• Nuclear Engineering and Technology
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• 제50권8호
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• pp.1372-1386
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• 2018

Despite recent advances in multi-hazard analysis, the complexity and inherent nature of such problems make quantification of the landslide effect in a probabilistic safety assessment (PSA) of NPPs challenging. Therefore, in this paper, a practical approach was presented for performing an earthquake-induced landslide PSA for NPPs subject to seismic hazard. To demonstrate the effectiveness of the proposed approach, it was applied to Korean typical NPP in Korea as a numerical example. The assessment result revealed the quantitative probabilistic effects of peripheral slope failure and subsequent run-out effect on the risk of core damage frequency (CDF) of a NPP during the earthquake event. Parametric studies were conducted to demonstrate how parameters for slope, and physical relation between the slope and NPP, changed the CDF risk of the NPP. Finally, based on these results, the effective strategies were suggested to mitigate the CDF risk to the NPP resulting from the vulnerabilities inherent in adjacent slopes. The proposed approach can be expected to provide an effective framework for performing the earthquake-induced landslide PSA and decision support to increase NPP safety.

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1814-1820
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• 2023

Safety classification of systems, structures, and components (SSC) is an essential activity for nuclear reactor design and operation. The current regulatory trend is to require risk-informed safety classification that considers first, the severity, but also the frequency of SSC failures. While safety classification for nuclear power plants is covered in many regulatory and scientific publications, research reactors received less attention. Research reactors are typically of lower power but, at the same time, are less standardized i.e., have more variability in the design, operational modes, and operating conditions. This makes them more challenging when considering safety classification. This work presents the Integrated Risk-Informed Safety Classification (IRISC) procedure which is a novel extension of the IAEA recommended process with dedicated probabilistic treatment of research reactor designs. The article provides the details of probabilistic analysis performed within safety classification process to a degree that is often missing in most literature on the topic. The article presents insight from the implementation of the procedure in the safety classification for the MARIA Research Reactor operated by the National Center for Nuclear Research in Poland.

• 한국방재학회 논문집
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• 제9권2호
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• pp.45-51
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• 2009

지구기후모델을 이용하여 예측된 (1) 물성치와 (2) 현재 및 미래의 표면 에너지 입력상수의 가변성을 고려한 동결 및 융해깊이를 예측하기 위하여 확률론적 접근법이 도입되었다. 확률론적 접근법을 예시하기 위하여 극지방에서의 융해깊이 예측을 고려해보았다. 특히 확률론적 융해깊이 예측을 위하여 몬테카를로 시뮬레이션과 함께 Stefan 공식이 사용되었다. 시뮬레이션 결과는 물성치의 가변성을 보여주었다. 표면 에너지 입력상수와 온도 데이터는 융해깊이를 예측하는데 상당한 불확실성을 야기시킬 수 있다.

• 한국식품위생안전성학회지
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• 제33권3호
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• pp.157-161
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• 2018

본 연구에서는 육제품의 다양한 조건(포장, 저장온도, 염농도, 아질산염농도)에서의 식중독세균의 생장을 예측하는소프트웨어를 예측미생물학에 대한 지식이 부족한 비전문가도 손쉽게 이용할 수 있도록 개발하였다. 육제품에서의 식중독세균예측소프트웨어(FAME: Foodborne bacteria Animal product Modeling Equipment)는 Javascript와 HTML을 이용하여 개발하였으며, 육제품에 대한 카이네틱모델과 확률모델을 포함하고있다. FAME에서는 검증(validation) 기능을 포함하고 있으며, FAME에 탑재 되어있는 예측모델의 수식을 자유롭게 수정할 수 있도록 고안 하였다. FAME에는 포장조건, 온도, 염농도, 아질산염농도 조합에 따라 실험한 데이터를 카이네틱모델(5,400 데이터)과 확률모델(345,600 데이터)에 탑재하였다. 사용자가 FAME을 이용하여 육제품의 제조 조건을 소프트웨어에 입력하면, 시간에 따른 식중독세균의 생장패턴과 생장확률이 즉시 계산 되어진다. 따라서 예측 미생물학에 대한 전문 지식이 없는 비전문가라고 하더라도 FAME을 이용하여 직접 실험을 하지 않고도 육제품에서의 식중독세균의 생장을 쉽고 빠르게 예측할 수 있어, 육가공분야에서 매우 유용하게 사용되어 질 수 있을 것으로 판단된다.

• Nuclear Engineering and Technology
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• 제52권4호
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• pp.764-775
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• 2020

Periodic safety reviews (PSRs) are conducted on operating nuclear power plants (NPPs) and have been mandated also for research reactors in Korea, in response to the Fukushima accident. One safety review tool, the probabilistic safety assessment (PSA), aims to identify weaknesses in the design and operation of the research reactor, and to evaluate and compare possible safety improvements. However, the PSA for research reactors is difficult due to scarce data availability. An important element in the analysis of research reactors is the reactor protection system (RPS), with its functionality and importance. In this view, we consider that of the AGN-201K, a zero-power reactor without forced decay heat removal systems, to demonstrate a risk-informed safety improvement study. By incorporating risk- and safety-significance importance measures, and sensitivity and uncertainty analyses, the proposed method identifies critical components in the RPS reliability model, systematically proposes potential safety improvements and ranks them to assist in the decision-making process.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1155-1162
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• 2004

This research proposes a new risk analysis method in order to guarantee successful performance of construction projects. The proposed risk analysis methods consists of four phases. First step, AHP model can help contractors decide whether or not they bid for a project by analysing risks involved in the project. Second step, the influence diagraming, decision tree and Monte Carlo simulation are used as tools to analyze and evaluate project risks quantitatively. Third step, Monte Carlo simulation is used to assess risk for groups of activities with probabilistic branching and calendars. Finally, Fuzzy theory suggests a risk management method for construction projects, which is using subjective knowledge of an expert and linguistic value, to analyze and quantify risk. The result of study is expected to improve the accuracy of risk analysis because three factors, such as probability, impact and exposure, for estimating membership function are introduced to quantify each risk factor. Consequently, it will help contractors identify risk elements in their projects and quantify the impact of risk on project time and cost.

• 전기전자학회논문지
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• 제14권3호
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• pp.236-243
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• 2010

전력품질 문제는 다양한 산업분야에서 중요한 역할을 차지한다. 전력품질솔루션 선택의 폭은 점점 다양해지고 있으며, 특히 순간전압강하와 정전에 대한 보상장치를 선정하는 것은 전력회사나 수용가 모두에게 중요한 과제이다. 이것은 기술적인 관점에서 뿐만 아니라 경제적인 관점에서도 같이 고려되어야 하는데 불행히도 지금까지는 주로 경험에 의해 결정되어졌다. 본 논문에서는 순간전압강하 보상장치 선정을 위한 위험도 분석을 확정적 방법과 확률론적 방법으로 수명비용을 계산하여 두 가지 방법의 결과 해석에 대한 차이점을 모의사례를 통하여 비교하고자한다.

• 지질공학
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• 제32권3호
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• pp.327-338
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• 2022

산사태 발생지역에서 측정된 토층심도 자료를 토대로 경험적 내지 통계적으로 토층심도를 예측하기 위하여 지형고도 기반의 Z-model과 확률론적 통계모델을 활용하여 산사태 발생구간에 대한 토층심도를 산정하고, 이를 토대로 강우사상에 따라 토층 내로 강우의 침투특성을 반영하여 분석할 수 있는 토층에 대한 포화깊이비 개념을 접목하여 산사태위험도 분석을 수행하였다. 그 결과, Z-model로 예측된 토층심도가 확률론적 통계모델로 산정된 결과보다는 본 연구지역에서 측정된 토층심도와 비교적 유사하게 산정된 것으로 나타났다. 이를 토대로 산사태 발생지역에 대해 확률론적 통계모델로 예측된 토층심도를 적용해 분석한 결과가 Z-model로 산정된 결과보다 산사태위험도 1등급 분포 비율이 2.5배 이상 높게 나타났다. 이는 토층심도가 직접적으로 산사태위험도 평가에 영향을 주는 것을 의미하는 것으로 산사태위험도 분석을 위해서는 대상지역의 토층심도 자료의 획득 및 적용이 중요함을 의미한다.

• 한국도로학회논문집
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• 제14권5호
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• pp.123-132
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• 2012

PURPOSES: This study is to investigate the consideration which relates with a disaster from route alignment process and proposed the method it will be able to evaluate a disaster danger fixed quantity. METHODS: Use the landslide disaster probabilistic map of GIS based and in about landslide occurrence of the route alignment at the time of neighboring area after evaluating a risk fixed quantity, it compared LCC expense in about each alternative route. It developed the system it will be able to analyze a LCC and a disaster risk in about the alternative route. In order to verify a risk analytical algorithm and the system which are developed it selected national road 59 lines on the demonstrative route and it analyzed a disaster risk. RESULTS: Demonstrative route not only the disaster risk to be it will be able to compare a disaster risk fixed quantity like the economical efficiency degree in compliance with LCC expense productions it compared and there being the designer will be able to decide the alternative route, it confirmed. CONCLUSIONS: Roads can be designed by considering occurs repeatedly landslides and debris flow caused by disasters in advance and expect to be able to effect that can reduce the overall cost to recover losses caused by the disaster, and temporally loss is expected.

• Earthquakes and Structures
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• 제20권4호
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• pp.445-455
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• 2021

Lake Van Basin, located in Eastern Turkey, is worth examining in terms of seismicity due to large-scale losses of property and life during the historical and instrumental period. The most important and largest province in this basin is Van. Recent indicators of the high seismicity risk in the province are damage occurring after devastating earthquakes in 2011 (Mw=7.2 and Mw=5.6) and lastly in 2020 Khoy (Mw=5.9). The seismic hazard analysis for Van and its districts in Eastern Turkey was performed in probabilistic manner. Analyses were made for thirteen different districts in Van. In this study, information is given about the tectonic setting and seismicity of Van. The probabilistic seismic hazard curves were obtained for a probability of exceedance of 2%, 10% and 50% in 50-year periods. The PGA values in the Van province vary from 0.24 g - 0.43 g for earthquakes with repetition period of 475 years. Risk priorities were determined for all districts. The highest risk was calculated for Çaldıran and the lowest risk was found for Gürpınar. Risk priorities for buildings in all districts were also determined via rapid seismic assessment for reinforced-concrete and masonry buildings in this study.