• 한국신뢰성학회지:신뢰성응용연구
• /
• 제10권1호
• /
• pp.57-64
• /
• 2010

The HANARO nuclear research reactor had been operated successfully and smoothly up to the year 2008 since its first year of instability in year 1995 just after the completion of construction. But the reliability of the reactor has been degraded from the year 2009 due to new experimental facilities such as Feul Test Loop(FTL) and Cold Neutron Source(CNS) which were installed in the HANARO plant. It turned out that these new facilities contributed unexpected stoppage of the plant. This paper describes causes of stoppage and suggestions to improve the reliability of the plant.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2003년도 춘계학술대회
• /
• pp.1897-1902
• /
• 2003

An 1/21.6 scaled experimental facility was prepared utilizing the results of a scaling analysis to simulate the APRI400 reactor and insulation system. The behaviors of the boiling-induced two-phase natural circulation flow in the insulation gap were observed, and the liquid mass flow rates driven by natural circulation loop were measured by varying the wall heat flux, upper exit slot area and configuration. And non-heating experiments have also been performed and discussed to certify the hydraulic similarity of the heating experiments by injecting air equivalent to the steam generated in the heating experimental condition.

• 한국가스학회:학술대회논문집
• /
• 한국가스학회 2007년도 춘계학술발표회 논문집
• /
• pp.27-32
• /
• 2007

Dimethyl Ether (DME, $CH_3OCH_3$) is the simplest ether and is considered as one of the leading candidates in the quest for a substitute fur petroleum-based fuels. In this work, we analyzed the one-step synthesis of DME in a shell and tube type fixed bed reactor and carried out a simulation with a one-dimensional, steady state model of a heterogeneous catalyst bed, while taking into consideration the heat and mass transfer between the catalyst pellets and reactants gas and the effectiveness factor of the catalysts, together with the reactor cooling through the reactor tube wall. The reactor simulation was carried out under steady state condition and we compared the simulation results with the experimental data obtained from operations of a pilot-scale reactor and found good agreement between them.

• 설비공학논문집
• /
• 제19권4호
• /
• pp.285-290
• /
• 2007

This study has been numerically conducted to investigate the removal efficiency of Volatile Organic Compound (VOC) in photocatalytic micro-reactor. This study has placed emphasis on the improvements of the working condition of photocatalytic micro-reactor. The micro-reactor consists of 19 microchannels with a rectangular cross-section. For the validation of the current numerical study, a computation has been carried out to simulate an existing experimental study on the cylindrical reactor, which has shown a good agreement. The degradation characteristics with different inlet concentrations and velocities have been obtained. The current results can be used for the design of advanced photocatalytic micro-reactor.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 C
• /
• pp.1777-1779
• /
• 2001

In this experiment, an attempt to use the sludge pellets as catalyst for NO removal from simulated gas is experimentally investigated by using cylinder type reactor. An experimental investigation has been conducted for NO concentration of 50[ppm], 100[ppm], 200[ppm] balanced with air. a gas flow rate of 5[1/min]. Cylinder type reactor is at upstream of system for corona discharge and packed bed type reactor filled with sludge pellets ate put at downstream of Cylinder type reactor for catalystic effect. And AC voltage to discharge the gases was supplied. In the result, NO removal with magnetic field is higher than that without magnetic field, when packed-bed reactor with sludge pellet is installed at downstream of cylinder reactor NO, $NO_2$ removal rate increased and $O_3$ is not generated.

• Nuclear Engineering and Technology
• /
• 제53권6호
• /
• pp.1731-1735
• /
• 2021

The operation of the nuclear reactor requires accurate and fast methods and techniques for analysing its kinetics. These techniques become even more important when the MOX-fuel is used due to the lower value of delayed neutron fraction 𝛽 for ²³⁹Pu. Based on a Birth-and-Death process review, the mathematical model of thermal reactor core has been proposed different from existing ones. The analytical method for thermal point-reactor parameters evaluation is described within this work. The proposed method is applied for analysis of the unsteady transient processes taking place in a thermal reactor at its start-up or shutdown power change, as well as during small accidental power variation from the rated value. Theoretical determination of MASURCA reactor core reactivity through the analysis of experimental data on neutron time spectra was made.

• 에너지공학
• /
• 제14권2호
• /
• pp.105-111
• /
• 2005

본 연구는 마이크로 채널 반응기를 이용하여 다양한 실험조건에서 D-glucose용액을 이용하여 광촉매 분해특성을 연구하였다. Titanium oxysulfate의 수산화반응을 통하여 합성한 $TiO_2$수용액을 이용하여 마이크로 채널 반응기에 $TiO_2$를 코팅하였다. D-glucose광촉매 분해특성은 반응기의 주입유속이 증가함에 따라 증가하는 것으로 나타났으며 반응속도 상수와 Langmuir 흡수 제수를 다양한 실험조건에서 계산하였다. 또한 반응 시스템에서의 광효율을 계산하였다 따라서 이 연구는 배치 시스템에 적용된 $TiO_2$코팅이 되어 있는 마이크로 채널 반응기의 광분해 특성을 이해하기 위한 것이다.

• 한국수소및신에너지학회논문집
• /
• 제25권4호
• /
• pp.364-377
• /
• 2014

The performances of a coupled reactor in which a steam reformer and a catalytic combustor were mounted simultaneously had been investigated and compared. The combustible offgas exhausted from the anode of SOFC and MCFC were utilized as heat sources for the endothermic steam methane reforming. The catalytic combustion was used in order to burn the combustible offgas. Thermal energy released by the catalytic combustion is directly transferred to the reformer surrounding the combustor. The various operational conditions such as fuel utilization rate, steam to carbon ratio, amount of catalysts, fuel cell loads were changed. And operating variables were comprehensively identified by sensitivity analysis. The fundamental results from this experimental study show the potential abilities of the coupled reactor. Therefore the results will be of help to design and manufacture the more better coupled reactor in the future.

• 한국전산유체공학회지
• /
• 제16권3호
• /
• pp.95-103
• /
• 2011

In the block type VHTR core, there are inevitable gaps among core blocks for the installation and refueling of the fuel blocks. These gaps are called bypass gap and the bypass flow is defined as a coolant flows through the bypass gap. Distribution of core bypass flow varies according to the reactor operation since the graphite core blocks are deformed by the fast neutron irradiation and thermal expansion. Furthermore, the cross-flow through an interfacial gap between the stacked blocks causes flow mixing between the coolant holes and bypass gap, so that complicated flow distribution occurs in the core. Since the bypass flow affects core thermal margin and reactor efficiency, accurate prediction and evaluation of the core bypass flow are very important. In this regard, experimental and computational studies were carried out to evaluate the core bypass flow distribution. A multi-block experimental apparatus was constructed to measure flow and pressure distribution. Multi-block effect such as cross flow phenomenon was investigated in the experiment. The experimental data were used to validate a CFD model foranalysis of bypass flow characteristics in detail.

• Nuclear Engineering and Technology
• /
• 제51권7호
• /
• pp.1715-1720
• /
• 2019

Jozef Stefan Institute (JSI), TRIGA Mark II reactor employs the homogeneous mixture of uranium and zirconium hydride fuel type. Since its upgrade, a series of fresh fuel steady state experimental benchmarks have been conducted. The benchmark results have provided data for testing computational neutronics codes which are important for reactor design and safety analysis. In this work, we investigated the JSI TRIGA Mark II reactor neutronics characteristics: the effective multiplication factor and two safety parameters, namely the control rod worth and the fuel temperature reactivity coefficient using SuperMC. The modeling and real-time cross section generation methods of SuperMC were evaluated in the investigation. The calculation analysis indicated the following: the effective multiplication factor was influenced by the different cross section data libraries; the control rod worth evaluation was better with Monte Carlo codes; the experimental fuel temperature reactivity coefficient was smaller than calculated results due to change in water temperature. All the results were in good agreement with the experimental values. Hence, SuperMC could be used for the designing and benchmarking of other TRIGA Mark II reactors.