• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.638-640
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• 2002

This paper introduces the design method of a Control Rod Drive Mechanism that consists of 3 coils -lift, movable gripper and stationary gripper coil. The vertical attraction forces of the lift, movable gripper, and stationary gripper armatures are calculated by FEM, then the dynamics with full load is demonstrated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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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.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(4)
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• pp.275-282
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• 1996

일체형 원자로는 증기발생기 및 가압기를 압력용기 내에 설치한 것으로서 연결배관이 없기 때문에 배관의 파단에 의한 대형 냉각재 상실사고를 근원적으로 배제하고 전체계통을 단순화 시킬 수 있다. 증기발생기는 대부분 관류식으로서 일체식과 모듈식이 사용되고 있다. 본 연구에서는 모듈식 나선형 증기발생기를 사용한 일체형 신형경수로의 예비 개념설계를 수행하였다. 가압기는 원자로 내에 별도의 용기를 설치하는 내장형 자기가압기를 채택하였다. 제어봉 구동장치는 핵분열 반응열을 이용한 원자로 기동을 위하여 반응도를 미세하게 조정하는 것이 가능하고 지진하중과 같은 동하중의 영향을 최소화하기 위하여 원자로용기 외부로의 돌출부분을 최소화하는 설계개념을 채택하였다. 냉각재 펌프는 Canned Motor Pump를 원자로용기 상부에 수직으로 직접 부착하는 개념을 사용하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.552-554
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• 2003

This paper is about the method by which Power Control Unit(PCU) of Control Rod Control System(CRCS) logs events in the system and the real-time monitoring display. This method enables the functions like the event logging of Control Rod Drive Mechanism(CRDM)/power Cabinet, the off-line show of the event data logged and the on-line show by communication between the PCU and the monitoring display. Operators in a nuclear power plant must be able to grasp any possible abnormal states correctly. Because our newly designed system has a good ability to log and display the kinds, tine, and the prior and posterior states of urgent or non-urgent events, the operators can judge, maintain and repair the abnormal event more easily.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.563-566
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• 2003

We have designed the power control unit which belongs to the power cabinet and controls the power supplied to Control Rod Drive Mechanism(CRDM) as a digital system based on Digital Signal Processor(DSP). The power control unit dualized as the form of Master/Slave has had its increased reality. The Central Process Unit(CPU) board of a power control unit possesses two Digital Signal Processors(DSPs) of the control DSP for performing the tasks of power control and system monitoring and the communication of the Control DSP and the Communication DSP. To accomplish the functions requested in the power control unit effectively, we have installed Field Programmable Gate Arrays(FPGAS) on the CPU board and have FPGAs perform the memory mapping, the generation of each chip selection signal, the giving and receiving of the signals between the power controllers dualized, the fault detection and the generation of the firing signals.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.2655-2657
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• 2005

When a fault relating to the urgent alarm occurs, we must prevent control rods from dropping and make one of two grippers in Control Rod Drive Mechanism (CRDM) grip the drive rod taking a control rod assembly. To enhance the reliability of holding control rods, we order two grippers to hold the drive rod. This action is called the double holding. In the middle of the movement of the drive rod, the latching of the drive rod can cause friction between a gripper and the drive rod. This state may give damage to both the gripper and the drive rod. In this paper, we have devised the method which can have two grippers hold the drive rod more stably, without damaging the equipment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2301-2303
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• 2004

This paper proposes a detection method for mechanically stuck control rod drive mechanisms (CRDMs) in the nuclear reactor. From an electrical viewpoint, a coil of an electro-mechanical CRDM is modelled as an R-L circuit with time-varying inductance. The inductance of the coil is estimated from the measured voltage and current by using the least square method. Numerical experiments are carried out to illustrate the proposed method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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• pp.98-100
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• 1999

A thermal analysis was performed for the electromagnet which is installed in the control element drive mechanism(CEDM) of the integral reactor SMART. A model for the thermal analysis of the electromagnet was developed and theoretical bases for the model were established. It is important that the temperature of the electromagnet windings be maintained within the allowable limit of the insulation, since the electromagnet of CEDM is always supplied with current during the reactor operation. So the thermal analysis of the winding insulation which is composed of polyimide and air were performed by finite element method. The thermal properties obtained here will be used as input for the optimization analysis of the electromagnet.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2646-2648
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• 2002

This paper deals with a comparative evaluation of the reliability of control rod drive mechanisms including their driving methods for nuclear power plants. Basically there exist two types of electromagnetic-jack-type drive mechanisms in commercial use that are called as Control Rod Drive Mechanism and Control Element Drive Mechanism. Each type has corresponding drive sequence to make the movements of insertion and withdrawal. A state-space model is derived for each model graphically. Then the evaluation of the reliability is carried out on the programming tool called SHARPE. The evaluation does not give any meaningful numerical values for the reliability but just shows a relative degree to each other in view of reliability.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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• pp.343-350
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• 2002

The structural stability of pressure housing of SMART CEDM forming pressure boundary must be evaluated. In this paper, the stress and thermal analyses of the upper pressure housing of CEDM are performed for design pressure, hydraulic test pressure and thermal loading. Finite element and boundary condition were generated from the model which is made by I-DEAS program and the stress and thermal analyses were performed by ANSYS Program. The upper Pressure housing was analysed using 2D axisymmetric model because it is symmetry about an axis. The stress values obtained by analysis were compared with the stress intensity limit of ASME and KEPIC MNB standard.