• Title/Summary/Keyword: System Risk Analysis

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Risk-informed approach to the safety improvement of the reactor protection system of the AGN-201K research reactor

  • Ahmed, Ibrahim;Zio, Enrico;Heo, Gyunyoung
    • Nuclear Engineering and Technology
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    • v.52 no.4
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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.

Development of Emergency Response System for Toxic Gas Facilities Using Quantitative Risk Analysis (독성가스 시설의 정량적 위험성 평가를 이용한 비상대응시스템 구축)

  • Yoo Jin Hwan;Kim Min Seop;Ko Jae Wook
    • Journal of the Korean Institute of Gas
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    • v.9 no.2 s.27
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    • pp.43-49
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    • 2005
  • Today toxic gas has various uses. If there is a release accident, the gas rapidly disperse into the atmosphere. The extent of damage due to toxic gas accident is very wide and fatal to human being. So, it is necessary for toxic gas facilities which have high risk to construct an emergency response system that prepare to toxic release and make immediate response to be possible at accident appearance. In this study accident scenario were selected and frequency analysis was executed using FTA technique. Dispersion effect of toxic gas release was analyzed using DNV company's PHAST(Ver. 6.2). Finally, an emergency response system was developed using results of quantitative risk analysis.

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A study on optimal planning of risk reduction for water suspension in water pipe system using fault tree analysis (결함트리분석을 이용한 상수관망 단수 리스크 저감 최적 방안 연구)

  • Choi, Tae Ho;Kim, A Ri;Kim, Min Cheol;Koo, Ja Yong
    • Journal of Korean Society of Water and Wastewater
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    • v.28 no.6
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    • pp.699-711
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    • 2014
  • This study was carried out to analyze water suspension in the water supply system through fault tree analysis. And quantitative factors was evaluated to minimize water suspension. Consequently the aim of this study is to build optimal planning by analyzing scenarios for water suspension. Accordingly the fault tree model makes it possible to estimate risks for water suspension, current risks is $92.23m^3/day$. The result of scenario analysis by pipe replacement, risks for water suspension was reduced $7.02m^3/day$ when replacing WD4 pipe. As a result of scenario analysis by water district connections, the amount of risk reduction is maximized when it is connecting to network pipe of D Zone. Therefore, connecting to network pipe for D Zone would be optimal to reduce risk for water suspension.

Predictors for Peer Relationships among Children and Adolescents in the Ecological System Perspective: A Multilevel Meta-Analysis (생태체계적 관점에서의 유아, 아동, 청소년의 또래관계 예측 요인: 다층메타분석)

  • Yun Hee Choi;BitNa Kim;Yeong Hee Kim
    • Human Ecology Research
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    • v.61 no.2
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    • pp.263-280
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    • 2023
  • This study examined four ecological systems, namely individual, family, school, and media environments. A series of moderator analyses were conducted to examine variations in effect size estimates across the study characteristics. The current study estimated that the effect size results were gleaned from 360 primary studies, including 90 journal articles and 270 thesis/dissertations, published between 2011 and 2022. The current meta-analysis results supported the ecological framework. That is, the impact of each ecological system on the development of positive and negative peer relationships varies depending on age groups and protective-risk factors. Specifically, for positive peer relationships, the largest effect size of the protective factor was found at the individual level for young and school- aged children, but at the school level for adolescents. Regarding the risk factors for positive peer relationships, the media was the ecological system with the strongest effect size for both young children and adolescents, while the individual-level demonstrating the strongest effect for school-aged children. Results from this meta-analysis allow us to identify some vital intervention areas in terms of healthy peer-relationship development, which should be of considerable interest to the educators and policymakers who are responsible for assessing and intervening with at-risk young children, school-aged children, and adolescents. From a practical standpoint, the current meta-analysis results are expected to contribute to developing effective prevention initiatives by targeting specific protective and risk factors for peer relationship development on the ecological system level.

Safety Management Information System in Roads Construction Work (도로 건설공사의 안전관리정보시스템 개발)

  • Park, Jong-Keun
    • Journal of the Korean Society of Safety
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    • v.27 no.2
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    • pp.72-77
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    • 2012
  • There are insufficient models that find problems and solutions for accident prevention through risk assessment and suggest safe work process and work instruction from foundation works to finish work for accident decrease. This paper presents a quantitative risk assessment model by analysis of risk factors in each process such as earth works, drainage works, pavement works, appurtenant works and etc based on accident examples and investigation on actual condition in roads construction work. In addition, the safety management system was developed to perform risk assessment of construction and use it for effective safety training for labor.

Safety Management Information System in Bridges Construction Work (교량 건설공사의 안전관리정보시스템 개발)

  • Park, Jong-Keun
    • Journal of the Korean Society of Safety
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    • v.26 no.5
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    • pp.73-80
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    • 2011
  • There are insufficient models that find problems and solutions for accident prevention through risk assessment and suggest safe work process and work instruction from foundation works to finish work for accident decrease. This paper presents a quantitative risk assessment model by analysis of risk factors in each process such as foundation, erection, pier, pier upper and etc based on accident examples and investigation on actual condition in bridges construction work. In addition, the safety management system was developed to perform risk assessment of construction and use it for effective safety training for labor.

Safety Management Information System in Plants Construction Work (플랜트 건설공사의 안전관리 정보시스템 개발)

  • Park, Jong-Keun
    • Journal of the Korea Safety Management & Science
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    • v.14 no.4
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    • pp.23-29
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    • 2012
  • There are insufficient models that find problems and solutions for accident prevention through risk assessment and suggest safe work process and work instruction from foundation works to finish work for accident decrease. This paper presents a quantitative risk assessment model by analysis of risk factors in each process such as appurtenant works, temporary works, structural works, equipment work, finishing work and etc based on accident examples and investigation on actual condition in plants construction work. In addition, the safety management system was developed to perform risk assessment of plants construction and use it for effective safety training for labor.

Exports of SMEs against Risk? Theory and Evidence from Foreign Exchange Risk Insurance Schemes in Korea

  • Lee, Seo-Young
    • Journal of Korea Trade
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    • v.23 no.5
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    • pp.87-101
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    • 2019
  • Purpose - This paper examines the effectiveness of the foreign exchange risk insurance system in the promotion of SME exports in Korea. The purpose of this study is to analyze the short-term and long-term responses of SME exports to foreign exchange risk insurance support policies. Based on these empirical studies, we would like to present some operational improvements to the operation of the foreign exchange risk insurance system. Design/methodology - In order to analyze the effect of exchange risk insurance on the exports of SMEs, a VAR model consisting of foreign exchange risk insurance underwriting values, export relative price, and domestic demand pressure, including export volume, was established. The study began with tests of the stationarity of time series data. The unit root tests showed that all concerned variables were non-stationary. Accordingly, the results of the cointegration test showed that the tested variables are not cointegrated. Finally, an impulse response function and variance decomposition analysis were conducted to analyze the impulse of foreign exchange risk insurance on exports of SMEs. Findings - As a result of estimating the VAR (1) model, foreign exchange risk insurance was found to be significant at a 1% significance level for SME' export promotion. In the impulse response analysis, SMEs' export response to the impulse of foreign exchange risk insurance showed that exports gradually increased until the third quarter, and then slowed down. However, the impulse did not disappear, and appeared continuously. Originality/value - This study analyzed the effect of foreign exchange insurance on exports of SMEs by applying the VAR model. In particular, this study is the first to analyze the short-term and long-term effects of foreign exchange risk insurance on exports of SMEs. The empirical evidence in the current study have a policy implication for the policy authority to support and promote the foreign exchange risk insurance in the effect of exchange rate volatility on Korea' export SMEs.

Alcohol Consumption and Risk of Cancer: a Systematic Literature Review

  • de Menezes, Raquel Ferreira;Bergmann, Anke;Thuler, Luiz Claudio Santos
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.9
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    • pp.4965-4972
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    • 2013
  • This study aimed to discuss the consumption of alcohol as a risk factor for major cancers. We performed a search in the PubMed database, using the following inclusion criteria: meta-analysis published in English in the last 10 years that addressed the relationship between alcohol and the risk of developing cancer. The results indicate that moderate to heavy consumption of alcohol increases the risk of developing cancer of the oral cavity and pharynx, esophagus, stomach, larynx, colorectum, central nervous system, pancreas, breast and prostate. This review did not find any association between alcohol consumption and an increased risk of cancers of the lung, bladder, endometrium and ovary. It was also observed that alcohol consumption may be inversely related to thyroid cancer. Our systematic review has confirmed consumption of alcohol as a risk factor for the development of several types of cancer.

Development of the Risk Assessment Model for Train Collision and Derailment (열차 충돌/탈선사고 위험도 평가모델 개발)

  • Choi, Don-Bum;Wang, Jong-Bae;Kwak, Sang-Log;Park, Chan-Woo;Kim, Min-Su
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.1518-1523
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    • 2008
  • Train collision and derailment are types of accident with low probability of occurrence, but they could lead to disastrous consequences including loss of lives and properties. The development of the risk assessment model has been called upon to predict and assess the risk for a long time. Nevertheless, the risk assessment model is recently introduced to the railway system in Korea. The classification of the hazardous events and causes is the commencement of the risk assessment model. In previous researches related to the classification, the hazardous events and causes were classified by centering the results. That classification was simple, but might not show the root cause of the hazardous events. This study has classified the train collision and derailment based on the relevant hazardous event including faults of the train related the accidents, and investigates the causes related to the hazardous events. For the risk assessment model, FTA (fault tree analysis) and ETA (event tree analysis) methods are introduced to assess the risk.

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