• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1021-1024
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• 2004

During demonstrations of a process conditioning spent nuclear fuels, it may be necessary to transport modularized parts of process equipment out of a hot cell because of modules' failure or completion of demonstrations. It may be not easy to transport modules because modules will be contaminated. For this purpose, we have developed a prototype of a device transporting radioactive contaminated materials. We have analyzed conditions of a hot cell and requirements of the device, designed and manufactured a scaled-down prototype of the device, and done some performance tests such as running on the rail, running on the flat floor, and carrying capability of a sliding upper part. From the tests, it has been shown that running on the rail and floor was smooth but the sliding part was deflected if the sliding distance was long. These result will be reflected to a design of the improved transporting device which will be used during demonstrations.

• Journal of Soil and Groundwater Environment
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• v.9 no.3
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• pp.1-11
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• 2004

To evaluate the applicability of dielectric constant measurement method on the geoenvironmental investigation of subsurface contaminated by landfill leachate, the analysis on dielectric characteristics of sand containing contaminated pore water by landfill leachate was performed. The separate real and imaginary parts of dielectric constant were investigated in the frequency range of 75kHz to 12MHz. The real part of dielectric constant increased at the lower frequency wherea the real part of dielectric constant decreased at the higher frequency as the concentration of leachate increased. These results can be explained by the frequency dependence of space charge polarization and orientation polarization. The imaginary part of dielectric constant on the contaminated sand with leachate increased with their concentration for whole frequency range. These results are caused by the increase of energy loss due to the enhancement of conduction in soil with leachate concentration. The results in this study indicate that the dielectric constant measurement method has potential in evaluating the contaminated soil and pore water by landfill leachate.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.271-278
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• 2011

The allelopathic effects of Lantana camara L. (Family:Verbenaceae) on germination and seedling establishment of some agricultural crops and weed species have been identified. Aqueous extracts of dry leaves and contaminated soil where L. camara is grown were used to verify allelopathic effect on seed germination of five bioassay species; Raphanus sativas, Capsicum annum, Lycopersicum esculantem, Crotalaria juncia and Chromoleana odorata. Fifty seeds from each bioassay species were placed in a petri dish containing leaf extracts or contaminated soil, and seed germination were examined after 3 days. The plant house experiments were carried out to evaluate the impact of L. camara contaminated soil and leaf debris using L. esculantem as the indicator plant. Seed germination of L. esculentem, C. junica and Capsicum annum was significantly inhibited by L. camara contaminated soil. However, the degree of inhibition varied among the bioassay species. The aqueous extract of dry leaves of L. camara was highly phytotoxic and it significantly reduced seed germination of all bioassay species. There was a decline in plant height, leaf area and shoot dry weight of tomato only in early growth stages when grown in L. camara contaminated soils. However, incorporation of leaf debris into soil affected the vegetative growth of tomato in early stages when the leaf debris concentration was increased. Growth recovered at the latter part of the life cycle. On the basis of these results it can be concluded that the allelochemicals in L. camara contaminated soils are harmful to the seed germination of crop species. The adverse effect was present only during the early growth stages and it did not suppress the latter part of the plant growth. These responses are attributed to allelopathic effects which need confirmation under field conditions.

• Journal of Environmental Impact Assessment
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• v.12 no.3
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• pp.199-209
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• 2003

The withdrawal method for protecting the uncontaminated part from the spread of contaminants was suggested by a simultaneous equation. The formulation of them is based upon the build up of the ridge part between the contaminated and uncontaminated parts that resulted from the efficient use of barrier wells. The quality in the withdrawn groundwater depends upon the heads at wells no. 5 and 6. The determination of pumping rates and qualities with changing the heads at wells no. 5 and 6 should be given by considering the demand for water use and the capacity and cost for removing the contained contaminants. The results of this study should be used in taking a plan for supplying water use as well as preventing the spread of contaminants from some known contaminated sources.

• Journal of Soil and Groundwater Environment
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• v.18 no.5
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• pp.56-64
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• 2013

After the law has been enacted for the prevention and recovery of mining damage in 2005, efforts of remediation have been started to recover heavy metal contaminated soils in agricultural land near mining sites. As part of an effort, the upper part of cultivation layer has been treated through covering up with clean soil, but the heavy metal contamination could be still spreaded to the surrounding areas because heavy metals may be remained in the lower part of cultivation layers. In this study, the most frequently occurring arsenic (As) contamination was selected to study in agricultural land nearby an abandoned metal mining site. We applied separation technologies considering the differences in the physical characteristics of soil particles (particle size, density, magnetic properties, hydrophobicity, etc.). Based on physical and chemical properties of arsenic (As) containing particles in agricultural lands nearby mining sites, we applied sieve separation, specific gravity separation, magnetic separation, and flotation separation to remove arsenic (As)-containing particles in the contaminated soil. Results of this study show that the removal efficiency of arsenic (As) were higher in the order of the magnetic separation, flotation separation, specific gravity separation and sieve separation.

• Nuclear Engineering and Technology
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• v.42 no.2
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• pp.175-182
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• 2010

As part of a fundamental study on the volume reduction of contaminated concrete wastes, the separation characteristics of the aggregates and the distribution of the radioactivity in the aggregates were investigated. Radioisotope $^{60}Co$ was artificially used as a model contaminant for non-radioactive crushed concrete waste. Volume reduction for radioactively contaminated dismantled concrete wastes was carried out using activated heavy weight concrete taken from the Korea Research Reactor 2 (KRR-2) and light weight concrete from the Uranium Conversion Plant (UCP). The results showed that most of the $^{60}Co$ nuclide was easily separated from the contaminated dismantled concrete waste and was concentrated mainly in the porous fine cement paste. The heating temperature was found to be one of the effective parameters in the removal of the radionuclide from concrete waste. The volume reduction rate achieved was above 80% for the KRR-2 concrete wastes and above 75% for the UCP concrete wastes by thermal and mechanical treatment.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.192-195
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• 2003

As a part of our research project for in-situ bioremediation of nitrate contaminated. groundwater, screening studies to determine an effective electron donor (EO) and/or carbon source (CS) such as acetate, ethanol, formate, fumarate, lactate, and propionate were conducted. To evaluate the feasibility for the biological degradation of nitrate, soil microcosm studies using nitrate-contaminated soil and groundwater were performed. The nitrate removal percentage in the order from the highest to the lowest was: formate, fumarate, and ethanol > lactate > propionate. Essentially no nitrate consumption was observed In acetate-fed microcosms. The order of nitrate removal rate from the highest to lowest was fumarate, formate, lactate, ethanol, and propionate. These results suggest that fumarate and formate are promising EDs/CSs for in-situ bioremediation of nitrate - contaminated oxygenated groundwater.

• Korean Journal of Food Science and Technology
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• v.19 no.6
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• pp.543-549
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• 1987

This study was carried out to estimate the change of Hg content in contaminated food materials including rice grain, soybean sprouts and crucian carp during their washing and cooking processes. The residue level of Hg in contaminated rice at 1 ppm level was decreased to the extent of 24% by three-times washing whereas it was not decreased in cooking. The removal efficiency of Hg in soybean sprouts contaminated at 80 ppm level was about 26% in three-times washing. While the Hg content was not decreased in blanching or cooking of soybean sprouts as a whole, the extent of leached Hg into the fluid part varied in the range of 23-41% depending on the heating time, salinity and volume of cooking water. While the Hg content in fish contaminated at 1 ppm level was not decreased in cooking as a whole, the leaching ratio of Hg into the fluid part was in the range of 2-10% depending on the salinity of cooking water. Disposal of inedible portion in cooked fish could remove 32% of contaminated Hg residue.

• Journal of Radiation Protection and Research
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• v.48 no.2
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• pp.68-76
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• 2023

Background: In the process of discussion on the possibility of using radionuclide-contaminated soil and debris generated by radiation disasters, a strategy for the proper management of radiation exposure protection while considering the source of the contaminated materials is necessary. Materials and Methods: The radiological protection criteria that are likely to be applied to the source-related approach based on the International Commission on Radiological Protection recommendations and the International Atomic Energy Agency safety standards are summarized. We proposed five interpretations of radiation protection to contribute to the promotion of discussion on the possibility of using a part of low-level-radionuclide-contaminated soil and debris in the post-accident rehabilitation. Interpretations I to III are based on the idea of "using a reference level to protect the public in post-accident rehabilitation," whereas IV and V are based on the idea of "using the dose constraint to protect the public in the post-accident rehabilitation when the sources are handled in a planned activity." The former idea is subdivided into three based on the definition of the source, which is managed by the reference level, and the latter idea is divided into two depending on whether or not additional dose from using contaminated materials is deemed acceptable. Results and Discussion: To confirm the applicability of the five interpretations presented, we suggested the concrete values of protection criteria via two feasible cases. In this case study, we proposed radiation protection by the dose constraint based on the Interpretation IV and chose 1 mSv/yr for the public and 20 mSv/yr for workers dealing with radionuclide-contaminated materials. Conclusion: We concretely and systematically demonstrated how the concept of radiation protection can be applied to the process of discussion on the possibility of using radionuclide-contaminated materials within the framework of an international system of protection. This study's findings can provide necessary information to discuss the possibility of using radionuclide-contaminated materials as an alternative option for recovery and reconstruction after a radiation disaster from the viewpoint of radiation protection.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.105-108
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• 2003

The intervention area located at rear hot cell can be contaminated by hot cell maintenance work. For effective decontamination of the intervention floor a wet type decontamination device was developed. The device was assembled with a brush rotating part, a washing liquid supplying part, an intake part for recovering contaminated liquid and a device moving cart part. The device was made of stainless steel for easy decontamination and corrosion resistance. The function test carried out at intervention area of the PIE facility showed good performance.