• Nuclear Engineering and Technology
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• v.33 no.2
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• pp.209-224
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• 2001

The SSC-K system analysis code is under development at the Korea Atomic Energy Research Institute (KAERI) as a part of the KALIMER project. The SSC-K code is being used as the principal tool for analyzing a variety of off-normal conditions or accidents of the preliminary KALIMER design. The SSC-K code features a multiple-channel core representation coupled with a point kinetics model with reactivity feedback. It provides a detailed, one-dimensional thermal-hydraulic simulation of the primary and secondary sodium coolant circuits, as well as the balance-of-plant steam/water circuit. Recently a two-dimensional hot pool model was incorporated into SSC-K for analysis of thermal stratification phenomena in the hot pool. In addition, SSC-K contains detailed models for the passive decay heat removal system and a generalized plant control system. The SSC-K code has also been applied to the computational engine for an interactive simulation of the KALIMER plant. This paper presents an overview of the recent activities concerned with SSC-K code model development This paper focuses on both descriptions of the newly adopted thermal hydraulic and neutronic models, and applications to KALIMER analyses for typical anticipated transients without scram.

• Nuclear Engineering and Technology
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• v.50 no.3
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• pp.504-511
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• 2018

In Lithuania, all spent nuclear fuel (SNF) resulted from the operation of the Ignalina Nuclear Power Plant (INPP), which had two Russian Acronym for "Channelized Large Power Reactor"-type reactors. After the final shutdown, the total amount of SNF at the INPP was approximately 22,000 fuel assemblies. All these assemblies will be stored for about 50 years and disposed of after that. The decision to shut down and decommission both reactors in Lithuania before termination of design period raises a significant challenge for the treatment of accumulated SNF. Therefore, various techniques and technologies for SNF management were developed and justified for that specific case, and a set of special equipment was installed at the INPP, the effectiveness of which was demonstrated during its operation. This article presents unique techniques related to the management of SNF adopted and commissioned at the INPP after its operation shutdown, namely fuel rod cladding leak tightness control system and special equipment for collection of possible spillage during handling of SNF assembly in the hot cell. The operational experience and measurement results of fuel rod cladding leak tightness control system are presented.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.1
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• pp.23-33
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• 2011

This experimental focus to characterize luminescence properties related to CNT (Carbon Nano Tube) element dispersedly implanted in ZnS-based phosphor thin film panel fabricated by a screen printing method. More specifically FE-SEM measurements, L-V(Luminescence vs. Voltage) and photo luminescence were carried out to determine an optimum value of CNT concentration and film thickness for the thin film structure of CNT-ZnS:(Cu, Al) by the screen printing method. We confirmed that an optimum value of CNT concentration in the ZnS:(Cu, Al) film panel is about 0.75 wt% resulting that the electric conductivity is 1.6 times higher than that of pure CNT sample and showing that the luminescence intensity is increasing until the optimum concentration. Clearly, CNT is presenting in the luminescence process providing a pathway for the creation of hot electron and a channel for the electron-hole recombination but overly inserted CNT may hinder to produce the hot electron for making an avalanching process. In case of the overly doped CNT 1.0 wt% in the ZnS-based phosphor, the luminescence intensity is decreasing although the electric conductivity is exponentially increasing. Based on these results, we realized that hot electron occurred by the external electric field or exciton arose by the external photon source are reduced dramatically over the critical value of CNT concentration because CNT element provide various isolated residues in the composites of ZnS based phosphor rather than pathway or channel for the D-A(Donnor to Acceptor) pair transition or the radiative recombination of electron-hole.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.231-234
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• 2010

Analysis of conjugated heat transfer has been conducted for the diffuser exposed to hot combustion gas to design the mechanical durability in high temperature. All the heat transfer means, conduction, convection and radiation have been considered to calculate the total heat flux from hot gas to diffuser surface. The calculation has been implemented by two kinds of methods. One thing is one dimensional method based on empirical equations. The other is CFD(Computational Fluid Dynamics) axisymmetric calculation containing ${\kappa}-{\omega}$ SST(Shear Stress Transport) turbulent model and DO(Discrete Ordinate) radiation model. The derived results of two methods have compared and showed similar values. From this result, the amount of cooling water and the dimension of water cooling channel were decided.

• Journal of the Korean Vacuum Society
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• v.2 no.2
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• pp.188-198
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• 1993

We have developed a technique for growing thin oxides (6~10 nm) by the Last step TCA method. N-channel metal-oxide-semiconductor (n-MOS) capacitor and n-channel metal-oxide-semiconductor field-effect transistor's (MOSFET's) having a gate oxide with chlorine incorporated $SiO_2/Si$ interface have been analyzed by electrical measurements and physical methods, such as secondary ion mass spectrometry (SIMS) and electron spectroscopy for chemical analysis (ESCA). The gate oxide grown with the Last strp TCA method has good characteristics as follows: the electron mobility of the MOSFET's with the Last step TCA method was increased by about 7% and the defect density at the $SiO_2/Si$ interface decreases slightly compared with that with No TCA method. In reliability estimation, the breakdown field was 18 MV/cm, 0.6 MV/cm higher than that of the gate oxide with No TCA method, and the lifetime estimated by TDDB measurement was longer than 20 years. The device lifetime estimated from hot-carrier reliability was proven to be enhanced. As the results, the gate oxide having a $SiO_2/Si$ interface incorporated with chlorine has good characteristics. Our new technique of Last step TCA method may be used to improve the endurance and retention of MOSFET's and to alleviate the degradation of thin oxides in short-channel MOS devices.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.6
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• pp.1291-1300
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• 2020

Recently, a deep learning-based non-profiling side-channel analysis was proposed. The deep learning-based non-profiling analysis is a technique that trains a neural network model for all guessed keys and then finds the correct secret key through the difference in the training metrics. As the performance of non-profiling analysis varies greatly depending on the neural network training model design, a correct model design criterion is required. This paper describes the two types of loss functions and eight labeling methods used in the training model design. It predicts the analysis performance of each labeling method in terms of non-profiling analysis and power consumption model. Considering the characteristics of non-profiling analysis and the HW (Hamming Weight) power consumption model is assumed, we predict that the learning model applying the HW label without One-hot encoding and the Correlation Optimization (CO) loss will have the best analysis performance. And we performed actual analysis on three data sets that are Subbytes operation part of AES-128 1 round. We verified our prediction by non-profiling analyzing two data sets with a total 16 of MLP-based model, which we describe.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.1
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• pp.49-59
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• 2005

The evaporation heat transfer experiments are conducted with the shell and plate heat exchanger (S&PHE) without oil in the refrigerant loop using R-410A. An experimental refrigerant loop has been established to measure the evaporation heat transfer coefficient h. of R-410A in a vertical S&PHE. Two vertical counter flow channels were formed in the S&PHE by three plates haying a corrugated trapezoid shape of a $45^{\circ}C$ chevron angle. UP flow of the boiling R-410A in one channel receives heat from the hot down flow of water in the other channel The effects of the refrigerant mass flux. average heat flux. refrigerant saturation temperature and vapor qualify are explored in detail. Similar to the case of a plate heat exchanger. even at a very low Reynolds number, the flow in the S&PHE remains turbulent. The Present data shows that the evaporation heat transfer coefficients of R-410A increased with the vapor qualify. The results indicate a rise in the refrigerant mass flux caused an increase in the h.. Raising the imposed wall heat flux is found to slightly improve h., while h, is found to be lower at a higher refrigerant saturation temperature. Based on the present data. empirical correlation of the evaporation heat transfer coefficient is proposed.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.6
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• pp.1026-1036
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• 2004

In this study, single-phase heat transfer experiments were conducted with Oblong Shell and Plate heat exchanger using water. An experimental water loop has been developed to measure the single-phase heat transfer coefficient and pressure drop in a vertical Oblong Shell and Plate heat exchanger. Downflow of hot water in one channel receives heat from the cold water upflow of water in the other channel. Similar to the case of a plate heat exchanger, even at a very low Reynolds number, the flow in the Oblong Shell and Plate heat exchanger remains turbulent. The present data show that the heat transfer coefficient and pressure drop increase with the Reynolds number. Based on the present data, empirical correlations of the heat transfer coefficient and pressure drop in terms of Nusselt number and friction factor were proposed. Also, performance prediction analyses for Oblong Shell and Plate heat exchanger were executed and compared with experiments. $\varepsilon$-NTU method was used in this prediction program. Independent variables are flow rates and inlet temperatures. Compared with experimental data, the accuracy of the program is within the error bounds of $\pm$5% in the heat transfer rate.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.2
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• pp.74-79
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• 2018

In this report, the results of a systematic study on the effects of polycrystalline silicon gate depletion on the reliability characteristics of metal-oxide semiconductor field-effect transistor (MOSFET) devices were discussed. The devices were fabricated using standard complimentary metal-oxide semiconductor (CMOS) processes, wherein phosphorus ion implantation with implant doses varying from $10^{13}$ to $5{\times}10^{15}cm^{-2}$ was performed to dope the polycrystalline silicon gate layer. For implant doses of $10^{14}/cm^2$ or less, the threshold voltage was increased with the formation of a depletion layer in the polycrystalline silicon gate layer. The gate-depletion effect was more pronounced for shorter channel lengths, like the narrow-width effect, which indicated that the gate-depletion effect could be used to solve the short-channel effect. In addition, the hot-carrier effects were significantly reduced for implant doses of $10^{14}/cm^2$ or less, which was attributed to the decreased gate current under the gate-depletion effects.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.7
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• pp.6-12
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• 2007

A flat fluorescent lamp (FFL) developed as a light source for LCD TV backlight was used as a light source for general lighting application and its electro-optical characteristics were measured and evaluated. The channels of FFL were formed from a flat glass at high temperature by using a mold. The performance of FFL with lighting future was shown to improve by optimizing the channel profile of FFL. In this paper, the brightness efficiency of FFL with lighting fixture was evaluated and compared with that of the hot cathode fluorescent lamp (HCFL), the major light source for general lighting. The optical efficiency of FFL with future was shown to be 72.7[1m/W].