• Journal of Nuclear Fuel Cycle and Waste Technology
• /
• v.1 no.1
• /
• pp.83-92
• /
• 2013

A novel methodology to evaluate remote dismantling equipment for a reactor pressure vessel (RPV) in a decommissioning project is presented in this paper. The remote dismantling equipment, mainly composed of cutting tools and positioning equipment, is absolutely required to cut and handle highly radioactive and large components in nuclear power plants (NPPs); this equipment has a great effect on the overall success of the decommissioning project. Conventional evaluation methods have only focused on cutting technologies or positioning equipment, although remote dismantling equipment cannot achieve its goal without organic interaction between the cutting tools and the positioning equipment. In this paper, the cutting tools and the positioning equipment are evaluated by performance parameters according to their original characteristics, the relationship between the two systems, and common factors. Finally, the remote dismantling equipment used in recent decommissioning projects has been evaluated based on the proposed methodology. The results of this paper are expected to be useful for future decommissioning projects.

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.455-460
• /
• 2004

The Fuel cell Rubber tired Train (FRT), which is now getting the attention as the next generation vehicle with its environment-friendliness, is the transportation for smooth connections of city traffic. It is the revival of the surface-car system with its revaluation of the function and technological development. Accordingly, fixed time operation and high speed driving became possible. FRT is operated together with other vehicles on the regular drive way. While this vehicle can solve the problem of traffic congestion in the urban area, it also can be cost-effective when it is compared to the cost of subway construction. It is also designed to minimize the underground or elevated traffic lane, to introduce the new construction technology, to reduce a term of works, and to cut down the operation cost by unmanned automatic driving system. Furthermore, it is considered as the alternative measure of other transportation due to its potential for the ecological way of speed improvement and the accessability to the disabled, elderly and children by developing the vehicle with folding steps or by building the high boarding platforms. In this research, I concentrated on the user oriented interior design of the FRT to make it passenger-friendly and safe in order to maximize the utilization of the vehicle so that all users including wheelchaired, user with baby carriage, elderly and children can conveniently use this vehicle.

• Journal of the Korean institute of surface engineering
• /
• v.32 no.3
• /
• pp.428-432
• /
• 1999

As metallic surface has its unique lustrous appearance and optical reflectance in visible range of light, the metallization of plastic surface has been an essential drive toward weight reduction for fuel economy and decorations in transportation industry and has been put into practiced from wet chemical-electrochemial to dry vacuum process in view of an environmental effect. Electron-beam metallization was used in this work with an aim at improving the scratchproof surface hardness of plastic substrate with metallic finish character. Thin film of Al ($1000\AA$) and $SiO_2$($7000\AA$) were metallized on substrate of PC and PMMA and the films were evaluated by pencil test for surface hardness and by cross-cut tape test for adhesion. The ion beam treatment improved around twice as hard as non-treat surface. The ion beam is effect on its hardness and adhesion to surface hardened PC substrate.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.19 no.3
• /
• pp.279-287
• /
• 2021

For application in nuclear decommissioning, underwater laser cutting studies were conducted on thick stainless-steel plates for various cutting directions using a 6 kW fiber laser. For cutting along the horizontal direction with horizontal laser irradiation, the maximum cutting speed was 110 mm·min^-1 for a 48 mm thick stainless-steel plate. For cutting along the vertical direction with horizontal laser irradiation, a maximum speed of 120 mm·min^-1 was obtained for the same thickness, which confirmed that the cutting performance was similar but slightly better. Moreover, when cutting with vertically downward laser irradiation, the maximum cutting speed was 120 mm·min^-1 for a plate of the same thickness. Thus, the cutting performance for vertical irradiation was nearly identical to that for horizontal irradiation. In conclusion, it was possible to cut thick stainless-steel plates regardless of the laser irradiation and cutting directions, although the assist gas rose up due to buoyancy. These observations are expected to benefit laser cutting procedures during the actual dismantling of nuclear facilities.

• Journal of the Korean Electrochemical Society
• /
• v.3 no.2
• /
• pp.115-120
• /
• 2000

All solid-state thin film micro-batteries consisting of lithium metal anode, an amorphous LiPON electrolyte and cathode of vanadium oxide have been fabricated and characterized, which were fabricated with cell structure of $Li/LiPON/V_2O_5Pt$. The effect of various oxygen partial pressure on the electrochemical properties of vanadium oxide thin films formed by d.c. reactive sputtering deposition were investigated. The vanadium oxide thin film with deposition condition of $20\%\;O_2/Ar$ ratio showed good cycling behavior. In in-siか process, the LiPON electrolyte was deposited on the $V_2O_5$ films without breaking vacuum by r.f. magnetron sputtering at room temperature. After deposition of the amorphous LiPON, the Li metal films were grown by a thermal evaporator in a dry room. The charge-discharge cycle measurements as a function of current density and voltage variation revealed that the $Li/LiPON/V_2O_5$ thin film had excellent rechargeable properly when current density was $7{\mu}A/cm^2$. and cut-off voltage was between 3.6 and 2.7V In practical experiment, a stopwatch ran on this $Li/LiPON/V_2O_5$ thin film micro-battery. This result means that thin film micro-battery fabricated by in-siか process is a promising for power source for electronic devices.

• Plant Journal
• /
• v.12 no.1
• /
• pp.29-36
• /
• 2016

It is becoming increasingly important to make use of alternative energy source. because It is not able to rely on only fossil fuel for the recent increasing demand of energy consumption. With this situation, lots of studies for utilizing low grade energy such as industrial waste heat, solar energy, and geothermal energy have been conducted. The aim of this study is to predict the operation characteristics of working fluid by using performance analysis program (ThermoFlex) through the system analysis which is not mixing district return water but using ORC(Organic Rankine Cycle, hereinafter ORC) as a downstream cycle when accumulating district heating (hereinafter DH). In this study, We conducted the performance analysis for the case which has the district heating water temperature($120^{\circ}C$) and Flow rate of $163m^3/h$ (including District Heating return water flow), and examined several working fluid which is proper to this temperature. The case using R245fa (which is the best-case) showed 269.2kW power output, 6.37% efficiency. Additionally, Cut down on fuel was expected because of the boiler inlet temperature increase by being Formed $57.3{\sim}85^{\circ}C$ in a temperature of district heating return water, depending on a pressure change of a condenser in ORC system.

• Clean Technology
• /
• v.20 no.4
• /
• pp.439-448
• /
• 2014

The potential mitigation of greenhouse gas (GHG) is studied in the Pohang steel industrial complex (PHSIC). The total GHG emission in 2010 is estimated to be in the range from 4,174,000 to 4,574,000 $tCO_2-eq$ in PHSIC. To meet the target proposed by the government, it is needed to reduce 552,000 $tCO_2-eq$ at minium by 2020. To estimate the potential amount of GHG reduction, the technologies used in the voluntary carbon reduction projects are applied to 51 companies which are subject to GHG target management. From the viewpoint of technological availability and payback period, the fuel conversion and waste heat recovery have an advantage in the short term with a possibility to reduce 160,000 $tCO_2-eq$. In the mid term, the thermal technologies in steel and iron industry have the potential to cut 229,000 $tCO_2-eq$, while the electrical technologies have the potential of 125,000 $tCO_2-eq$ reduction. The gap between the target GHG mitigation and potential reduction using the short and mid term technologies is about 38,000 $tCO_2-eq$, which should be compensated by the fundamental process innovation and the implementation of the most cutting-edge technologies including renewable energy.

• Transactions of the Korean hydrogen and new energy society
• /
• v.28 no.1
• /
• pp.40-46
• /
• 2017

We reviewed the electrical properties of SOFC anode manufactured using spherical Ni and nano YSZ powder. When core-shell is fabricated by using submicron Ni as core and nano-sized YSZ as shell for SOFC anode, the electrical conductivity of the $0.2{\mu}m$ Ni-YSZ core-shell was 3 times higher than that of $1.0{\mu}m$ NiO or $1.0{\mu}m$ Ni-YSZ. Hydrogen selectivity was similar at $800^{\circ}C$, but hydrogen selectivity and methane conversion rate under $750^{\circ}C$ was 10~25% higher, Power density was more than 2 times, ASR was about 1/3, when exposed to $H_2$ atmosphere at $750^{\circ}C$ for a long time, Ni particles did not have any growth or cut off conduction path.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.18 no.5
• /
• pp.492-497
• /
• 2015

Currently, there are many kinds of tracked armored vehicles in service and they have encountered various environment and situations. So there are many obstacles to operate them improperly such as an engine stall. The causes of engine stall are an insufficient fueling, a mixture of air-fuel or vapor lock, and load increment which results from a rapid steering or increasing a viscosity of lubricant by low temperature. In this paper, engine stall by load increment due to a rapid steering or increasing of lubricant viscosity on tracked armored vehicles is analyzed, the ways to prevent it are applied, and their degrees of improvement are evaluated.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.19 no.1
• /
• pp.73-83
• /
• 2016

Forest degradation reduces ecosystem services provided by forest and could lead to change in composition of species. In North Korea, there has been significant forest degradation due to conversion of forest into terrace fields for food production and cut-down of forest for fuel woods. This study analyzed the phenological changes in North Korea, in terms of vegetation and moisture in soil and vegetation, from March to Octorber 2013, using MODIS (MODerate resolution Imaging Spectroradiometer) images and indexes including NDVI (Normalized Difference Vegetation Index), NDSI (Normalized Difference Soil Index), and NDWI (Normalized Difference Water Index). In addition, marginal farmland was derived using elevation data. Lastly, degraded terrace fields of 16 degree was analyzed using NDVI, NDSI, and NDWI indexes, and marginal farmland characteristics with slope variable. The accuracy value of land cover classification, which shows the difference between the observation and analyzed value, was 84.9% and Kappa value was 0.82. The highest accuracy value was from agricultural (paddy, field) and forest area. Terrace fields were easily identified using slope data form agricultural field. Use of NDVI, NDSI, and NDWI is more effective in distinguishing deforested terrace field from agricultural area. NDVI only shows vegetation difference whereas NDSI classifies soil moisture values and NDWI classifies abandoned agricultural fields based on moisture values. The method used in this study allowed more effective identification of deforested terrace fields, which visually illustrates forest degradation problem in North Korea.