• 한국지하수토양환경학회지:지하수토양환경
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• 제20권2호
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• pp.41-46
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• 2015

The drag of the excess charge in an electrical double layer at the solid fluid interface due to water flow induces the streaming current, i.e., the streaming potential (SP). Here we introduce a sandbox experiment to study this hydroelectric coupling in case of a tracer test. An acrylic tank was filled up with homogeneous sand as a sand aquifer, and the upstream and downstream reservoirs were connected to the sand aquifer to control the hydraulic gradient. Under a steady-state water flow condition, a tracer test was performed in the sandbox with the help of peristaltic pump, and tracer samples were collected from the same interval of five screened wells in the sandbox. During the tracer test, SP signals resulting from the distribution of 20 nonpolarizable electrodes were measured at the top of the tank by a multichannel meter. The results showed that there were changes in the observed SP after injection of tracer, which indicated that the SP was likely to be related to the solute transport.

• 방사성폐기물학회지
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• 제21권2호
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• pp.225-234
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• 2023

In the design of HLW repositories, it is important to confirm the performance and safety of buffer materials at high temperatures. Most existing models for predicting hydraulic conductivity of bentonite buffer materials have been derived using the results of tests conducted below 100℃. However, they cannot be applied to temperatures above 100℃. This study suggests a prediction model for the hydraulic conductivity of bentonite buffer materials, valid at temperatures between 100℃ and 125℃, based on different test results and values reported in literature. Among several factors, dry density and temperature were the most relevant to hydraulic conductivity and were used as important independent variables for the prediction model. The effect of temperature, which positively correlates with hydraulic conductivity, was greater than that of dry density, which negatively correlates with hydraulic conductivity. Finally, to enhance the prediction accuracy, a new parameter reflecting the effect of dry density and temperature was proposed and included in the final prediction model. Compared to the existing model, the predicted result of the final suggested model was closer to the measured values.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 학술논문집
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• pp.121-121
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• 2004

As one of the major activities of the International Atomic Energy Agency (IAEA), a Coordinated Research Program (CRP) has been implemented with the aim of solving many of the problems facing the Member States by integrating various different levels of each country's technical capabilities in the areas which the Agency needs further technology development. To establish the strategy for an active participation In the CRP and its effective implementation, general features of the current IAEA programs and a prospect of the future program for 2006-2007 are described.(omitted)

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2005년도 춘계 학술대회
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• pp.344-349
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• 2005

Neutron count rate measurements to assay fissile content of uranium powder have been carried out in a neutron counter. The induced fission neutrons by Cf-252 neutron source are counted as the variation of fissile material in fuel material. The measured counts are compared with equivalent results obtained from calculation. It shows that the measured neutron counts versus quantity of $UO_2$ powder enrichment agreed reasonably well with the calculated values.

• 에너지공학
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• 제21권4호
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• pp.373-377
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• 2012

Among the fossil fuels, the brown coal is a great deal of resources. However, it is hardly used due to the high moisture content and low calorific value. It has both the week points such as spontaneous combustion and high volatile content and the strong points such as the low-sulfur and low ash content. If we overcome these week points, the using amount of brown coal would be increased. Also, it is well known that biomass is one of the important primary renewable energy sources because of carbon neutral energy. Furthermore, the utilization of biomass has been more and more concerned with the depletion of fossil fuel sources as well as the global warming issues. Combustion and thermal decomposition of biomass is one of the more promising techniques among all alternatives proposed for the production of energy from biomass. In this study, combustion of brown coals and mushroom waste was done. Mass change of samples and emission of hydrocarbon components were measured. As the results, we obtained combustion rate constant. Also activation energy was calculated in char combustion step. Hydrocarbon components were more generated in low oxygen concentration than high. Emission amount of hydrocarbon components in mushroom waste was significantly increased comparing to brown coal.

• 에너지공학
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• 제23권3호
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• pp.235-240
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• 2014

본 연구에서는 음식물쓰레기를 반탄화 하여 생성된 생성물의 특성 및 온도에 대한 영향을 비교하여 연료화 가능성을 파악하고자 하였다. 반응온도를 $180^{\circ}C{\sim}270^{\circ}C$ 조절하고 열전달방식을 질소가스 열전달방식과 열매체유 열전달방식으로 나누어 실험한 결과 생성물의 생산 수율과 수분함량은 온도가 높아짐에 따라 감소하였고 특히 $240^{\circ}C$이상에서는 수분감소 뿐만 아니라 열적변화도 확인 할 수 있었다. 반응온도가 낮을수록 열매체유 열전달방식이 수분감소에 더 좋은 열전달 효율을 보였지만 온도가 높아질수록 그 차이는 미미한 것을 확인할 수 있었다. 발열량의 경우 초기 660 Kcal/kg 에서 질소가스 열전달방식 6,400 Kcal/kg 간접방식 6,890 Kcal/kg 으로 상승 되었고, 원소분석결과 반응온도가 상승할수록 반탄화 생성물의 탄소원소의 함량증가와 산소원소 함량 감소를 확인 하였으며 석탄밴드 분석결과 저급석탄에 가까운 H/C와 O/C의 범위를 나타내었다. 음식물쓰레기를 반탄화를 통하여 연료개질이 가능하다는 것을 확인 할 수 있었으며, 반응온도가 높아질수록 저급석탄에 더 가까워짐을 확인할 수 있었다.

• 방사성폐기물학회지
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• 제18권spc호
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• pp.51-62
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• 2020

In this paper, an approach developed by the Finnish nuclear waste management organization, Posiva, for the construction license of a geological repository was reviewed. Furthermore, a computer program based on the approach was developed. By using the computer program, the lifetime of a copper disposal canister, which was a key engineered barrier of the geological repository, was predicted under the KAERI Underground Research Tunnel (KURT) geologic conditions. The computer program was developed considering the mass transport of corroding agents, such as oxygen and sulfide, through the buffer and backfill. Shortly after the closure of the repository, the corrosion depths of a copper canister due to oxygen in the pores of the buffer and backfill were calculated. Additionally, the long-term corrosion of a copper canister due to sulfide was analyzed in two cases: intact buffer and eroded buffer. Under various conditions of the engineered barrier, the corrosion lifetimes of the copper canister due to sulfide significantly exceeded one million years. Finally, this study shows that it is necessary to carefully characterize the transmissivity of rock and sulfide concentration during site characterization to accurately predict the canister lifetime.

• 유기물자원화
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• 제21권4호
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• pp.50-61
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• 2013

교내 식당에서 분리 수거된 음식물류 폐기물에서 재생 에너지인 메탄가스를 생산하기 위해 혐기성 소화시스템에 대한 연구가 수행되었다. 1차 실험에서 침출수 인발/반송도 없고 혼합도 없는, 침출수 인발/반송은 없고 혼합이 있는, 침출수 인발/반송은 있고 혼합이 없는, 그리고 침출수 인발/반송은 있고 혼합이 있는 4개의 혐기성 시스템에서 침출수 인발/반송은 있고 혼합이 없는 시스템에서 가스발생이 가장 많은 것으로 나타났다. 반응조 혼합이 없고 침출수 인발/반송이 수행되는 시스템에서는 침출수의 반응조 내 침출수 유출속도가 빠른 경우에 혐기성 반응이 활발히 일어난 것으로 관찰되었다. 가스수집기 무게가 1kg이고 음식물류 폐기물 C/N비가 10이상이 되는 경우 혐기성 반응조의 가스가 소모되어 가스수집기에 부압이 걸리는 것이 관찰되었는데, 이에 대한 원인을 밝히는 것이 음식물류 폐기물에서 재생에너지를 회수하는데 필수적이다.

• 한국폐기물자원순환학회지
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• 제35권7호
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• pp.660-669
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• 2018

Domestic automotive shredder residue (ASR) recycling facilities must comply with 60% of the energy recovery criteria calculated by the waste control act, based on resource circulation of electrical and electronic equipment and vehicles. The method of calculating energy recovery criteria was newly enacted on November 6, 2017, and it has been judged that it is necessary to consider applicability. In this study, the energy recovery efficiency of 7 units was calculated by past and present calculation methods. Furthermore, this study attempts to find applicability and a method of increasing the energy recovery efficiency by taking advantage of available potentials. An analysis of the calculation results showed that the average values calculated by past methods, present methods, and the method that includes available potentials are 76.35%, 70.68%, and 78.24%, respectively. Therefore, the new calculation method for energy recovery efficiency is also applicable to domestic automotive shredder residue recycling facilities.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1996년도 사용종료 매립지의 안정화 에 관한 국제 세미나
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• pp.97-101
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• 1996

Municipal and sanitary landfills can pose environmental problems due to leachate, landfill gas md unstable geotechnical properties. Most governmental bodies delay the correction of landfill problems or landfill replacement until a crises stage is reached. The replacement of a landfill is often made difficult due to costly regulatory controls, public opposition to siting and the high cost of closure for the previous landfill unit. Solutions to extending landfill life and capacity Involve waste minimization by recycling, refuse compaction and waste-to-energy incineration. Incineration can reduce the volume of refuse by 50-95%. The largest installed bases of municipal waste Incinerators are located in Japan and the U.S. The volume of waste contained in a landfill can be estimated by load count tabulations, weight-and-volume measurements or a material balance analysis based on the trash profile of user categories. for an existing landfill, core samples may be collected and analyzed for use in a material balance analysis. Newly generated refuse contains approximately 50% of the heating value of coal. However, landfill properties vary significantly due to the waste profile of the contributors and biodegradation due to time and weathering. The volume of the Nanji-do landfill