• Title/Summary/Keyword: Performance-based regulatory approach

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ISSUES IN FORMULATING PERFORMANCE-BASED APPROACHES TO REGULATORY OVERSIGHT OF NUCLEAR POWER PLANTS

  • YOUNGBLOOD R. W.;KIM I. S.
    • Nuclear Engineering and Technology
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    • v.37 no.3
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    • pp.231-244
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    • 2005
  • In recent decades, significant effort has led to risk-informed improvements to regulation. Performance-based approaches also promise significant gains in efficiency (level of safety versus effort). However, significant work remains to be done before performance-based approaches realize their full potential in regulation of nuclear power plants. This paper reviews key concepts related to performance-based regulation, discusses some applications of performance-based approaches, and identifies issues that still need to be addressed. Realistic, experience-based models of licensee performance are still lacking; this makes it difficult to assess the prospective effectiveness of any given regulatory approach, in light of the performance issues that it will actually face. Also, while 'compliance' is an intuitively straightforward concept to apply within a prescriptive implementation, its analog in a performance-based approach remains unclear. An overarching theme of the paper is that formal methods of decision analysis are very helpful in developing appropriate regulatory approaches, especially performance-based ones; this theme is illustrated at several points.

TECHNOLOGY-NEUTRAL NUCLEAR POWER PLANT REGULATION: IMPLICATIONS OF A SAFETY GOALS- DRIVEN PERFORMANCE-BASED REGULATION

  • MODARRES MOHAMMAD
    • Nuclear Engineering and Technology
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    • v.37 no.3
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    • pp.221-230
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    • 2005
  • This paper reviews the pivotal phases of the evolution of the current technology-dependent nuclear power safety regulation in the United States. Understanding of this evolution is essential to the development of any future regulatory paradigm, including the technology-neutral regulatory approach that the U.S. Nuclear Regulatory Commission (NRC) has recently embarked on to develop. The paper proposes and examines the implications of a predominately rationalist and best-estimate probabilistic regulatory framework called safety goals-driven performance-based regulation. This framework relies on continuous assessment of performance of a set of time-dependent safety-critical systems, structures and components that assure attainment of a broad set of technology-neutral protective, mitigative, and preventive goals. Finally, the paper discusses the steps needed to develop a corresponding technology-neutral regulatory system from the proposed framework.

Inferring Relative Activity between Pathway and Downstream Genes to Classify Melanoma Cancer Progression

  • Jung, In-Kyung;Lee, Jung-Sul;Choi, Chul-Hee;Kim, Dong-Sup
    • Interdisciplinary Bio Central
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    • v.3 no.1
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    • pp.5.1-5.5
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    • 2011
  • Introduction: Many signal transduction pathways mediate cell's behavior by regulating expression level of involved genes. Abnormal behavior indicates loss of regulatory potential of pathways, and this can be attributed to loss of expression regulation of downstream genes. Therefore, function of pathways should be assessed by activity of a pathway itself and relative activity between a pathway and downstream genes, simultaneously. Results and Discussion: In this study, we suggested a new method to assess pathway's function by introducing concept of 'responsiveness'. The responsiveness was defined as a relative activity between a pathway itself and its downstream genes. The expression level of a downstream gene as a function of an upstream pathway activation characterizes disease status. In this aspect, by using the responsiveness we predicted potential progress in cancer development. We applied our method to predict primary and metastatic status of melanoma cancer. The result shows that the responsiveness-based approach achieves better performance than using gene or pathway information alone. The mean of ROC scores in the responsiveness-based approach was 0.90 for GSE7553 data set, increased more than 40% compared to a gene-based method. Moreover, identifying the abnormal regulatory patterns between pathway and its downstream genes provided more biologically interpretable information compared to gene or pathway based approaches.

Consequence-based security for microreactors

  • Emile Gateau;Neil Todreas;Jacopo Buongiorno
    • Nuclear Engineering and Technology
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    • v.56 no.3
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    • pp.1108-1115
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    • 2024
  • Assuring physical security for Micro Modular Reactors (MMRs) will be key to their licensing. Economic constraints however require changes in how the security objectives are achieved for MMRs. A promising new approach is the so-called performance based (PB) approach wherein the regulator formally sets general security objectives and leaves it to the licensee to set their own specific acceptance criteria to meet those objectives. To implement the PB approach for MMRs, one performs a consequence-based analysis (CBA) whose objective is to study hypothetical malicious attacks on the facility, assuming that intruders take control of the facility and perform any technically possible action within a limited time before an offsite security force can respond. The scenario leading to the most severe radiological consequences is selected and studied to estimate the limiting impact on public health. The CBA estimates the total amount of radionuclides that would be released to the atmosphere in this hypothetical scenario to determine the total radiation dose to which the public would be exposed. The predicted radiation exposure dose is then compared to the regulatory dose limit for the site. This paper describes application of the CBA to four different MMRs technologies.

Proposed Data-Driven Approach for Occupational Risk Management of Aircrew Fatigue

  • Seah, Benjamin Zhi Qiang;Gan, Wee Hoe;Wong, Sheau Hwa;Lim, Mei Ann;Goh, Poh Hui;Singh, Jarnail;Koh, David Soo Quee
    • Safety and Health at Work
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    • v.12 no.4
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    • pp.462-470
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    • 2021
  • Background: Fatigue is pervasive, under-reported, and potentially deadly where flight operations are concerned. The aviation industry appears to lack a standardized, practical, and easily replicable protocol for fatigue risk assessment which can be consistently applied across operators. Aim: Our paper sought to present a framework, supported by real-world data with subjective and objective parameters, to monitor aircrew fatigue and performance, and to determine the safe crew configuration for commercial airline operations. Methods: Our protocol identified risk factors for fatigue-induced performance degradation as triggers for fatigue risk and performance assessment. Using both subjective and objective measurements of sleep, fatigue, and performance in the form of instruments such as the Karolinska Sleepiness Scale, Samn-Perelli Crew Status Check, Psychomotor Vigilance Task, sleep logs, and a wearable actigraph for sleep log correlation and sleep duration and quality charting, a workflow flagging fatigue-prone flight operations for risk mitigation was developed and trialed. Results: In an operational study aimed at occupational assessment of fatigue and performance in airline pilots on a three-men crew versus a four-men crew for a long-haul flight, we affirmed the technical feasibility of our proposed framework and approach, the validity of the battery of assessment instruments, and the meaningful interpretation of fatigue and work performance indicators to enable the formulation of safe work recommendations. Conclusion: A standardized occupational assessment protocol like ours is useful to achieve consistency and objectivity in the occupational assessment of fatigue and work performance.

Tuning of a PID Controller Using Soft Computing Methodologies Applied to Basis Weight Control in Paper Machine

  • Nagaraj, Balakrishnan;Vijayakumar, Ponnusamy
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.43 no.3
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    • pp.1-10
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    • 2011
  • Proportional.Integral.Derivative control schemes continue to provide the simplest and effective solutions to most of the control engineering applications today. However PID controller is poorly tuned in practice with most of the tuning done manually which is difficult and time consuming. This research comes up with a soft computing approach involving Genetic Algorithm, Evolutionary Programming, and Particle Swarm Optimization and Ant colony optimization. The proposed algorithm is used to tune the PID parameters and its performance has been compared with the conventional methods like Ziegler Nichols and Lambda method. The results obtained reflect that use of heuristic algorithm based controller improves the performance of process in terms of time domain specifications, set point tracking, and regulatory changes and also provides an optimum stability. This research addresses comparison of tuning of the PID controller using soft computing techniques on Machine Direction of basics weight control in pulp and paper industry. Compared to other conventional PID tuning methods, the result shows that better performance can be achieved with the soft computing based tuning method. The ability of the designed controller, in terms of tracking set point, is also compared and simulation results are shown.

A New Approach to Selection of Inspection Items using Risk Insight of Probabilistic Safety Assessment for Nuclear Power Plants

  • Park, Younwon;Kim, Hyungjin;Lim, Jihan;Choi, Seongsoo
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.14 no.2
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    • pp.49-58
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    • 2018
  • The regulatory periodic inspection program (PSI) conducted at every overhaul period is the most important process for confirming the safety of nuclear power plants. The PSI for operating nuclear power plants in Korea mainly consist of component level performance check that had been developed based on deterministic approach putting the same degree of importance to all the inspection items. This inspection methodology is likely to be effective for preoperational inspection. However, once the plant is put into service, the PSI must be focused on whether to minimize the risk of accident using defense-in-depth concept and risk insight. The incorporation of defense-in-depth concept and risk insight into the deterministic based safety inspection has not been well studied so far. In this study, two track approaches are proposed to make sure that core damage be avoided: one is to secure success path and the other to block the failure path in a specific event tree of PSA. The investigation shows how to select safety important components and how to set up inspection group to ensure that core damage would not occur for a given initiating event, which results in strengthening defense-in-depth level 3.

Design response spectra-compliant real and synthetic GMS for seismic analysis of seismically isolated nuclear reactor containment building

  • Ali, Ahmer;Abu-Hayah, Nadin;Kim, Dookie;Cho, Sung Gook
    • Nuclear Engineering and Technology
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    • v.49 no.4
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    • pp.825-837
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    • 2017
  • Due to the severe impacts of recent earthquakes, the use of seismic isolation is paramount for the safety of nuclear structures. The diversity observed in seismic events demands ongoing research to analyze the devastating attributes involved, and hence to enhance the sustainability of base-isolated nuclear power plants. This study reports the seismic performance of a seismically-isolated nuclear reactor containment building (NRCB) under strong short-period ground motions (SPGMs) and long-period ground motions (LPGMs). The United States Nuclear Regulatory Commission-based design response spectrum for the seismic design of nuclear power plants is stipulated as the reference spectrum for ground motion selection. Within the period range(s) of interest, the spectral matching of selected records with the target spectrum is ensured using the spectral-compatibility approach. NRC-compliant SPGMs and LPGMs from the mega-thrust Tohoku earthquake are used to obtain the structural response of the base-isolated NRCB. To account for the lack of earthquakes in low-to-moderate seismicity zones and the gap in the artificial synthesis of long-period records, wavelet-decomposition based autoregressive moving average modeling for artificial generation of real ground motions is performed. Based on analysis results from real and simulated SPGMs versus LPGMs, the performance of NRCBs is discussed with suggestions for future research and seismic provisions.

Qualitative Literature Analysis: The Current Challenges and their Solutions in the Beauty Care industry

  • Eun-Jung SHIN
    • The Journal of Industrial Distribution & Business
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    • v.15 no.6
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    • pp.25-32
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    • 2024
  • Purpose: This research explores to (1) identify the leading challenges that the beauty care industry faces currently, which includes sustainable development, ethics, and industry laws, (2) describe how these challenges impact industries' practices and customer experience, and (3) propose plausible strategies to address these issues in an effort to enhance sustainability, ethical business practices, and compliance with legal norms in the beauty care industry. Research design, data and methodology: The research approach used is the systematic literature review approach to identify the relevant literature that addresses the current challenges in the beauty care industry and to assess the results of prior studies. Results: The finding indicated the following solutions to handle the current issues in the beauty industry: Solution to (1) Environmental Impact: Sustainable Production and Packaging, (2) Ethical Concerns: Enhancing Supply Chain Transparency, (3) Regulatory Challenges: Proactive Compliance and International Standardization, and (4) Technological Challenges: Personalization and Digital Engagement. Conclusion: Based on the conclusions made in the findings' section, this research examines the implications of the solutions to provide an insight into how the strategies can guide future practices in the beauty care industry. It also points out how these insights can be applied by industry practitioners to improve sector operational and strategic performance.

Effect of Regulatory focus and Theory of Intelligence in the order of learning (학습순서 결정에서 지능관점과 조절초점의 영향)

  • Cho, Hyeseung;Kim, Kyungil;Bae, Jinhee
    • Korean Journal of Cognitive Science
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    • v.31 no.4
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    • pp.137-154
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    • 2020
  • Psychological properties of learners have influence on learning behaviors in various ways. The purpose of this study was to examine how the goal orientation of learners affected the learning time distribution method. Regulatory focus and theories of intelligence were measured and manipulated in order to differentiate participants' goal-oriented state. Two variables are known to be key variables influencing learner's goal orientation, inducing the approach-avoidance strategy and mastery-performance oriented attitude. In the experiment, the control focus was divided into two groups based on the inclination test score (regulatory Focus Questionnaire, RFQ), and TOI(theory of intelligence) was temporally induced through manipulation to confirm the interaction between the two variables. Participants were able to determine the order of learning freely by learning a set of Spanish-Korean word pairs and then selecting the items they would like to re-learn. Word pairs consisted of difficult or easy items, and learners could learn the same word many times if they wanted to. In the results, promotion-incremental group showed allocating difficult word-pairs in early time.