모델을 손상함수를 이용하여 표현하였으며, 손상감지정도에 따른 Event Tree Analysis를 통하여 유지보수에 따른 파괴확률을 랜덤진동이론을 이용하여 산출한다. 예제로서 10경간 연속교의 최적유지보수방법을 살펴본 결과, 가속도계수가 증가하고, 연약지반일수록 최적유지보수회수는 증가하는 것으로 나타났다. In the maintenance and retrofit planning of a bridge system, the optimal strategy for inspection and repair are suggested by minimizing the expected total life-cycle cost, which includes the initial cost, the costs of inspection, repair, and failure. Degradation of seismic performance is modeled by using a damage function. And failure probability is computed according to the degree of damage detection by random vibration theory and the event tree analysis. As an example to illustrate the proposed approach, a 10-span continuous bridge structure is used. The numerical results show that the optimum number of the inspection and the repair are increased, as the seismic intensity is increased and the soil condition of a site becomes more flexible.

영국철도시스템에 적용된 리스크평가 사례

이동하,정광태,Lee, Dong-Ha,Jeong, Gwang-Tae 대한인간공학회 2003 大韓人間工學會誌 Vol.22 No.1

The British railway safety research group has developed a risk assessment model for the railway infrastructure and major railway accidents. The major hazardous factors of the railway infrastructure were identified and classified in the model. The frequency rates of critical top events were predicted by the fault tree analysis method using failure data of the railway system components and ratings of railway maintenance experts, The consequences of critical top events were predicted by the event tree analysis method. They classified the Joss of accident due to railway system into personal. commercial and environmental damages. They also classified 110 hazardous event due to railway system into three categories. train accident. movement accident and non-movement accident. The risk assessment model of the British railway system has been designed to take full account of both the high frequency low consequence type events (events occurring routinely for which there is significant quantity of recorded data) and the low frequency high consequence events (events occurring rarely for which there is little recorded data). The results for each hazardous event were presented in terms of the frequency of occurrence (number of events/year) and the risk (number of equivalent fatalities per year).

혼산에 의한 폭발사고의 화학반응 경로 분석 - 화학물질 운반 선박을 중심으로 -

강유미,임정빈 해양환경안전학회 2017 海洋環境安全學會誌 Vol.23 No.6

본 연구의 목적은 혼산 화물의 폭발사고에 대한 화학반응 경로를 분석하는데 있다. 분석에는 사건-가지분석기법을 적용한 구조 적인 시나리오를 이용하였다. 구조적인 시나리오는 재결서에 기록된 혼산 화물 사고의 내용에서 다양한 화학반응 경로를 추정하여 구축하 였다. 분석에는 화학 이론에 의거한 정성적 분석과 화학 반응식을 이용한 정량적 분석 및 설문조사를 통한 확률적 분석 등 세 가지 방법을 혼합 적용하였다. 분석결과, 사고 발생의 주요 경로는 진한 황산과 물이 반응하여 폭발하는 경로, 혼산과 금속이 반응하여 폭발하는 경로, 특수한 물질과 합성하여 폭발하는 경로 등 세 가지로 나타났다. 이 결과는 재결서에 기록된 경로와 유사함을 알았고, 이를 통해서 본 연구 에서 제안한 화학물질의 경로분석 기법이 타당함을 알았다. 본 연구에서 제안한 방법은 다양한 화학물질 사고의 화학반응 경로 추정에 적 용 가능할 것으로 기대된다. The purpose of this study is to analyze the chemical reaction pathway for explosion accident of mixed cargo. The analysis used a structural scenario using event-tree analysis. Structural scenarios were constructed by estimating various chemical reaction paths in the content of the mixed cargo accident recorded in the written verdict. The analytical method was applied to three kinds of analysis: chemical analysis based on chemical theory, quantitative analysis using chemical reaction formula, and probabilistic analysis through questionnaire. As a result of analysis, the main pathway of the accident occurred in three ways: the path of explosion due to the reaction of concentrated sulfuric acid with water, the path of explosion due to the reaction of metal and mixed acid, and the path of explosion by synthesizing with special substances. This result is similar to the path recorded in the validation, and it leads to thar the proposed path analysis method is valid. The proposed method is expected to be applicable to chemical reaction path estimation of various chemical accidents.

ETA를 통한 연구실험실 콘센트회로의 전기재해 분석

김두현 ( Doo-hyun Kim ),김성철 ( Sung-chul Kim ),박종영 ( Jong-young Park ),김상철 ( Sang-chul Kim ) 한국안전학회 2017 한국안전학회지 Vol.32 No.2

This study is intended to identify issues on the basis of investigating the actual state of laboratory environment and outlet circuit, and derive end states by expressing sequences from the initiating event of disaster to accident in leakage current, poor contact and overload through ETA(event tree analysis). To this end, this study investigated the actual state of electric equipment of laboratory at universities in all parts of country. And it is shown that most of them are failure in electric work and user negligence in the investigation of actual state. It is found that there is earth fault and defect in wire diameter in the failure of electric work and the problem of partial disconnection due to wire bundling and poor contact in user negligence. Outlet-related component, failure rate and initiating events are composed of a total of 41 initiating events, i.e., 30 internal initiating events and 11 external initiating events. And end states are composed of a total of 15 parts, i.e., 3 electric power parts and 12 safety parts. Earthing class 3 is the most important safety device against leakage current (initiating event). And in case of poor contact, it is necessary for manager to check thoroughly because there is no safety device. In case of overload/overcurrent, when high-capacity equipment is connected, a molded case circuit breaker, safety device, worked. However, in most cases, it is verified that this doesn`t work. This study can be utilized as electric equipment safety guide for laboratory safety manager and managers.

사건수목분석을 통한 수배전설비의 전기화재위험성 분석

박영호 ( Young Ho Park ),김두현 ( Doo-hyun Kim ),김성철 ( Sung-chul Kim ) 한국안전학회(구 한국산업안전학회) 2016 한국안전학회지 Vol.31 No.5

The purpose of this paper is to conduct ETA on 15 components of power installations: the DS/LBS, LA, MOF, CT, PT, A/V meter, VCB, OCR, COS, PF, Transformer, Condenser(C), Grounding, Cable and Connector. To achieve that, power installations work flow and its components are categorized. Based on performance, human, environmental, management, and safety, this paper drew Initiation events (IE) and End states (ES). ETA is applied to the main functions of each component, and the end states that may occur in one initiation event are suggested. In addition, detailed classification was performed to induce various end states on the basis of the suggested initiation events. If the suggested IEs and ESs are applied on the basis of power installations event cases, it is expected to prevent the same kinds of accident and operate power installations safely.

의사결정나무를 이용한 스포츠 이벤트 선택속성의 만족 차이연구: 2018 자카르타-팔렘방 아시안게임을 대상으로

최종률 ( Jonglyul Choi ),김장원 ( Jangwon Kim ),안덕수 ( Deoksoo Ahn ) 관광경영학회 2020 관광경영연구 Vol.100 No.-

The purpose of this study is to find out the difference in satisfaction of sports events according to demographic characteristics and then devise a differentiated marketing plan. In addition, by deriving a selection attribute with high satisfaction among the event selection attributes, it is useful for managing sustainable and successful sports events in countries and cities that want to host sports events, and provides data that can be used in practice. To this end, a survey was conducted on 375 Indonesian visitors of the Asian Games in Jakarta-Palembang. The implications derived through empirical analysis are as follows. First, it is necessary to actively promote offline promotions and advertisements such as SNS, Internet, and organizational homepage, and devise a plan to implement viewing vouchers, package admission tickets, discount tickets for specific games or times, etc. for visitors. Second, the stadium should have facilities like an amusement park. In addition, comfortable and comfortable accommodation facilities and friendly volunteers are needed to recharge the enthusiastic visitors. In addition, clean and hygienic food is the most important attribute for enjoying and viewing sports events.

Application of Dynamic Probabilistic Safety Assessment Approach for Accident Sequence Precursor Analysis: Case Study for Steam Generator Tube Rupture

이한설,김태완,허균영 한국원자력학회 2017 Nuclear Engineering and Technology Vol.49 No.2

The purpose of this research is to introduce the technical standard of accident sequenceprecursor (ASP) analysis, and to propose a case study using the dynamic-probabilistic safetyassessment (D-PSA) approach. The D-PSA approach can aid in the determination of highrisk/low-frequency accident scenarios from all potential scenarios. It can also be used toinvestigate the dynamic interaction between the physical state and the actions of theoperator in an accident situation for risk quantification. This approach lends significantpotential for safety analysis. Furthermore, the D-PSA approach provides a more realistic riskassessment by minimizing assumptions used in the conventional PSA model so-called thestatic-PSA model, which are relatively static in comparison. We performed risk quantificationof a steam generator tube rupture (SGTR) accident using the dynamic event tree (DET)methodology, which is the most widely used methodology in D-PSA. The risk quantificationresults of D-PSA and S-PSA are compared and evaluated. Suggestions and recommendationsfor using D-PSA are described in order to provide a technical perspective.