• 자원환경지질
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• 제27권6호
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• pp.601-609
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• 1994

Uranium resources of Mongolia are generally confined to sediments deposited during Jurassic to Cretaceous volcanism. Territory of Mongolian uranium deposits is divided into four districts as follows; Mongol-Priargun, Gobi-Tamtsag, Hentii-Dauer, North-Mongolian. Potential uranium deposits were discovered by Airborne Gamma ray Spectrometric Survey(AGSM). One of them, Haraat deposit, which was interested to us, has been under detailed survey for exploitation by one of American companies, Concord company. The Erdes uranium mine is partly operated by about hundred Russian staffs at the open pit, while underground mining facilities such as the main hoist are almost closed. Ore minerals of the Erdes Mine are coffinite and pitchblende. Uranium content in ore ranges from 0.06% to 1%, averaging 0.2%. Ore reserves of uranium ore in the Dornod deposit including the Erdes Mine accounts 29,000 ton. It is reported that Uranium resources of Mongolia are 1,471,000 ton.

• Nuclear Engineering and Technology
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• 제50권3호
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• pp.453-461
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• 2018

Shaft stations of underground uranium mines in China are not only utilized as waiting space for loaded mine-cars queuing to be hoisted but also as the principal channel for fresh air taken to working places. Therefore, assessment of how mine-car queuing processes affect shaft station radon concentration was carried out. Queuing network of mine-cars has been analyzed in an underground uranium mine, located in Quzhou, Zhejiang province of Eastern China. On the basis of mathematical analysis of the queue network, a MATLAB-based quasi-random number generating program utilizing Monte-Carlo methods was worked out. Extensive simulations were then implemented via MATALB operating on a DELL PC. Thereafter, theoretical calculations and field measurements of shaft station radon concentrations for several working conditions were performed. The queuing performance measures of interest, like average queuing length and waiting time, were found to be significantly affected by the utilization rate (positively correlated). However, even with respect to the "worst case", the shaft station radon concentration was always lower than $200Bq/m^3$. The model predictions were compared with the measuring results, and a satisfactory agreement was noted. Under current working conditions, queuing-induced variations of shaft station radon concentration of the study mine are not remarkable.

• 자원환경지질
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• 제31권2호
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• pp.101-110
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• 1998

The purpose of this study is to elucidate the source of U anormaly formed in stream water of the drainage system around the Shinbo talc mine area based on the hydrochemical properties of water masses including surface water and groundwater. The hydrochemical properties of water masses in the Shinbo talc mine area are divide into three types; Type I : $Ca(Mg)SO_4$ type with high U content as shown in the stream water flowout from the mine, Type II : $Ca(HCO_3)_2$ type with high U content as in deep groundwater, Type III : $Ca(HCO_3)_2$, type with low U content as in the other stream water and shallow groundwater. It is necessary to emphasize that in deducing the uranium source, a distinct discrimination between type I and type II is showed in their hydrothermal properties in spite of commonly having a high uranium content, which in turn means the occurrence of a different water-rock interaction processes between both type. All evidences suggest that type II groundwater have acted as a primary media in the transport of uranium and that, as the groundwater flows through the talc mineralization zone, water composition of type II was transformed into that of type I water as the results of a secondary water rock interaction process, caused by imposition of new mineralogically controlled thermodynamic constraints. Consequently, in the viewpoint of hydrochemical exploration, the investigation of the hydrologic circulation system and the hydrogeologic properties for the aquifer of type II groundwater shall be done first of all and will provide a crucial clue on tracing the uranium mineralization zone occurred in the Shinbo talc mine area.

• 자원환경지질
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• 제18권2호
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• pp.135-138
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• 1985

The radioautographing of U-bearing cloaly slate samples were initiated in order to clarify the uranium distribution patterns in the samples of Ogcheon system. Moreover, x-ray powder diffraction and x-ray single crystal analysis studies were undertaken to identify the uranium mineral which was extracted from U-bearing coaly slate. The handspecimens were collected from the Boseong mine, located in Deokpyeong area, Goesan-gun, Chungcheongbug-do. According to the experimental studies, it has been found the following facts: (1) fixed carbon has close relation with uranium contents, (2) quartz veins developed in U-bearing coaly slate are diveded into two groups based on mode of occurrence, formation stage and uranium distribution pattern; early quartz vein ($QV_1$) with low uranium concentration and late quartz vein ($QV_2$) with high uranium concentration, (3) matrixes around $QV_1$ are displayed homogeneous and high uranium concentration, while matrixes around $QV_2$ are low uranium concentration, (4) uranium mineral is identified as a variety of autunite.

• 자원환경지질
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• 제33권5호
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• pp.367-377
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• 2000

The purpose of this study is to elucidate the source of U anomaly formed in stream water of the drainage system around the Shinbo talc mine area based on the O, H, S and Sr isotopic characteristics of water masses and wall rocks. The ${\delta}$D and ${\delta}^{18}O$ of surface and ground waters show highly restricted range and plotted on the same meteoric water line, indicating that they are all originated from the meteoric water. The ${\delta}^{34}S$value of the ground water containing high U shows slightly negative (-0.2${\textperthousand}$) and quite distinct from those of the other surface and ground waters that are similar to those of wall rocks (>5.8${\textperthousand}$), indicating that they have a different S isotopic fractionation or less probably, source. The $^{87}Sr/^{86}{Sr}$ratios of water masses around the Shinbo talc mine area show a variable range from 0.724325 to 0.744928, but tend to increase with increasing U concentration of water mass. Although it is not possible to determine precisely the source rock of U anomaly formed in the hydrologic system around the Shinbo talc mine, the evidence obtained from the Sr isotopic compositions strongly suggests that coal schist and/or pegmatite vein could be the most likely candidate for the source rock.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1175-1184
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• 2022

The pore structure of uranium-bearing sandstone is one of the critical factors that affect the uranium leaching performance. In this article, uranium-bearing sandstone from the Yili Basin, Xinjiang, China, was taken as the research object. The fractal characteristics of the pore structure of the uranium-bearing sandstone were studied using mercury intrusion experiments and fractal theory, and the fractal dimension of the uranium-bearing sandstone was calculated. In addition, the effect of the fractal characteristics of the pore structure of the uranium-bearing sandstone on the uranium leaching kinetics was studied. Then, the kinetics was analyzed using a shrinking nuclear model, and it was determined that the rate of uranium leaching is mainly controlled by the diffusion reaction, and the dissolution rate constant (K) is linearly related to the pore specific surface fractal dimension (D_S) and the pore volume fractal dimension (D_V). Eventually, fractal kinetic models for predicting the in-situ leaching kinetics were established using the unreacted shrinking core model, and the linear relationship between the fractal dimension of the sample's pore structure and the dissolution rate during the leaching was fitted.

• Nuclear Engineering and Technology
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• 제52권7호
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• pp.1471-1480
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• 2020

This research presents a case study on the remediation of a radioactive waste (uranium: U) utilizing a multi-objective fuzzy optimization in an electrocoagulation process for the iron-stainless steel and aluminum-stainless steel anode/cathode systems. The incorporation of the cumulative uncertainty of result, operational cost and energy consumption are essential key elements in determining the feasibility of the developed model equations in satisfying specific maximum contaminant level (MCL) required by stringent environmental regulations worldwide. Pareto-optimal solutions showed that the iron system (0 ㎍/L U: 492 USD/g-U) outperformed the aluminum system (96 ㎍/L U: 747 USD/g-U) in terms of the retained uranium concentration and energy consumption. Thus, the iron system was further carried out in a multi-objective analysis due to its feasibility in satisfying various uranium standard regulatory limits. Based on the 30 ㎍/L MCL, the decision-making process via fuzzy logic showed an overall satisfaction of 6.1% at a treatment time and current density of 101.6 min and 59.9 mA/㎠, respectively. The fuzzy optimal solution reveals the following: uranium concentration - 5 ㎍/L, cumulative uncertainty - 25 ㎍/L, energy consumption - 461.7 kWh/g-U and operational cost based on electricity cost in the United States - 60.0 USD/g-U, South Korea - 55.4 USD/g-U and Finland - 78.5 USD/g-U.

• 자원환경지질
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• 제45권1호
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• pp.31-40
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• 2012

본 논문은 전라북도 진안군 신보광산의 동부지역에서 고품위 우라늄 지화학 이상대와 지질구조 사이의 상관관계를 규명하고 지하수 흐름에 대한 기본적인 정보를 제공하기 위해 암상구분에 의한 상세한 지질도를 작성하고 이들 구성암류에 발달하는 연성 및 취성 구조요소의 특성을 파악하였다. 그 결과, 이 지역은 주로 동북동-서남서 방향으로 대상 분포를 보이는 선캠브리아기 규암, 변성이질암, 변성사질암과 이를 관입하는 시대미상의 페그마타이트와 백악기 반암류 등으로 구분되고, 추정과 달리 이들 암상을 부정합으로 피복하는 백악기 진안층군은 관찰되지 않았다. 선캠브리아기 변성퇴적암류의 주요 연성 변형구조는 적어도 세 번의 변형단계 [동북동 방향성의 광역엽리 (D1) -> 동북동 내지 동서 방향성의 파랑엽리 (D2) -> 서북서 내지 동서 방향성의 개방, 밀착, 킹크 습곡 (D3)]를 걸쳐 형성되었고, S1 광역엽리의 방향성은 선캠브리아기 변성퇴적암류의 대상 분포 방향과 유사한 동북동 주향에 남쪽으로 경사하는 것이 우세하게 나타난다. 지하수의 유동과 밀접한 관련성 있는 취성 고각 단열 (경사각${\geq}45^{\circ}$)의 방향성[동북동 (출현빈도: 24.3%), 남북 (23.9%), (북)북서 (18.8%), 서북서 (16.9%), 북동 (16.1%) 단열조 순]은 변성퇴적암류의 대상 분포 방향성 및 S1 광역엽리의 우세 방향성과 일치하는 동북동 주향에 남쪽으로 경사하는 것이 가장 우세하게 나타나고 남북 주향에 동서 방향으로 경사하는 것이 다음으로 우세하게 나타난다. 상기된 선캠브리아 변성퇴적암류의 대상 분포 방향성과 S1 광역엽리 및 고각 단열의 우세 방향성 등으로부터 신보광산과 그 동부지역의 우라늄 지화학 이상대의 형성요인을 고찰해 볼 때 이들 지역에서 기대되는 우라늄의 초생적인 근원암은 기존연구 결과와 같이 페그마타이트이며 광산지역의 우라늄 지화학 이상대는 이를 대수층으로 하는 지하수가 광산지역으로 통과하면서 이차적으로 부화되었을 가능성이 높다고 판단된다.

• Nuclear Engineering and Technology
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• 제55권4호
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• pp.1476-1484
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• 2023

Laboratory experiments and point monitoring of reservoir sediments have proven that stable sulfate reduction (SSR) can lower the concentrations of toxic metals and sulfate in acidic groundwater for a long time. Here, we hypothesize that SSR occurred during in situ leaching after uranium mining, which can impact the fate of acid groundwater in an entire region. To test this, we applied a sulfur isotope fractionation method to analyze the mechanism for natural attenuation of contaminated groundwater produced by acid in situ leaching of uranium (Xinjiang, China). The results showed that δ³⁴S increased over time after the cessation of uranium mining, and natural attenuation caused considerable, area-scale immobilization of sulfur corresponding to retention levels of 5.3%-48.3% while simultaneously decreasing the concentration of uranium. Isotopic evidence for SSR in the area, together with evidence for changes of pollutant concentrations, suggest that area-scale SSR is most likely also important at other acid mining sites for uranium, where retention of acid groundwater may be strengthened through natural attenuation. To recapitulate, the sulfur isotope fractionation method constitutes a relatively accurate tool for quantification of spatiotemporal trends for groundwater during migration and transformation resulting from acid in situ leaching of uranium in northern China.

• 자원환경지질
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• 제45권4호
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• pp.385-396
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• 2012

옥천변성대의 남서부에 위치하는 전라북도 진안군 신보광산과 그 동부지역에서 고품위 우라늄 지화학 이상대가 보고된 바가 있다. 본 논문은 선캠브리아기 변성퇴적암류(규암, 변성이질암, 변성사질암)와 이를 관입하는 시대미상의 페그마타이트와 백악기 반암류 등이 분포하는 신보광산 동부지역에서 이들 구성암류가 경험한 변형작용과 변성광물의 성장 사이의 상대적인 시간관계에 대한 미구조의 연구결과를 보고하고, 기존 연구결과를 종합하여 광화작용의 상대적인 시기를 고찰하였다. D1 변형작용은 홍주석 반상변정 내에서 주로 신장된 석영, 흑운모, 불투명광물 등으로 정의되는 직선 형태의 내부엽리 Si 를 형성시켰다. Si 엽리를 미습곡시키고 S2 파랑엽리를 형성시키는 D2 변형작용은 전기 파랑습곡작용과 후기 파랑습곡작용으로 구분된다. 전자는 홍주석의 맨틀부에서 곡선 형태의 Si 를 형성시켰다. 후자는 홍주석을 포획하며 그 외부에서 S1-2 복합엽리를 형성시켰다. 홍주석 반상변정은 직선 Si 엽리에 해당하는 S1 엽리가 형성된 이후의 비변형작용 조건하에서 출현하여 후기 파랑습곡작용 이전까지 성장하였다. 시대미상의 페그마타이트는 D2 변형 이후에 관입하여 S1-2 복합엽리를 무질서하게 덮는 섬유상 규선석을 성장시켰다. D3 변형작용은 S1-2 복합 엽리와 D2 파랑습곡 그리고 섬유상 규선석을 미습곡시키는 F3 습곡을 형성시켰다. 이는 섬유상 규선석의 성장과 관련된 페그마타이트의 관입은 D2 변형과 D3 변형 사이의 비변형조건하에서 발생하였음을 지시한다. 흑운모의 녹니석화작용과 홍주석 반상변정 내부에서 S1-2 복합엽리와 F3 습곡축면에 평행한 두 방향의 벽개 라멜라에 의해 인지되는 후퇴변성작용은 각각 D2 후기변형과 D3 변형과 함께 발생하였다. 따라서 우라늄의 초생적 근원암을 페그마타이트로 간주하는 기존 연구결과를 고려해 볼 때, 시대미상의 페그마타이트는 지각이 상승하는 후퇴변성작용 동안에 해당하는 D2 변형과 D3 변형 사이의 비변형조건하에서 관입하여 신보광산 주변지역에 우라늄 광화대를 형성시킨 것으로 고찰된다.