• Proceedings of the KIEE Conference
• /
• 2004.07d
• /
• pp.2200-2202
• /
• 2004

This paper deals with the design of the Control Cabinet in Control Rod Control System(CRCS), 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 skill 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 our own I&C system by applying this domestic DCS to nuclear I&C system and confirming its successful operation, in this paper.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.14 no.3
• /
• pp.23-30
• /
• 2010

Seismic qualification (SQ) is required prior to the installation of safety related electrical cabinets in nuclear power plants (NPPs). Modal identification of the electrical equipment is one of the most significant steps to perform SQ, and is an essential process to construct a realistic analytical model. In this study, shaking table tests were conducted to identify a variation of the dynamic characteristics of a seismic monitoring system cabinet installed in NPPs according to the excitation level. Modal identification of the cabinet has been performed by a frequency domain decomposition method. The results of this study show that the dynamic properties of the cabinet are nonlinearly varied according to the excitation level and the specimen behaves significantly in a nonlinear manner under safe shutdown earthquake motion in Korea. The main sources of the nonlinear behavior of the specimen have been judged by friction forces and geometrical nonlinearity rather than material nonlinearity. The nonlinear variation of the dynamic characteristics of the electrical cabinet might be accepted as an important fact that should be considered during the SQ of safety related equipment.

• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.3524-3528
• /
• 2007

In this study, the Peltier effect was applied to eliminate moistures in the air enclosed by a cabinet. We have developed the new electronic dehumidifier which has a new function of automatically evaporating the condensed water inner cabinet into the outside air. To obtain this function, the processes of dehumidification is that it condensed the moistures on the cold side heat sink and drained it into the hot side heat sink by the both gravitational and capillary forces and the droplets on the hot side heat sink surface was evaporated into the air outside the cabinet by the heat conducted through the hot side heat sink surface and the forced heat convection through the fan for cooling hot side heat sink. Compared to existing electronic dehumidifiers, this manufactured one showed a good performance that the electric power consumption for the same dehumidifying quantity was reduced by 50% compared with that of existing ones.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.24 no.2
• /
• pp.103-110
• /
• 2020

Seismic qualification of instruments and devices mounted on electrical cabinets in a nuclear power plant is performed in this study by means of the in-cabinet response spectrum (ICRS). A simple method and two rigorous methods are proposed in the EPRI NP-7146-SL guidelines for generating the ICRS. The simple method of EPRI can give unrealistic spectra that are excessively conservative in many cases. In the past, the time domain analysis (TDA) methods have been mostly used to analyze a structure. However, the TDA requires the generation of an artificial earthquake input motion compatible to the target response spectrum. The process of generating an artificial earthquake may involve a great deal of uncertainty. In addition, many time history analyses should be performed to increase the accuracy of the results. This study developed a numerical analysis program for generating the ICRS by frequency domain analysis (FDA) method. The developed program was validated by the numerical study. The ICRS calculated by FDA thoroughly matched with those obtained from TDA. This study then confirms that the method it proposes can simply and efficiently generate the ICRS compared to the time domain method.

• Fire Science and Engineering
• /
• v.31 no.2
• /
• pp.52-60
• /
• 2017

Numerical simulations were performed to evaluate the habitability of an operator for a cabinet fire in the main control room of a nuclear power plant presented in NUREG-1934. To this end, a Fire Dynamics Simulator (FDS), as a representative fire model, was used. As the criteria for determining the habitability of operator, toxic products, such as CO, were also considered, as well as radiative heat flux, upper layer temperature, smoke layer height, and optical density of smoke. As a result, the probabilities of exceeding the criteria for habitability were evaluated through the sensitivity analysis of the major input parameters and the uncertainty analysis of fire model for various fire scenarios, based on V&V (Verification and Validation). Sensitivity analyses of the maximum heat release rate, CO and soot yields, showed that the habitable time and the limit criterion, which determined the habitability, could be changed. The present methodology will be a realistic alternative to enhancing the reliability for a habitability evaluation in the main control room using uncertain information of cabinet fires.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.12 no.5
• /
• pp.57-63
• /
• 2008

This paper presents a seismic response prediction method using vibration tests of cabinet-type electrical equipment installed in a nuclear power plant. The proposed method consists of three steps: 1) identification of earthquake-equivalent forces based on lumped-mass system idealization, 2) identification of a state-space-equation model relating input-output measurements obtained from the vibration tests, 3) seismic prediction using the identified earthquake-equivalent forces and the identified state-space-equation. The proposed method is advantageous compared to other methods based on FEM (finite element method) model update, since the proposed method is not influenced by FEM modeling errors. Through a series of numerical verifications on a frame model and 3-dimensional shell model, it was found that the proposed method could be used to accurately predict the seismic responses, even under considerable measurement noise conditions. Experimental validation is needed for further study.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.8
• /
• pp.1617-1621
• /
• 2011

In this paper, in order to reduce the electrical disaster such as electrical fire at traditional markets, we need to develop the circuit breaker which is able to monitor the power status of electrical equipments. Therefore, for solving the those problems, we developed the detection censor(ZCT, CT) and equipment of data analysis and transmission. The detection censor and equipment is able to monitor the electrical equipments condition(over current, leakage current, arc, etc.). We constructed Test-Bed for testing reliability of the circuit breaker and obtained certification. And we tested the over current, leakage current and arc under the normal condition. This paper will be used to the data for development an cabinet panel which is able to monitor the actual loads.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.25 no.7
• /
• pp.92-96
• /
• 2011

In this paper, in order to reduce the electrical disaster such as electrical fire at traditional markets, we need to develop the ESMS(electrical safety monitoring system) which is able to monitor the power status of electrical equipments. Therefore, for solving the those problems, we developed the detection censor(ZCT, CT) and equipment of data analysis and transmission. The detection censor and equipment are able to monitor the electrical equipments condition(over current, leakage current, arc, etc.). We constructed Test-Bed for testing reliability of the ESMS and obtained certification. And we tested the over current, leakage current and arc under the normal condition.

• Journal of Advanced Marine Engineering and Technology
• /
• v.22 no.6
• /
• pp.871-879
• /
• 1998

The refrigerator consists of many components such as compressor condenser expansion valve evaporator and the cabinet which filled by urethane foam. In this paper the heat leakage of refriger-ator is measured by the new experiment method which is different from a present method, The devi-ation of the UA(overall heat transfer coefficient times area) between the simulation and experiments is about 7-8%. Using the modeling of various components of refrigeration system a performance analysos of CFC 12 and HFC 134a is performed numerically on the UA. As the results of this study according to increase the heat leakage the refrigeration load and mass flow rate of refrigerant are increased. And the increase of the mass flow rate results in the increase of the condensing and evapo-rating temperature. Therefore according to increase of the heat leakage the COP leads to increase because the increase of refrigeration capacity is larger than the increase if compressor power.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.5
• /
• pp.593-602
• /
• 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.