• Journal of Soil and Groundwater Environment
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• v.20 no.3
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• pp.1-6
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• 2015

The rapid industrial development is facing problem due to energy depletion in Korea. So that, it can be necessary to develop alternative energy sources. Alternative energy like biofuels can be produced by using waste fuel, which is ecofriendly. As we know, the organic waste was banned to dump in landfill and ocean dumping. The most practicable method usually used to reduce organic waste is getting feedstuff or composting, considering the discharge characteristics of agricultural by-products waste treatment were selected. In this study, bio-coal was made using agriculture by product. Biocoal was prepared by adding 50 g of uniformly mixture into reactor and was carbonized at low temperatures 210, 220, and 230℃. The time of reaction was 1, 2 and 3 hours. Bio-coal approximately was similar to the standard of solid fuels. Other characteristics of fuel were also studied. The experiments which were analyzed were moisture content and calorific value, ash, chlorine, sulfur and heavy metals analysis as mercury, cadmium, lead, arsenic, and chromium. As a result, bio-coal 220℃, 2 hours was the optimal conditions while heating.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.2
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• pp.271-279
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• 2018

During the seven years from 2009 to 2016, PWR SNF (spent nuclear fuel) transportation and storage systems suitable for domestic conditions were developed by the government to cope with the saturation of wet storage capacity in NPPs. One of the developed systems is a multipurpose metal cask applicable for transportation/storage; the other is a concrete cask dedicated to storage. Efficient cask technologies were secured utilizing the characteristics and experience of relevant industrial, academic and research institutes. Technological independence was also achieved through several patent registrations of research outcomes. To prepare for a rapid increase of demand in the near future, technology transfer of secured patents and technologies to the domestic industry was carried out twice in the years of 2016 and 2017.

• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.2
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• pp.28-34
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• 2002

The purpose of this study is the RDF process development for the disposal of marine debris, and physical properties of RDF was analyzed for the reliability as a industrial fuel. By the separation of lead from the waste rope and the pelletizing of burning material, marine debris changes to fuel resources. The resource recycling process is effective in the clean treatment of waste and the secure of substitute energy.

• Nuclear Engineering and Technology
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• v.55 no.11
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• pp.4173-4180
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• 2023

The stability of engineered barriers in high-level radioactive waste disposal systems can be influenced by the decay heat generated by the waste. This study focuses on the thermal analysis of various canister designs to effectively lower the maximum temperature of the engineered barrier. A numerical model was developed and employed to investigate the heat dissipation potential of copper rings placed across the buffer. Various canister designs incorporating copper rings were presented, and numerical analysis was performed to identify the design with the most significant temperature reduction effect. The results confirmed that the temperature of the buffer material was effectively lowered with an increase in the number of copper rings penetrating the buffer. Parametric studies were also conducted to analyze the impact of technical gaps, copper thickness, and collar height on the temperature reduction. The numerical model revealed that the presence of gaps between the components of the engineered barrier significantly increased the buffer temperature. Furthermore, the reduction in buffer temperature varied depending on the location of the gap and collar. The methods proposed in this study for reducing the buffer temperature hold promise for contributing to cost reduction in radioactive waste disposal.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.751-754
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• 2001

A possibility of using waste plastics as a source of secondary fuel in blast furnace has been of recent interest. The success of this process, however, will be critically dependent upon the optimization of operating systems. for instance, the supply of waste plastics must be reliable as well as economically attractive compared with conventional secondary fuels such as heavy oil, natural gas and pulverized coal. In this work, we put special importance on the improvement of the combustibility of waste plastics as a way to enhance energy efficiency in blast furnace. As experimental variables to approach this target, the effects of plastic particle size, blast temperature, and the level of oxygen enrichment were investigated using a custom-made blast model designed to simulate a real furnace. Lastly, the combustion efficiency of the mixture of waste plastics and pulverized coal was tested. The observations made from these experiments led us to the conclusion that with the increase of both blast temperature and the level of oxygen enrichment, and with the decrease of particle size, the combustibility of waste PE could be improved at a given distance from tuyere. Also it was found that the efficiency of coal combustion decreased with the addition of plastics; however, the combustion efficiency of mixture could be comparable at longer distance from tuyere.

• Nuclear Engineering and Technology
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• v.40 no.5
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• pp.429-438
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• 2008

The objective of the present study is the depth and layout optimizations of a single layer, high level radioactive waste repository in a discontinuous rock mass with special joint set arrangements. A single layer repository model, considering variations in the repository depths, pitches, and tunnel spacings, is used to analyze the thermomechanical interaction behavior. It is assumed that the repository is constructed in saturated granite with joints; the PWR spent fuel in a disposal canister is installed in a deposition drift which is then sealed with compacted bentonite; and the backfill material is filled in the repository tunnel. The decay heat generated by the high level radioactive wastes governs the thermomechanical behavior of the near field rock mass of the repository. The temperature and displacement behavior of the repository is influenced more by the pitch variations than the tunnel spacing and repository depth. However, the stress behavior is influenced more by the repository depth variations than the pitch and tunnel spacing. For the final selection of the tunnel spacing, pitch, and repository depth, other aspects such as the nuclide migration through a groundwater flow path, construction costs, operation costs, and so on should be considered.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.2
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• pp.141-154
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• 2015

In general, conventional criticality analysis for spent fuel transport/storage systems have been performed based on the assumption of fresh fuel concerning the potential uncertainties from number density calculations of actinide nuclides and fission products in spent fuel. However, these evaluation methods cause financial losses due to an excessive criticality margin. In order to overcome this disadvantage, many studies have recently been conducted to design and commercialize a transportation and storage cask applied to the Burnup Credit (BUC). This study conducted an assessment to ensure criticality safety for reactor operating parameters, axial burn-up profiles and misload accident conditions, which are the factors that are likely to affect criticality safety when the BUC is applied to the dual-purpose cask under development at the KOrea RADioactive waste agency (KORAD). As a result, it was found that criticality resulting from specific power, changed substantially and relied on conditions of low enrichment and high burn-up. Considering the end effect in the case of high burn-up produced a positive-definite result. In particular, the increment of maximum effective multiplication factors due to misloading was 0.18467, confirming that misload is a factor that must be taken into account when applying the BUC. The results of this study may therefore be utilized as references in developing technologies to apply the BUC to domestic models and operational procedures or preventing any misload accidents during the process of spent fuel loading.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.4
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• pp.351-357
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• 2007

The Japanese Government selected Mutsu, Aomori Prefecture as a provisional spent-fuel repository site. This comes as a result of the prefecture's five-year campaign to host the site since 2000. Korea stores spent nuclear fuel within sites of nuclear power plants, and expects the storage capacity to reach its limit by the year 2016. This compels Korea to learn the cases of Japan. Having successfully hosted Gyeongju as a site for low-to-intermediate-level nuclear waste repository, Korea has already learned the potential process of hosting spent fuel storage site. The striking difference between the two countries in the process of hosting the site is that the Korean government had to offer the local city a large amount of subsidy for hosting through competitive citizens' referendum among candidate cities while it was the leadership of the local municipality that enabled the controversial decision in Japan. It is also a distinguishable characteristics of Japan that not a huge subsidy is provided to the local host city. I hope this study offers an idea to Korea's future effort to select a spent-fuel host site.

• Journal of Energy Engineering
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• v.27 no.2
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• pp.49-54
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• 2018

The common rail diesel engine used in this study is a remanufactured waste engine. The fuel injection timing of the waste engine is set to be suitable for the operating conditions of the vehicle. However, the engine of a generator is operated at a constant speed and mainly at partial load. Therefore, it is necessary to change the fuel injection timing suitable for the power generation engine, and the cost and the time required for such change must be minimized as much as possible. As a result of the analysis, it was confirmed that the fuel efficiency improves according to the fuel injection timing suitable for the engine for the generator, thereby increasing the performance and fuel efficiency.

• Journal of the Korean Institute of Gas
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• v.18 no.2
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• pp.28-34
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• 2014

In the natural gas pressure regulation station, high pressure natural gas is decompressing using pressure regulation valves. Waste pressure occurred in the pressure regulation process can be recovered through adopting turbo expanders. However, in the waste pressure recovery process, Joule Thompson effect causes below $0^{\circ}C$ and this low temperature freezes outside land of pipeline or generates methane hydrate in the pipeline which can block the pipeline. Therefore, turbo expander systems are accompanying with a boiler for preheating natural gas. Molten carbonate fuel cell (MCFC), one of the high temperature fuel cell, can use natural gas as a direct fuel and is also exhausting low emission gas and generating electricity. In this paper, a thermodynamic analysis on the hybrid MCFC-turbo expander system is conducted. The fuel cell system is analyzed for the base load of the hybrid system.