• 제목/요약/키워드: waste disposal

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미소 초점 X선 CT를 이용한 암석 내 공극의 분포 및 공극률 분석 (Analysis of Porosity and Distribution of Pores in Rocks by Micro Focus X-Ray CT)

  • 정교철
    • 지질공학
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    • 제20권4호
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    • pp.461-465
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    • 2010
  • 암석에서의 풍화 및 투수성은 방사성폐기물 지하동굴처분 및 암반구조물의 안정성 확보 및 장기적 관리측면에서 매우 중요한 역할을 한다. 이들 암석의 풍화 및 투수성은 암석의 내 구조 특성에 따라 크게 영향을 받는다. 즉 암석 내부의 공극, 미소 크랙 등의 양적 정도에 의해 풍화가 빨리 진행되기도 한다. 또한 암석 내부구조의 양적 평가는 그 암석의 풍화 정도를 정량적으로 평가할 수 있는 수단이 되기도 한다. 따라서 암석의 내부구조를 3치원적으로 정확하게 파악한다는 것은 암반구조물의 장기적 관리 측면에서 매우 중요하다고 하겠다. 이 연구는 국내 신선한 화강암과 풍화된 화강암을 대상으로 X선 CT촬영을 실시하여 3차원으로 공극의 분포를 분석하였다. 분석 결과는 암석 내부의 공극의 분포와 공극률을 잘 표현하고 있다.

재생미분말의 유해성 분석 및 재생미분말을 혼입한 콘크리트의 특성 (Analysis on the Harmful Effect of Recycled Powder and Properties of Concrete Admixture by Recycled Powder)

  • 이승환;최익창;한상국
    • 해양환경안전학회지
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    • 제14권4호
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    • pp.289-295
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    • 2008
  • 건설폐기물의 처리는 국가 사회적 문제로 제기되고 있으며 순환골재의 생산과정에서 발생하는 미분말은 전량 폐기 매립되고 있다. 미분말의 유해성을 분석한 결과 세포독성을 함유하고 있어 토양 및 지하수오염 등 2차 오염을 초래할 수 있다. 본 연구에서는 미분말을 재활용하기 위한 방법으로 콘크리트의 혼화재로 활용하고자 시멘트 대신 미분말을 혼입한 콘크리트의 역학적 특성과 작업성을 비교 분석하였다. 콘크리트의 실험 결과에서, 혼화제를 적절히 사용하면 미분말을 시멘트 대신 20% 이하 치환한 경우 콘크리트에 적용 가능할 것으로 판단된다. 또한 고강도 콘크리트에서도 적용할 수 있다.

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사용후핵연료 운반용기 및 건식저장 기술 동향 (Technology Trends in Spent Nuclear Fuel Cask and Dry Storage)

  • 신중철;양종대;성운학;류승우;박영우
    • 한국압력기기공학회 논문집
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    • 제16권1호
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    • pp.110-116
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    • 2020
  • As the management plan for domestic spent nuclear fuel is delayed, the storage of the operating nuclear power plant is approaching saturation, and the Kori 1 Unit that has reached its end of operation life is preparing for the dismantling plan. The first stage of dismantling is the transfer of spent nuclear fuel stored in storage at plants. The spent fuel management process leads to temporary storage, interim storage, reprocessing and permanent disposal. In this paper, the technical issues to be considered when transporting spent fuel in this process are summarized. The spent fuels are treated as high-level radioactive waste and strictly managed according to international regulations. A series of integrity tests are performed to demonstrate that spent fuel can be safely stored for decades in a dry environment before being transferred to an intermediate storage facility. The safety of spent fuel transport container must be demonstrated under normal transport conditions and virtual accident conditions. IAEA international standards are commonly applied to the design of transport containers, licensing regulations and transport regulations worldwide. In addition, each country operates a physical protection system to reduce and respond to the threat of radioactive terrorism.

SRF 사용 시 발생되는 대기오염물질 (PM, NOx)의 국가배출량 기여도 평가 (SRF Combustion Pollutants' Impact on Domestic Emissions Assessments)

  • 김상균;장기원;김종현;유철;홍지형;김형천
    • 한국대기환경학회지
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    • 제28권6호
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    • pp.656-665
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    • 2012
  • Recently, yearly production of SRF (Solid Recovered Fuel) as an alternative fuel has been rapidly increasing because of the limited waste disposal, rise in oil prices and reduction of greenhouse gas emission. However, SRF using facilities are excluded from the National Air Pollutant Emission Estimation because SRF using facilities are not yet included among the SCC (Source Classification Code). The purpose of this research was to estimate the emission and emission factor of SRF using facilities' PM and $NO_x$, in order to investigate whether or not they are included in the National Air Pollutant Emission Estimation. The emission factors of SRF using facilities' PM and $NO_x$ are calculated as 0.216 kg/ton, and 3.970 kg/ton, and the emission was estimated based on the yearly total SRF usage of 2011. The results above was 18.7% for PM and 12.8% for $NO_x$ emissions from combustion facility (SCC2) in manufacturing industry combustion (SCC1) of CAPSS. If CAPSS estimate the emission by adding SCC on unlisted SRF in case of Boiler (SCC3) fuel, both PM and $NO_x$'s emissions would increase by 15.8% and 11.3% compare to the emissions for the existing combustion facility. As a result, emissions caused by SRF should be considered when calculating the National Air Pollutant Emission Estimation. In addition, further researches to develop emission factor and improve subdivided SCC should be done in the future, for the accurate and reliable estimation of National Emission.

매립장 침출수 환경 재해에 관한 연구 (Analysis of Environmental Hazard by the Leachate from Disposal Waste)

  • 김준경;배효준;최오순
    • 한국방재학회 논문집
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    • 제3권4호
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    • pp.145-151
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    • 2003
  • 생활폐기물 및 산업폐기물은 인간의 활동으로부터 배출되며 소각법 혹은 매립법 또는 2가지 방법을 동시에 이용하여 처리되고 있다. 특히 매립법은 침출수로 인하여 매립지가 있는 지역의 지하수계를 심각하게 오염시켜 환경재해를 발생시키고 있다. 따라서 오염지역의 침출수 오염특성을 3차원적으로 조사하여 환경재해를 최소화하는 것이 중요하다. 본 연구는 비위생 매립지인 충주시 노은 매립장의 3차원적 침출수 오염특성을 조사하였다. 조사를 위한 1개 측선의 방향은 주된 매립지 경계와 평행하도록 설치하였다. 노은 매립장을 탐사한 결과 가장 상부층은 안정화가 완전하게 진행되었으나 가장 하부층은 부분적으로 침출수가 일부 존재하는 것으로 분석되었다.

지하저장공동 주변 불연속 암반에서의 가스-물 천이유동해석을 위한 개별균열 유동모델의 개발 및 응용 (Development and Its Application of a Discrete Fracture Flow Model for the Analysis of Gas-Water Transient Flow in Fractured Rock Masses Around Storage Cavern)

  • 나승훈;성원모
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2000년도 가을 학술발표회 논문집
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    • pp.705-712
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    • 2000
  • The fluid generally flows through fractures in crystalline rocks where most of underground storage facilities are constructed because of their low hydraulic conductivities. The fractured rock is better to be conceptualized with a discrete fracture concept, rather continuum approach. In the aspect of fluid flow in underground, the simultaneous flow of groundwater and gas should be considered in the cases of generation and leakage of gas in nuclear waste disposal facilities, air sparging process and soil vapor extraction for eliminating contaminants in soil or rock pore, and pneumatic fracturing for the improvement of permeability of rock mass. For the purpose of appropriate analysis of groundwater-gas flow, this study presents an unsteady-state multi-phase FEM fracture network simulator. Numerical simulation has been also conducted to investigate the hydraulic head distribution and air tightness around Ulsan LPG storage cavern. The recorded hydraulic head at the observation well Y was -5 to -10 m. From the results obtained by the developed model, it shows that the discrete fracture model yielded hydraulic head of -10 m, whereas great discrepancy with the field data was observed in the case of equivalent continuum modeling. The air tightness of individual fractures around cavern was examined according to two different operating pressures and as a result, only several numbers of fractures neighboring the cavern did not satisfy the criteria of air tightness at 882 kPa of cavern pressure. In the meantime, when operating pressure is 710.5 kPa, the most areas did not satisfy air tightness criteria. Finally, in the case of gas leaking from cavern to the surrounding rocks, the resulted hydraulic head and flowing pattern was changed and, therefore, gas was leaked out from the cavern ceiling and groundwater was flowed into the cavern through the walls.

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Relationship of Ceramic Insulation Panel System Development and Verification of LCC

  • Han, Min-Cheol;Jeon, Kyu-Nam;Lee, Gun-Cheol;Kim, Tae-Hui
    • 한국건축시공학회지
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    • 제12권4호
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    • pp.386-392
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    • 2012
  • In this study, life cycle cost (LCC) is analyzed according to insulation panel system type using a deterministic LCC analysis method. Through this analysis, it was found that the construction cost in the deterministic LCC analysis for Ceramic panels was low compared to the construction cost for metal and stone panels. Also, the difference in cost between the Ceramic panel and the metal panel was about 2 times. In the area of maintenance cost, it was found to be similar to the previously analyzed construction cost, in which the metal panel has the highest cost due to the high cost of construction and the frequent need for maintenance. In the case of the stone panel, a small difference in cost is shown compared with that of the Ceramic panel, but the cost is higher than the Ceramic panel. Regarding the cost of waste disposal, the Ceramic panel can reduce the cost by at least 1.5 times and up to 2 times compared to other panel systems. Finally, in the analysis of sensitivity according to changes in discount rates, the Ceramic panel and metal panel systems have a similar cost, and the cost of the metal panel is a bit larger than that of other panel systems. Thus, in the subjects used in the analysis, the Ceramic panel system shows the highest economic benefits.

Current Status of Infection Prevention and Control Programs for Emergency Medical Personnel in the Republic of Korea

  • Oh, Hyang Soon;Uhm, Dong Choon
    • Journal of Preventive Medicine and Public Health
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    • 제48권6호
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    • pp.330-341
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    • 2015
  • Objectives: Emergency medical personnel (EMPs) are pre-hospital emergency responders who are at risk of exposure to infections and may also serve as a source for the transmission of infections. However, few studies of infection control have specifically addressed EMPs in the Republic of Korea (hereafter Korea). The goal of this study was to assess the current status of infection prevention and control programs (IPCPs) for EMPs in Korea. Methods: A cross-sectional survey was conducted to quantitatively assess the resources and activities of IPCPs. A total of 907 EMPs in five metropolitan cities completed a structured questionnaire from September 2014 to January 2015. The data were analyzed using descriptive statistics, multi-response analysis, and the chi-square test. Results: The mean age of the participants was $34.8{\pm}15.1years$. IPCPs were found to have weaknesses with regard to the following resources: the assignment of infection control personnel (ICP) (79.5%), hand hygiene resources such as waterless antiseptics (79.3%), the use of paper towels (38.9%), personal protective equipment such as face shields (46.9%), and safety containers for sharps and a separated space for the disposal of infectious waste (10.1%). Likewise, the following activities were found to be inadequately incorporated into the workflow of EMPs: education about infection control (77.5%), post-exposure management (35.9%), and the decontamination of items and spaces after use (88.4%). ICP were found to have a significant effect on the resources and activities of IPCPs (p<0.001). The resources and activities of IPCPs were found to be significantly different among the five cities (p<0.001). Conclusions: IPCPs for EMPs showed some limitations in their resources and activities. IPCPs should be actively supported, and specific IPCP activities for EMPs should be developed.

Applying a Life-Cycle Assessment to the Ultra Pure Water Process of Semiconductor Manufacturing

  • Tien, Shiaw-Wen;Chung, Yi-Chan;Tsai, Chih-Hung;Yang, Yung-Kuang;Wu, Min-Chi
    • International Journal of Quality Innovation
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    • 제6권3호
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    • pp.173-189
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    • 2005
  • A life-cycle assessment (LCA) is based on the attention given to the environmental protection and concerning the possible impact while producing, making, and consuming products. It includes all environmental concerns and the potential impact of a product's life cycle from raw material procurement, manufacturing, usage, and disposal (that is, from cradle to grave). This study assesses the environmental impact of the ultra pure water process of semiconductor manufacturing by a life-cycle assessment in order to point out the heavy environmental impact process for industry when attempting a balanced point between production and environmental protection. The main purpose of this research is studying the development and application of this technology by setting the ultra pure water of semiconductor manufacturing as a target. We evaluate the environmental impact of the Precoat filter process and the Cation/Anion (C/A) filter process of an ultra pure water manufacturing process. The difference is filter material used produces different water quality and waste material, and has a significant, different environmental influence. Finally, we calculate the cost by engineering economics so as to analyze deeply the minimized environmental impact and suitable process that can be accepted by industry. The structure of this study is mainly combined with a life-cycle assessment by implementing analysis software, using SimaPro as a tool. We clearly understand the environmental impact of ultra pure water of semiconductor used and provide a promotion alternative to the heavy environmental impact items by calculating the environmental impact during a life cycle. At the same time, we specify the cost of reducing the environmental impact by a life-cycle cost analysis.

Ammonium Chloride Solution Leaching of Crude Zinc Oxide Recovered from Reduction of EAF′s Dust

  • Youn, Ki-Byoung
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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    • pp.365-369
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    • 2001
  • EAF's dust has been treated mainly by pyrometallurgical reduction process in rotary kiln furnace to recover valuable metal elements such as Zn and to avoid the disposal of hazardous materials to waste. Recently, hydrometallurgical eletrowinning of zinc from a zinc-amino chloride solution obtained by the leaching of EAF's dust was developed to recover high grade zinc metal from EAF’s dust. But there are some disadvantages in each process such as difficulty of operation condition control and sticking problem in kiln process and low extractability and recovery of zinc owing to insoluble zinc-ferrite in electrowinning process. We propose a new combined process of pyrometallurgical one and hydrometallurgical one to treat EAF's dust efficiently and economically. In this study, ammonium chloride solution leaching of crude zinc oxide recovered from reduction of EAF's dust was carried out to find out the efficiency of zinc extraction from it and the possibility for performance of eletrowinning in the proposed process. Effects of various leaching variables ruck as leaching temperature, concentration of leaching solution and leaching time were investigated. And the leaching results of the crude zinc oxide were compared with those of EAF's dust. The extraction percents of zinc in ammonium chloride solution leaching of the crude zinc oxide recovered from reduction of EAF's dust were above 80% after 60 minutes of leaching under the leaching condition of 4M NH$_4$CI concentration and above leaching temperature of 7$0^{\circ}C$. And the concentrations of zinc in the leached solution were obtained above 50g/$\ell$. The activation energy calculated for zinc extraction in NH$_4$CI leaching was 58.1 KJ/㏖ for EAF's dust and 15.8 KJ/㏖ for the crude zinc oxide recovered from reduction of EAF's dust.

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