• Nuclear Engineering and Technology
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• v.44 no.2
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• pp.161-176
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• 2012

McCARD is a Monte Carlo (MC) neutron-photon transport simulation code. It has been developed exclusively for the neutronics design of nuclear reactors and fuel systems. It is capable of performing the whole-core neutronics calculations, the reactor fuel burnup analysis, the few group diffusion theory constant generation, sensitivity and uncertainty (S/U) analysis, and uncertainty propagation analysis. It has some special features such as the anterior convergence diagnostics, real variance estimation, neutronics analysis with temperature feedback, $B_1$ theory-augmented few group constants generation, kinetics parameter generation and MC S/U analysis based on the use of adjoint flux. This paper describes the theoretical basis of these features and validation calculations for both neutronics benchmark problems and commercial PWR reactors in operation.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.71.1-71.1
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• 2012

Proton Exchange Membrane Fuel Cells (PEMFCs) have been of great interest particularly in the automobile industries because of their high energy density and low pollutant emission. However, some of the issues such as, the necessarily high contents of Pt catalysts and their slow kinetics of cathode oxygen reduction reaction remain as obstacles in the commercialization of the PEMFC. In this presentation, after brief explanation on basic principles of PEMFC and its application to FC vehicles, recent researches to improve the activity and durability of Pt-based nano catalysts toward oxygen reduction will be introduced. It covers size and shape control of Pt nano particle, binary and ternary Pt-M alloys, novel core-shell nano structures of Pt, and a little bit about non-Pt catalysts. Strategies and methodologies for design and synthesis of novel catalysts will also be included.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.429-436
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• 1997

운전원 훈련용 시뮬레이터의 국산화 개발계획에 따라 영광 원자력 3,4호기 발전소 운전원 훈련용 시뮬레이터가 국내 최초로 개발되었다. STK(space and time kinetics)와 RETACT (Real Time Advanced Core and Thermohydraulics)코드를 이용하여 영광 3,4호기 시뮬레이터의 실시간 NSSS 모델을 생성하였다. 생성된 모델의 검증(Verification Validation)을 위해 정상상태(Steady State)에서의 주요인자들이 ANS3.5의 오차범위이내임을 확인하였다. 과도상태(Transient)의 검증을 위해 터빈정지 과도상태와 주증기 관파열(Main Steam Line Rupture)사고를 실제 발전소 시험 데이터 및 성능해석 코드(NPA)를 이용하여 분석한 결과와 비교하였다. 비교 결과 기준발전소의 반응과 큰 차이 없이 운전원 훈련용 시뮬레이터의 규격인 ANS 3.5를 잘 만족함을 확인 할 수 있었다.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.605-610
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• 1997

A simple dynamic model is developed for the transient simulation of the nuclear power reactor. The dynamic model includes the normalized neutron kinetics model with reactivity feedback effects and the core thermal-hydraulics model. The main objective of this paper demonstrates the capability of the developed dynamic model to simulate various important variables of interest for a nuclear power reactor transient. Some representative results of transient simulations show the expected trends in all cases, even though no available data for comparison. In this work transient simulations are performed on a microcomputer using the DESIRE/N96T continuous system simulation language which is applicable to nuclear power reactor transient analysis.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.1
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• pp.24-33
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• 1997

In this paper, aging of insulating oil in pole transformer has been studied by performing accelerated thermal aging test. Dissolved gases were extracted by air bubbling method. Concentration of dissolved gases were modified by extraction ratio of each gases in insulting oil. Aging of insulting materials were proceeded by thermal degradation and oxidation reaction. Both of the reactions followed zeroth order kinetics. Formation rate equations for hydrocarbons, carbon oxides, and hydrogen were derived. It was conformed by gas analysis and UV-visible spectrophotometric method that iron core and copper coil in pole transformer act as catalyst during the aging process.

• Nuclear Engineering and Technology
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• v.49 no.6
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• pp.1339-1345
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• 2017

In the framework of the EU funded project NURESAFE, the subchannel code CTF and the neutronics code DYN3D were integrated and coupled on the NURESIM platform. The developments achieved during this 3-year project include assembly-level and pin-by-pin multiphysics thermal hydraulics/neutron kinetics coupling. In order to test this coupling, a PWR rod ejection transient was simulated on a MOX/UOX minicore. The transient is simulated using two different models of the minicore. In the first simulation, both codes model the core with an assembly-wise resolution. In the second simulation, a pin-by-pin fuel-centered model is used in CTF for the central assembly, and a pin power reconstruction method is applied in DYN3D. The analysis shows the influence of the different models on global parameters, such as the power and the average fuel temperature, but also on local parameters such as the maximum fuel temperature.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.05a
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• pp.119-126
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• 1999

농축우라늄 고체핵연료를 사용하는 기존의 발전용 원자로 개념에서는 냉각기능의 상실 또는 반응도 상실사고와 같은 극심한 열적 불균형에 의해 핵연료의 온도가 급격히 증가하고, 결과적으로 핵연료의 파손 및 용융으로 발전할 수 있다. 본 연구는 이러한 기존 발전로의 고유 안정성 문제를 획기적으로 해결할 수 있는 혁신형으로서 Th/$^{233}$ U 용융염핵연료주기를 사용하며 원자로계통 전체를 원자로용기에 내장하는 일체형 원자로개념의 AMBIDEXTER (Advanced Molten-salt Break-even Inherently-safe Dual-mission Experimental and TEst Reactor) 원자력 에너지시스템의 동특성을 해석하기 위해 수행되고 있다.(중략)

• Nuclear Engineering and Technology
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• v.49 no.5
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• pp.920-927
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• 2017

With ever-advancing computer technology, the Monte Carlo (MC) neutron transport calculation is expanding its application area to nuclear reactor transient analysis. Dynamic MC (DMC) neutron tracking for transient analysis requires efficient algorithms for delayed neutron generation, neutron population control, and initial condition modeling. In this paper, a new MC steady-state simulation method based on time-dependent MC neutron tracking is proposed for steady-state initial condition modeling; during this process, prompt neutron sources and delayed neutron precursors for the DMC transient simulation can easily be sampled. The DMC method, including the proposed time-dependent DMC steady-state simulation method, has been implemented in McCARD and applied for two-dimensional core kinetics problems in the time-dependent neutron transport benchmark C5G7-TD. The McCARD DMC calculation results show good agreement with results of a deterministic transport analysis code, nTRACER.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.52-71
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• 2018

RO membranes, the core elements for RO process formed using polyamide, have found prominent space in membrane technology. RO membranes with better application perspective could be achieved by precise controlling the kinetics of IP reaction and surface modification strategy. Despite huge progresses, great challenges still exist in trade-off between flux, rejections and fouling. More works are necessary to enhance the performance and stability of RO membranes via surface modification. Further insights into the use of natural monomers are necessary. It is anticipated that this article can provide clues for further in-depth evaluation and research in exploring more advanced RO membranes.

• Journal of the Korean Institute of Gas
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• v.6 no.4 s.18
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• pp.8-16
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• 2002

Since hydrate has been discovered on the earth, many numbers of experimental studies have been conducted for characterizing the fundamental properties of hydrates, such as equilibrium conditions, thermodynamic properties, structures, kinetics, etc. It is considered naturally occurred hydrates in porous rocks have a great potential as a future of unconventional energy resources, and the investigations of formation and dissociation of hydrates in porous media are required. In this study, an experimental apparatus was designed to perform experiments of hydrates in porous core. With the apparatus developed, firstly, isochoric experiments were conducted to find hydrate equilibrium conditions in porous media, and the results were compared with reference data to verify experimental apparatus and methods in this study. Secondly, experiment of formation was examined by observing the behaviors of pressure and electrical resistance and the effects of initial water saturation on formation were analysed.