• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.3 s.49
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• pp.13-20
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• 2006

Substations in electric power transmission network systems (EPTS) operate using several transformers in parallel to increase the efficiency in terms of stability of energy supply. We present a seismic reliability assessment method of EPTS considering the parallel operation of transformers. Two methods for damage state model are compared in this paper: bi-state and multi-damage model. Simulation results showed that both models yielded similar network reliability indices and the reliability indices of the demand nodes using hi-state model exhibited higher damage probability. Particularly, the corresponding EENS (Expected Energy Not Supplied) index was significantly larger than that of the multi-damage state.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.2
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• pp.233-238
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• 2011

In piping design of nuclear power plant facilities, the load stress according to self-weight is important for design values in test run(shutdown and starting). But sometimes it needs more studies, such as seismic analysis of an earthquake of power plant area and fatigue life and stress of thermal expansion and anchor displacement in operating run. In this paper, seismic evaluations were performed to nuclear piping system of Shin-Kori NO. 3&4 being built in Pusan lately. Results of seismic analysis are evaluated on basis of KEPIC MN code. The structural integrity on RCB piping system was proved.

• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.6
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• pp.283-291
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• 2023

Unlike other facilities, maintaining processes is essential in industrial facilities. Pipe racks, which support pipes of various diameters, are important structures used in industrial facilities. Since the transport process of pipes directly affects the operation of industrial facilities, a fragility curve should be derived based on considering not only the pipe racks' structural safety but also the pipes' transport process. There are several studies where the fragility curves have been determined based on the structural behavior of pipe racks. However, few studies consider the damage criteria of pipes to ensure the transportation process, such as local buckling and tensile failure with surface defects. In this study, an analysis model of a typical straight pipe rack used in domestic industrial facilities is constructed, and incremental dynamic analysis using nonlinear response history analysis is performed to estimate the parameters of the fragility curve by the maximum likelihood estimation. In addition, the pipe rack's structural behavior and the pipe's damage criteria are considered the limit state for the fragility curve. The limit states considered in this paper to evaluate fragility curves are more reasonable to ensure the transportation process of the pipe systems.

• Journal of the Korean Institute of Gas
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• v.13 no.1
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• pp.40-44
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• 2009

This is a comparative structural analysis for a steel roof LNG storage tank that has some advantages relatively in designing larger scale tanks and construction cost, etc. compared with a conventional concrete roof LNG storage tank as the capacity of LNG storage tanks is bigger. Structural analysis was performed on a 200,000$k{\ell}$ steel roof LNG storage tank and a concrete of the same capacity in condition of three critical load combination cases, a normal operation, a LNG spillage and seismic case by using finite element method. And comparative structural safety evaluation was carried out by using strength ratio in places of concrete wall, foundation and roof with a quantitative method.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.13-16
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• 2005

원자력발전소의 안전과 관련된 기기는 원전의 정상상태 운전조건뿐만 아니라 원전의 설계기준사고 조건에서도 기기의 안전관련 기능을 충분하게 수행할 수 있음이 입증되어야만 한다. 아울러 기기의 설치 환경은 원전의 설계기준사고조건(DBE))으로서 지진만이 고려되는 온화한 환경(mild zone)과 냉각재상실사고(LOCA) 주증기관파단사고(MSLB) 등과 같이 고온, 고압 등의 환경요건이 급격히 변화하는 가혹한 환경(harsh zone)으로 구별되므로 안전관련 기기의 검증 또한 이러한 환경요건에 따라 수행되어져야 한다. 본 연구에서는 당사가 개발한 가혹환경용 안전관련 고압전동기의 개발사례를 중심으로 가혹환경요건에 대한 기기의 검증절차와 방법을 제시하였다.