• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1678_1679
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• 2009

원전에 설치되어 있는 노외 핵계측 검출기는 설계수명과 품질보증 수명의 차이가 크기 때문에 적절한 검출기 교체 프로그램의 수립이 어렵다. 따라서 본 논문에서는 노외 핵계측검출기에 대한 노화 진행정도 판단 및 최적 교체주기 수립을 위한 원전 노외 핵계측 검출기 성능진단 시스템 및 분석기술에 대해 고찰하였다.

• Nuclear Engineering and Technology
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• v.41 no.3
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• pp.225-236
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• 2009

This study has identified human performance research issues associated with the implementation of new technology in nuclear power plants (NPPs). To identify the research issues, current industry developments and trends were evaluated in the areas of reactor technology, instrumentation and control technology, human-system integration technology, and human factors engineering (HFE) methods and tools. The issues were prioritized into four categories based on evaluations provided by 14 independent subject matter experts representing vendors, utilities, research organizations and regulators. Twenty issues were categorized into the top priority category. The study also identifies the priority of each issue and the rationale for those in the top priority category. The top priority issues were then organized into research program areas of: New Concepts of Operation using Multi-agent Teams, Human-system Interface Design, Complexity Issues in Advanced Systems, Operating Experience of New and Modernized Plants, and HFE Methods and Tools. The results can serve as input to the development of a long-term strategy and plan for addressing human performance in these areas to support the safe operation of new NPPs.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.804-806
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• 1998

Most of Instrumentation and control system in Nuclear Power Plant using analog equipment has a limitations in system designing and operation. So the network based PLC application to Nuclear Power Plant has been studied so far. This paper defines the configuration and method with Prototype which are to be applied to NPCS(NSSS Process Control System) of KNGR (Korea Next Generation Reactor). It is expected that Test result of NPCS Pototype will satisfy the essential requirements in designing KNGR.

• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.867-876
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• 2019

Second harmonic generation using nonlinear ultrasonic waves have been shown to be an early indicator of possible fatigue damage in nuclear power plant components. This technique relies on measuring amplitudes, making it highly susceptible to variations in transducer coupling and instrumentation. This paper proposes an experimental procedure for in-situ surface wave nonlinear ultrasound measurements on specimen with permanently mounted transducers under high cycle fatigue loading without interrupting the experiment. It allows continuous monitoring and minimizes variation due to transducer coupling. Moreover, relations describing the effects of the measurement system nonlinearity including the effects of the material transfer function on the measured nonlinearity parameter are derived. An in-situ high cycle fatigue test was conducted using two 304 stainless steel specimens with two different excitation frequencies. A comprehensive analysis of the nonlinear sources, which result in variations in the measured nonlinearity parameters, was performed and the effects of the system nonlinearities are explained and identified. In both specimens, monotonic trend was observed in nonlinear parameter when the value of fundamental amplitude was not changing.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.559-561
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• 2004

In this paper, we design two types of Main Control Unit for Control Rod Control System and Control Element Drive Mechanism Control System, respectively, using a domestic Distributed Control System(DCS) developed to localize the instrumentation and control(I&C) system for nuclear power plant(NPP). There are many parts developed by domestic skills and being operated successfully in NPP, but the development of I&C system as an essential part has been slow in progress. We will show the great possibility of developing peculiar Korean I&C system by applying this domestic DCS to nuclear I&C system and confirming its successful operation.

• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2847-2851
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• 2020

A simple water level measurement method based on wavelength division multiplexing (WDM) is proposed and demonstrated. The measurement principle is based on the change of Fresnel reflection occurring at the end facet of the optical fiber tip (OFT). To increase the spatial resolution of water level sensing, a broadband light source (BLS) and an arrayed waveguide grating (AWG) are employed. The OFTs are multiplexed with the dedicated wavelength channels of AWG. By measuring all of the reflection powers reflected at the OFTs with a proposed on-site reflectometer, the water level can be monitored continuously for a fast emergency response. Moreover, it can be implemented easily with the commercially available optical components and devices with the simple configuration.

• Nuclear Engineering and Technology
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• v.41 no.6
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• pp.849-858
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• 2009

Risk caused by safety-critical instrumentation and control (I&C) systems considerably affects overall plant risk. As digitalization of safety-critical systems in nuclear power plants progresses, a risk model of a digitalized safety system is required and must be included in a plant safety model in order to assess this risk effect on the plant. Unique features of a digital system cause some challenges in risk modeling. This article aims at providing an overview of the issues related to the development of a static fault-tree-based risk model. We categorize the complicated issues of digital system probabilistic risk assessment (PRA) into four groups based on their characteristics: hardware module issues, software issues, system issues, and safety function issues. Quantification of the effect of these issues dominates the quality of a developed risk model. Recent research activities for addressing various issues, such as the modeling framework of a software-based system, the software failure probability and the fault coverage of a self monitoring mechanism, are discussed. Although these issues are interrelated and affect each other, the categorized and systematic approach suggested here will provide a proper insight for analyzing risk from a digital system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.3
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• pp.561-570
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• 2014

Nuclear Power Plant Instrumentation and Control System(NPP I&C) which is used to operate safely is changing from analog technology to digital technology. Ever since NPP Centrifuge of Iran Bushehr was shut down by Stuxnet attack in 2010, the possibility of cyber attacks against the NPP has been increasing. However, the domestic and international regulatory guidelines that was published to strengthen the cyber security of the NPP I&C describes security requirements and method s to establish policies and procedures. These guidelines are not appropriate for the development of real applicable cyber security technology. Therefore, specialized cyber security technologies for the NPP I&C need to be developed to enhance the security of nuclear power plants. This paper proposes a cyber security technology development system which is exclusively for the development of nuclear technology. Furthermore, this method has been applied to the ESF-CCS developed by The KINCS R&D project.

• Nuclear Engineering and Technology
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• v.48 no.1
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• pp.87-97
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• 2016

The new generation of nuclear power plants (NPPs) will likely make use of state-of-the-art technologies in many areas of the plant. The analysis, design, and selection of advanced human-system interfaces (HSIs) constitute an important part of power plant engineering. Designers need to consider the new capabilities afforded by these technologies in the context of current regulations and new operational concepts, which is why they need a more rigorous method by which to plan the introduction of advanced HSIs in NPP work areas. Much of current human factors research stops at the user interface and fails to provide a definitive process for integration of end user devices with instrumentation and control and operational concepts. The current lack of a clear definition of HSI technology, including the process for integration, makes characterization and implementation of new and advanced HSIs difficult. This paper describes how new design concepts in the nuclear industry can be analyzed and how HSI technologies associated with new industrial processes might be considered. It also describes a basis for an understanding of human as well as technology characteristics that could be incorporated into a prioritization scheme for technology selection and deployment plans.

• Nuclear Engineering and Technology
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• v.52 no.10
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• pp.2262-2273
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• 2020

Digital twin technology can provide significant value for the prognostics and health management (PHM) of critical plant components by improving insight into system design and operating conditions. Digital twinning of systems can be utilized for anomaly detection, diagnosis and the estimation of the system's remaining useful life in order to optimize operations and maintenance processes in a nuclear plant. In this regard, a conceptual framework for the application of digital twin technology for the prognosis of Control Element Drive Mechanism (CEDM), and a data-driven approach to anomaly detection using coil current profile are presented in this study. Health management of plant components can capitalize on the data and signals that are already recorded as part of the monitored parameters of the plant's instrumentation and control systems. This work is focused on the development of machine learning algorithm and workflow for the analysis of the CEDM using the recorded coil current data. The workflow involves features extraction from the coil-current profile and consequently performing both clustering and classification algorithms. This approach provides an opportunity for health monitoring in support of condition-based predictive maintenance optimization and in the development of the CEDM digital twin model for improved plant safety and availability.