• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 추계종합학술대회
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• pp.467-474
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• 1999

본 논문에서는 제어 시스템의 신뢰도를 높이고 중단없는 제어 동작을 실현하기 위하여 제어기를 삼중화한 내고장성 디지털 조속기를 설계하였으며, 이 시스템을 Markov process로 모델링하여 신뢰도를 해석하였다. 임무시간에서 삼중화 시스템은 단일 제어기 시스템에 비해 신뢰도 86[%]수준에서 약 1.8 배, 95[%]수준에서 약 2.8배, 99[%]수준에서 약 6배 증가함을 확인하였다. 또한 북제주 화력 발전소의 터빈 속도제어 시스템을 대상으로 디지털 속도제어 시스템을 설계하였으며, 설계된 디지털 속도제어 시스템의 유효성을 입증하기 위해 모의실험을 행하였다.

• Nuclear Engineering and Technology
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• 제51권6호
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• pp.1540-1553
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• 2019

A nuclear power plant (NPP) is a highly complex system-of-systems as manifested through its internal systems interdependence. The negative impact of such interdependence was demonstrated through the 2011 Fukushima Daiichi nuclear disaster. As such, there is a critical need for new strategies to overcome the limitations of current risk assessment techniques (e.g. the use of static event and fault tree schemes), particularly through simulation of the nonlinear dynamic feedback mechanisms between the different NPP systems/components. As the first and key step towards developing an integrated NPP dynamic probabilistic risk assessment platform that can account for such feedback mechanisms, the current study adopts a system dynamics simulation approach to model the thermal dynamic processes in: the reactor core; the secondary coolant system; and the pressurized water reactor. The reactor core and secondary coolant system parameters used to develop system dynamics models are based on those of the Palo Verde Nuclear Generating Station. These three system dynamics models are subsequently validated, using results from published work, under different system perturbations including the change in reactivity, the steam valve coefficient, the primary coolant flow, and others. Moving forward, the developed system dynamics models can be integrated with other interacting processes within a NPP to form the basis of a dynamic system-level (systemic) risk assessment tool.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2488-2491
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• 2000

A Neural network is possible to nonlinear function mapping and parallel processing. Therefore It has been developing for a Diagnosis system of nuclear plower plant. In general Neural Networks is a static mapping but Dynamic Neural Network(DNN) is dynamic mapping. When a fault occur in system, a state of system is changed with transient state. Because of a previous state signal is considered as a information. DNN is better suited for diagnosis systems than static neural network. But a DNN has many weights, so a real time implementation of diagnosis system is in need of a rapid network architecture. This paper presents a algorithm for RCP monitoring Alarm diagnosis system using Self Dynamic Neural Network(SDNN). SDNN has considerably fewer weights than a general DNN. Since there is no interlink among the hidden layer. The effectiveness of Alarm diagnosis system using the proposed algorithm is demonstrated by applying to RCP monitoring in Nuclear power plant.

• 한국압력기기공학회 논문집
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• 제6권1호
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• pp.9-15
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• 2010

This paper describes the Visual Tool for automatic ultrasonic examination that is under developing as a part of the project for development of automatic ultrasonic wave acquisition and analysis program. This tool that is supported by various image processing techniques will be adopted to detect the flaws in the component and piping welds in NPP. Visual Tool will enhance the integrity of nuclear power plant. The object of this paper is to address the Visual Tool which is developing for automatic ultrasonic inspection of welds in NPP.

• 한국항공운항학회지
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• 제23권1호
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• pp.1-7
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• 2015

The aircraft maintenance demands a lot of aviation mechanics in urgent according to the high season and low season in seasonal demand adjusted, unplanned maintenance work such as AD (airworthiness directives) and troubleshooting of aircraft system fault. The advent of Super-Large Aircraft such as A380 with aircraft materials, power plant and avionics systems which were not in previous models must be expected to increase the complexity of the aircraft maintenance system. This study is intended to propose the development plan for formation of positive flexibility culture in aircraft maintenance organization through the review of previous research on flexibility culture of organization and through empirical research for bureaucratic and poor factors by the evaluation of flexibility culture level of domestic aircraft maintenance organization.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.292-294
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• 2005

전력계통에 고장이 발생할 경우 dc성분이 많이 포함된 고장전류가 발생될 가능성이 높아진다. 이때, 고장이 발생 되었다가 dc성분이 소멸되면서 만들어낸 자속이 CT의 포화에 가장 큰 영향을 미치게 된다. 특히 발전소 구내에서 고장이 발생되면 dc성분이 많이 포함된 고장전류가 발생되어 CT가 포화하는 현상을 자주 볼 수 있다. 이로 인해 보호계전기에 유입되는 2차 전류가 왜곡되고 이로 인해 보호계전기가 오동작을 하게 된다. 본 논문에서는 대용량 발전소의 스위치야드 차단기 혹은 모선에서 발생한 고장으로 Unit 보호계전기가 오동작한 사례를 분석한 내용이다.

• Nuclear Engineering and Technology
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• 제19권4호
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• pp.279-291
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• 1987

현재 원자력발전소의 확률론적 위해도 평가에 사용되는 사상 수목이나 고장수목 기법은 부품이나 계통의 이원적상태와 정적 묘사에 근거하고 있다 이 기법이 대부분의 안전해석에는 적합하지만, 요사이 점차 중요관심사가 되고 있는 발전소의 이용률 측정이나 기술 사양서 평가 같은 문제를 정확하게 다루기 위해서는 마코프 신뢰도 분석과 같은 보다 진보된 기법이 필요하다. 이 논문은 가압경수로의 원자로 보호계통을 위한 마코프 신뢰도 모델을 기술하고 기술사양서의 두 검사 절차를 분석한 결과를 제시한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.953-958
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• 1993

We develop a neural network control algorithm for the ACS (Advanced Control System). The ACS is an extended version of the DCS (Distributed Control System) to which functions of fault detection and diagnosis and advanced control algorithms are added such as neural networks, fuzzy logics, and so on. In spite of its usefulness proven by computer simulations, the neural network control algorithm, as far as we know, has no tool which makes it applicable to process control. It is necessary that the neural network controller should be turned into the function code for its application to the ACS. So we develop a general method to implement the neural network control systems for the ACS. By simulations using the simulator for the boiler of 'Seoul fire power plant unit 4', the methodology proposed in this paper is validated to have the applicability to process control.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.250-255
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• 1993

In this paper, for detection and isolation of instrument and process faults related with steam generator(S/G) in nuclear power plant, two types of observers are designed based on the linearized dynamic model of S/G : a bank of Dedicated Observers (DOS) for instrument faults detection and a bank of Unknown Input Observers(UIO) for process faults detection. And then, they are combined to decide which one between the above two faults occurs. In principle, the failure in ith instrument(process) can be isolated by monitoring the error between the ith output and its estimation obtained from the ith DOS(UIO). It is shown via computer simulations that the present scheme is feasible in finding out the source of a fault.

• 지질공학
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• 제24권4호
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• pp.609-613
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• 2014

The Korean Peninsula, located at the southeastern tip of the Eurasian Plate, is known to be tectonically stable, and no critical evidence has yet been found that would override the safety design of nuclear facilities in South Korea. Because a nuclear power plant, like other major social overhead capital facilities, could cause great damage to both the environment and society through an unexpected tectonic event, even one of extremely low probability, like the Fukushima accident, a defense-in-depth safety approach is required in geological and geotechnical site safety evaluation for nuclear projects. This paper introduces the regulatory procedures that are in place to confirm nuclear site safety and site monitoring (e.g., earthquakes and groundwater) systems applied to nuclear facilities in order to reduce inherent uncertainties within the site safety review of geological and seismological issues related with a NPP project.