• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.2
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• pp.179-188
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• 2016

Spent fuels from nuclear power plants, as well as high-level radioactive waste from the recycling of spent fuels, should be safely isolated from human environment for an extremely long time. Recently, meaningful studies on the development of deep borehole radioactive waste disposal system in 3-5 km depth have been carried out in USA and some countries in Europe, due to great advance in deep borehole drilling technology. In this paper, domestic deep geoenvironmental characteristics are preliminarily investigated to analyze the applicability of deep borehole disposal technology in Korea. To do this, state-of-the art technologies in USA and some countries in Europe are reviewed, and geological and geothermal data from the deep boreholes for geothermal usage are analyzed. Based on the results on the crystalline rock depth, the geothermal gradient and the spent fuel types generated in Korea, a preliminary deep borehole concept including disposal canister and sealing system, is suggested.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.4
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• pp.245-255
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• 2008

Korea Hydro and Nuclear Power Company(KHNP) conducted site investigations for a low and intermediate-level nuclear waste repository in the Gyeong Ju site. The site characterization work constitutes a description of the site, its regional setting and the current state of the geosphere and biosphere. The main objectives of hydogeological investigation aimed to understand the hydrogeological setting and conditions of the site, and to provide the input parameters for safety evaluation. The hydogeological characterization of the site was performed from the results of surface based investigations, i.e geological mapping and analysis, drilling works and hydraulic testing, and geophysical survey and interpretation. The hydro-structural model based on the hydrogeological characterization consists of one-Hydraulic Soil Domain, three-Hydraulic Rock Domains and five-Hydraulic Conductor Domains. The hydrogeological framework and the hydraulic values provided for each hydraulic unit over a relevant scale were used as the baseline for the conceptualization and interpretation of flow modeling. The current hydrogeological characteristics based on the surface based investigation include some uncertainties resulted from the basic assumption of investigation methods and field data. Therefore, the reassessment of hydrostructure model and hydraulic properties based on the field data obtained during the construction is necessitated for a final hydrogeological characterization.

• Economic and Environmental Geology
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• v.24 no.2
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• pp.97-105
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• 1991

Oxygen and sulfur isotope composition of pyrophyllite and pyrite from six pyrophyllite deposits in the Yangsan-Milyang areas (the Cheonbulsan, Dumyong, Dongrae, Youkwang, Sungjin and Milyang mines), and five deposits in the Whasoon-Dado-Haenam areas (the Byuksong, Songseok, Dado, Bugock and Nowha mines) were measured. Pyrophyllite ores both from the Yangsan-Milyang areas and the Dado-Haenam areas are composed mainly of high alumina minerals such as pyrophyllite, sericite and kaolinite. Most of altered rocks show diagnostic chacteristics of bleaching effect. Major minerals of the Songseok ore deposit in the Whasoon area are pyrophyllite, and diaspore with minor amounts of kaolinite and quartz. The Byuksong ores from the Whasoon area were composed mainly of andalusite, kaolinite, pyrophyllite and mica with small amounts of chloritoid, quartz and carbonaceous matter. The Byuksong and Songseok ores show metamorphic textures such as porphyroblastic, and pressure solution textures, and have low whiteness values, The ${\delta}^{18}O$ values of pyrophyllite from the Cheonbulsan and Dumyong mines in the Yangsan area, and the Dado and Nowha mines in the Dado-Haenam areas were in the range of 0.23~5.36%,. The relatively low 8 180 values provide conclusive evidence for hydrothermal activity in these deposits. The ${\delta}^{18}O$ values of pvrophvllite from the Songseok mine in the Whasoon area were measured as 6.70-8.13%, and these higher ${\delta}^{18}O$ values suggest that the Songseok ore deposit have been probably subjected to metamorphism. ${\delta}^{34}$S(pyrito) values from the Cheonbulsan, Dumyong, Youkwang, Dongrae, Sungjin and Milyang deposits in the Yangsan-Milyang areas, and the Dado pyrophyllite deposits in the Dado area range from -5.8 to 2.7%, which means that the pyrite sulfur could be of igneous origin. ${\delta}^{34}$S(pyrito) from the Nohwa mine in the Haenam area is, however, measured as -12.4%" implying the contamination of sulfur derived from the sedimentary country rocks. All of the studied high alumina deposits in the Yangsan-Milyang areas and the Dado-Haenam areas were hydrothermal in origin, whereas the Byuksong and Songseok ore deposits in the Whasoon area were probably of metamorphic origin.

• Economic and Environmental Geology
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• v.35 no.5
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• pp.407-420
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• 2002

The Buddhist Triad Cave in Gunwi (National treasure No. 109) consists of porphyritic biotite granite, and it has been deteriorated into microorganic smears, white films, brown rusts, granular decay, color changes, and joints by the same weathering factors as rain, moisture, temperature variation and microorganic living. Main origin is probably the rain that leaks into the cave along joints in Palgongsan granite, and then its moisture grows many microorganism and is frozen over during winter. The granites around the cave regularly develop two NEE and NWW joint sets that are conjugate to be a joint system. The NEE set extends far away with narrow joint spacings and affects the leakage of the rains, and is divided into 4 joint zones, among which J$_{m}$ and J$_{3}$ immediately affect the leaking water into the cave. An extensional Joint, in northern wall of the cave, was formed by toppling of the block between J$_{m}$and J$_{3}$joint zones from widening the Jm aperture by roots of a big pine tree, and passes through the J$_{m}$joint zone. This bypass allows no circulation of small rain, but a good circulation of heavy rain from influx to the cave for a long pathway. Many Joints and cracks, in the ceiling near the cave entrance, immediately get through the J$_3$ joint zone, and have a good circulation of small rain 10 mm. Both J$_{m}$and J$_{3}$ joint zones are, therefore, chief influxes that cause leakage of the rains.

• Economic and Environmental Geology
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• v.44 no.4
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• pp.289-302
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• 2011

Since the frequency of the earthquake occurrence in Korean peninsular is continuously increasing, the possibility that massive landslides are triggered by earthquake is also growing in Korea. Previously, the landslide is known to be induced by large magnitude earthquake, whose magnitude is larger than 6.0. However, the landslide can be induced by only small magnitude earthquake, especially in the fully saturated soil. Therefore, the susceptibility of landslide caused by small magnitude earthquake in fully saturated soil is analyzed in this study. For that, the topographical and geological characteristics of the site were obtained and managed by GIS software. In the procedure of the study, slope angle, cohesion, friction angle, unit weight of soil were obtained and constructed as a spatial database layer. Combining these data sets in a dynamic model based on Newmark's displacement analysis, the landslide displacements were estimated in each grid cell. In order to check out the possibility of the earthquake induced landslides, the level of the groundwater table is varied from dry to 80% saturated soil. In addition, in order to analyze the effect of the magnitude of earthquake and distance to epicenter, four different earthquakes epicenters were considered in the study area.

• Economic and Environmental Geology
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• v.50 no.1
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• pp.27-34
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• 2017

Mineral carbonation for the storage of carbon dioxide is a CCS option that provides an alternative for the more widely advocated method of geological storage in underground formation. Carbonation of magnesium- or calcium-based minerals, especially the carbonation of waste materials and industrial by-products is expanding, even though total amounts of the industrial waste are too small to substantially reduce the $CO_2$ emissions. The mineral carbonation was performed with steelmaking reduction slag as starting material. The steelmaking reduction slag dissolution experiments were conducted in the $H_2SO_4$ and $NH_4NO_3$ solution with concentration range of 0.3 to 1 M at $100^{\circ}C$ and $150^{\circ}C$. The hydrothermal treatment was performed to the starting material via a modified direct aqueous carbonation process at the same leaching temperature. The initial pH of the solution was adjusted to 12 and $CO_2$ partial pressure was 1MPa for the carbonation. The carbonation rate after extracting $Ca^^{2+}$ under $NH_4NO_3$ was higher than that under $H_2SO_4$ and the carbonation rates in 1M $NH_4NO_3$ solution at $150^{\circ}C$ was dramatically enhanced about 93%. In this condition well-faceted rhombohedral calcite, and rod or flower-shaped aragonite were appeared together in products. As the concentration of $H_2SO_4$ increased, the formation of gypsum was predominant and the carbonation rate decreased sharply. Therefore it is considered that the selection of the leaching solution which does not affect the starting material is important in the carbonation reaction.

• Economic and Environmental Geology
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• v.50 no.1
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• pp.45-59
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• 2017

In this research, we have extracted historical records regarding the geotechnology from the Goryeosa and the Annals of the Joseon Dynasty which are rated as ancient books that have objective views in the Goryeo Dynasty and the Joseon Dynasty in order to understand the national awareness and the social situation of the past events. We used the Korean history database system of National Institute of Korean History (NIKH) and collected related records by searching specific keywords such as volcano, mining, hot spring, and meteorite. According to the historical records, geological events such as the volcano and meteorite were regarded as important issues which were enough to be recorded in annals and surveyed by the dispatched government officials to the fields of events. In case of the hot springs, government officials conducted explorations of hot springs at king's orders and developed the potential areas of hot springs. Among the historical records on mining, the contents of geotechnology including the contents about discovered minerals and its locations can be easily found from those ancient books. Especially, it is possible to understand the history of geotechnology such as an establishment of modern organizations and a capitalistic flow for development through the history of the mining in the late Joseon Dynasty.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.479-489
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• 2020

A fault is a geological structure that can be a migration path or a cap rock of hydrocarbon such as oil and gas, formed from source rock. The fault is one of the main targets of seismic exploration to find reservoirs in which hydrocarbon have accumulated. However, conventional fault detection methods using lateral discontinuity in seismic data such as semblance, coherence, variance, gradient magnitude and fault likelihood, have problem that professional interpreters have to invest lots of time and computational costs. Therefore, many researchers are conducting various studies to save computational costs and time for fault interpretation, and machine learning technologies attracted attention recently. Among various machine learning technologies, many researchers are conducting fault interpretation studies using the support vector machine, multi-layer perceptron, deep neural networks and convolutional neural networks algorithms. Especially, researchers use not only their own convolution networks but also proven networks in image processing to predict fault locations and fault information such as strike and dip. In this paper, by investigating and analyzing these studies, we found that the convolutional neural networks based on the U-Net from image processing is the most effective one for fault detection and interpretation. Further studies can expect better results from fault detection and interpretation using the convolutional neural networks along with transfer learning and data augmentation.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.491-504
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• 2020

Given the continued climate change and global warming, various technologies for greenhouse gas reduction were discussed worldwide as all 195 countries participated in the Paris Agreement on the reduction of greenhouse gases. The agreement was adopted at the 21st Conference of Parties to the UNFCCC (COP21), which was held in Paris, France, in December 2015, and it revealed that reducing CO₂ is the most efficient method of greenhouse gas reduction. Accordingly, carbon capture/utilization/storage (CCUS) technology has been noted as a means of making practical contributions to CO₂ reduction, and research and development (R&D) activities in many countries are active in the field of CCUS technology. Therefore, this study aims to provide a basis for CCUS R&D and strategic support measures by analyzing patent trends in technologies related to CCUS. The patent analysis collected a total of 10,137 patents in the United States, Korea, Japan, Europe, and China; the number of patents in the United States was the highest according to patent analysis by country. According to an analysis by technology, capture-related technology was high at 60%, but given the recent increase in technology related to utilization, technology demonstration, R&D, and policy support should be continued.

• The Journal of Engineering Geology
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• v.15 no.4 s.42
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• pp.381-390
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• 2005

S City depends on the T River as source water for water supply. Arsenic and boron from the hot-spring waste-water discharged from the hot-spring spa resort and emerging from the fractures of bedrock of the river have been prevalent contaminant of the T River water. This research was conducted to propose the simple and quick surrogate parameter for water quality management easily. And through making hexa-diagram of principal ions in the water samples, existing state of the water and influence of the human activity or geological origin can be figured out. As a results of characteristics of the T River water quality using principal component analysis, the contributory percentages of the 1st, 2nd and 3rd principal components were $40.80\%,\;21.40\%\;and\;11.31\%$, respectively. Therefore it was clarified that the quality of the T River water could be explained by these three principal components. Concentration of the chloride ion, which is one of the characteristics of the hot-spring water, was well correlated to both arsenic and boron concentrations. Hence concentrations of the arsenic and boron in the raw water of the water reatment plant can be predicted by the measurement of concentration of the chloride ion.