• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 추계학술발표회논문집(1)
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• pp.713-718
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• 1997

In the TMI-2 accident, approximately twenty(20) tons of molten core material drained into the lower plenum. Early advanced light water reactor (LWR) designs assumed a lower head failure and incorporated various measures for ex-vessel accident mitigation. However, one of the major findings from the TMI-2 Vessel Investigation Project was that one part of the reactor lower head wall estimated to have attained a temperature of 1100$^{\circ}C$ for about 30 minutes has seemingly experienced a comparatively rapid cooldown with no major threat to the vessel integrity. In this regard, recent empirical and analytical studies have shifted interests to such in-vessel retention designs or strategies as reactor cavity flooding, in-vessel flooding and engineered gap cooling of the vessel Accurate thermohydrodynamic and creep deformation modeling and rupture prediction are the key to the success in developing practically useful in-vessel accident/risk management strategies. As an advanced in-vessel design concept, this work presents the COrium Attack Syndrome Immunization Structures (COASIS) that are being developed as prospective in-vessel retention devices for a next-generation LWR in concert with existing ex-vessel management measures. Both the engineered gap structures in-vessel (COASISI) and ex-vessel (COASISO) are demonstrated to maintain effective heat transfer geometry during molten core debris attack when applied to the Korean Standard Nuclear Power Plant(KSNPP) reactor. The likelihood of lower head creep rupture during a severe accident is found to be significantly suppressed by the COASIS options.

• 한국해안해양공학회지
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• 제14권1호
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• pp.1-7
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• 2002

과거, 울진원전 부지의 지진해일에 대한 안전성 평가는 가상최대 지진규모와 그에 상응하는 단층 파라미터를 이용하여 수행되었으나. 최근 지진공백역 이론에 근거하여, 과거 평가 규모 이상의 지진발생 가능성이 지진학자들에 의하여 제기되고 있다. 본 연구에서는 선형·비선형천수방정식 기반의 유한차분법을 이용하여 지진해일 안전성을 재평가하였다. 먼저, '83년 지진해일을 모의하고 이를 동해안 임원항의 최고 범람 수위와 비교하였다. 다음으로 '83년, '93년 지진해일과 위험 단층으로 분류되고 있는 5개 지진공백역 단층에 대하여 울진원전부지 도수로에서의 수위 상승과 저하를 계산하여, 울진원전이 평가대상 단층으로 의한 지진해일 발생시에도 필요 냉각수의 취수가 가능함을 보였다.

• Earthquakes and Structures
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• 제24권4호
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• pp.275-288
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• 2023

Based on the crucial role of high-speed railway bridges (HSRBs) in the safety of high-speed railway operations, it is an important approach to mitigate earthquake hazards by proceeding with seismic risk assessments in their whole life. Bridge seismic risk assessment, which usually evaluates the seismic performance of bridges from a probabilistic perspective, provides technical support for bridge risk management. The seismic performance of bridges is greatly affected by the degradation of material properties, therefore, material damage plays a nonnegligible role in the seismic risk assessment of the bridge. The effect of material damage is not considered in most current studies on seismic risk analysis of bridges, nevertheless. To fill the gap in this area, in this paper, a nonlinear dynamic time-history analysis has been carried out by establishing OpenSees finite element model, and a seismic vulnerability analysis is carried out based on the incremental dynamic analysis (IDA) method. On this basis, combined with the site risk analysis, the time-dependent seismic risk analysis of an offshore three-span HSRB in the whole life cycle has been conducted. The results showed that the seismic risk probabilities of both components and system of the bridge increase with the service time, and their seismic risk probabilities increase significantly in the last service period due to the degradation of the material strength, which demonstrates that the impact of durability damage should be considered when evaluating the seismic performance of bridges in the design and service period.

• KDI Journal of Economic Policy
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• 제46권1호
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• pp.21-51
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• 2024

Since the Global Financial Crisis of 2008-2009, the importance of nonbank financial institutions in macroprudential management has increased significantly. Consequently, major countries and international financial institutions have been actively discussing and implementing macroprudential supervision and regulation for non-bank financial institutions (NBFI). In this context, this paper analyzes the systemic risk of both banks and non-bank sectors (securities firms and insurance companies) in South Korea over different time periods. Using the widely recognized ΔCoVaR methodology for measuring systemic risk, the analysis reveals that systemic risk increased substantially across all three sectors (banks, securities firms, and insurance companies) during the Global Financial Crisis, the European Sovereign Debt Crisis, and the COVID-19 pandemic. Although the banking sector exhibited relatively high systemic risk compared to the securities and insurance sectors, the relative differences in systemic risk varied across the different crisis periods. Notably, during the margin call crisis in March of 2020, the gap in systemic risk between the banking and securities sectors decreased significantly compared to that during both the Global Financial Crisis and the European Sovereign Debt Crisis, indicating that securities firms had a more substantial impact on risk in the overall financial system during this period. Furthermore, I analyze the impact of the issuance of equity-linked securities (ELS) by financial institutions on systemic risk, as measured by ΔCoVaR, finding that an increase in the outstanding balance of ELS issuance by financial institutions had an impact on increasing ΔCoVaR during the three crisis periods. These findings underscore the growing importance of non-bank financial institutions in relation to South Korea's macroprudential management and supervision. To address this evolving landscape, enhanced monitoring and regulatory measures focusing on non-bank systemic risk are essential components of maintaining financial stability in the country.

• 한국건설순환자원학회논문집
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• 제11권1호
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• pp.79-88
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• 2023

본 연구에서는 철근 부식에 의한 콘크리트 단면의 구조적 거동을 정량화하기 위해 철근 표면에 형성되는 녹을 모델링했으며, 변수로는 철근과 콘크리트 사이의 계면 공극, 피복두께, 철근 직경을 취했다. 철근 부식시 구조적 한계에 가장 큰 영향을 미치는 인자는 계면의 공극크기였으며, 철근 직경, 피복두께 순으로 나타났다. 피복두께 75 mm, 철근직경 20 mm의 콘크리트 단면에서 계면의 공극이 1 ㎛에서 10 ㎛로 증가되면, 균열을 유발시키는 철근 부식량은 16.95 ㎛에서 27.69 ㎛로 크게 증가 되었다. 또한 철근 표면에 형성된 녹이 계면의 공극을 다 채우기 전까지 콘크리트 단면에는 손상이 발생되지 않았으며, 계면공극 범위를 넘어서는 양의 녹이 철근 표면에 형성된 후 콘크리트 단면은 항복, 균열 및 파단 상태에 이르렀다.

• 무역상무연구
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• 제37권
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• pp.187-216
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• 2008

Risk regarding the possibility of loss can be especially problematic. If a loss is certain to occur, it may be planned for in advance and treated as a definite, known expense. It is when there is uncertainty about the occurrence of a loss that risk becomes an important problem. The word risk is often used in connection with insurance. No one generally accepted definition of risk exists, however. Of the many definitions, two distinctive ones are commonly used. One defines risk as the variation in possible outcomes of an event based on chance. That is, the greater the number of different outcomes that may occur, the greater the risk. Another way of expressing this concept is to state: The greater the variation around an average expected loss, the greater the risk. The second definition of risk is the uncertainty concerning a possible loss. The definition of risk as a useful one because it focuses attention on the degree of risk in given situations. The degree of risk is a measure of the accuracy with which the outcome of an event based on chance can be predicted. For now, it will serve our purpose to note the more accurate the prediction of the outcome of an event based on chance, the lower the degree of risk. After sources of risks are identified and measured, a decision can be made as to how the risk should be handled. A pure risk that is not identified does not disappear, the business merely loses the opportunity to consciously decide on the best technique for dealing with that risk. The process used to systematically manage risk exposures is known as risk management. Some persons use the term risk management only in connection with businesses, and often the term refers only to the management of pure risks. In this sense, the traditional risk management goal has been to minimize the cost of pure risk to the company. But as firms broaden the ways that they view and manage many different types of risk, the need for new terminology has become apparent. The terms integrated risk management and enterprise risk management reflect the intent to manage all forms of risk, regardless of type. International trade transaction is called between countries has features of globalism, cultural gap, long distance and long terms for the transaction. It is riskier than domestic transaction has its specific risks, such as foreign exchange risk and political risk, and requires various active risk management skills. Risks in relation to the international trade transaction are the contract risk, transit risk and payment risk, etc. The risk management in relation to the international trade transaction is to identify and measure these risks. The purpose of this study is to analyse the practical problems and its solution plan by analyzing various cases related to the risk management of bill of lading in the international trade transaction.

• Safety and Health at Work
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• 제4권2호
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• pp.87-94
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• 2013

Background: In times of continuous change and volatile markets, organizations are increasingly characterized by downsizing, work intensification, and resource rationalization. This has resulted in diversification, and the emergence of newrisks within the field of occupational health and safety, with an important impact. This paper focuses on one such type of risk in the modern workplace-psychosocial risks. The current study aimed to explore stakeholder perspectives, regarding the extent to which psychosocial risks are incorporated into strategic risk management practices, at both the business and policy level. Methods: Semi-structured interviews were conducted with 14 professionals, representing employer, expert, policy maker, and trade union stakeholder perspectives. Results: It was found that the majority of organizations do not sufficiently, if at all, understand and incorporate psychosocial risks into strategic decision making, whereby the key barrier related to practical difficulties of not knowing how to manage psychosocial risks adequately. Conclusion: The study found that there is a need to close the gap between policy and practice on a number of levels. Future recommendations comprise a policy framework and infrastructure underpinned by educational initiatives, partnerships, and networks to drive a shift in attitudes toward recognizing the duality of the concept of risk (including both potential negative and positive outcomes) and moving beyond simple regulatory compliance.

• Safety and Health at Work
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• 제12권2호
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• pp.261-267
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• 2021

Background: The series of serious industrial accidents in recent years at contractors to large companies has highlighted risk outsourcing as a real and urgent problem. This study aims to review the difference in the degree of risk exposure and the occurrence of industrial accidents depending on the type of company relations. Among in-house contractors, the focus will be on those handling hazardous chemicals that include companies for which outsourcing requires approval. Methods: This study uses the 9th wave of the Industrial Safety and Health Survey (2018). For determining the degree of risk exposure, the occurrence of industrial accidents, and industrial accident rate, multivariate, logistic, and fractional logit, regression analyses were used, respectively. Results: First, In-house contractors' degree of risk exposure is higher than that of the client companies. In particular, this gap is even greater for companies dealing with chemicals. Second, among only those that handle hazardous chemicals, in-house contractors do show a significantly higher rate of industrial accident occurrence. Third, In-house contractors have a significantly higher rate of industrial accidents from diseases than client companies. Conclusion: The analysis supports the intent of the legal amendment that strengthens the protection of in-house contracted workers who handle hazardous chemicals. Second, the results of this study suggest that safety and health management must go beyond legal compliance and ensure that it has substance and effectiveness. Last, there should be policy consideration is necessary to reduce attempts to hide industrial accidents.

• 한국건설관리학회논문집
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• 제15권3호
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• pp.66-73
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• 2014

2008년 세계경제 금융위기 발생 이후 건설 수주물량이 감소되었고, 건설사업관리 (Construction Management) 업체들의 무리한 저가 수주로 인해 업체 경쟁력은 저하되었다. 이로 인해 CM기업들은 리스크 관리 대처능력 저하 등 여러 가지 문제점들이 발생되었다. 시공학적인 측면에서는 리스크 관리에 대한 연구는 지속되고 있지만 CM분야에 대한 리스크 연구는 매우 드물다. 따라서 본 연구는 국내 CM기업들의 리스크 관리 실태를 조사하여 문제점들을 분석하였으며 분석된 문제점들에 대한 효율적 관리를 위한 리스크 인자 도출 방안 및 리스크 관리 시스템 개발방안에 대한 방향을 제시하였다. 또한 본 연구에서 제안에 대한 실무자들의 설문을 통해 개발방안에 대한 효율성을 검증하였다.

• 한국건축시공학회지
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• 제10권2호
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• pp.133-138
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• 2010

건축 프로젝트에서 개산견적은 많은 부분들이 확정되지 않은 상태에서 수행되기 때문에 개산견적으로 산출된 공사비와 실제 시공 공사비는 차이가 발생할 수밖에 없다. 이러한 공사비의 차이를 신뢰할 수 있는 수준 이하로 관리할 필요가 있다. 따라서 본 연구에서는 건축 프로젝트 초기단계에서 실시하는 개산견적의 신뢰도를 관리할 수 있는 체계적인 프로세스를 구축하는 것을 목적으로 한다. 본 연구를 수행하기 위하여 개산견적 전문가와 면담조사를 실시하였으며, 리스크 관리 프로세스에 대한 고찰도 실시하였다. 연구결과 개산견적 신뢰도 관리를 위해서는 기존의 개산견적 프로세스에 신뢰도를 평가와 향상 방안 도출 과정이 필요하며, 유사 프로젝트를 토대로 신뢰도 관리 전략 수립 과정이 필요하다. 이러한 과정을 통해서 개산견적의 신뢰도를 당초에 설정된 허용가능한 수준 이하로 관리하여 프로젝트 공사비에 대한 리스크를 감소시켜 프로젝트를 성공적으로 수행할 수 있게 도움을 줄 수있다.