• 제목/요약/키워드: Rod Control System

검색결과 205건 처리시간 0.105초

Study on Rod Position Indication System using Permanent Magnets with Shielding Plates for a Control Rod Drive Mechanism

  • Lee, Jae Seon;Cho, Sang Soon;Kim, Jong Wook
    • Journal of Magnetics
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    • 제20권4호
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    • pp.439-443
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    • 2015
  • A control rod drive mechanism (CRDM) is an electromechanical equipment that provides linear movement for the control rods to control the nuclear reactivity in a nuclear reactor. A rod position indication system (RPIS) detects the control rod's position. To enhance the measurement accuracy of the system, a magnetostrictive type sensor with capability of generating operation limiting signals would be adapted instead of a conventional RPIS for a CRDM. An RPIS was modelled for a numerical analysis with the permanent magnets at the stationary limit positions and magnetic shielding plates with a moving permanent magnet. The performance analysis of the RPIS were conducted, and the results were discussed here.

Research on aging-related degradation of control rod drive system based on dynamic object-oriented Bayesian network and hidden Markov model

  • Kang Zhu;Xinwen Zhao;Liming Zhang;Hang Yu
    • Nuclear Engineering and Technology
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    • 제54권11호
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    • pp.4111-4124
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    • 2022
  • The control rod drive system is critical to the reactor's reliable operation. The performance of its control system and mechanical system will gradually deteriorate because of operational and environmental stresses, thus increasing the reactor's operational risk. Currently there are few researches on the aging-related degradation of the entire control rod drive system. Because it is difficult to quantify the effect of various environmental stresses and establish an accurate physical model when multiple mechanisms superimposed in the degradation process. Therefore, this paper investigates the aging-related degradation of a control rod drive system by integrating Dynamic Object-Oriented Bayesian Network and Hidden Markov Model. Uncertainties in the degradation of the control system and mechanical system are addressed by using fuzzy theory and the Hidden Markov Model respectively. A system which consists of eight control rod drive mechanisms divided into two groups is used to demonstrate the method. The aging-related degradation of the control rod drive system is analyzed by the Bayesian inference algorithm based on the accelerated life test data, and the impact of different operating schemes on the system performance is also investigated. Meanwhile, the components or units that have major impact on the system's performance are identified at different operational phases. Finally, several essential safety measures are suggested to mitigate the risk caused by the system degradation.

Development of a Prototype Control Rod Control System (제어봉 구동장치 제어기기 Prototype 개발)

  • Kim, C.K.;Cheon, J.M.;Kim, S.J.;Lee, J.M.;Ahn, J.B.;Kweon, S.M.
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2002년도 하계학술대회 논문집 D
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    • pp.2182-2184
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    • 2002
  • In this paper we describe a prototype Control Rod Control System(CRCS). The CRCS controls the motion of the full length rod drive mechanisms in response to signals from the Reactor Operator and the Reactor Control System. Each mechanism belongs to either Shutdown Banks or Control Banks. The CRCS also provides information regarding the rod motion, rod position, and the status of the Rod Control System. The prototype CRCS will be used to obtain the requirements for detailed design of a full-scale CRCS.

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Study of Design and Verification for Control Rod Control System (제어봉 구동장치 제어기기 설계 및 검증에 관한 연구)

  • Yook, Sim-Kyun;Lee, Sang-Yong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • 제28권5호
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    • pp.593-602
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    • 2004
  • We have developed a digital control rod control system not only to improve its performance but also to improve its reliability and speed of response so that it can replace the old fashioned analog system. However, a new developed digital control system should be tested to prove the validity by using any prototype or mock-up before application. The reliability prediction and the reliability block diagram analysis methods were adopted to verify the reliability of the developed hardware. For the case of software, especially fur a new developed control algorithm it has been tested to prove performances and validation by using a dynamic simulator and mock-up of control rod drive mechanism altogether. Here we want to present some key factors regarding to the new developed digital system with some verification procedures.

Control Characteristics Improvement of Single Rod Hydraulic Cylinder Subjected to Varying Load (가변하중을 받는 유압실린더의 제어특성개선)

  • Yum, Man-Oh
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • 제2권4호
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    • pp.46-52
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    • 2003
  • For position control of electro-hydraulic servo system, single rod cylinders and double rod cylinders are used. Single rod cylinders have simple structure for manufacturing but different volume ratio of two sides induce to non-linearity in process of then mathematical modeling. So only with conventional PID control method it is difficult to control single rod cylinders precisely. For mole precise position control of single rod cylinders, a controller which is inserted a velocity feedback PID controller and MRAC controller are proposed. With experiment control performances of three control methods are compared. In case of experiment, for external varying load to the system, a hydraulic cylinder and a pressure control valve are used. In conclusion a MRAC is considered a suitable control method for external varying load.

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The Design, Fabrication, and Characteristic Experiment for Control Rod Position Indicator Using Reed Switch in System-Integrated Modular Advanced Reactor (리드스위치를 이용한 일체형원자로용 제어봉 위치지시기 설계 제작 및 특성해석)

  • Hur, Hyung;Kim, Jong-In;Kim, Kern-Jung
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • 제52권8호
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    • pp.452-461
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    • 2003
  • The reliability and accuracy of the information on control rod position are very important to the reactor safety and the design of the core protection system. A survey on the RSPT(Reed Switch Position Transmitter) type control rod position indicator system and its actual implementation in the existing nuclear power plants in Korea was performed first. The control rod position indicator having the high performance for SMART was developed on the basis of RSPT technology identified through the survey. The arrangement of permanent magnet and reed switches is the most important procedure in the design of control rod position indicator. The hysteresis of reed switches is one of the important factors in a repeat accuracy of control rod position indicator as well. This paper investigates efficiency of the magnetic flux concentrator and the hysteresis using FEM and verified differences in physicals characteristics by comparing the results of FEM and those of the experiment. As a result, it is shown that the characteristics of prototype control rod position indicator have a good agreement with the results of FEM.

A Research on Optimization of Lead-lag Controller Setpoint for Rod control system to prevent fluctuation for NPP (원전 제어봉제어계통 순시변동을 방지하기위한 지상-지연회로 설정치 최적화 연구)

  • Yoon, Duk-Joo;Lee, Jae-Yong;Kim, In-Hwan;Kim, Joo-Sung
    • Proceedings of the KSME Conference
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.1149-1154
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    • 2007
  • Fluctuation of control rod was experienced when plant was operating in normal operation mode in WH type NPPs. In order to cope with increased control rod fluctuation, the lead-lag controller setpoint for rod control system was optimized and resulted in increasing the margin of operation and minimizing unnecessary control rod movement. By optimization of the time constant, the margin of operation was increased by $1.5^{\circ}F$ and the control rod movement was not occurred due to mitigation of temperature fluctuation in loop. According to the mitigation of time constant, the margin of operation was increased but safety margin can be affected badly, so that the influences to FSAR design reference was evaluated. As the result of this evaluation, it satisfied the design reference of the existing safety analysis and was applied to NPP after obtaining the approval.

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Stable Control-rod Double Hold Method of Control Rod Drive Mechanism (원자로 제어봉구동장치의 안정적 제어봉 이중 유지 방법)

  • Cheon, Jong-Min;Kim, Choon-Kyung;Lee, Jong-Moo;Jung, Soon-Hyun;Kim, Seog-Ju;Kwon, Soon-Man
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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    • pp.555-558
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    • 2003
  • 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 laking a control rod assembly. If a gripper with any problem is ordered to grip the drive rod, the gripper which cannot latch the rod stably will fail to take the rod. On the purpose of escaping this bad case, we order two grippers to hold the drive rod and enhance the reliability of holding control rods. This action is called the double hold. 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.

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A Power Control System for the Rod Drive Coil of Control Element Drive Mechanism in Pressurized Water Reactor

  • Hwang, Dong-Hwan;Seong, Se-Jin;Park, Gwang-Seok
    • Nuclear Engineering and Technology
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    • 제31권1호
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    • pp.1-8
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    • 1999
  • In this paper, we propose a new type of power control system for the rod drive coil of the CEDM of the PWR NPP in order to supply more reliable DC power The electrical modelling of the controlled rod drive coil was done by referring related documentations. The design of the proposed system is based on this electric81 model satisfying the existing specification. A high power DC-DC converter scheme is adopted utilizing the SMPS technique in the design of the proposed system. In order to show the effectiveness of the proposed system, an experimental system with the capability of 3.2 K Watt was set up for a rod with four cores and some computer simulations and experimentations were carried out. The result shows a very similar tracking performance with that of the existing system to the driving command. As a result of this, the proposed method can be applied to the power control system for the rod drive coil of the CEDM of the PWR NPP.

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THE RELIABILITY PREDICTION OF CONTROL CABINET OF CONTROL ROD CONTROL SYSTEM (제어봉 제어 시스템의 제어함에 대한 RBD 분석)

  • Jung, Hae-Won;Sur, Jung-Suk;Yook, Sim-Kyun;Nam, Jung-Han
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2003년도 하계학술대회 논문집 D
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    • pp.2055-2057
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    • 2003
  • This paper describes the results of RBD(Reliability Block Diagram) analysis of control rod control system, which is being developed as part of KNICS project. The results of RBD indicate unavailability of control cabinet for control rod control system. A purpose of RBB is to evaluate unavailability of control cabinet, identify the design drawbacks of control cabinet, and propose design improvement to a designer to help design the more reliable control rod control system. This RBD defines the logical interaction of failure within a system.

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