• Title/Summary/Keyword: risk-based corrective action

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Development of a Leading Performance Indicator from Operational Experience and Resilience in a Nuclear Power Plant

  • Nelson, Pamela F.;Martin-Del-Campo, Cecilia;Hallbert, Bruce;Mosleh, Ali
    • Nuclear Engineering and Technology
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    • v.48 no.1
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    • pp.114-128
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    • 2016
  • The development of operational performance indicators is of utmost importance for nuclear power plants, since they measure, track, and trend plant operation. Leading indicators are ideal for reducing the likelihood of consequential events. This paper describes the operational data analysis of the information contained in the Corrective Action Program. The methodology considers human error and organizational factors because of their large contribution to consequential events. The results include a tool developed from the data to be used for the identification, prediction, and reduction of the likelihood of significant consequential events. This tool is based on the resilience curve that was built from the plant's operational data. The stress is described by the number of unresolved condition reports. The strain is represented by the number of preventive maintenance tasks and other periodic work activities (i.e., baseline activities), as well as, closing open corrective actions assigned to different departments to resolve the condition reports (i.e., corrective action workload). Beyond the identified resilience threshold, the stress exceeds the station's ability to operate successfully and there is an increased likelihood that a consequential event will occur. A performance indicator is proposed to reduce the likelihood of consequential events at nuclear power plants.

Human Risk Assessment of a Contaminated Site Using Korean Risk-Based Corrective Action (K-RBCA) Software (한국형 소프트웨어를 이용한 유류.중금속 복합오염지역의 인체위해성평가 및 RBCA Tool Kit과의 비교분석)

  • Nam, Taek-Woo;Ryu, Hye-Rim;Kim, Young-Jin;Ko, Seok-Oh;Baek, Ki-Tae;Nam, Kyoung-Phile
    • Journal of Soil and Groundwater Environment
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    • v.16 no.1
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    • pp.32-41
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    • 2011
  • By using a newly developed Korean risk-based corrective action (K-RBCA) software (K-RBCA) and the RBCA Tool Kit, risk assessment was performed on a site that was contaminated with aromatic hydrocarbons and heavy metals. Eight chemicals including benzene, ethylbenzene, xylenes, naphthalene, benz(a) anthracene, benzo(b) fluoranthene, benzo(a) pyrene, and arsenic that exceeded the US EPA Soil Screening Level were chosen as the target pollutants. A conceptual site model was constructed based on the site-specific effective exposure pathways. According to the RBCA Tool Kit the carcinogenic risk of arsenic was larger than $10^{-6}$, which is the generally acceptable carcinogenic risk level. The K-RBCA estimated the same level of carcinogenic risk for arsenic. With the RBCA Tool Kit, the carcinogenic risk of benzo(a) pyrene was estimated to be about $1.3{\times}10^{-6}$. However, with the K-RBCA benzo(a) pyrene did not exhibit any risk. The inconsistency between the softwares was attributed to the different fundamental settings (i.e., medium division) between the two softwares. While the K-RBCA divides medium into surface soil, subsurface soil, and groundwater, the RBCA Tool Kit divides medium into only soil and groundwater. These differences lead to the different exposure pathways used by the two softwares. The K-RBCA considers the exposure pathways in surface soil and subsurface soil separately to estimate risk, however, the RBCA Tool Kit considers the surface soil and subsurface soil as one and uses the integrated exposure pathways to estimate risk. Thus the resulting risk is higher when the RBCA Tool Kit is used than when the K-RBCA is used. The results from this study show that there is no significant difference in the risks estimated by the two softwares, thus, it is reasonable to use the K-RBCA we developed in risk assessment of soil and groundwater. In addition, the present study demonstrates that the assessor should be familiar with the characteristics of a contaminated site and the assumptions used by a risk assessment software when carrying out risk assessment.

Risk Evaluation Based on the Hierarchical Time Delay Model in FMEA (FMEA에서 계층적 시간 지연 모형에 근거한 위험평가)

  • Jang, Hyeon Ae;Lee, Min Koo;Hong, Sung Hoon;Kwon, Hyuck Moo
    • Journal of Korean Society for Quality Management
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    • v.44 no.2
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    • pp.373-388
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    • 2016
  • Purpose: This paper suggests a hierarchical time delay model to evaluate failure risks in FMEA(failure modes and effects analysis). In place of the conventional RPN(risk priority number), a more reasonable and objective risk metric is proposed under hierarchical failure cause structure considering time delay between a failure mode and its causes. Methods: The structure of failure modes and their corresponding causes are analyzed together with the time gaps between occurrences of causes and failures. Assuming the severity of a failure depends on the length of the delayed time for corrective action, a severity model is developed. Using the expected severity, a risk priority metric is defined. Results: For linear and quadratic types of severity, nice forms of expected severity are derived and a meaningful metric for risk evaluation is defined. Conclusion: The suggested REM(risk evaluation metric) provides a more reasonable and objective risk measure than the conventional RPN for FMEA.

Applicability of NIOSH Lifting Equation to analysis of Workload for Patients Transferring (병원 환자 운반 업무의 작업 부하 분석에 NIOSH 들기 작업 공식의 적용 가능성)

  • Gi, Do-Hyeong
    • Journal of the Ergonomics Society of Korea
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    • v.25 no.2
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    • pp.43-50
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    • 2006
  • The purpose of this study was to investigate applicability of NIOSH lifting equation(NLE) to analysis of workload for patient transferring. In principle, the NLE is not applied to analyzing workload of patient transferring, because 1) the task is generally performed by two or more persons; 2) unlike ordinary objects, human body of patients is basically unstable load with their location of the center of mass significantly varying during lifting activity; and 3) the task is done in a restricted work space. This study was conducted through comparison of NIOSH lifting indexes(LIs) and L5/S1 compressive forces by 3DSSPP for patient transferring tasks performed by 2~6 persons. The results showed that LIs are linearly correlated with L5/S1 compressive forces with correlation coefficient of 0.92, which resulted in a significant simple linear regression equation for LIs and L5/S1 compressive forces. Consequently, it was concluded that the NLE is applicable to transferring patient only with slight modification. Based on the results, instead of 1.0 originally used by NIOSH, the LI of 1.5 was proposed as a gauge to estimate whether or not the task needs corrective action to reduce risk for developing lifting-related low back pain.

Risks and Supervisory Challenges of Financial Conglomerates in Korea (금융그룹화와 금융위험: 실증분석 및 정책과제)

  • Hahm, Joon-Ho;Kim, Joon-Kyung
    • KDI Journal of Economic Policy
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    • v.28 no.1
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    • pp.145-191
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    • 2006
  • This paper studies implications of financial conglomeration for both financial risk of individual conglomerates and systemic risk potential in post-crisis Korea. Our analyses suggest that we cannot conclude that financial conglomerates are taking on higher risks relative to non-conglomerate independent institutions. We also find that larger financial institutions show a significantly higher profitability and lower variability in profitability operating on a superior efficient frontier. However, it turns out that the consolidation has raised systemic risk potential as direct and indirect interdependencies among large banking institutions have substantially increased. Furthermore, financial conglomerates have become more vulnerable to contagion risks from non-bank sectors and capital markets. In the face of the shifting risk structure, financial supervisory and regulatory systems must be upgraded toward a more risk-based, consolidated supervision. Prompt corrective action provision for financial conglomerates must be based upon fully consolidated group risks, and effective supervisory devices need to be introduced to avoid inadvertent extension of public safety net to cross-sectoral activities of financial conglomerates. It is also critical to strengthen internal control and risk management capacities at financial conglomerates, and to establish strong market discipline by improving information transparency and monitoring incentives in the financial market.

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Risk Assessment of Groundwater and Soil in Sasang Industrial Area in Busan Metropolitan City (부산광역시 사상공단지역의 지하수 및 토양 위해성 평가)

  • Jeon, Hang-Tak;Hamm, Se-Yeong;Cheong, Jae-Yeol;Ryu, Sang-Min;Jang, Seong;Lee, Jeong-Hwan;Lee, Soo-Hyung
    • The Journal of Engineering Geology
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    • v.19 no.3
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    • pp.295-306
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    • 2009
  • The risk assessment of groundwater and soil in Sasang industrial complex in Busan Metropolitan City was carried out in order to estimate risks to human health and the environment. The carcinogenic risk (CR) of receptors to soil and air was not identified. However, the CRs for TCE and PCE were 6.7E-6 and 1.0E-5, respectively. Hazard quotient (HQ) and hazard index (HI) did not appear through air exposure pathways. Yet the HQ and HI of soil were 3.4E-5 and 5E-5, respectively, and lower than the critical value (1.0). On the contrary, HQ and HI with respect to groundwater were calculated as 0.7 (not hazardous) and 1.4 (hazardous). The constituent reduction factor (CRF) for TCE in the study area was determined as 2.5, and thus remediation work is demanded. As a result of sensitivity analysis for 18 exposure factors, eight exposure factors (life time of carcinogens, age, body weight, exposure duration, exposure frequency, dermal exposure frequency, water ingestion rate, and soil ingestion rate) varied with the variation of risk.

Psychophysical Discomfort Evaluation of Complex Trunk Postures (복합적인 몸통 자세의 심물리학적 불편도 평가)

  • Lee, In-Seok;Ryu, Hyung-Gon;Chung, Min-K.;Kee, Do-Hyung
    • Journal of Korean Institute of Industrial Engineers
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    • v.27 no.4
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    • pp.413-423
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    • 2001
  • Low back disorders (LBDs) are one of the most common and costly work-related musculoskeletal disorders. One of the major possible risk factors of LBDs is to work with static and awkward trunk postures, especially in a complex trunk posture involving flexion, twisting and lateral bending simultaneously. This study is to examine the effect of complex trunk postures on the postural stresses using a psychophysical method. Twelve healthy male students participated in an experiment, in which 29 different trunk postures were evaluated using the magnitude estimation method. The results showed that subjective discomfort significantly increased as the levels of trunk flexion, lateral bending and rotation increased. Significant interaction effects were found between rotation and lateral bending or flexion when the severe lateral bending or rotation were assumed, indicating that simultaneous occurrence of trunk flexion, lateral bending and rotation increases discomfort ratings synergistically. A postural workload evaluation scheme of trunk postures was proposed based on the angular deviation levels from the neutral position. Each trunk posture was assigned numerical stress index depending upon its discomfort rating, which was defined as the ratio of discomfort of a posture to that of its neutral posture. Four qualitative action categories for the stress index were also provided in order to enable practitioners to apply corrective actions appropriately. The proposed scheme is expected to be applied to several field areas for evaluating trunk postural stresses.

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In Situ Surfactant Flushing of Contaminated Site (계면 활성제를 이용한 In Situ 토양 세척)

  • 염익태;안규홍
    • Journal of Korea Soil Environment Society
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    • v.2 no.2
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    • pp.9-24
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    • 1997
  • Surfactant-aided in situ soil flushing has been proposed as an alternative for the expensive and time consuming 'pump and treat' technology in remediation of contaminated soil and groundwater Injected surfactants can effectively solubilize contaminants sorbed to the soil matrix or nonaqueous phase liquids(NAPLs) in residual saturation. The contaminants solubilized in groundwater are recovered and treated further. The theoretical background of the technology and the results of the field operations, mostly in the US. were summarized. In addition, the factors crucial to the successful application of the technology were discussed. Cost analyses and technical limitations in current applications were also discussed. In conclusion, it is likely that in situ surfactant flushing become a viable option for soil remediation in limited cases. Currently, further advances with respect to operation cost and to treatment efficiency are required for more extensive application of the technology. However, the current trends in soil remediation, specially the growing emphasis on risk based corrective action and natural attenuation, will increase the competitiveness of the technology. For example, removal of easily washable contaminants by short term soil flushing followed by long term monitoring and natural attenuation can greatly reduce the operation cost and time.

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How to Reflect Sustainable Development in Overseas Investment including Equator Principles (해외투자(海外投資)와 지속가능발전 원칙 - 적도원칙(赤道原則)(Equator Principles)을 중심으로 -)

  • Park, Whon-Il
    • 한국무역상무학회:학술대회논문집
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    • 2006.06a
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    • pp.45-72
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    • 2006
  • The Equator Principles are a set of voluntary environmental and social guidelines for ethical project finance. These principles commit banks and other signatories to not finance projects that fail to meet these guidelines. The principles were conceived in 2002 on an initiative of the International Finance Corporation and launched in 2003. Since then, dozens of major banks have adopted the Principles, and with these banks among them accounting for more than three quarters of all project loan market volume the Principles have become the de facto standard for all banks and investors on how to deal with potential social and environmental effects of projects to be financed. While regarding the Principles an important initiative, NGOs have criticised the Principles for not producing real changes in financing activities and for allowing projects to go through that should have been screened out by the Principles, such as the Sakhalin-II oil and gas project in Russia. In early 2006, a process of revision of the principles was begun. The Equator Principles state that endorsing banks will only provide loans directly to projects under the following circumstances: - The risk of the project is categorized in accordance with internal guidelines based upon the environmental and social screening criteria of the International Finance Corporation (IFC). - For all medium or high risk projects (Category A and B projects), sponsors complete an Environmental Assessment, the preparation of which must meet certain requirements and satisfactorily address key environmental and social issues. - The Environmental Assessment report addresses baseline environmental and social conditions, requirements under host country laws and regulations, applicable international treaties and agreements, sustainable development and use of renewable natural resources, protection of human health, cultural properties, and biodiversity, including endangered species and sensitive ecosystems, use of dangerous substances, major hazards, occupational health and safety, fire prevention and life safety, socio-economic impacts, land acquisition and land use, involuntary resettlement, impacts on indigenous peoples and communities, cumulative impacts of existing projects, the proposed project, and anticipated future projects, participation of affected parties in the design, review and implementation of the project, consideration of feasible environmentally and socially preferable alternatives, efficient production, delivery and use of energy, pollution prevention and waste minimization, pollution controls (liquid effluents and air emissions) and solid and chemical waste management. - Based on the Environmental Assessment, Equator banks then make agreements with their clients on how they mitigate, monitor and manage those risks through an 'Environmental Management Plan'. Compliance with the plan is required in the covenant. If the borrower doesn't comply with the agreed terms, the bank will take corrective action, which if unsuccessful, could ultimately result in the bank canceling the loan and demanding immediate repayment. - For risky projects, the borrower consults with stakeholders (NGO's and project affected groups) and provides them with information on the risks of the project. - If necessary, an expert is consulted. The Principles only apply to projects over 50 million US dollars, which, according to the Equator Principles website, represent 97% of the total market. In early 2006, the financial institutions behind the Principles launched stakeholder consultations and negotiations aimed at revising the principles. The draft revised principles were met with criticism from NGO stakeholders, who in a joint position paper argued that the draft fails by ignoring the most serious critiques of the principles: a lack of consistent and rigorous implementation.

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