LNG 저장시설에 있어서의 탱크지역에 대한 사고영향분석

고재선(Ko, Jae-Sun),김효(Kim, Hyo) 한국화재소방학회 2003 한국화재소방학회 학술대회 논문집 Vol.2003 No.춘계

소방수 공급설비에 대한 공통원인고장을 고려한 확률론적 신뢰도 분석

고재선(Ko, Jae-Sun),김효(Kim, Hyo) 한국화재소방학회 2003 한국화재소방학회논문지 Vol.17 No.4

본 논문에서는 공통원인고장의 이론적 고찰로서 정의와 그 원인, 분석방법을 기술하고 대표적인 소방설비의 하나인 소방펌프에 대해 공통원인고장을 고려한 신뢰도분석에 적용함으로써 공통원인고장의 중요성과 그 한계성을 규명하고자 한다. 공통원인고장을 고려한 소방수 공급설비에 대한 신뢰도분석 결과 알 수 있듯이 펌프의 운전고장이 계통실패의 가장 큰 요인으로 나타났으며 특히 두 펌프의 공통원인고장이 지배적이다. 다시 말하면 공통원인고장을 고려하지 않을 경우에 계통신뢰도를 실제보다 2배 이상 초과하여 평가할 수 있다는 것이다. 이로서 계통 신뢰도분석에서 공통원인고장의 중요성을 인식할 수 있으며 분석결과는 공통원인고장의 변수인자의 값에 크게 의존하는 것을 알 수 있다. 그리고 소방수 공급설비설계에 계통설계 시 다중성을 반영하면 신뢰도가 증가하는 것은 사실이나 공통원인고장 요인 때문에 다중기기 설치대수에 비례하는 정도의 신뢰도 향상을 얻지 못할 수도 있다. 또한 공통원인고장의 한계성으로는 분석모델의 차이로 인한 차이는 미미한 수준이었으나 각각 다른 데이터 원을 사용했을 경우 그 결과는 큰 차이를 나타내었다. 따라서 공통원인고장 분석에 사용되는 모델보다는 이용 가능한 경험데이터의 품질이 그 분석결과의 신뢰성에 큰 영향을 미친다는 것을 알 수 있었다. 결과적으로 다중기기의 공통원인고장을 방지하기 위한 기본적이고 공학적인 방안으로는 설계시 요구되는 적정 신뢰도를 유지하는 것이므로 적어도 소방펌프에 요구되는 신뢰도수준으로 설계되어야 한다. 즉 SIS(Safety Instrumented system)에 요구되는 신뢰도수준인 안전건전성수준(SIL; Safety integrity level)에 적합한가의 유무를 PFD를 활용하여 정량적으로 파악하는 것이다. 공통원인고장을 고려한 소방수 공급설비에 대한 신뢰도분석 결과 계통작동요구시 실패확률(PFD: Probability of failure on demand), 즉 계통 이용 불능도는 3.80E-3이므로 규정목표인 SIL5의 범주 안에 들어있지 않아 안전건전성수준으로 설계되어 있지 않다고 판단되며, 만일 공통원인고장을 고려하지 않았을 경우인 계통 이용불능도 또한 1.82E-3으로 계산되는데, 이 또한 SIL5의 범주 안에 들어있지 않으므로 단전건전성수준으로 설계되어 있지 않다고 판단된다. In this study, we write down the definitions, their causes and the techniques of analysis as a theoretical consideration of common cause failures, and investigate the limitation and the importance of the common cause failures by applying to the analysis on the fire protection as a representative safety facility. As you can know in the reliability analysis, most impressive cause is the malfunctions of pumping operations; especially the common cause failure of two pumps is dominant. In other words, it is possible to assess system-reliability as twice as actual without CCF From these, CCF is extraordinarily important and the results are highly dependent on the CCF factor. And although it would increase with multiple installations, the reliability are not defined as linear with those multiplications. In addition, the differences in results due to the models for analysis are not significant, whereas the various sources of data produce highly different results. Therefore, we conclude that the reliabilities are dependent on the quality of the usable data much better than the variety of models. As a result, the basic and engineering device for the preventions of CCF of the multiple facilities is to design it as reliably as to design the fire-water pump. That is to say, we must assess those reliabilities using PFD whether they are appropriate to SIL (Safety Integrity Level) which is required for the reliability in SIS (Safety Instrumented System). The result of the analysis on the reliability of the fire-water supply with CCF shows that PFD is 3.80E-3, so that it cannot be said to be designed as safely as in the level of SIL5. However, without CCF, PFD is 1.82E-3 which means that they are designed as unsafely as before.

LPG 기화기의 화재·폭발사고 예측모델개발에 관한 연구

고재선(Jae Sun Ko) 한국가스학회 2010 한국가스학회지 Vol.14 No.1

We have garnered 3,593 data of gas accidents reported for 12 years from 1995, and then analyzed the LPG vaporizer accidents according to their types and causes based on the classified database. According to the results the gas rupture has been the most common accident followed by the release, explosion and then fire accidents, the most frequent accident-occurring sub-cause is LPG check floater faults. In addition, we have applied the Poisson Probability Functions to predict the most-likely probabilities of fire, explosion, release and rupture with the LPG vaporizer in the upcoming 5 years. In compliance with Poisson Probability Functions results, in the item which occurs below 3 “LPGVaporizer-Fire”, in the item which occurs below 5 “LPG-Vaporizer-Products Faults-Check Floater” and the item which occurs below 10 appeared with “LPG-Vaporizer-Products Faults. From this research we have assured the successive database updating will highly improve the anticipating probability accuracy and thus it will play a key role as a significant safety- securing guideline against the gas disasters.

염소저장탱크에서의 가스 누출시 공정위험검토 및 결과영향분석

고재선(Ko, Jae-Sun),김효(Kim, Hyo) 한국화재소방학회 2003 한국화재소방학회논문지 Vol.17 No.3

화학공장에서 발생되는 사고 중 대부분은 저장탱크나 운송배관의 손상에 의한 휘발성 유독성물질의 대량 누출이며, 이 경우 누출된 지역의 자연환경과 대기조건에 따른 유동성물질의 확산거동이 안전성평가의 가장 중요한 관심 대상이 된다. 따라서 본 연구에서는 이러한 누출물질에 대한 대기 중 확산을 모사하기 위하여 염소저장탱크에서 염소가 누출될 경우를 예제로 선택하여, 위험성평가와 확산모델(dense gas model)을 이용한 결과해석을 수행하였다. 해석결과를 살펴보면 Fire & Explosion Index를 적용한 결과 포괄적인 위험의 정도는 90.7로서 약간 위험한 정도로 나타났으며, 대기확산 모델(PHAST6.0/ALOHA)은 소프트웨어 운용한 결과, Gas Model에 대한 입력 자료 값에 따라 미치는 결과영향이 다소 차이가 있음을 발견하였으나 각 시나리오별 경향은 상당히 일치함을 나타내고 있다. 따라서 향후 보다 정확한 물성입력자료와 지형인자를 고려한다면 이와 같은 연구방법은 유독성물질 누출에 따른 위험성평가를 보다 효율적으로 수행하는데 도움을 줄 것으로 기대된다. Most of the accidents occurred from the chemical plants are related to the catastrophic gas release events when the large amount of toxic materials is leaked from its storage tank or transmitting pipe lines. In this case, the greatest concerns are how the spreading behaviors of leakages are depended on the ambient conditions such as air stability and other environmental factors. Hence, we have focused on the risk assessments and consequential analysis for chlorine as an illustrative example. As appeared in the result, Fire & Explosion Index depicted it a bit dangerous with presenting the comprehensive degrees of hazard 90.7. And as a result of Phast6.0/ALOHA, the trends of each scenario appeared considerably identical although there are some differences in the resulting effects according to the input data for the Gas Model. The consequence analysis is performed numerically based on the dense gas mode. In the future, using more correct input data, material properties, and topographical configuration, the method of this research will be useful for the guideline of the risk assessment when the release of toxicants breaks out.

국내 LP 및 천연가스사고 Database 구축 및 분석에 관한 연구

고재선(Jae-Sun Ko),박선영(Sun-Young Park),김효(Hyo Kim) 한국가스학회 2008 한국가스학회지 Vol.12 No.3

We have garnered 3,593 data of gas [Natural Gas (NG) and Liquefied Petroleum Gas (LPG)] accidents reported for 16 years from 1991, and then analyzed the accidents according to their types and causes based on the classified database. According to the results the gas leak has been the most common accident followed by the explosion and then fire accidents. The most frequent accident-occurring locations for fire, explosion and leak are recognized around the valve, hose and pipeline, respectively. In addition, we have applied the Poisson analysis to predict the most-likely probabilities of fire, explosion and release in the upcoming 5 years. From this research we have assured the successive database updating will highly improve the anticipating-probability accuracy and thus it will play a key role as a significant safety-securing guideline against the gas disasters.

국내 가스 사고사례 중 NG 및 LPG의 가스 화재·폭발사고 예측시스템 구축에 관한 연구

고재선(Jae-Sun Ko),김효(Hyo Kim) 한국가스학회 2006 한국가스학회지 Vol.10 No.1

고장수목을 중심으로 한 LNG저장탱크의 정량적 위험성평가

고재선 ( Jae-sun Ko ),김효 ( Hyo Kim ) 한국화학공학회 2007 화학공학의이론과응용 Vol.10 No.2

국,내외 사고사례를 통한 주유취급 시설의 위험방지대책

고재선 ( Ko Jae-sun ),김효 ( Kim Hyo ) 한국화학공학회 2007 화학공학의이론과응용 Vol.10 No.1

화학물질 테러에 대한 소방적 대응활동의 문제점 및 대책에 관한 연구

고재선(Ko Jae Sun) 한국테러학회 2013 한국테러학회보 Vol.6 No.4

Spreading terrorism cannot be suppressed with responses of the past since the chemical terrorism is diversified and globalized more and more. Particularly in Korea, there are numerous chemical plants that may cause mass casualties if attacked. It is not an exaggeration to say the whole nation is a soft target vulnerably exposed to any terror attack with many public facilities and industrial facilities concentrated in the greater Seoul and its metropolitan area. It not only makes the attack easier but also could damage the surrounding areas. The most important first responders could be fire fighting force; however, it is neither fully prepared for any chemical attacks nor fully capable in counter –terrorism. Special support and training are in order to be equipped with sufficient personnel, knowledge, skills and equipment and to retain a dedicated counter-terrorism organization. The following measures are to improve the fire fighting force in detail. First, Chemical incident response information system (CARIS) sharing between the corresponding agencies are required for the first responders such as the fire fighting force and police to respond efficiently since here is a limitation in identifying accidents prior to dispatch. Developments of competent professionals to respond to the chemical incidents and manage such disasters are required. Second, the delay in response time in spite of the necessity of quick respond with human and material mobilization of the first responders should be improved. Third, development of an application program in connection with smart phone to fit in with the digital age to provide real-time communication system is required. The fire-fighting communication network which is viewed as the most essential factor remains to be in UHF or VHF networks or depends on the public land lines. Forth, professional and sizable terror and special incidents response team has to be established since there are higher possibility of terrorist attacks including catastrophic accidents. Fifth, an efficient program for bilateral communication system between HQ and the site to deliver information should be developed: such as an emergency standard system to send the first responders bypassing the danger zone to help prevent further contamination of personnel and equipment, and an ungraded vehicular AVL device (Automatic Vehicle Locator) linking system. Sixth, enough level A chemical suits and special equipment to analyze various chemicals should be obtained since there is a lack of chemical protective clothing and chemical detection equipment. Seventh, barriers, dedicated transportation trailer and multi-functional decontaminating system are required to prevent discharge of contaminants and to minimize the secondary fatalities. As mentioned above, it is necessary to establish the goals of the National Emergency Management Agency in being aware of change in fire-fighting ability from prompt to safe suppression, information sharing, improving equipment to ensure accurate communication and procurement and training of experts.

LNG 생산기지 내 저장탱크에 대한 Risk Matrix을 이용한 안전투자비용의 산정

고재선(Ko, Jae-Sun),김효(Kim, Hyo) 한국화재소방학회 2003 한국화재소방학회 학술대회 논문집 Vol.2003 No.추계