• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1331-1344
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• 2021

This study is to evaluate the seismic capacity of the fire-damaged cabinet facility in a nuclear power plant (NPP). A prototype of an electrical cabinet is modeled using OpenSees for the numerical simulation. To capture the nonlinear behavior of the cabinet, the constitutive law of the material model under the fire environment is considered. The experimental record from the impact hammer test is extracted trough the frequency-domain decomposition (FDD) method, which is used to verify the effectiveness of the numerical model through modal assurance criteria (MAC). Assuming different temperatures, the nonlinear time history analysis is conducted using a set of fifty earthquakes and the seismic outputs are investigated by the fragility analysis. To get a threshold of intensity measure, the Monte Carlo Simulation (MCS) is adopted for uncertainty reduction purposes. Finally, a capacity estimation model has been proposed through the investigation, which will be helpful for the engineer or NPP operator to evaluate the fire-damaged cabinet strength under seismic excitation. This capacity model is presented in terms of the High Confidence of Low Probability of Failure (HCLPF) point. The results are validated by the proper judgment and can be used to analyze the influences of fire on the electrical cabinet.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2144-2145
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• 2011

We carry out a demonstration project to verify performance of a Home- Smart Cabinet Panel(H-SCP) at the child care facility. It is difficult to prevent an electrical disaster using a existing cabinet panel because electrical events are invisible and unforeseeable. So we construct a integrated information system with a Home-Smart Cabinet Panel(H-SCP) for management of low-voltage customers. The integrated information system with the H-SCP maintain the transmitted data from H-SCP, alert a electrical event to a administrator and show a state of customer health in real time respectively. A manager of electrical safety can prevent electrical disaster to maintain electrical facilities after analysis on the integrated information system.

• Journal of the Korean Institute of Gas
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• v.26 no.5
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• pp.35-40
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• 2022

PCVD (Plasma Chemical Vapor Deposition), a solar cell manufacturing facility, is a facility that deposits plasma generated in a chamber (NH₃, SIH₄, O₂ on a wafer. In the PCVD facility, gas movement and injection is performed in the gas cabinet, and there are many leak points inside because MFC, regulator, valve, pipe, etc. are intricately connected. In order to prevent explosion in case of leakage of NH₃ with an upper explosive limit (UEL) of 33.6% and a lower explosive limit (LEL) of 15%, the dilution capacity must be capable of allowing the concentration of NH₃ to be out of the explosive range. This study was analyzed using the CFD analysis technique, which can confirm the dilution ability in 3D and numerical values when NH₃ gas leaks from the existing PCVD gas cabinet. As a result, it was concluded that it corresponds to medium dilution and that testicular ventilation is possible through facility improvement.

• Nuclear Engineering and Technology
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• v.53 no.9
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• pp.3100-3111
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• 2021

Numerical modeling for the safety-related equipment used in a nuclear power plant (i.e., cabinet facilities) plays an essential role in seismic risk assessment. A full finite element model is often time-consuming for nonlinear time history analysis due to its computational modeling complexity. Thus, this study aims to generate a simplified model that can capture the nonlinear behavior of the electrical cabinet. Accordingly, the distributed plasticity approach was utilized to examine the stiffness-degradation effect caused by the local buckling of the structure. The inherent dynamic characteristics of the numerical model were validated against the experimental test. The outcomes indicate that the proposed model can adequately represent the significant behavior of the structure, and it is preferred in practice to perform the nonlinear analysis of the cabinet. Further investigations were carried out to evaluate the seismic behavior of the cabinet under the influence of the constitutive law of material models. Three available models in OpenSees (i.e., linear, bilinear, and Giuffre-Menegotto-Pinto (GMP) model) were considered to provide an enhanced understating of the seismic responses of the cabinet. It was found that the material nonlinearity, which is the function of its smoothness, is the most effective parameter for the structural analysis of the cabinet. Also, it showed that implementing nonlinear models reduces the seismic response of the cabinet considerably in comparison with the linear model.

• Steel and Composite Structures
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• v.36 no.1
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• pp.17-29
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• 2020

This paper presents experimental and numerical studies on the seismic responses of the steel cabinet facility considering the nonlinear behavior of connections and site-response effects. Three finite element (FE) models with differences of type and number of connections between steel plates and frame members have been developed to demonstrate adequately dynamic responses of structures. The screw connections with the bilinear force-deformation relationship are proposed to represent the inelastic behavior of the cabinet. The experiment is carried out to provide a verification with improved FE models. It shows that the natural frequencies of the cabinet are sensitive to the plate and frame connectors. The screw connections reduce the free vibration compared to the weld one, with decreased values of 2.82% and 4.87% corresponding to front-to-back and side-to-side directions. Additionally, the seismic responses are investigated for various geological configurations. Input time histories are generated so that their response spectrums are compatible with a required response spectrum via the time-domain spectral matching. The results indicate that both site effects and nonlinear behavior of connections affect greatly on the seismic response of structures.

• Nuclear Engineering and Technology
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• v.52 no.6
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• pp.1318-1326
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• 2020

Structural modification in the electrical cabinet is investigated by a proposed procedure that comprises of an experimental, analytical and numerical solution. This research emphasizes the linear dynamic analysis of the cabinet that is studied under the seismic excitation to demonstrate the real behavior of the cabinets in NPP. To this end, an actual electric cabinet is experimentally tested using an impact hammer test which reveals the fundamental parameters of the cabinet. The Frequency-domain decomposition (FDD) method is used to extract the dynamic properties of the cabinet from the experiment which is then used for numerical modeling. To validate the dynamic properties of the cabinet an analytical solution is suggested. The calibrated model is analyzed under the floor response obtained from the Connecticut nuclear power plant structure excited by Tabas 1978 (Mw 7.4) earthquake. Eventually, the grouping effect of the cabinets is proposed which represents the influence on the dynamic modification. This grouping of the cabinets is described more sophisticatedly by the theoretical understating, which results in a significant change in the seismic response. Considering the grouping effects will be helpful in the assessment of the real seismic behavior, design, and performance of cabinets.

• Journal of the Korean Institute of Gas
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• v.24 no.5
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• pp.74-81
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• 2020

In general, when manufacturing a semiconductor, a number of hazardous and dangerous substances such as flammability, toxic, and corrosiveness are used. In particular, semiconductors are manufactured using specialty gas in processes such as CVD and etching. The specialty gas is filled in a container in the state of compressed or liquefied gas, and a gas cylinder cabinet is used as a facility for supplying this specialty gas to the semiconductor manufacturing process. When a accident occurs in the gas supply system, gas is released through a pressure release device installed in the gas cylinder to secure the safety of the supply system. In this case, the gas released inside the gas cabinet, there is a risk of leaking to the outside. After that, by analyzing the gas flow in the gas cabinet, it is intended to identify the risk associated with leak and to provide measures to prevent accidents.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.50-55
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• 2018

Earthquakes are almost impossible to predict and take place in a short time. In addition, there is little time to take aggressive action when an earthquake occurs. Therefore, there are more casualties and property damage than with other natural disasters. Recently, earthquakes have been occurring all over the world. As the number of earthquakes increase, studies on the safety of structures are being carried out. On the other hand, there are few studies on the electric facilities, which are relatively non - structural factors. Currently, electrical equipment in Korea is often not designed for earthquake safety and is quite vulnerable to damage when an earthquake occurs. Therefore, in this study, modeling was conducted through ABAQUS similar to an actual cabinet panel and 3D dynamic nonlinear analysis was performed using a natural seismic. According to seismic zone I and normal ground rock conditions of the power transmission and transmission facility seismic design practical guide, the maximum response acceleration of the performance level was 0.157g. In this study, however, it was not safe to reach the limit state of 30% of the analytical result at 0.1g for the general cabinet panel. From the results, the seismic fragility curve was derived and analyzed. The derived seismic fragility curve is presented as a quantitative basis for determining the limit state of the cabinet panel and can be utilized as basic data in related research.

• Journal of the Korean Institute of Gas
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• v.20 no.6
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• pp.80-88
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• 2016

A fire station and scuba have operated filling facilities for respiratory high-pressure cylinder without getting authority or reporting according to High-Pressure Gas Safety Control Act. They need facility improvement and special management to make provision for the time of accident during filling process. The Government have strived to correct illegal operations and suggested an alternative, establishing and operating the safety cabinet. It insures a safety being distance from danger caused by overpressure and a safety provoked by the protective wall equals or superiors. The safety cabinet is required to have an internal structure that smoothly distribute overpressure at the time of rupture. Plus, it needs to minimize fragments. It is also equipped with the performance of protective wall that makes overpressure to outside vent on the place where there is no person (top or bottom). This study calculated the consequence of physical explosion damage and built a prototype of safety cabinet. In addition, through the gas burst test, it derives for the ways to mitigate the physical explosion damage.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.583-588
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• 2004

Opening commercial service of KTX at the time of demanding more flexible train set for HONAM line and JEONLA line, it's necessary for the Korean High speed train, performing the stabilization; to modify the design in aspect of passenger and maintenance. In order to ensure the optimized interior design in Korean High speed train, it is necessary to review the major items such as disabled passenger facility, toilet, seat arrangement, compartment partition and door, access door, electrical cabinet, color and paint through the European standard and compare with other high speed train.