• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.426-430
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• 2004

현재 복원사업이 진행 중인 서울시 청계천은 상류와 하류에서 하천의 유량이나 하폭 등에서 서로 다른 특성을 보인다. 본 연구에서는 청계천 상류와 하류에서의 지하수 유동을 모델링을 통하여 해석하였다. 그 결과 청계천 상류에서는 하천과 지하수면이 서로 분리되어 있는 분리손실하천의 형태를 보이는 반면, 청계천 하류에서는 하천과 지하수면이 서로 연결되어 있는 연결손실하천의 형태로 나타났다. 또한, 본 연구에서는 지하수 모델링 결과를 이용하여 하천-지하수의 상호작용을 zone analysis 통하여 분석하였다. 청계천 상, 하류 모두 대수층으로 유입되는 대부분의 물이 하천에서 오지만, 하류에서는 대수층에서 하천으로도 물이 유출되는 것을 확인할 수 있었다. 그 외에도 zone analysis의 결과는 손실하천에서의 유량 확보 또는 유지를 위한 계획을 구상하는 데에 있어서 중요한 지표를 제시해줄 수 있다.

• Nuclear Engineering and Technology
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• v.27 no.6
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• pp.938-943
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• 1995

지하 암반내에 방사성 폐기물 영구 처분을 위한 동굴이 건설될 경우 정상 상태에서 처분동굴 주변 암반이 균질 다공성 매질이라는 가정 아래 동굴내로 유입되는 지하수량을 NAMMU 컴퓨터 프로그램을 이용하여 계산하였다. 계산 결과는 산정상 밑과 해저밑이 약간 유입량이 많았으나 위치에 크게 영향 받지는 않았다. 계산값의 검증을 위해서 비교적 단순 지형에 대한 해석해를 유도하여 비교하였다. 처분시설 페쇄후 성능 평가를 위해 지하수 유동 거리가 가장 길 것으로 예상되는 산정상 밑 동굴에 대해 유동경로 분석을 수행하여, 처분 동굴로부터 지표수로의 지하수 유동 거리 및 유동 시간 등을 구하였다. 또한, 산정상 밑 처분동굴을 실제와 같이 5개로 모델링하여 유입량의 변화를 살펴보았으며, 동굴 주변 암반 특성의 값에 대한 지하수 유입량 변화를 알아보았다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.259-262
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• 2006

본 연구는 지하처분연구시설(URT : Underground Research Tunnel)시설 건설공사와 관련하여 굴착 후의 지하수유동체계 변화를 예측하기 위하여 수행되었다. 지하수유동체계 모사를 위해 사용된 모델은 연속체 매질 개념의 Visual Modflow이며, URT 주변의 시추공에서 조사된 자료를 초기 입력자료로 이용하였다. 1단계 터널굴착 후에 계측된 지하수위 및 터널 내 지하수 유입량을 토대로 모델교정을 수행하였고, 교정된 모델을 이용하여 2단계 터널굴착 후의 지하수유동체계를 예측하였다. 1단계 굴착 후 약 4.3m의 수위강하가 발생한 KP-2번공은 2단계 굴착 후에는 약 0.05m의 수위강하가 예측되었다. 또한 2단계 굴착 후의 지하수위는 터널 입구를 기준으로 약 108m지점부터 터널 종점부 175m까지는 터널 상부에 분포하며, 종점부 175m지점에서는 지하수위가 터널 천장(roof)부로부터 약 12.7m 상부에 위치하는 것으로 예측되었다. 지하수위의 강하범위는 터널 중심부로부터 반경 약 300m까지 발생되는 것으로 예측되었고, 예상 지하수 유입량은 24.7ton/day로 1단계 공사 후보다. 약 2.7ton/day 증가하며, 공동굴착 전 터널 중심부의 지하수가 지표까지 도달하는 시간은 약 39.8년이 소요되는 것으로 나타났다.

• The Journal of Engineering Geology
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• v.9 no.1
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• pp.17-29
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• 1999

There are three major processes to impact the groundwater flow near underground storage caverns in the coastal area; effect of topography, effect of sea water intrusion, and effect of excavation. In this paper, the effects of three items were numerically studied to identify the major cause for altering the flow pattern. It turned out that the excavation is the most significant effect on the groundwater flow system. The groundwater pressure distributions and consequent groundwater pathways were significantly altered near the openings. By increasing the groundwater pressures from water curtain holes, the potential leakage of storage cavern was properly prevented

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.3
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• pp.149-159
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• 2011

Nuclear power utilities should establish a site-specific groundwater monitoring program for early detection of unplanned radioactive material's releases which can occur due to degradation of systems, structures and components of the nuclear power plants in order to keep the impact of the unplanned releases on the environment and the residents as low as reasonably achievable. For this end, groundwater flow on site should be evaluated based on characterization of the hydrogeology of a site of concern. This paper aims to provide data necessary for establishing groundwater monitoring program which is currently considered at Kori nuclear power plant 1 by characterizing groundwater flow system on the site based on the existing hydrogeological studies and related documents, and by modeling tritium transport. The results showed that the major groundwater flow direction was south-west and that most of groundwater entered a southern and eastern seas. Although the tritium plume also released into the sea, its rate was delayed by dewatering sump.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.382-385
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• 2002

부산 금정산 일대의 평균 수리전도도는 1E-6m/sec ~ 1E--8m/sec차수의 범위로 시험공별로 차이를 보이고 있다. 이 지역에서 지표면의 해발고도(X)에 따른 지하수위(Y)의 상관식 Y =1.00024*X - 3.26725 으로부터 지하수위를 추정하였다. 이 지역에 내린 총 강수량은 함양지역(24,524,131$m^2$)에 연평균강수량(1477.5mm)를 곱한 값(36,234,404㎥/yr)이고, 총 함양량은 기저유출량까지 합한 양(9,073,254㎥/yr)이다 증발산량은 강수량의 약 49%이므로 17,754,858㎥/yr이다. 온천수 사용량은 2,500㎥/day이고, 산성마을의 지하수 사용량은 1,000㎥/day으로 보면, 인위적인 양수량은 1,095,000㎥/yr(강수량의 3%)가 된다. 3차원 지하수유동 모델링 소프트웨어인 GMS package의 MODFLOW를 사용하여 분석한 결과, 금정터널 예정 구간(9.99km)에서의 최대 유출량은 99,200㎥/day이다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2
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• pp.119-131
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• 2020

A numerical model was developed using COMSOL Multiphysics to evaluate groundwater flow that causes radionuclide migration in the unsaturated zone of a near-surface disposal facility, which is considered as a domestic low and an intermediate-level radioactive waste disposal facility. Each scenario was modeled by constructing a two-dimensional domain that included the disposal vault, backfill, disposal cover, and unsaturated aquifer. A comparison of the continuous and intermittent rainfall conditions exhibited no significant difference in any of the factors considered except the wave pattern of water saturation. The input data, such as porosity and residual water content of the unsaturated aquifer, were observed to not have a significant effect on the groundwater flow. However, the hydraulic conductivity of the unsaturated aquifer was found to have a significant effect on the groundwater flow. Therefore, it is necessary to assess the hydraulic conductivity of an unsaturated aquifer to determine the extent of groundwater infiltration into the disposal vault.

• The Journal of Engineering Geology
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• v.11 no.1
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• pp.37-50
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• 2001

Through the modeting study on the groundwater now system around the underground stockpile site of crude oil near Seoul, we carried out the research on the influence of the groundwater yield near the site, the effect of the water curtain construction in order to reduce the influence of water yield, and the realized case study by measuring the water level change after the construction of the water curtain. For the simu1ation of the water yield and the water curtain, the nwnerical analysis code, MODFLOW has been utilized. Groundwater levels of the observation wells which were established to observe the hydraulic head around underground oil storage cavern of the study area have been changed in the range of from EL.+30 to +60 meter, while the simulation study revealed that groundwater levels changed in the range of from EL.+20 to +5Om. The hydrogeological condition of the underground oil storage cavern becomes stable by injection water to maintain the groundwater level around the cavern. The result shows the proper input of the hydrogeological factors helps the management to be effective for the oil stockpile site.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.3
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• pp.143-149
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• 2012

Groundwater flow simulations were performed to obtain data of groundwater flow used in a safety assessment for a hypothetical geological disposal facility assumed to be located in the KURT (KAERI Underground Research Tunnel) site. A regional scale modeling of the groundwater flow system was carried out to make boundary conditions for a local scale modeling. And, fracture zones identified at the study site were involved in the local scale groundwater flow model. From the results of the local scale modeling, a hydraulic head distribution was indicated and it was used in a particle tracking simulation for searching pathway of groundwater from the location of the hypothetical disposal facility to the surface where the groundwater reached. The flow distance and discharge rate of the groundwater in the KURT site were calculated. It was thought that the modeling methods used in this study was available to prepare the data of groundwater flow in a safety assessment for a geological disposal facility of radioactive wastes.

• The Journal of Engineering Geology
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• v.6 no.1
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• pp.1-13
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• 1996

The fracture transmissivity($T_f$) is the most important parameter of fracture in assessing groundwater flow in fractured rock masses by using the DFN(Discrete Fracture Network) modeling. $T_f$, the most sensitive parameter m DFN modeling, is dependent upon aperture, size and filling characteristics of each fracture set. In the field test, the accuracy of $T_f$ can be increased with Borehole Acoustic Scanning (Televiewer) and Fixed Interval Length(FIL) test in constant head. $T_f$ values measured from FIL test was modified and estimated by each fracture set on the basis of the Cubic Law and the information of aperture and filling characteristics obtained from Televiewer. The modified $T_f$ results in the increase of confidence and reliability of modeling results including the amount of tunnel inflow.And, this approach would reduce the uncertaintity of the assessment for groundwater flow in fractured rock masses using the DFN modeling.