• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.1
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• pp.31-39
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• 2013

Nuclear fuel can be damaged under unexpected circumstances in a nuclear reactor. Fuel rod failure can be occurred due to debris fretting or excessive hydriding or PCI (Pellet-to-clad Interaction) etc. It is important to identify the causes of such failed fuel rods for the safe operation of nuclear power plants. If a fuel rod failure occurs during the operation of a nuclear power plant, the coolant water is contaminated by leaked fission products, and in some case the power level of the plant may be lowered or the operation stopped. In addition, all spent fuels must be transferred to a dry storage. But failed fuel can not be transferred to a dry storage. Therefore, the purpose of this study is to develop a system which is capable of inspecting whether the spent fuel in the storage pool is failed or not. The sipping technology is to analyze the leakage of fission products in state of gas and liquid. The failed fuel inspection system with gamma analyzer has successfully demonstrated that the system is enough to find the failed fuel at Wolsong plant.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.4
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• pp.299-314
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• 2014

A lifting device is used to deal with transport cask for the transportation of spent fuels from nuclear power plants. This study performed theoretical analysis and numerical simulation to evaluate the structural integrity of the lifting device based on Nuclear Safety and Security Commission(NSSC) Notice No.2013-27 and US 10CFR Part 71 ${\S}71.45$. The results of theoretical analysis showed that the maximum stresses of all components were below the allowable values. This result confirmed that the lifting device was structurally safe during operation. The results of finite element analysis also showed that it was evaluated to satisfy the design criteria bothyielding and ultimate condition. All components have been shown to ensure the structural safety due to sufficient safety margins. In other words, the safety factor was 3 or more for the yielding condition and was 5 or more for the ultimate condition.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.3
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• pp.147-151
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• 2012

Carbon dioxide ($CO_2$) could be stored in the form of Ca and Mg compounds including alkaline earth metal by carbonation. The possibility of $CO_2$ storage was tested by using desulfurized ash from fluidized bed type boiler as raw material. Autoclave was used for maintaining the reaction pressure and temperature for the carbonation. The analysis of weight change rate, XRD, and TG/DTA proved that more than 15 % of carbonation rate was obtained under 10 $kgf/cm^2$ and $120^{\circ}C$-10 min.

• Resources Recycling
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• v.9 no.2
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• pp.11-17
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• 2000

Consumption of nickel is continuously increasing and the wastes of secondary battery, ferrite and catalyst containing Ni are also generated periodically. Among those wastes, the aim of this research is the recovery of nickel from used Ni-Cd recharge battery. Battery consisted of Ni 24 wt%, Fe 30 wt% and Cd 18.5 wt%. Metal was recovered by solvent extraction after leaching. Cadmium was leached completely in 1N-HCl and Ni was recovered above 70%. 30 vol% MSP-8 separated Cd and Ni completely from acidic leaching solution. In addition $NH_4NO_3$ as one of ammonium salt type leachants showed an excellent leaching selectivity to Ni and Cd. Ni in leached solution was recovered completely by LIX-extractant and more than 70% of Cd in raffinate was by D2EHPA.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.11a
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• pp.213-234
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• 2002

우리 나라는 70년대까지 광업은 부흥하였으나, 그 이후 급속히 위축되면서 80년대 이후 거의 대부분 광산들이 폐광 또는 휴광된 실정이다. 그 결과 현재 전국 각지에 다수의 폐갱도가 존재하게 되었으며, 이제는 지반침하 및 각종 침출수의 원인자로 간주될 정도이다. 최근 지자체에서는 이런 폐갱도를 지역 자원으로서 가치를 인정하고 지역 활성화를 위해 재 이용하려는 움직임이 보이고 있는데, 구체적으로는 관광시설, 연구시설, 농업생산시설, 저장시설, 폐기물처리시설 등이다. 일본은 폐광된 금속광산 재활용을 위해 입지여건과 주변지역, 입갱 가능성 등 기초조사를 하였다. 조사결과 폐갱도의 문제점으로 입갱이 가능한 광산이 적다는 점을 들 수 있다. 대부분의 광산은 갱구가 함몰되었거나, 갱내에 지하수가 차 있어 접근이 불가능한 경우가 대부분이다. 비교적 양호한 암반 경우는 서브 레벨 스토핑, 잔주, 주방식 등의 채굴법에 의해 대규모 공동이 잔존하고 있는 경우도 있지만 그리 많지 않았다. 폐광된 광산 재활용 여건은 우리 나라와 일본이 대동소이 경우로 현실적으로 활용이 가능한 폐광은 많지 않으며 활용코자 할 때에는 기존갱도를 활용하면서 암반이 견고한 곳에 새로운 갱도를 설치하여야 한다. 그러나 몇몇 곳에서는 매우 유용하게 잘 활용되고 있는 곳도 있고, 연구 검토하면 충분한 활용성이 있다고 생각되는 곳도 있다. 그러므로 현재의 상황을 보고 판단할 것이 아니라, 활용기술과 접목해서 활용성을 검토함으로써 불용 자산의 유용화 방안이 검토되어야 할 것이다. 현재 가행중인 광산은 입지여건 및 암반이 양호하고, 대형갱도를 굴착하는 석회석광산 등을 선택하여 폐광 후 활용이 가능토록 채광기술 발전시켜 나가야 하며, 인간 중심적인 시설 또는 산물 중심적인 시설로 구분하여 폐광 후 복구비용을 우선 지원하는 방식 등을 통하여 시추, 탐광굴진, 현대화, 수갱굴착, 자금융자 등을 지원하는 우리 공사와 산업자원부가 지자체, 산림청, 건교부, 농림부 등과 연계하여 종합적인 지원육성책을 마련하여야 할 것이다. 결과적으로, 지방자치단체 등에서 관심을 갖고 있는 저장시설, 폐기물처리시설, 관광시설, 농업생산시설, 연구시설 등을 중심으로 ＆apos;광산 채굴적을 미래에 어떻게 활용한 것인가＆apos;를 선진외국 사례를 벤치마킹하고, 연구ㆍ검토하여 친환경적인 광산개발이 되도록 기본적인 방향과 개념을 갖도록 하여 관련 정책을 계획적이고, 체계적으로 수립 일관성 있게 추진해 나가야 할 것이다.

• Economic and Environmental Geology
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• v.42 no.5
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• pp.471-477
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• 2009

An experimental removal of dissolved uranium (U) exsiting as uranyl ion (${UO_2}^{2+}$) was carried out using Shewanella p., iron-reducing bacterium. By the microbial reductive reaction, initial U concentration ($50{\mu}M$) was constantly decreased, and most U were removed from solution after 2 weeks. Major mechanism that U was removed from the solution was adsorption, precipitation and mineralization on the microbe surface. Under the transmission electron microscopy, the U adsorbed on the microbe was observed as being crystallized and eventually enlarged to several ${\mu}m$ sizes of minerals by combining with individual microbes and organic exudates. It seems that such U growth and mineralization on the microbial surface could affect the U behavior in a radioactive waste disposal site. Thus, the biogechemical reaction of metal-reducing bacteria observed in this experiment could give an affirmative measure that the microbial activity may retard U movement in subsurface environment.

• Resources Recycling
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• v.30 no.3
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• pp.63-69
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• 2021

Supply deficit of lead commodities and environmental pollution can be simultaneously resolved through the recovery and recycling of waste lead. The recent recovery of lead through recycling of the lead battery waste is a positive development. To maximize the effect of lead recovery and recycling in the future, the updated status of the lead material flow should be recognized. However, such an analysis at the preliminary stages may be cumbersome owing to the complexity and diversity of emission sources and material streams. At this stage, a preliminary screening by domestic lead flow using public information should be feasible. Therefore, in this study, using the data from the UN Comtrade and domestic PRTR (Pollutant Release and Transfer Register) databases, the amounts of lead import, emission, and transfer were identified and cross-checked with the domestic lead flow described in the National Material Flow Analysis database. The lead flow for major categories such as waste lead-acid batteries showed a rough consistency between the databases.

• Economic and Environmental Geology
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• v.54 no.2
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• pp.285-297
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• 2021

Globally, nuclear-decommissioning facilities have been increased in number, and thereby hundreds of thousands of wastes, such as concrete, soil, and metal, have been generated. For this reason, there have been numerous efforts and researches on the development of technology for volume reduction and recycling of solid radioactive wastes, and this study reviewed and examined thoroughly such previous studies. The waste concrete powder is rehydrated by other processes such as grinding and sintering, and the processes rendered aluminate (C3A), C4AF, C3S, and ��-C2S, which are the significant compounds controlling the hydration reaction of concrete and the compressive strength of the solidified matrix. The review of the previous studies confirmed that waste concretes could be used as recycling cement, but there remain problems with the decreasing strength of solidified matrix due to mingling with aggregates. There have been further efforts to improve the performance of recycling concrete via mixing with reactive agents using industrial by-products, such as blast furnace slag and fly ash. As a result, the compressive strength of the solidified matrix was proved to be enhanced. On the contrary, there have been few kinds of researches on manufacturing recycled concretes using soil wastes. Illite and zeolite in soil waste show the high adsorption capacity on radioactive nuclides, and they can be recycled as solidification agents. If the soil wastes are recycled as much as possible, the volume of wastes generated from the decommissioning of nuclear power plants (NPPs) is not only significantly reduced, but collateral benefits also are received because radioactive wastes are safely disposed of by solidification agents made from such soil wastes. Thus, it is required to study the production of non-sintered cement using clay minerals in soil wastes. This paper reviewed related domestic and foreign researches to consider the sustainable recycling of concrete waste from NPPs as recycling cement and utilizing clay minerals in soil waste to produce unsintered cement.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.2
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• pp.65-71
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• 2018

Paper packs, glass bottles, metal cans, and plastic materials are classified according to packaging material recycling groups that are Extended Producer Responsibility (EPR). In the case of waste paper pack, the compressed cartons are dissociated to separate polyethylene films and other foreign substance, and then these are washed, pulverized and dried to produce toilet paper. Glass bottle for recycling is provided to the bottle manufacturers after the process of collecting the waste glass bottle, removing the foreign substance, sorting by color, crushing, raw materializing process. Waste glass recycling technology of Korea is largely manual, except for removal of metal components and low specific gravity materials. Metal can is classified into iron and aluminum cans through an automatic sorting machine, compressed, and reproduced as iron and aluminum through a blast furnace. In the case of composite plastic material, the selected compressed product is crushed and then recycled through melt molding and refined products are produced through solid fuel manufacturing steps through emulsification and compression molding through pyrolysis. In the recycling process of paper packs, glass bottles, metal cans, and plastic materials, the influx of recycled materials and other substances interferes with the recycling process and increases the recycling cost and time. Therefore, the government needs to improve the legal system which is necessary to use materials and structure that are easy to recycle from the design stage of products or packaging materials.

• Resources Recycling
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• v.13 no.3
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• pp.50-57
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• 2004

Waste aluminum dross is a major waste in the aluminum scrap smelters and its components are mostly alumina and remained metallic aluminum. In the process to extract the remained aluminum from the waste dross by leaching with sodium hydroxide solution, residue is generated and its main component is alumina. This residue could be recycled into ceramic materials such as alumina castable refractories by going through a series of treatments such as washing, drying and roasting. In this study, a pilot plant was constructed and tested to demonstrate the developed technology. One thousand tons of waste aluminum dross could be processed, and about seven hundred tons of ceramic materials produced in the demonstration line. From the test run of the pilot plant, although it was confirmed that the developed technology could be applied to commercialization, several technical improvements were found to be necessary for reducing impurities such as Na, Fe and for reforming drying equipment.