• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.711-714
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• 2001

A new technology to make fluoride gas such as NF$_3$contained in the exhaust gas from semiconductor manufacturing plants convert directly into a harmless substance have been established and new concept on the disposal treatment of global warming gases were presented. Experimental results verify that the chemical reactions can be take place at substantially lower temperature of 80-40$0^{\circ}C$ as compared with the combustion treatment method. Reaction product is mainly metal fluoride which is a harmless and a valuable chemical material as one of new resources. The other favorable characteristics are that the continuous treatment is possible at a low temperature under atmospheric pressure. Furthermore this process is compact, easily controllable and safely operable at low running cost. This paper concerns with a new harmless disposal treatment of toxic global warming gas.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.2
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• pp.110-118
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• 2014

This paper addresses the fugitive emission factors of Reefer Container at use-phase and disposal-phase. The residual quantities and operation time of thirty nine Container were weighed, using a commercial recover of refrigerants to determine the emission factors at the use-phase. The emission factor at the disposal-phase, refrigerant is accomplished has not recycled, the residual rate was assumed that the emission factor. The average residual rate of thirty nine Container is determined to be $70.8{\pm}4.0%$. The emission factor at the use-phase is estimated to be $4.9{\pm}0.9%/yr$ in the case of using average age of 8.1 years and the average residual rate determined here. We estimate 162.7 g/yr for the average emission quantity of refrigerant per operating Container, while 2038.1 g for that per waste Container. Since the chemical compositions of refrigerant of waste Container were the same as those of new refrigerant, it is expected that the refrigerant recovered from waste Container can be reused for refrigerant.

• Journal of radiological science and technology
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• v.41 no.1
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• pp.67-73
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• 2018

In this paper, risk assessment was conducted to verify self - disposal requirements by landfill for exempted incineration ash by using Resrad Ver.6.5 computer code. The result of risk assessment by landfill for the incineration by-product is that individual dose is $6.91{\times}10^{-2}{\mu}Sv\;y-1$ and collective dose is $3.475{\times}10^{-7}man-Sv\;y-1$. It proved that the result meets reference dose of individual dose $10{\mu}Sv\;y-1$ and collective dose 1 man-Sv y-1 for general public. According to the current 'Nuclear Safety Commission Notice [No. 2014-3]', it states that the exempted wastes can be disposed of by incineration, landfill and recycling. However, most of recently documents and papers related to exempted wastes are disposed of by landfill and recyling and it could not confirm the case of exempt by incineration. If the national consensus is derived and treating the waste by using process of incineration is activated, it could be considered to treat low level of radiation wastewater and activated carbon excluded from exempted waste because of nuclide $^3H$ and $^{14}C$.

• Advances in environmental research
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• v.3 no.4
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• pp.337-353
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• 2014

The determination of the effectiveness of the immobilization of blasting dust (waste generated in galvanic activities) in cement matrix, as well of mechanical, physical and microstructural properties of concrete paving blocks produced with partial replacement of cement was the objective of this work. The results showed that blasting dust has high percentage of silica in the composition and very fine particle size, characteristics that qualify it for replacement of cement in manufacturing concrete blocks. The replacement of Portland cement by up to 5% residues did not cause a significant loss in compressive strength nor increase in water absorption of the blocks. Chemical tests indicated that there is no problem of leaching or solubilization of contaminants to the environment during the useful life of the concrete blocks, since the solidification/stabilization process led to the immobilization of waste in the cement mass. Therefore, the use of blasting dust in the manufacture of concrete paving blocks is promising, thus being not only an alternative for proper disposal of such waste as well as a possibility of saving raw materials used in the construction industry.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2418-2426
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• 2022

The grouping analysis is a method guided by the Korea Radioactive Waste Agency for efficient analysis of radioactive waste for disposal. In this study, experiments to verify the adequacy of grouping analysis were conducted with radioactive soil, concrete, and dry active waste in similar environments. First, analysis results of the major radionuclide concentrations in individual waste samples were reviewed to evaluate whether wastes from similar environments correspond to a single waste stream. As a result, the soil and concrete waste were identified as a single waste stream because the distribution range of radionuclide concentrations was "within a factor of 10", the range that meet the criterion of the U.S. Nuclear Regulatory Commission for a single waste stream. On the other hand, the dry active waste was judged to correspond to distinct waste streams. Second, after analyzing the composite samples prepared by grouping the individual samples, the population means of the values of "composite sample analysis results/individual sample analysis results" were estimated at a 95% confidence level. The results showed that all evaluation values for soil and concrete waste were within the set reference values (0.1-10) when five-package and ten-package grouping analyses were conducted, verifying the adequacy of the grouping analysis.

• Applied Chemistry for Engineering
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• v.3 no.2
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• pp.213-223
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• 1992

Although landfill has been heavily relied upon as a final hazardous waste disposal method in Korea, the legal and technical problems associated with the landfill severely hinder proper disposal of hazardous wastes. The single largest legal problem is simply that, in spite of the recent amendments, the law regulating the hazardous waste landfill is yet in its primitive stage that even the lawful landfill sites cannot be regarded safe. The technical problems include improper selection of landfill sites, poor design and construction of landfill facilities, and lack of QA/AC and post-closure cares. These technical problems stem from inexperience and lack of resources. For the reduction of the potential danger from the improper landfills of hazardous wastes, it is an immediate need to further refine the law and to resolve the technical problems.

• Nuclear Engineering and Technology
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• v.22 no.1
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• pp.29-35
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• 1990

Uranium solubilities have been calculated for a range of conditions expected in a nuclear waste disposal repository. Variables taken into consideration include the pH and Eh range expected for deep groundeaters, the effect of the composition of groundwater. The model used in these calculations is based on the assumption of chemical equilibrium. Calculations show that the major variables influencing uranium solubility under the repository conditions are pH and Eh. The results of this study can be applied to an assessment of the nuclear waste disposal.

• Journal of Soil and Groundwater Environment
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• v.20 no.3
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• pp.7-14
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• 2015

In this study, land farming and chemical oxidation of a diesel-contaminated site is compared to evaluate the environmental impact during soil remediation using the Spreadsheet for Environmental Footprint Analysis by U.S. EPA. Each remediation process is divided into four phases, consisting of soil excavation, backfill and transportation (Phase 0), construction of remediation facility (Phase 1), remediation operation (Phase 2), and restoration of site and waste disposal (Phase 3). Environmental footprints, such as material use, energy consumption, air emission, water use and waste generation, are analyzed to find the way to minimize the environmental impact. In material use and waste generation, land farming has more environmental effect than chemical oxidation due to the concrete and backfill material used to construct land farming facility in Phase 1. Also, in energy use, land farming use about six times more energy than chemical oxidation because of cement production and fuel use of heavy machinery, such as backhoe and truck. However, carbon dioxide, commonly considered as important factor of environmental impact due to global warming effect, is emitted more in chemical oxidation because of hydrogen peroxide production. Water use of chemical oxidation is also 2.1 times higher than land farming.

• 수도
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• v.25 no.1 s.88
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• pp.25-35
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• 1998

Factors controlling water quality, water-quality standards, and normal ranges of concentrations in unpolluted fresh water and the sources of elements were explained in this paper. In particular, the sources of groundwater contamination such as the disposal of domestic waste water, landfills, chemical spills and leaking underground tanks, and agricultural and mining activities were discussed.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.351-354
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• 2000

In recent years, the world development of alternative construction materials is associated with disposal problems of waste materials as a result of industrial activities. Technologies of refining gypsum to several gypsum modifications ($\alpha$ and $\beta$-hemihydrate) which can be used as construction material in a large scale do actually exist or are under development. This paper provides a technical and economic perspective of the waste gypsum treatment. Especially, several applications particularly of $\alpha$-hemihydrate will be presented, e.g. artificial gypsum aggregate and light-weight masonry units.