• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2396-2406
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• 2021

The Pacific Earthquake Engineering Research (PEER) Center has been developing a performance-based earthquake engineering (PBEE) methodology, which is based on explicit determination of performance, e.g., monetary losses, in a probabilistic manner where uncertainties in earthquake ground motion, structural response, damage estimation, and losses are explicitly considered. To carry out the PEER PBEE procedure for a component of the nuclear power plant (NPP) such as the cable tray system, hazard curve and spectra were defined for two hazard levels of the ground motions, namely, operation basis earthquake, and safe shutdown earthquake. Accordingly, two sets of spectral compatible ground motions were selected for dynamic analysis of the cable tray system. In general, the PBEE analysis of the cable tray in NPP was introduced where the resulting floor motions from the time history analysis (THA) of the NPP structure should be used as the input motion to the cable tray. However, for simplicity, a finite element model of the cable tray was developed for THA under the effect of the selected ground motions. Based on the structural analysis results, fragility curves were generated in terms of specific engineering demand parameters. Loss analysis was performed considering monetary losses corresponding to the predefined damage states. Then, overall losses were evaluated for different damage groups using the PEER PBEE methodology.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.4
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• pp.89-96
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• 2017

A cable tray is a structure made of metal or a non-combustible material that supports cables in the electrical wiring of buildings. Cable trays should be developed to meet the various requirements of the construction site. In this study, a design system was developed to calculate the maximum support load and the maximum deflection according to the cross-sectional shape of the cable tray. The cross-sections of cable trays were modeled by combining linear and arc elements, and cross-sectional characteristics such as the 2nd moment of area were calculated. The distributed load and the concentrated load were applied to the cable tray using the Euler beam theory, and then the deflection profiles and maximum stress were calculated. To verify the developed system, deflection distributions and maximum stresses for two types of cable trays were calculated and compared. The maximum deflection and maximum stress errors calculated from the developed system were found to be less than 4% compared with numerical analysis results.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.4
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• pp.143-149
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• 2018

A cable tray is a fixture to support and protect electrical and communication cables. In this study, a roll-forming analysis is conducted to produce an all-in-one cable tray. The number of process stands is calculated using an empirical formula. By applying bending methods to the design of the roll flower pattern, the final process stands and forming angles are determined. The shape and stress variations in the cable tray are modeled and observed by roll forming analysis using LS-DYNA Software. The width of the side rail and the maximum stress on all stands does not exceed the reference values. The forming machine and rolls are manufactured based on the results of the roll forming analysis. In addition, all-in-one cable trays satisfy the National Electrical Manufacturers Association standards when they are manufactured according to this design.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.4
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• pp.413-420
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• 2013

This paper includes the results of the electromagnetic finite element analysis with regard to overheating problem of the power cable tray due to asymmetric magnetic flux density. This phenomenon was experienced in the utility power plant, Korea. The influences of the power cable arrangements and material of the tray were analyzed to find the best solutions using the eddy current-thermal coupled analysis.

• Nuclear Engineering and Technology
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• v.53 no.10
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• pp.3314-3318
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• 2021

This paper presents a mode-matching analysis of the electromagnetic coupling between open cable trays in an indoor structure when an electric-line current is generated as an electromagnetic source. We validated the mode-matching method by comparing the mode-matching results with those computed from a commercial electromagnetic simulator and then investigated the strength of the electric-field coupled in a victim cable tray while varying the distances between cable trays and architectural surfaces. The results of this study provide geometrical information on the placement of open cable trays to avoid electromagnetic interference problems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.632-637
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• 2019

The cable tray design of an offshore plant production design is to optimally arrange the 3D modeling so that the cable can be installed without interfering with the structural members and various outfit equipment, and it is performed using a PDMS (Plant design management system), which is a 3D CAD system for an offshore plant layout. This study reviewed the development of PML (Programmable macro language) for a PDMS supporting offshore plant cable tray design and examined the efficiency compared to the existing method. Cable tray design PML developed in this paper enables fully parametric design using electrical outfit template library, allowing a rapid response to frequent modifications due to design changes and minimizing repetitive work fatigue by reflecting the accumulated design experience. In addition, the developed system was applied to the offshore plant structure module and it improved the work efficiency by more than 50% compared to the existing method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.607-614
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• 2016

In generating station, cable spreading design is a very important task, which is very much time consuming, due to the type of cable used in generating station is very diverse. The raceway means the cable line section from source equipment to destination, and consists of cable tray and conduit. The process of existing cable spreading design was written in by hand. Thereby, there are grossly inefficient gain such as cable omission and unfixed fill value by a personal and time investment. In this paper, we proposed and implemented the automated cable route design based flexible cable fill check in generating station, and proposed the automated cable route design can be calculated the cable fill with flexible changing of raceway. Some experimental result shows that implemented cable route design is well performed and conducted as the design specifications, and it will be able to reduce the cable spreading design time.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1571-1584
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• 2023

In this study, a numerical analysis was performed as part of an international joint research project to reproduce a real cable tray fire that occurred in the heater bay area of the turbine building of a nuclear power plant. A sensitivity analysis was performed on various input parameters to derive results consistent with the sprinkler activation time obtained from the fire event analysis. For all sensitive parameters, the normalized sprinkler activation time correlated well with the power function of the normalized sprinkler height. A correlation equation was developed to identify the sprinkler activation time at any location when determining the slope or fire growth rate under the conditions assuming a linear or t-squared heat release rate (HRR) time curve. Various cable fire growth assumptions were used to determine which assumption was better to provide the prediction coincident with the information given from the fire event analysis in terms of the sprinkler activation time and total energy generated from cables damaged by fire. In the comprehensive analysis of all the sensitive parameters, the standard deviation of the input parameters increased as the sprinkler height decreased. Within the range of the sensitivity parameter values given in this study, when considering all sprinkler heights, the standard deviation of the cable model change was the largest and that of the overhang position change was the smallest.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.109-110
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• 2011

• Journal of the Korean Society of Safety
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• v.28 no.3
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• pp.39-43
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• 2013

The present study has been conducted to investigate the fire combustion properties and fire behavior of an IEEE-383 qualified flame retardant cable. The reference reaction rate and reference temperature which are commonly used in pyrolysis model of fire propagation process was obtained by the thermo-gravimetric analysis of the cable component materials. The mass fraction of FR-PVC sheath abruptly decreased near temperature range of $250{\sim}260^{\circ}C$ and its maximum reaction rate was about $2.58{\times}10^{-3}$[1/s]. For the XLPE insulation of the cable, the temperature causing maximum mass fraction change was ranged about $380{\sim}390^{\circ}C$ and it has reached to the maximum reaction rate of $5.10{\times}10^{-3}$[1/s]. The flame retardant cable was burned by a pilot flame meker buner and the burning behavior of the cable was observed during the fire test. Heat release rate of the flame retardant cable was measured by a laboratory scale oxygen consumption calorimeter and the mass loss rate of the cable was calculated by the measured cable mass during the burning test. The representative value of the effective heat of combustion was evaluated by the total released energy integrated by the measured heat release rate and burned mass. This study can contribute to study the electric cable fire and provide the pyrolysis properties for the computational modeling.