• The Journal of the Petrological Society of Korea
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• v.25 no.4
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• pp.335-348
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• 2016

The fluvial Tamna Formation, consisting of conglomerate, sandstone and mudstone layers, is widely distributed in Jeiu Island. Various sizes of quartz crystals were identified from most of the Tamna Formation, including the mudstone layer. XRD analysis also shows that the mudstone layer is composed of various minerals, quartz, plagioclase, K-feldspar, mica, magnetite, hematite, olivine, amphibole, gibbsite, calcite, analcime and clay minerals such as illite, kaolinite, vermiculite, smectite, chlorite, $10{\AA}$-halloysite. There is a tendency showing that the more amount of kaolinite, vermiculite, and chlorite is present where the more amount of quartz crystals is present. It is likely that the main source materials contributing to the Tamna Formation were from the parental rocks containing abundant quartz grains, suggesting that the Tamna Formation could not be related to Jeju volcanic rocks, but possibly to pre-existing basement rocks. Thus, we propose that the Tamna Formation was formed from the materials derived from both pre-existing basement rocks and Jeju volcanic rocks, which were subsequently affected by diagenesis, hydrothermal alteration and weathering process.

• The Journal of Engineering Geology
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• v.30 no.1
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• pp.71-84
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• 2020

Various geological structures are found on the slope of Bangnim district in Pyeongchang, Gangwon-do, based on the Paleozoic Joseon Supergroup Limestone. The recumbent fold observed on the slope is a very rare geological structure that has not been found in Korea, and has important academic value in exploring the formation process of the Paleozoic geological structures in the Gangwon region. In this study, discussed the geological value of the geological structure observed on the slope of the road, and studied the management method of rockfall problem slopes. The state of development of recumbent folds has conservation value in geological scarcity and specificity. Preservation management measures should be prepared through the protection of slopes and measures to reduce of rockfall risks as geoheritage with an important value in geology science and education. Furthermore, it is expected to be preserved and utilized as a geopark.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.705-711
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• 2007

We should treat carefully the one related to human rights among a large number of decision-making in our daily lives. As it is necessary to obtain physical evidences in the process of criminal investigation for solving a certain crime based on the principle of evidence, it leads to an increase in demand for forensic science and forensic geology. Forensic geology could be regarded as a fusion discipline of geology and forensic investigation and it is principally concerned to the study on the connection of a suspect and a crime scene with soil evidence which could be experimented using geological data and methods. So these results could be used as valuable information in a court. After its academic foundation has been builded since the last 1970s, its research objects have been expanded from soil evidence like rocks, minerals, soils, sediments to sociocultural, political, military and medical objects like ancient relics, mines, corpses. Its role is expanded from the simple finding of a particular location to the examination of archaeological theories and historical facts, the testimony of the cause of environmental pollution and the chronic demonstration of geological distribution of plants and anthropological origination. And these bring this discipline promptly to accept developed geological methodologies and to satisfy various forensic geological needs. Specialized forensic investigation institutes work actively for the R&D activities of forensic geology. In Korea, national institute of scientific investigation works a small part of forensic geological activities in total activities of forensic investigation. In conclusion, we concern to the importance of systematic discussion of building in proper position of forensic geology through its R&D methods, application cases of its performance and etc. based on geological characteristics in our country by a specialized geoscience institute.

• Economic and Environmental Geology
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• v.56 no.5
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• pp.533-545
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• 2023

In this study, an investigation was conducted on the features, events, and processes (FEP) that could impact the long-term safety of the natural barriers constituting high-level radioactive waste geological repositories. The FEP list was developed utilizing the IFEP list 3.0 provided by the Nuclear Energy Agency (NEA) as foundational data, supplemented by geological investigations and research findings from leading countries in this field. A total of 49 FEPs related to the performance of the natural barrier were identified. For each FEP, detailed definitions, classifications, impacts on long-term safety, significance in domestic conditions, and feasibility of quantification were provided. Moreover, based on the compiled FEP list, three scenarios that could affect the long-term safety of the disposal facility were developed. Geological factors affecting the performance of the natural barrier in each scenario were selected and their relationships were visualized. The constructed FEP list and the visualization of interrelated factors in various scenarios are anticipated to provide essential information for selecting and organizing factors that must be considered in the development of mathematical models for quantitatively evaluating the long-term safety of deep geological repositories. In addition, these findings could be effectively utilized in establishing criteria related to the key performance of natural barriers for the confirmation of repository sites.

• The Journal of Engineering Geology
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• v.34 no.1
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• pp.117-136
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• 2024

Deep geological disposal of high-level radioactive waste is imperative to national safety and environmental protection and it relies on establishing siting criteria suited to the geological and social conditions of each country. This paper compares the various geological and social criteria applied by different countries in the process of securing sites for the deep geological disposal of high-level radioactive waste. The present comparative analysis considers the siting criteria established by the worlds leading countries in high-level radioactive waste disposal with the aims of establishing detailed criteria appropriate to Korea's conditions and applying the criteria to explore safe and suitable sites for deep geological disposal. The findings of this research are expected to serve as a foundation for establishing criteria for the selection of disposal sites for high-level radioactive waste in Korea and are anticipated to contribute significantly to sustainable national development and environmental protection.

• Journal of the Korean earth science society
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• v.38 no.4
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• pp.303-320
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• 2017

Purpose of this study is understanding of group modeling process focusing on constraints with geological field trip applied on social-construction of scientific model. This study was carried out on 12 students of 3 groups who participate in the study 'S' gifted education center. Students were conducted to theme of 'How was formation of Mt. Gwanak?' on 2 field trip classes and 3 modeling classes. Semi-structured interviews, all discourse of field trip and modeling classes, records of personal and group activity were analyzed to constraints based on theoretical background proposed by Nersessian (2008). Results as follows. First, sources of constraints are scientific knowledge, contents observed by students during field trips and additional materials things to be explained by model during modeling class with geological field trip applied on social-construction of scientific model. Second, there are 3 types of constraints to affect making group modeling. It is that shared constraint which used commonly by all the group members. It called selected constraint that used during the initial modeling and later were reflected on for use in the group modeling. And it is that generated constraints, which were not in the initial modeling but were used later in the group modeling. This study suggests that not only the constraints can help to understand of making group model through how they used but also show that example of learning with geological field trip on social-construction of scientific model to contribute school science.

• Journal of Soil and Groundwater Environment
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• v.22 no.3
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• pp.1-9
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• 2017

The numerical analysis of groundwater flow is indispensable for predicting problems associated with water resource development, civil works, environmental hazards, and nuclear power plant construction. Korea lacks public regulatory procedures and guidelines for groundwater flow modeling, especially in nuclear facility sites, which makes adequate evaluation difficult. Feasible step-by-step guidelines are also unavailable. Consequently, reports on groundwater flow modeling have low-grade quality and often present controversial opinions. Additionally, without public guidelines, maintaining consistency in reviewing reports and enforcing laws is more challenging. In this study, the guidelines for groundwater flow modeling were reviewed for three countries - the United States (Documenting Groundwater Modeling at Sites Contaminated with Radioactive Substances), Canada (Guidelines for Groundwater Modelling to Assess Impacts of Proposed Natural Resource Development Activities), and Australia (Australian Groundwater Modelling Guidelines), with the aim of developing groundwater flow modeling regulatory guidelines that can be applied to nuclear facilities in Korea, in accordance with the Groundwater Act, Environmental Impact Assessment Act, and the Nuclear Safety Act.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.20 no.1
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• pp.1-12
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• 2022

Bentonite is the most probable candidate to be used as a buffer in a deep geological repository with high swelling properties, hydraulic conductivity, thermal conductivity, and radionuclide sorption ability. Among them, the radionuclide sorption ability prevents or delays the transport of radionuclides into the nearby environment when an accident occurs and the radionuclide leaks from the canister, so it needs to be strengthened in terms of long-term disposal safety. Here, we proposed a surface modification method in which some inorganic additives were added to form NaP zeolite on the surface of the bentonite yielded at Yeonil, South Korea. We confirmed that the NaP zeolite was well-formed on the bentonite surface, which also increased the sorption efficiency of Cs and Sr from groundwater conditions. Both NaP and NaX zeolite can be produced and we have demonstrated that the generation mechanism of NaX and NaP is due to the number of homogeneous/heterogeneous nucleation sites and the number of nutrients supplied from an aluminosilicate gel during the surface modification process. This study showed the potential of surface modification on bentonite to enhance the safety of deep geological radioactive waste repository by improving the radionuclide sorption ability of bentonite.

• Korean Journal of Environmental Agriculture
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• v.41 no.3
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• pp.217-221
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• 2022

BACKGROUND: Gotjawal forest on Jeju Island is characterized by uneven topography that developed as a result of freezing-thawing weathering process and irregular substrates caused by numerous lava-flow collapses. Sanyang Gotjawal, located in southwest of Jeju Island, is a well-developed forest with a long history. In addition to photographs, there is a need for a good way to describe the unique features of Gotjawal, including its geology and vegetation. METHODS AND RESULTS: We illustrated the area's natural features using Clip Studio Paint 1.12.0. To reveal its complexity, we separated the vegetation and geological features in the illustrations. CONCLUSION(S): We drew a cross-section of Gotjawal's unique layers, including lava flows. In addition to an eco-geological approach, we described the dominant vegetation and geological characteristics of the three forest layers (trees, shrubs, and herbs) in Gotjawal.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.21 no.1
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• pp.23-41
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• 2023

Coupled thermo-hydraulic-mechanical (THM) processes are essential for the long-term performance of deep geological disposal of high-level radioactive waste. In this study, a numerical sensitivity analysis was performed to analyze the effect of rock properties on THM responses after the execution of the heater test at the Kamaishi mine in Japan. The TOUGH-FLAC simulator was applied for the numerical simulation assuming a continuum model for coupled THM analysis. The rock properties included in the sensitivity study were the Young's modulus, permeability, thermal conductivity, and thermal expansion coefficients of crystalline rock, rock salt, and clay. The responses, i.e., temperature, water content, displacement, and stress, were measured at monitoring points in the buffer and near-field rock mass during the simulations. The thermal conductivity had an overarching impact on THM responses. The influence of Young's modulus was evident in the mechanical behavior, whereas that of permeability was noticed through the change in the temperature and water content. The difference in the THM responses of the three rock type models implies the importance of the appropriate characterization of rock mass properties with regard to the performance assessment of the deep geological disposal of high-level radioactive waste.