• Journal of Soil and Groundwater Environment
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• v.8 no.3
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• pp.37-44
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• 2003

Fuel oxygenates, such as Methyl tertiary Butyl Ether (MTBE) is additive in gasoline used to reduce air pollution. Gasoline components and fuel additives can leak: form underground storage tanks. MTBE is far more water soluble than gasoline hydrocarbons like BTEX then it travels at essentially the same velocity as groundwater. MTBE in drinking water causes taste and odor problems. Therefore, the purpose of the this study is to examine the ability of ground tire to sorb MTBE in water. The study consisted of running both batch and column tests to determine the sorption capacity, the required sorption equilibration time, and the flow through utilization efficiency of ground tire. The batch test result indicated that ground tire can attain equilibrium sorption capacities about 0.5 mg of MTBE. The result of column test indicate that ground tire has on the 36% utilization rate. Finally, it is clear that ground tire represented an attractive and relatively inexpensive sorption medium for a MTBE. Authors thought that to determine the economic costs of ground tire utilization, the cost to sorb a given mass of contaminant by ground tire will have to be compared to currently accepted sorption media. The cost comparison will also have to include regeneration and disposal cost.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.3
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• pp.151-159
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• 2012

The potential repository domains for A-KRS (Advanced Korean Reference Disposal System for High Level Wastes) in geological characteristics of KURT (KAERI Underground Research Tunnel) facility site were proposed to develop a repository system design and to perform the safety assessment. The host rock of KURT facility site is one of major Mesozoic plutonic rocks in Korean peninsula, two-mica granite, which was influenced by hydrothermal alteration. The topographical features control the flow lines of surface and groundwater toward south-easterly and all waters discharge to Geum River. Fracture zones distributed in study site are classified into order 2 magnitude and their dominant orientations are N-S and E-W strike. From the geological features and fracture zones, the potential repository domains for A-KRS were determined spatially based on the following conditions: (1) fracture zone must not cross the repository; and (2) the repository must stay away from the fracture zones greater than 50 m. The western region of the fracture zones in the N-S direction with a depth below 200 m from the surface was sufficient for A-KRS repository. Because most of the fracture zones in N-S direction were inclined toward the east, we expected to find a homogeneous rock mass in the western region rather than in the eastern region. The lower left domain of potential domains has more suitable geological and hydrogeological conditions for A-KRS repository.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.1
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• pp.13-19
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• 2012

The long-lived fission products $^{79}Se$ and $^{99}Tc$ have been considered as the major concern nuclides for the disposal of radioactive waste because of their high solubilities and the existence of anionic species in natural water. In this study, the solubilities of $FeSe_2(s)$ and $TcO_2(s)$, known as respective Solubility Limiting Solid Phase (SLSP) of selenium and technetium, were measured in the KURT (KAERI Underground Research Tunnel) groundwater under various pH and redox conditions. And their solubilities and major species were also calculated using geochemical codes under conditions similar to experimental solutions. Experimental results and calculation for $FeSe_2$ show that the solubility of selenium was found to be below $1{\times}10^{-6}mol/L$ under the condition of pH 8~9.5 and Eh=-0.3~-0.4 V while the dominant species was identified as $HSe^-$. For $TcO_2$, the solubility of technetium was found to be $5{\times}10^{-8}{\sim}1{\times}10^{-9}mol/L$ in the solutions of pH 6~9.5 and Eh<-0.1 V, while the dominant species was $TcO(OH)_2$. However, when the Eh of the solution is -0.35 V, $TcO(OH)_3^-$ and $TcO_4^-$ are calculated as the dominant species at pH 10.5~12 and pH>12, respectively.

• Journal of the Mineralogical Society of Korea
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• v.20 no.3
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• pp.165-173
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• 2007

The KAERI Underground Research Tunnel (KURT) located in KAERI (Korea Atomic Energy Research Institute) was recently constructed following the site investigation in 2003. Its dimension is 180 m in length, 6 m in width, and 6 m in height, and it has a horseshoe-like cross-sec-lion and is located in the ground to the depth of 90 m. When the tunnel was dug into the ground with 100 m in length, fresh rocks, weathered rocks and fracture-filling materials were taken and examined by mineralogical and chemical analyses. There are phyllosilicate minerals such as illite, smectite and chlorite including calcite, which are filling some faults and cracks of the KURT rock. The illite and smectite usually coexist in the fracture, where their content ratio is different according to which mineral is predominant. There are high concentrations of U and Th in the rocks coated with iron-oxides and filled with secondary materials as compared with those in the fresh rocks. It seems that the radionuclides, which are slowly leached from the parent rocks or exist as a dissolved form in the groundwater and hydrothermal solution, may have been migrated along the fractures and thereafter selectively sorbed and coprecipitated on the iron-oxides and the fracture-filling materials. These results will be very useful far the evaluation of environmental factors affecting the nuclides migration and retardation when long-term safety is considered to the geological disposal of high-level radioactive wastes in the future.

• Economic and Environmental Geology
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• v.39 no.4 s.179
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• pp.441-450
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• 2006

The on-land seismic survey in Korea was begun in mid-1960s. Kim et al.(1967) of Korea Geological Survey reported on the result of gravity and seismic reflection surveys conducted in the Pohang area for the period of 1963-64 to assess its possibility of oil entrapment. Hyun and Kim (1966) carried out a refraction survey on the tunnel wall. Since then, the KGS geophysicists had conducted seismic surveys on Kyungsang sedimentary basin as a main project for several years. In 1970s, on-land seismic surveys had been conducted for various purposes such as site investigation for the nuclear power plants and industrial complex, exploration for ground water, mineral resources and underground tunnel. The first reflection survey with CMP acquisition was attempted in 1978 by using a digital recording system. But most of on-land seismic surveys had employed the refraction method until 1980s. In 1990s, high resolution reflection and various borehole seismic surveys such as tomography, uphole, downhole, cross-hole methods have been attempted by universities and engineering companies. The applications of on-land seismic surveys have been enlarged for both academic and industrial purposes such as investigation of geologic structure of the fault and tidal flat area, construction of highway, railroad and dam, geothermal energy and mineral resource exploration, environmental assessment for waste disposal sites and archaeological investigations. In 2002, the first crustal seismic survey was carried out on the profile of 294km length across the whole peninsular. It is expected that the advanced technology and experience acquired through offshore seismic surveys, which have been conducted in continental shelf of Korea and foreign oil fields, will stimulate the more active on-land seismic explorations.

• Tunnel and Underground Space
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• v.29 no.6
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• pp.439-455
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• 2019

A buffer is the major component of a high level radioactive waste repository. Due to their thermal conductivity and low permeability, bentonites have been considered as a key component of a buffer system in most countries. The deep geological condition generates ground water inflow and results in swelling pressure in the buffer and backfill. Investigation of swelling pressure of bentonite buffer is an important task for the safe disposal system. The swelling pressure that can be critical is affected by mechanical and hydro properties of the system. Therefore, in this study, a sensitivity analysis was conducted to examine the effect of hydro-mechanical (HM) behaviors in the MX-80 bentonite. Based on the results of the swelling pressure generation with HM model parameters, a coupled HM analysis of an unsaturated buffer and backfill in a deep geological repository was also carried out to investigate the major factor of the swelling pressure generation.

• Analytical Science and Technology
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• v.23 no.6
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• pp.566-571
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• 2010

This paper describes the sorption behaviors of aqueous uranium ions on the K-birnessite. K-birnessite was synthesized by adding a concentrated HCl to an aqueous solution of $KMnO_4$. Physicochemical characteristics of the K-birnessite, such as structure, specific surface area and surface charge, were investigated. K-birnessite is a layered material and the $K^+$ ions exist in the interlayer of layered K-birnessite. BET specific surface area of the K-birnessite was 38.30 m2/g. The surface charge of K-birnessite was $-1.65\;C/m^2$ at pH 5.00 and ionic strength of 0.010 M $NaClO_4$, at which the sorption experiments of uranium ions were carried out. Uranium ions were incorporated into the interlayer of the K-birnessite by cation-exchange reaction with $K^+$ ions, and the distribution coefficient is quite similar to those of common ion-exchange materials. The results might be applicable in the retardation of migration of radioactive materials from the underground disposal site of high-level radioactive waste.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.2
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• pp.115-122
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• 2010

In this study, the removal of Cs and Tc from a simulated fission products (FP) solution which were co-dissolved with U during the oxidative-dissolution of spent fuel in a mixed carbonate solution of $(Na_2CO_3-NaHCO_3)-H_2O_2$ was investigated by using a selective precipitation method. As Cs and Tc might cause an unstable behavior due to the high decay heat emission of Cs as well as the fast migration of Tc when disposed of underground, it is one of the important issues to removal them in views of the increase of disposal safety. The precipitation of Cs and Re (as a surrogate for Tc) was examined by introducing sodium tetraphenylborate (NaTPB) and tetraphenylphosponium chloride (TPPCl), respectively. Precipitation of Cs by NaTPB and that of Re by TPPCl were completed within 5 minutes. Their precipitation rates were not influenced so much by the temperature and stirring speed even if they were increased by up to $50^{\circ}C$ and 1,000 rpm. However, the pH of the solution was found to have a great influence on the precipitation with NaTPB and TPPCl. Since Mo tends to co-precipitate with Re at a lower pH, especially, it was effective that a selective precipitation of Re by TPPCl was carried out at pH of above 9 without co-precipitation of Mo and Re. Over 99% of Cs was precipitated when the ratio of [NaTPB]/[Cs]>1 and more than 99% of Re, likewise, was precipitated when the ratio of [TPPCl]/[Re]>1.

• Tunnel and Underground Space
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• v.27 no.3
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• pp.146-160
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• 2017

$CO_2$ sequestration for alleviating global warming is a hot issue in the world. In this study, TOUGH2 and FLAC3D were combined for analyzing the hyro-mechanical coupling behaviors expected in $CO_2$ sequestration and applied it to Sleipner project carried out in Norway. In the analysis, the influence of pore pressure on in situ stress was considered and the influence of caprock permeability on hydro-mechanical behaviors was analyzed. In the condition of constant injection rate, pressure and saturation at the injection well, liquid and gas saturation in rock, major and minor stress variations with time and distance from the injection well, and horizontal and vertical displacements after injection could be investigated. The major principal stress was quickly increased in the early stage and then slowly decreased to a stable value, which was higher than the initial value. In contrast, the minor principal stress returned to initial value after some increase in the early stage. Surface upheaval was steadily increased and it was up to 15mm in 2 years after injection. When the caprock's permeability was changed from $3e-15m^2{\sim}3e-18m^2$, it was found that the injection well pressure and surface upheaval were inversely propotional to the permeability.

• Journal of Wetlands Research
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• v.20 no.3
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• pp.219-226
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• 2018

Interceptor sewer is installed underground near to the river side mostly ofstate-owned land and the management efficiency of public sewage disposal facilities is decreasing as too much infiltration/inflow(I/I) and river flow to interceptor sewer are caused by broken or deteriorated sewer. This also affects the sewer pipeline project and decreases its efficiency. Therefore, the aim of this study is to investigate interceptor sewer which has influence on the reduction of the project effect. The investigation were performed for three study areas. The study includes the investigation of current condition of interceptor sewer(sewer extension, pipe diameter, pipe type, installed year, installed locations, etc), investigation of inside of sewer by CCTV accompanied by pumping and dredging works where required, investigation of inside of manholes by eyes, calculation of pollutant load using the results of investigation of flow quantity and quality. Multipoint investigations were simultaneously performed for flow quantity at confluence area and other investigations were also performed for flow quantity and BOD for interceptor sewer and comparison of pollutant load, investigation of infiltration/inflow(I/I) caused by deterioration of interceptor sewer. As the result of the study, a main reason for reduced effect of sewer pipe improvement project was analyzed as the low-density sewage and I/I in public seweage treatment Facility due to deteriorated and unmanaged interceptor sewers.