• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.3
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• pp.449-458
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• 2022

In a power plant, the utility operates controllers include safety program that has performed several stages verification to prevent accidents in preparation for accidents, or to stably operate in accident. This paper describes the virtualization technology so that the verified binary operating system and application program can operate on the controller processor used in the power plant safety control facility. The technology applied to this virtualization processor uses commercial tools to implement the essential components for the operation of the safety-grade controller processor module, such as command interpreters and analyzers, and the virtualization platform was developed in a Linux-based operating system using the Imperas Tool. In addition, it was checked whether the implemented virtual processor module can normally interpret and execute binary-type instructions.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10a
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• pp.655-657
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• 2004

본 논문은 안전등급 제어 기 기(Programmable Logic Controller) 에서 동작하는 실시간 운영체제의 안전성을 요구사항 단계에서 평가할 수 있는 검토항목을 개발하고 HAZOP(Hazard and Operability) 을 이용하여 현재 개발중인 PLC 운영체제에 적용한 경험 을 기술한다. HAZOP은 화학공장과 같은 산업에서 안전성을 평가하기 위한 방법으로 사용했던 방법론이다. 원자력발전소에 적용하기 위해 운영체제가 갖추어야 할 안전성 요건은 NUREG-0800의 BTP-14(Branch Technical Position)의 소프트웨어 기능특성 및 공정특성에 기술되어 있다. 이러한 기능적인 특성을 정확도, 신뢰성, 타이밍/사이징, 기능성, 강인성, 보안성 항목으로 나누고 세부적인 검토리스트를 만들어 HAZOP을 적용하여 평가하였다.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1761-1762
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• 2006

지금까지 원전 계측제어계통은 안전을 위한 보수적인 설계기준을 적용하여 아날로그 기기를 사용하여 설계되었다. 그러나 최근에는 아날로그 기기의 생산 중단으로 기기 및 장비의 예비품 조달에 어려움을 겪게 되었고, 점차 복잡하면서도 편리한 기능에 대한 사용자 요구로 인해 디지털 기기의 사용이 확대되고 있는 추세이다. 프로그램 가능한 논리제어기 (Programmable Logic Controller:PLC)는 기존의 산업체에서 널리 사용되고 있지만, 높은 수준의 안전성 기준 때문에 일부 극소수의 PLC만이 원자력에 적용되고 있는 실정이다. 최근 국내에서도 원전 안전등급의 보호, 제어 및 감시계통에 디지털 기기의 적용을 위해 많은 노력을 하고 있다. 원전 계측제어계통의 디지털화는 부품 단종 및 설비 노후화 문제 등을 해결할 수 있는 장점이 있는 반면에 디지털화로 인한 새로운 안전 현안이 제기될 수 있다. PLC를 기반으로 하는 원전 계측제어계통은 안전등급의 보호, 제어 및 감시 기능을 수행하게 되므로, 고신뢰도 소프트웨어 적용등의 안전계통 개발에서 요구하는 요건을 만족해야 한다. 따라서 상용 또는 신규 개발되는 PLC를 사용하여 발전소보호계통을 구현할 경우에 적용 가능한 기술기준 및 계통요건이 필요하다. 본 논문에서는 발전소보호계통에 적용하기 위한 PLC 평가 항목을 개발하고, 각 부분별 평가 항목에 대해 소개한다.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1995-1996
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• 2006

검출기 안내관은 노내 핵계측 계통의 중성자 분포 측정을 위한 이동형 검출기의 이동경로를 제공할 뿐만 아니라 원자로 냉각수 계통의 압력경계를 유지하는 안전성 등급의 중요한 설비이다. 그러나, 인출과 삽입을 위한 검출기 안내관 취급은 의외로 낙후되어 작업자의 인력에만 의존하고 있는 실정이며, 원자로 격납용기 내부에 위치한 고방사선 지역에서 작업이 수행되고 있는 실정이다. 따라서 노내 핵계측 계통의 검출기 안내관의 안정적인 관리를 위해 검출기 안내판을 일정한 힘으로 인출하고 삽입할 수 있는 자동화시스템의 개발이 이루어지고 있다. 전력연구원에서 개발한 안내관 취급기구는 롤러에 의해 안내관을 파지하고, DC 모터 구동에 의해 안내관을 인출하고 삽입하는데, 본 논문에서는 안내관 취급 기구의 제어 시스템 구성과, 롤러와 안내관 사이에 발생하는 슬립을 고려한 제어기 구조를 제안하고, 실험을 통해 구현한 제어 시스템의 효용성을 보인다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.1
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• pp.11-17
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• 2015

High-density polyethylene (HDPE) piping, which has recently been applied to safety class III piping in nuclear power plants, can be butt-joined through the thermal fusion process, which heats two fused surfaces and then subject to axial pressure. The thermal fusion process generates bead shapes on the butt fusion. The stress concentrations caused by the bead shapes may reduce the fatigue lifetime. Thus, investigating the effect of the thermal butt fusion beads on fatigue behavior is necessary. This study examined the fatigue behavior of thermal butt fusion via a tensile fatigue test under stress-controlled conditions using finite element elastic stress analysis. Based on the results, the presence of thermal butt fusion beads was confirmed to reduce the fatigue lifetime in the low-cycle fatigue region while having a negligible effect in the medium- and high-cycle fatigue regions.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.1
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• pp.43-47
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• 2017

A SIL(Safety Integrity Level) assignment method is used for preventing failure action. The goal of safety system for processing automation is to reduce the human fatal risk. Even if we have developed the processing automation according to developing technology, we are also realized on increasing the human fatal risk cause of unexpected accidents. This study is directed the solution of decision for safety level for safety system and the best architecture for safety system in process automation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.464-466
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• 2019

Controllers used in nuclear power plants require high reliability. A controller including a Field Programmable Gate Array (FPGA) and a Complex Programmable Logic Device (referred to hereinafter as FPGA) has been applied to many Nuclear Power Plants (NPP) in the past, including the APR1400 (Advanced Power Reactor 1400), a Korean digital nuclear power plant. Initially, the FPGA was considered as a general IC (Integrated Circuit) and verified only by device verification and performance testing. In the 1990s, research on FPGA verification began, and until the FPGA became a chip, it was regarded as software and the software Verification and Validation (V&V) using IEEE 1012-2004 was implemented. Currently, IEC 62566, which is a European standard, has been applied for a lot of verification. This method has been evaluated as the most sensible method to date. This is because the method of verifying the characteristics of SoC (System on Chip), which has been a problem in the existing verification method, is sufficiently applied. However, IEC 62566 is a European standard that has not yet been adopted in the United States and maintains the application of IEEE 1012 for FPGA. IEEE 1012-2004 or IEC 62566 is a technical standard. In practice, various methods are applied to meet technical standards. In this paper, we describe the procedure and important points of verification method of Nuclear Safety Class FPGA applying SoC verification method.

• Journal of Applied Reliability
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• v.16 no.3
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• pp.231-237
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• 2016

Purpose: It is not easy to suggest a quantitative data related to safety analysis. The objective of this paper is to propose a method of Safety Integrity Level (SIL) analysis and to suggest a SIL analysis result for single station controller in nuclear power plant based on IEC 61508. Methods: The Failure Modes and Effects Diagnostic Analysis (FMEDA) and average probability of failure on demand (PFD) are used for SIL assessment. Results: A SIL of single station controller is evaluated 4 by a reliability analysis results and PFD. Conclusion: A SIL analysis method and result for single station controller based on IEC 61508 are proposed in this paper. It can applicable for a manufacturer data in safety-related system.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.279-286
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• 2012

Recently, design of Universal Soft Controller(USC) has been applied to the advanced control room for nuclear power plant. USC is software-based manual control means to control safety components as well as non-safety components in the highly-integrated control room. Therefore, design feature of USC is essential for the implementation of a single workstation in the advanced control room. The traditional control room is replaced by computer-driven consolidated operator interfaces. Considering our design has further reduced the probability of USC spurious signals by requiring two distinct operator control actions to generate any control signal. The reality of USC does not increase the probability of reactor trip because the probability of spurious USC signal is negligible. Universal Soft Control represents a significant evolution in nuclear I&C/HSI System. USC integrates the indicators and controls from multiple divisions into a single integrated visual display unit(VDU) based HSI(Human System Interface). In order to prevent adverse influence on safety function performance from USC failure, ESFAS signals are applied to safety components or functions. In addition, safety manual switches have priority over USC's signals. Therefore, spurious USC signals can be momentarily blocked by selecting a soft control command from the safety VDU.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.1
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• pp.1-9
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• 2010

Numerical study on coastal water quality management was conducted to examine the response of summer water quality to the flow into the sea of land based pollution load in Ulsan Bay, Korea The abatement of pollution load. from point sources of land was estimated on the basis of Korean coastal water quality standard using an ecosystem model. The results of the ecological model simulation showed that COD values in the inner part of the bay were greater than 280mg/L, and exceeded the grade III limit of Korean coastal water quality standard 30% of all land based pollution loads or organic and inorganic material loads from point sources should be cut down to keep the COD levels below 2mg/L. As environmental carrying capacity was estimated to be 7,193kgCOD/day to keep the COD levels below 2mg/L in Ulsan Bay, 3,083kgCOD/day of land based organic loads should be reduced. The phytoplankton blooms have occurred in the Teahwa river mouth or estuary repetitively, so it is important to control land based nutrients loads for removal of autochthonous organic loads around Ulsan Bay.