• Nuclear Engineering and Technology
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• v.48 no.1
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• pp.153-163
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• 2016

Environments in nuclear power plants (NPPs) are changing as the design of instrumentation and control systems for NPPs is rapidly moving toward fully digital instrumentation and control, and modern computer techniques are gradually introduced into main control rooms (MCRs). Within the context of these environmental changes, the level of performance of operators in a digital MCR is a major concern. Situation awareness (SA), which is used within human factors research to explain to what extent operators of safety-critical systems know what is transpiring in the system and the environment, is considered a prerequisite factor to guarantee the safe operation of NPPs. However, the safe operation of NPPs can be guaranteed through a team effort. In this regard, the operating team's SA in a conventional and digital MCR should be measured in order to assess whether the new design features implemented in a digital MCR affect this parameter. This paper explains the team SA measurement method used in this study and the results of applying this measurement method to operating teams in different MCR environments. The paper also discusses several empirical lessons learned from the results.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.338-341
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• 2005

In this paper, a real-time communication method using a PICNET-NP(Plant Instrumentation and Control Network for Nuclear Power Plant) is proposed with an analysis of the control network requirements of DCS (Distributed Control System) in nuclear power plants. The method satisfies deadline in case of worst data traffics by considering aperiodic and periodic real-time data and others. In addition, the method was used to analyze the data characteristics of the DCS in existing nuclear power plant. The result shows that use of this method meets the response time requirement(100ms).

• Nuclear Engineering and Technology
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• v.49 no.3
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• pp.484-494
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• 2017

In industrial plants such as nuclear power plants, system operations are performed by embedded controllers orchestrated by Supervisory Control and Data Acquisition (SCADA) software. A targeted attack (also termed a control aware attack) on the controller/SCADA software can lead a control system to operate in an unsafe mode or sometimes to complete shutdown of the plant. Such malware attacks can result in tremendous cost to the organization for recovery, cleanup, and maintenance activity. SCADA systems in operational mode generate huge log files. These files are useful in analysis of the plant behavior and diagnostics during an ongoing attack. However, they are bulky and difficult for manual inspection. Data mining techniques such as least squares approximation and computational methods can be used in the analysis of logs and to take proactive actions when required. This paper explores methodologies and algorithms so as to develop an effective monitoring scheme against control aware cyber attacks. It also explains soft computation techniques such as the computational geometric method and least squares approximation that can be effective in monitor design. This paper provides insights into diagnostic monitoring of its effectiveness by attack simulations on a four-tank model and using computation techniques to diagnose it. Cyber security of instrumentation and control systems used in nuclear power plants is of paramount importance and hence could be a possible target of such applications.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.8
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• pp.107-112
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• 2016

Safety Critical Instrumentation and Control Systems perform those functions to maintain nuclear power plants' parameters within acceptable limits established for a design basis events and anticipated operating occurrence to ensure safety function. Those digitalized systems shall protect inadvertent and non-malicious behavior to ensure the reliable operation of systems, known as a Secure Development and Operational Environment(SDOE). SDOE would be established through managerial and technical controls. The objective of this paper is to evaluate the effectiveness of Cyclic Redundancy Checksum diagnostic, which is one of technical controls for SDOE, that can confirm the integrity of software of I&C systems to establish the secure environment. The results of this assessment would be the practical implementation of design and safety review of nuclear I&C systems.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.11a
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• pp.85-90
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• 1996

In this paper, the self-organizing fuzzy logic controller is developed for water level control of steam generator. In comparison with conventional fuzzy logic controllers, this controller performs control task with no control rules at initial and creates control rules as control behavior goes on, and also modifies its control structure when uncertain disturbance is suspected. Selected parameters in the fuzzy logic controller are updated on-line by the gradient descent loaming algorithm based on the performance cost function. This control algorithm is applied to water level control of steam generator model developed by Lee, et al. The computer simulation results confirm good performance of this control algorithm in all power ranges. This control algorithm can be expected to be used for automatic control of feedwater control system in the nuclear power plant with digital instrumentation and control systems.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.10
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• pp.1117-1123
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• 2014

Nuclear industries have faced unfavorable circumstances such as an obsolescence of the instrumentation and control system, and therefore nuclear society is striving to resolve this trouble fundamentally. FPGAs are currently highlighted as an alternative means for obsolete control systems. Because of the obsolescence-unaffected characteristics, FPGA should be highly reliable in order to be a replacement for PLC (Programmable Logic Controller). Therefore, it is necessary to establish a software development aspect strategy that enhances the reliability of an FPGA-based controller. The reliability analysis including the MTBF (Mean Time Between Failures) is carried out based on the MIL-HDBK-217F. MTBFs are compared with the FPGA-based controller COMMON-Q PLC. As an analysis result, it shows that the reliability of the FPGA-based controller is better than or equal to that of PLC.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2275-2277
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• 2004

Korea Next Generation Reactor(KNGR) is in the midst of being developed and will exceed Korea Standard Nuclear Power Plant(KSNP) economically. Domestic Instrumentation and Control(I&C) systems shall be applied to KNGR and the development of Control Element Drive Mechanism Control System(CEDMCS) considered as an essential part in nuclear I&C system will be dealt with in this paper. The newly developed CEDMCS has the control cabinet using the nuclear Distributed Control System(DCS) made in Korea and the power cabinet produced by our research institute and interfaced with the DCS control cabinet.

• Journal of the Ergonomics Society of Korea
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• v.27 no.1
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• pp.21-27
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• 2008

An increased use of teams of actors within complex systems has led to the emergence of various approaches for the assessment of different features associated with team performance. Over the last two decades, the performance of teams in complex systems has received considerable attention from the human factors community, and a number of methods have been developed in order to assess and evaluate team performance. The purpose of this paper is to propose a methodology for measuring team efficiency of operators in the advanced main control room of Korean nuclear power plant. Team efficiency is an index which is estimated of gabs between individual performances and team performance. The index was developed to compare among teams through past all performance measurements.

• Nuclear Engineering and Technology
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• v.49 no.5
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• pp.896-904
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• 2017

Several Generation IV nuclear reactor concepts have goals for optimizing investment recovery through phased introduction of multiple units on a common site with shared facilities and/or reconfigurable energy conversion systems. Additionally, small modular reactors are suitable for remote deployment to support highly localized microgrids in isolated, underdeveloped regions. The long-term economic viability of these advanced reactor plants depends on significant reductions in plant operations and maintenance costs. To accomplish these goals, intelligent control and diagnostic capabilities are needed to provide nearly autonomous operations with anticipatory maintenance. A nearly autonomous control system should enable automatic operation of a nuclear power plant while adapting to equipment faults and other upsets. It needs to have many intelligent capabilities, such as diagnosis, simulation, analysis, planning, reconfigurability, self-validation, and decision. These capabilities have been the subject of research for many years, but an autonomous control system for nuclear power generation remains as-yet an unrealized goal. This article describes a functional framework for intelligent, autonomous control that can facilitate the integration of control, diagnostic, and decision-making capabilities to satisfy the operational and performance goals of power plants based on multimodular advanced reactors.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.1013-1016
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• 1999

In this paper, a real-time communication method using a PICNET-NP(Plant Instrumentation and Control Network for Nuclear Power plant) is proposed with an analysis of the control network requirements of DCS (Distributed Control System) in nuclear power plants. The method satisfies deadline in case of worst data traffics by considering aperiodic and periodic real-time data and others. In addition, the method was used to analyze the data characteristics of the DCS in existing nuclear power plant. The result shows that use of this method meets the response time requirement(100ms)