• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.92-93
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• 2017

Recently, there has been an increasing interest in natural radioactive gas radon(Rn-222), the problem of indoor air quality pollution to worldwide. It has been scientifically proven to be hazardous to various diseases such as lung cancer and skin cancer if the human body is exposed to long-term accumulation of atomic nuclei due to the destruction of radon and alpha lines. Based on the indoor air quality control policy, this study is a basic experiment in the manufacture of a selective elimination function to containing radon adsorption and reduction of radon concentration, which is used to absorb radioactive isotopes such as phosphorus and radon in indoor environment.

• 분석과학
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• 제18권1호
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• pp.5-12
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• 2005

고정밀 전자소자의 오동작의 한 원인인 soft error는 원료물질에 함유된 U, Th과 같은 알파방출 불순물로 알려져 있으며 전자소자의 소형화, 고집적화에 따라서 이들 불순물의 규제함량은 기존의 분석법으로는 불가능할 정도로 낮아지고 있다. 연구의 목적은 다양한 전자소자의 밀봉소재로 사용되는 EMC (epoxy molding compound)의 주 원료인 고순도 실리카에 함유되어 있는 U, Th을 고감도 (ng/g이하)로 분석할 수 있는 방사화분석법과 감마선분광분석법의 개발이다. 지금까지 방사화분석법에 이용하던 PTS (pneumatic transfer system) 중성자 조사 설비로는 산업계에서 요구하는 분석 감도를 충족시킬 수 없기 때문에 의약용 혹은 산업용 RI 생산에 주로 사용되고 있는 HTS (Hydraulic transfer system) 중성자 조사 설비를 이용한 방사화분석 조건을 확립하였다. 또한, 공기중 라돈 ($^{222}Rn$)과 자핵종 (progenies)에 의한 불안정한 바탕방사능은 분석의 감도는 물론 정확도를 저하시키는 주 요인으로 작용하므로 질소가스 유입시스템을 제작하여 라돈에 의한 바탕방사능을 소멸 혹은 안정화시켰다. 그 결과 U과 Th의 분석한계를 각각 0.1 ng/g, 0.01 ng/g까지 낮출 수 있었다.

• 한국물환경학회지
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• 제23권2호
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• pp.201-205
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• 2007

This paper reports the amount of $^{222}Rn$ and $^{238}U$ in 18 sites of ground water and 30 sites of surface water. The instrument used to count $^{222}Rn$ activity was the liquid scintillation counter (LSC) which could resolute ${\alpha}$ and ${\beta}$ radiations. And $^{238}U$ was analyzed by the inductively coupled plasma (ICP). Radon and Uranium were not detected in raw and treated water which were sampled in a water treatment plant. However, radon ($^{222}Rn$) was high concentration in ground water from Jeon-la, Gang-won. So was uranium ($^{238}U$) in case of ground water from Gang-won, Choong-chung. Radon ($^{222}Rn$) activities were detected less than 15 pCi/L at 5 sampling points, 15~300 pCi/L at 7 sampling points, 300~4000 pCi/L at 6 sampling points. However, Radon ($^{222}Rn$) activities of all ground water samples were less than 4,000 pCi/L, which was bellow American Alternative Maximum Contamination Level (AMCL). Uranium ($^{238}U$) concentrations were less than $0.1{\mu}g/L$ at 5 sampling points, from $0.1{\mu}g/L$ to $20{\mu}g/L$ at 13 sampling points. Uranium was not detected in about 30% of the whole samples, but the concentration ranged from relatively low to high concentrations depending on the sampling point. The minimum detectable activity (MDA) of radon was 15 pCi/L. and the detection limit of uranium was $0.1{\mu}g/L$.

• 한국물환경학회지
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• 제22권4호
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• pp.632-638
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• 2006

최근에 오염된 토양을 정화하기 위해서 다양한 방법들이 사용되고 있으나 이들 대부분은 이미 오염된 토양에 대한 정화기술로서 많은 비용이 수반되는 단점이 있다. 본 연구에서는 이들 방법과는 달리 잠재적인 토양오염지역에서 오염되기 전이나 혹은 진행 중일 때 지형학적인 특징, 지표 위나 아래의 배수시스템의 재배열 및 선행계획을 통해 토양자체의 정화능력을 이용하는 새로운 정화방법을 고찰하였다. 즉, 토양자체 정화과정이 왜, 어떻게 발전되는가에 대해 단계적으로 규명하였다. 해안지역에서 오염된 바닷물의 침투와 거주지역에서 유해 라돈가스($^{222}Rn$)의 조절 및 제거 등 두 가지 사례를 통해 흙의 자체정화 능력을 이용한 토양정화방법의 효율성을 평가하였다.

• KIEAE Journal
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• 제1권2호
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• pp.21-28
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• 2001

Naturally-ocurring short-lived decay products of radon gas in indoor air are the dominant source of ionizing radiation exposure to the general public. It is written in BEIR VI Report(l999l the radon progeny were identified as the second cause of lung cancer next to cigarette or 10 % to 14 %(15,400 to 21,800 persons p.a.) of all lung cancer deaths in USA. Indoor radon concentrations in houses typically result from radon gaining access to houses mainly from the underlying soil. In the States, they have "Indoor Radon Abatement Act" which was converted from "Toxic Substance Control Act" in 1988 to establish the national long-term goal that indoor air should be as free of radon as the ambient air outside of buildings. To review and study techniques for controlling radon, two test cells were constructed for a series of tests and are under measuring indoor and soil gas (underneath of floor slab)radon concentrations according to EPA's measurement protocol. In this paper, important theoretical studies are previewed and the following paper will explain the test results and confirm the theories reviewed to find out suitable coefficients. On the basis of test analysis, it will be described and evaluated various techniques that can be used to mitigate elevated indoor concentration of radon including the control of radon and its decay products.

• 암석학회지
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• 제17권3호
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• pp.179-190
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• 2008

부산 금정구일대의 암석, 토양 및 토양가스 내 주요 환경방사성 핵종들($^{40}K$, $^{228}Ac$, $^{226}Ra$, $^{222}Rn$) 및 U의 분포 특성에 대하여 연구하였다. 연구지역의 화강암질 암석들에서 환경방사성 핵종들의 방사능은 $^{40}K$>토륨붕괴계열>우라늄붕괴계열 순으로 낮게 나타나 화강암질 암석에서 U에 비해 Th이 상대적으로 많이 부화됨을 잘 나타내고 있다. 그러나 암석 내 U 농도 및 $^{226}Ra$ and $^{228}Ac$ 방사능은 암석의 분화단계를 잘 반영하지 못하고 있다. 잔류토양 내 환경방사성 이 핵종들의 방사능과 U의 농도는 모암에 비해 높게 나타나며. 토양가스, 토양 및 암석에서 환경방사성 핵종들의 분포는 낮은 정의 상관관계를 보인다. 이러한 사실들은, 토양가스 및 토양에서 환경방사성 핵종들의 방사능은 모암에 의한 영향보다, 암석의 풍화작용과 토양형성작용 동안 이들 핵종들과 모핵종들의 용탈 및 흡착 등의 거동 특성에 의한 영향을 더 크게 받음을 시사한다.

• 자원환경지질
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• 제31권3호
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• pp.215-222
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• 1998

The radon (Rn-222) potential of metropolitan subway stations and soils in Seoul city were delineated using alpha-track filter and EDA-200 radon detectors, respectively. The uranium (U) and thorium (Th) contents were also determined using a Multi Channel Analyzer to identify the sources of radon gas. The average U concentrations in Seoul varies according to basement rock types. For example, there is $9.40{\pm}10.11ppm$ in the Precambrian metasedimentary rock (PM), $9.08{\pm}2.85ppm$ in the Jurassic Kwanaksan granite (JK) and $4.94{\pm}1.43ppm$ in the Jurassic Seoul granite (JS). Uranium contents in soil samples are $10.30{\pm}4.74ppm$ in JK, $10.10{\pm}7.43ppm$ in PM and $6.69{\pm}3.95ppm$ in JS and these closely reflect the content of uraniferous minerals. The levels of soil radon are $604{\pm}273pCi/L$ in JK, $502{\pm}275$ in JS and $262{\pm}211pCi/L$ in PM. The soil radon concentrations are shown to reflect soil permeability and porosity rather than their U contents. The mean indoor radon contents in subway stations are $1.50{\pm}0.62pCi/L$ on the 4th line, $1.41{\pm}0.95pCi/L$ on the 3rd line, $0.84{\pm}0.13pCi/L$ on the 1st line and $0.80{\pm}0.25pCi/L$ on the 2nd line. The subway stations located in the JK have the highest average radon concentration with $2.04{\pm}0.65pCi/L$, where levels of $1.57{\pm}0.81pCi/L$ occur in the JS and $0.80{\pm}0.23pCi/L$ in the PM. The highest radon levels of 4.1 pCi/L occur mainly in Keongbokkung station on the 3rd line and these exceed 4 pCi/L of the US EPA action level.

• 지질공학
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• 제26권4호
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• pp.531-549
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• 2016

화강암, 화강편마암, 변성퇴적암류와 같이 다양한 지질환경에서 지하수내 자연방사성물질인 우라늄과 Rn-222의 산출특성에 대한 지하수의 수리화학적 영향, 지질과의 상관성, 단층대의 영향 등에 대해서 알아보고자 하였다. 이 연구를 위하여 영동지역을 대상으로 2차례에 걸쳐 지하수 49점, 지표수 4점을 채취하였다. 지하수내 우라늄과 지표 암석과의 상관성을 알아보기 위해 감마스펙트로메트리를 이용하여 40지점에서 지표방사능을 측정하였다. 지하수 화학적 유형 $Ca-HCO_3$, $Na-HCO_3$, $Ca-HCO_3(SO_4+NO_3)$등 3가지 유형을 보인다. 환경부 권고치인 우라늄 $30{\mu}g/L$를 초과하는 지하수는 총 49지점 중 2점이며, Rn-222의 경우 미국 EPA 기준치인 148 Bq/L를 초과하는 지하수는 총 40지점중 11점이다. 초과하는 지하수는 주로 화강편마암과 흑운모편마암 지질과 지질경계부에 분포한다. 지표방사능 세기와 지하수내 우라늄함량과는 뚜렷한 상관관계를 보여지 않는다. 아울러 $N45^{\circ}E$ 방향의 주향이동단층인 영동단층은 $82^{\circ}$의 고경도로 상반에 해당되는 화강암 및 화강편마암지역에서 고함량의 우라늄과 Rn-222가 산출되며, 하반에 해당되는 퇴적암지역에는 고함량의 지하수가 확인되지 않는데, 이와 같은 뚜렷한 차이는 지질의 영향과 더불어 단층대가 방사성물질의 이동 및 확산을 차단시키는 역할에도 원인이 있을 것으로 추정된다.

• 한국환경과학회지
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• 제15권4호
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• pp.311-317
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• 2006

The purpose of this study was to investigate Rn concentration and annual radiation exposure level in the basement and first floor. The Rn Cup monitors were placed in different environments such as shopping stage, office building, Apartment, Hospital, house in Seoul from Match 1996 to April 1997 and CR-39 films were collected every two months. The mean radon concentration in the basement of house($88.6\;Bq/m^3$) showed the highest level among the areas, while radon concentration on the first floor of house($50.5\;Bq/m^3$) showed the higher than other areas. The annual radiation exposure dose that person on the floor / in the basement of differential place in the seoul can be exposed during living was estimated from 24.11 to 87.64 mRem/yr. This radiation dose is significantly lower than 130mRem maximum radiation dosage from the radon nuclide prescribed by the ICRP, with respect to the overall average exposure of the working adult. this study indicated that possible radon sources on the first floor / in the basement areas are radon intrusion from soil gas, construction materials, or ground water leaking. Further study is needed to quantitatively assess major contributions of radon-222 and health effect to radon exposure.

• 한국대기환경학회지
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• 제23권5호
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• pp.612-624
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• 2007

The real-time monitoring of radon ($^{222}Rn$) concentrations has been carried out to evaluate its ambient background concentration levels in Gosan site, Jeju Island between January 2001 and December 2004. In addition, the atmospheric TSP aerosols have been sampled, and their ionic and metallic components were analyzed to understand the characteristics of air pollution. The mean concentration of radon was $3,121{\pm}1,627\;mBq/m^3$, and the seasonal mean concentrations for spring, summer, fall and winter seasons were 2,898, 2,398, 3,571 and $3,646\;mBq/m^3$, respectively, The hourly concentrations have shown the highest value at 7 a.m. and the lowest value at 2 p.m. From the backward trajectory analyses, the radon concentrations have increased, when the air parcels were moved from the Chinese continent to Jeju area. On the other hand, they have decreased, when the air parcels from the North Pacific Ocean. In the analytical results of ionic species and metal elements of TSP aerosols, the concentrations of $nss-{SO_4}^{2-}$ and S were higher in June and March. Meanwhile, the concentrations of other anthropogenic species as well as soil components were mostly higher in March and April. On the basis of factor analysis, the TSP aerosols at Gosan area were largely influenced by soil sources, followed by anthropogenic sources and marine sources. From the result of backward trajectory analyses, the concentrations of $nss-{SO_4}^{2-},\;{NO_3}^-$, Al and Ca were mostly higher, when the air parcels moved from Chinese continent to Jeju area. On the other hand, their concentrations were lower, when the air parcels drifted from the North Pacific Ocean.