• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2001년도 춘계학술발표회요약집
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• pp.474.2-474
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• 2001

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 요약집 춘계학술발표대회
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• pp.460.2-460.2
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• 2004

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 춘계학술발표회
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• pp.1168-1169
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• 2005

• Journal of Advanced Research in Ocean Engineering
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• 제1권4호
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• pp.211-226
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• 2015

Membrane type Mark III cargo containment system (CCS) is considered in this study to investigate its strength capability under applied loads due to liquefied natural gas (LNG) cargo. A rectangular plated structure supported by inner hull structure is exemplified from Mark III CCS according to classification society's guidance and it is assumed as multi-layered structure by stacking plywood, triplex, reinforced polyurethane (PU) foam and series of mastic upon inner hull structure. Commercially available general purpose finite element analysis package is used to have reliable FE models of Mark III CCS plate. The FE models and anisotropic failure criteria such as maximum stress, Hoffman, Hill, Tsai-Wu and Hashin taking into account the direction dependent material properties of Mark III CCS plate components and their material properties considering a wide variation of temperature due to the nature of LNG together form the strength analysis procedure of Mark III CCS plate. Strength capability of Mark III CCS plate is understood by its initial failure and post-initial failure states. Results are represented in terms of failure loads and locations when initial failure and post-initial failures are occurred respectively. From the results the basic design information of Mark III CCS plate is given.

• 에너지공학
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• 제24권3호
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• pp.96-108
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• 2015

피동원자로건물냉각계통(Passive Containment Cooling System; PCCS)은 전원 공급 없이도 원자로건물 내부의 열을 제거하여 그 건전성을 유지시키기 위한 안전설비이다. 본 연구에서는 현재 연구중인 PCCS를 1400 MWe 가압경수형 원전(APR1400)에 설치하는 경우 PCCS 성능을 분석하였다. 분석도구로 계통열수력분석코드 MARS-KS1.3을 사용하였다. PCCS의 성능분석을 위해 APR 1400 표준안전성분석 보고서를 참고하여 원자로건물 내부의 최대압력을 유발하는 사고 시나리오인 저온관 양단 파단사고를 모의하였다. 이 계산에서는 PCCS, 원자로냉각계통 및 원자로건물의 열수력을 동시에 모의하였다. 계산결과를 통해 기존의 원자로건물 살수계통을 대체하여 PCCS가 원자로건물의 건전성을 유지시킬 수 있음을 확인하였다. 또한 PCCS의 성능에 영향을 줄 수 있는 여러 인자를 변경해가며 민감도 분석을 수행하였고 PCCS의 문제점도 확인하였다.

• Computers and Concrete
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• 제3권1호
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• pp.1-15
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• 2006

The seismic safety of reinforced concrete containment building can be evaluated by probabilistic analysis considering randomness of earthquake, which is more rational than deterministic analysis. In the safety assessment of earthquake-resistant structures by the deterministic theory, it is not easy to consider the effects of random variables but the reliability theory and random vibration theory are useful to assess the seismic safety with considering random effects. The reliability assessment of reinforced concrete containment building subjected to earthquake load includes the structural analysis considering random variables such as load, resistance and analysis method, the definition of limit states and the reliability analysis. The reliability analysis procedure requires much time and labor and also needs to get the high confidence in results. In this study, random vibration analysis of containment building is performed with random variables as earthquake load, concrete compressive strength, modal damping ratio. The seismic responses of critical elements of structure are approximated at the most probable failure point by the response surface method. The response surface method helps to figure out the quantitative characteristics of structural response variability. And the limit state is defined as the failure surface of concrete under multi-axial stress, finally the limit state probability of failure can be obtained simply by first-order second moment method. The reliability analysis for the multiaxial strength limit state and the uniaxial strength limit state is performed and the results are compared with each other. This study concludes that the multiaxial failure criterion is a likely limit state to predict concrete failure strength under combined state of stresses and the reliability analysis results are compatible with the fact that the maximum compressive strength of concrete under biaxial compression state increases.

• 한국전산구조공학회논문집
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• 제18권4호통권70호
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• pp.335-345
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• 2005

이 논문에서는 프리스트레스트 콘크리트 구조로 건설된 원자로 격납건물의 극한내압평가를 위해 비선형 유한요소해석을 수행하였다. 특히, 상용프로그램 사용 시 콘크리트와 긴장재의 완전부착 가정으로 인해 고려할 수 없었던 콘크리트와 긴장재 사이의 슬립효과를 모사할 수 있는 알고리즘을 개발하였다. 부착된 긴장재의 경우 부착-슬립효과를 기초로 유도된 겉보기 항복응력으로 두 재료의 상호거동을 모사할 수 있고, 비부착된 긴장재의 경우 반복해석에 의해 긴장재 전체 길이방향으로의 슬립효과를 모사할 수 있다. 개발된 알고리즘을 이용하여 도출된 긴장재의 응력-변형률 관계를 이용하여 격납건물의 축소모델에 대한 비선형 해석을 수행하였고, 수행한 결과를 바탕으로 격납건물의 극한내압은 가압중수로형과 가압경수로형 모두 설계압력의 약 3배 이상 구조적 여유가 있음을 확인하였다.

• 한국지진공학회논문집
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• 제23권6호
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• pp.301-309
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• 2019

A methodology to assess seismic fragility of a nuclear power plant (NPP) using a conditional mean spectrum is proposed as an alternative to using a uniform hazard response spectrum. Rather than the single-scenario conditional mean spectrum, which is the conventional conditional mean spectrum based on a single scenario, a multi-scenario conditional mean spectrum is proposed for the case in which no single scenario is dominant. The multi-scenario conditional mean spectrum is defined as the weighted average of different conditional mean spectra, each one of which corresponds to an individual scenario. The weighting factors for scenarios are obtained from a deaggregation of seismic hazards. As a validation example, a seismic fragility assessment of an NPP containment structure is performed using a uniform hazard response spectrum and different single-scenario conditional mean spectra and multi-scenario conditional mean spectra. In the example, the number of scenarios primarily influences the median capacity of the evaluated structure. Meanwhile, the control frequency, a key parameter of a conditional mean spectrum, plays an important role in reducing logarithmic standard deviation of the corresponding fragility curves and corresponding high confidence of low probability of failure (HCLPF) capacity.

• Nuclear Engineering and Technology
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• 제54권1호
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• pp.386-400
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• 2022

Seismic fragility analysis, a part of seismic probabilistic risk assessment (SPRA), is commonly used to establish the relationship between a representative property of earthquakes and the failure probability of a structure, component, or system. Current guidelines on the SPRA of nuclear power plants (NPPs) used worldwide mainly reflect the earthquake characteristics of the western United States. However, different earthquake characteristics may have a significant impact on the seismic fragility of a structure. Given the concern, this study aimed to investigate the effects of earthquake characteristics on the seismic fragility of concrete containments housing the OPR-1000 reactor. Earthquake time histories were created from 30 ground motions (including those of the 2016 Gyeongju earthquake) by spectral matching to the site-specific response spectrum of Hanbit nuclear power plants in South Korea. Fragility curves of the containment structure were determined under the linear response history analysis using a lumped-mass stick model and 30 ground motions, and were compared in terms of earthquake characteristics. The results showed that the median capacity and high confidence of low probability of failure (HCLPF) tended to highly depend on the sustained maximum acceleration (SMA), and increase when using the time histories which have lower SMA compared with the others.

• 한국전산구조공학회논문집
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• 제28권5호
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• pp.535-542
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• 2015

원자로 격납건물은 냉각재상실사고와 같이 내부의 과도한 압력이 유발되는 사고에 있어서도 방사성 물질이 외부로 누출되지 않도록 막는 최종의 방벽이다. 이러한 격납건물의 기능적 중요성에 기인하여, 건설 초기 구조건전성시험(SIT)을 수행한다. 이러한 SIT거동을 가장 실제와 가깝게 예측하기 위한 해석 연구를 수행하였다. 해당 연구의 결과는 2편의 논문으로 정리되었는데, 본 논문은 그 중 II편으로 I편의 해석모델 구성 시의 주요 고려사항의 분석 및 예비해석 결과를 반영한 상세 해석 모델의 구성 과정 및 해석 결과를 제시하고 있다. 특히 비부착식 텐던으로 시공된 구조물에서 덕트관에 의한 강성 저감효과 및 덕트관을 사이에 둔 텐던과 콘크리트간의 밀착 여부에 따른 영향을 해석 시 최대한 고려하고자 하였다. 이러한 과정을 통해 구축된 해석 모델에 따른 변위과 신고리 3호기 SIT 측정변위를 비교한 결과, ASME CC-6000 기준을 충분히 만족시키는 결과가 나타남을 확인하였다.