• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.10-13
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• 2003

6.6㎸rms/200Arms DC reactor type superconducting fault current limiter (SFCL) has been developed. This paper deals with the manufacture and short-circuit test of the SFCL. DC reactor was the HTS solenoid coil whose inductance was 84mH. AC/DC power converter was performed as the dual-mode operation. The short-term run(1 sec) and short-circuit test of this SFCL was performed successfully. The experimental results have a similar tendency to the simulation results. In short-circuit test, at 2 cycles after the fault, fault current limitation rate was about 30％.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2001년도 춘계학술발표회요약집
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• pp.105.2-105
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• 2001

• Korean Chemical Engineering Research
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• 제46권1호
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• pp.82-87
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• 2008

Methane의 부분산화에 의하여 일산화탄소를 발생시키고 이를 이용하여 온실가스로 알려져 있는 $N_2O$를 분해시키기 위한 이중 촉매 반응시스템의 반응 특성을 살펴보았다. 일산화탄소를 발생시키기 위한 제1 반응기의 조건은 Co-Rh-Al (1/0.2/1) 촉매를 사용할 때 $500^{\circ}C$의 온도에서 methane과 산소의 비율이 5:1이고 GHSV $8,000h^{-1}$ 일때 가장 적합하였다. 제1 반응기에서 methane을 부분산화시켜 얻은 혼합 가스를 사용하는 이중 반응시스템에서 제2 반응기에 촉매로 Co-Rh-Al(1/0.2/1)과 Co-Rh-Zr-Al(1/0.2/0.3/1)을 사용한 경우 Co-Rh-Al(1/0.2/1) 촉매를 사용한 single bed system 보다 $250^{\circ}C$ 이하의 저온에서 우수한 분해성능을 나타내었다. 두 경우 모두 $250^{\circ}C$ 이상의 온도에서는 $N_2O$가 100% 분해되었다. 또한, 제2 반응기에서 $N_2O$ 분해성능은 NO의 존재 유무에 관계없이 산소의 농도가 증가할수록 감소함을 보여주었다. 다만 NO가 존재할 경우 산소의 농도가 10,000 ppm 이하일 때 100% 분해율을 보이며 그 이상일 경우 급격히 감소하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.556-558
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• 1994

This paper proposes a new converter that can reduce the harmonics like conventional 12-pulse dual thyrister converters with the input transformers. Both the bridges are controlled with the shifted firing angle and connected through current sharing reactors. Using the center tapped reactor, the DC link current is controlled with the different two values in order to make the input current waveform 12 pulses.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1998년도 춘계 학술발표회 논문집
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• pp.235-242
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• 1998

Aiming at one of decisive alternatives for long term aspect of nuclear power concerns, an integral and closed nuclear system, AMBIDEXTER (Advanced Molten-salt Break-even Inherently-safe Dual-mission Experimental and TEst Reactor) concept is under development. The AMBIDEXTER complex essentially comprises two mutually independent loops of the radiation/material transport and the heat/energy conversion, centered at the integrated reactor assembly, which enables one to utilize maximum benefits of nuclear energy under minimum risks of nuclear radiation. And it provides precious radioisotopes and radiation sources from its waste stream. Also the reactor operates at very low level of fission products inventory throughout its lifetime. The nuclear and thermalhydraulic characteristics of the molten TH/$^{233}$ U fuel salt extend the capability of the self-sustaining AMBIDEXTER fuel cycle to enhance resource security and safeguard transparency. The reactor system is consisted of a single component module of the core, heat exchangers and recirculation pumps with neither pipe connections nor active valves in between, which will significantly improve inherent features of nuclear safety. States of the core technologies associated with designing and developing the AMBIDEXTER concept are mostly available in commercialized form and thus demonstration of integral aspects of the concept should be the prime area in future R＆D programs.

• 한국초전도ㆍ저온공학회논문지
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• 제6권2호
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• pp.25-28
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• 2004

Three-phase inductive superconducting fault current limiter (SFCL) with DC reactor rated on 6.6 $KV_{rms}/200 A_{rms}$ has been developed in Korea. This system consists of one DC reactor, AC/DC power converter, and a three-phase transformer, which is called magnetic core reactor (MCR). This paper deals with the short-circuit analysis of the SFCL. The DC reactor was the HTS solenoid coil whose inductance was 84mH. The power converter was performed as the dual-mode operation for dividing voltage between the rectifying devices. The short-term normal operation (1 see) and short-circuit tests (2∼3 cycles) of this SFCL were performed successfully. In regular short-circuit test, the fault current was limited as 30% of rated short-circuit current at 2 cycles after the fault. The experimental results have a very similar tendency to the simulation results. Using the technique for the fault detection and SCR firing control, the fault current limiting rate of the SFCL was improved. From this research, the parameters for design and manufacture of large-scale SFCL were obtained.

• Nuclear Engineering and Technology
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• 제41권7호
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• pp.929-944
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• 2009

The present study is concerned with the extension of the Effective Convectivity Model (ECM) to the phase-change problem to simulate the dynamics of the melt pool formation in a Light Water Reactor (LWR) lower plenum during hypothetical severe accident progression. The ECM uses heat transfer characteristic velocities to describe turbulent natural convection of a melt pool. The simple approach of the ECM method allows implementing different models of the characteristic velocity in a mushy zone for non-eutectic mixtures. The Phase-change ECM (PECM) was examined using three models of the characteristic velocities in a mushy zone and its performance was compared. The PECM was validated using a dual-tier approach, namely validations against existing experimental data (the SIMECO experiment) and validations against results obtained from Computational Fluid Dynamics (CFD) simulations. The results predicted by the PECM implementing the linear dependency of mushy-zone characteristic velocity on fluid fraction are well agreed with the experimental correlation and CFD simulation results. The PECM was applied to simulation of melt pool formation heat transfer in a Pressurized Water Reactor (PWR) and Boiling Water Reactor (BWR) lower plenum. The study suggests that the PECM is an adequate and effective tool to compute the dynamics of core melt pool formation.

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2395-2406
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• 2023

To study the influence of parameter uncertainty in small pressurized water reactor (SPWR) once-through steam generator (OTSG), the nonlinear mathematical model of the SPWR is firstly established. Including the reactor core model, the OTSG model and the pressurizer model. Secondly, a control strategy that both the reactor core coolant average temperature and the secondary-side outlet pressure of the OTSG are constant is adopted. Then, the uncertainty quantification method is established based on Latin hypercube sampling and statistical method. On this basis, the quantitative platform for parameter uncertainty of the OTSG is developed. Finally, taking the uncertainty in primary-side flowrate of the OTSG as an example, the platform application work is carried out under the variable load in SPWR and step disturbance of secondary-side flowrate of the OTSG. The results show that the maximum uncertainty in the critical output parameters is acceptable for SPWR.

• 조명전기설비학회논문지
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• 제14권5호
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• pp.1-11
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• 2000

본 논문은 CANDU 형 원자력 발전소의 Dual Tower 종수증기 회수 계통을 경제적, 효율적으로 운천하기 위하여 PLC를 사용한 제어기를 개발한다. 기계식 타이머와 릴레이를 사용한 기존의 제어기의 문제점을 분석하고 해결힘으로써 향상된 운전 성능을 제공한다. 개발된 제어가는 PLC의 기능을 이용하여 시간제어와 노점제어를 결합한 형태의 제어 알고리즘 채용하고 각종 감시 및 보호기능을 추가함으로써 더욱 정밀하고 안전한 운전기능을 제공한다. 제안된 제어기를 사용함으로쩌 운전비용 및 성능 측면에서의 최적화를 얻을 수 있다.

• 한국항공우주학회지
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• 제34권3호
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• pp.87-92
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• 2006

고농도 과산화수소는 별도의 산화제가 필요치 않은 단일추진제로써 상온에서 액상인 장점이 있어 다양한 장치의 추진제로 이용되고 있다. 본 연구에서는 상온에서의 시동 성능 보완을 위해 이원 촉매층을 이용한 실험적인 연구를 수행하였다. 상온에서의 뛰어난 성능을 바탕으로 $K_2MnO_4$를 도입부의 촉매로 선정하였으며 이를 위해 알루미나 졸-겔법을 이용한 새로운 코팅법을 개발하였다. 가스발생기를 이용한 반응실험을 통해 설계유량에 적합한 기화기의 길이를 결정하였고 이를 이용한 이원 촉매 가스발생기의 성능평가를 수행하였다. 성능평가 결과, $10^{\circ}C$ 이하의 온도에서 냉시동(cold-start)에 성공하였으며 높은 분해효율을 확인하였다.