• 한국지하수토양환경학회지:지하수토양환경
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• 제16권5호
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• pp.67-73
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• 2011

Groundwaters were sampled from 730 wells being used for drinking purposes during 2007-2009. These samples were analysed using a gas-flow type GPC (Gas Proportional Counter) according to the USEPA method (900.0). We obtained a gross-alpha counting TDS (total dissolved solid) efficiency curve (Y = 0.0017X2 - 0.3122X + 19.165, X = TDS, Y = efficiency, $R^2$ = 0.9734) using natural uranium standard to get gross ${\alpha}$ value of the samples. The gross alpha values ranged from MDA (minimum detectable activity) to 14.88 pCi/L and 429 samples showed values higher than MDA (< 0.9 pCi/L). Correlations of the uranium values with the total alpha values and the gross-alpha values indicate that uranium values have high impacts on gross-alpha values. Groundwater samples of study areas were classified into four regions according to the rock types; plutonic (granite) rock region (427 areas), metamorphic rock region (181 aeras), sedimentary rock region (70 areas), volcanic rock region (52 areas). Groundwater of Cretaceous granite presented the highest gross-alpha value. Gross alpha in groundwaters showed no relationship with uranium in terms of the geological ages, rocks and minerals.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4554-4560
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• 2023

Continuous monitoring of radioactive substances over a prolonged duration can yield crucial insights into the levels of radiation exposure through inhalation, both in the vicinity of nuclear facilities and/or general environments. In this study, we evaluated long-term measurements (2012-2022) of gross alpha-beta activities in the air in the vicinity of nuclear facilities and reference site, distribution characteristics of temporal trends and spatial fluctuations, and factors affecting radioactivity levels. The average airborne gross-α (in mBq m^-3) for onsite and off-site were 0.124 and 0.117, respectively, and the average airborne gross-β (in mBq m^-3) measurements were 1.10 and 1.04, respectively. The activity ratio (AR) of gross-α and gross-β were calculated as a ratio of 0.12. The distribution characteristics of gross-α and gross-β activities in this study area are likely influenced by the meteorological factors and variations in airborne PM concentrations rather than the operation of the nuclear facility.

• 방사성폐기물학회지
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• 제18권2_spc호
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• pp.227-235
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• 2020

우리는 실험과 MCNP 시뮬레이션을 통해 전알파 분석법의 한계를 설명하였다. 국내에서 중·저준위 방사성폐기물 인도 규정 관련, 전알파 분석법은 방사성폐기물을 처분하기 위해 반드시 규명해야 할 방사성 특성평가 인자이다. 전알파 분석법은 시료 준비 절차가 간단하고 신속한 분석 결과를 제공하지만, 정량분석 인자로 사용하는 것은 적절하지 않다. KCl과 ²⁴¹Am을 이용하여 시편 건조고형물 무게에 따른 전알파 계측효율을 평가하였다. 동일한 무게의 시편일지라도 계측효율의 차이가 20% 나는 것을 확인하였고, 이는 시편의 물리적 형태가 서로 다르기 때문인 것으로 보인다. 토양 중 우라늄을 화학분리 한 후, ICP-MS로 우라늄을 직접 측정한 결과와 전알파 농도를 비교하였다. 전알파는 실제 우라늄 농도에 비해 50% 과소평가되었다. 알파핵종별 전알파 계측효율이 최대 3배 차이 나기 때문에, 전알파 분석결과는 개별 알파핵종의 합과 비교하기 보다는 스크리닝 개념으로 사용하는 것이 적절하다.

• 한국해양학회지
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• 제10권1호
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• pp.17-24
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• 1975

In order to clarify the accumulation of radioactive materials in marine organisms of Korea, the present investigation is carried out with 54 samples of edible seaweeds collected from eight sampling sites along the coast of Korea during September, 1973 and April, 1974. In this paper, ash contents, gross alpha activities and gross beta activities are detected. The ash content is 7.53- 15.95% in the species investigated. Among the algal phyla it is about 13.13% in green algae, 12.77% in brown algae, and 10.77% in red algae on an average. On the other hand, gross alpha activities fluctuate from 180.0 pCi/Kg to 1082.6 pCi /Kg-fresh material experimented, and are 530.72 pCi/Kg on an average. They increase from green to red and brown algae, in turn. The activities in a single species collected at the same season increse from eastern to western and southern coasts of Korea, in turn. Gross beta activities, however, fluctuate from 2.40 nCi/Kg to 22.14 nCi/Kg-fresh material experimented, and 9.03 nCi/Kg on an average. They increase also from green to red nd brown algae, in turn. The gross beta activities are specially higher in Sargassum thunbergii, 22.14 nCi/Kg It is expected that this plant could be an indicator to detect the activities in the marine algae along the coast of Korea.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권3호
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• pp.104-110
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• 2014

In order to study gross alpha analysis method using LSC, the efficiency tests with uranium standard materials were performed and then compared with the GPC method (US EPA 900.0 method) using 15 groundwater samples. For 15 groundwater samples, the average efficiencies of the GPC and LSC method were 7~11% and 90%, respectively. The average precisions of the GPC and LSC method were 16.16% and 6.00%, respectively. Also, The average standard deviations for 15 samples were 7.38 pCi/L and 2.95 pCi/L, respectively. The determination coefficient of the tested results by two methods was 0.9948. As a result, the LSC method tested in this study was applicable for the screening of the gross alpha and showed the advantages in the gross alpha measurement due to the simple measurement procedures.

• Journal of Radiation Protection and Research
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• 제46권4호
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• pp.194-203
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• 2021

Background: Surface soil radiation monitoring around nuclear facilities is important to classify and characterize the contaminated areas. A scanning and direct measurement technique can survey the sites rapidly before starting sampling analysis. Materials and Methods: Regarding this, we test and suggest a measurement technique for gross alpha/beta and ⁹⁰Sr activities in surface soil based on a mobile ZnS(Ag)/PVT (polyvinyltoluene) array and a handheld PVT rod, respectively. To detect ⁹⁰Sr selectively in soil mixed with naturally occurring radioactive materials, chosen energy channel counts from the multichannel analyzers were used instead of whole channel counts. Soil samples contaminated with exempt liquid ⁹⁰Sr with 1 Bq·g^-1, 3 Bq·g^-1, and 10 Bq·g^-1 were prepared and hardened by flocculation. Results and Discussion: The mobile ZnS(Ag)/PVT array could discriminate gross alpha, gross beta, and gamma radiation by the different pulse-shaped signal features of each sensor material. If the array is deployed on a vehicle, the scan minimum detectable concentration (MDC) range will be about 0.11-0.17 Bq·g^-1 at 18 km·h^-1 speed, highly sensitive to actual sites. The handheld PVT rod with 12 mm (Φ) × 20 mm (H) size can directly measure ⁹⁰Sr selectively if channels on which energies are from 1,470 and 2,279 keV are gated, minimizing crossdetection of other radionuclides. These methods were verified by measuring soil samples fabricated with homogeneous ⁹⁰Sr concentrations, showing static MDC of 2.16 Bq·g^-1 at a measurement time of 300 seconds. Conclusion: Based on the results, comprehensive procedures using these detectors are suggested to optimize soil sites survey.

• Molecular & Cellular Toxicology
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• 제3권1호
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• pp.68-75
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• 2007

[ $\alpha$ ]-Terpinene has been known as a repellent against the mosquito Culex pipiens pallens Coquillett based on a human forearm bioassay. $\alpha$-Terpinene showed significantly greater repellency than a commercial formulation, N, N-diethyl-m-methylbenzamide (deet). In this study, skin and eye sensitivity of $\alpha$-terpinene (2%) was examined with bioassays using white New Zealand rabbits. There were somewhat gross and histological changes observed in these treatments. Eye irritancy assays examined gross changes to cornea, iris and conjuctiva, and histological changes to smear of ocular discharge and eye tissue. Treated rabbits were divided into two cohorts, a saline washed cohort (W) or a non-washed cohort (NW). Opacity of cornea and redness, chemosis and discharge of conjuctiva were observed in both cohorts, but disappeared within 4 and 10 days in W and NW, respectively. Main components of ocular discharges were fibrin, epithelial or epitheloid cells, lymphoid cells, erythrocytes and granulocytes. These abnormal cellular components disappeared within 4 days and 10 days in W and NW, respectively. No permanent histological differences were observed between the two cohorts. However, severe irritation was determined as 57.2 of I.I.O.I value on the first day after treatment. These findings indicate a spray-type solution containing 2% $\alpha$-terpinene may serve as an alternative mosquito repellent and further studies need to reduce the eye irritation with formulation changes.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2019년도 춘계학술논문요약집
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• pp.195-196
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• 2019

• Journal of Radiation Protection and Research
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• 제37권4호
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• pp.226-230
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• 2012

방사선 사고시 피폭환자로부터 채취된 스메어 시료의 전알파 방사능 측정법을 수립하였으며 이를 바탕으로 피폭환자의 후속조치 절차를 확립하였다. 국내방사선사고 대응기관에서 사용중인 스메어용 면봉을 이용하여 계측 절차를 검증하였다. 액체섬광계수기를 이용하여 표준선원을 점적한 시료의 계측 결과 20% 이내에서 인증값과 잘 일치하였으며, 채취 조건은 세정제 등을 이용하는 것이 더 높은 스메어 효율을 보였다. 액체섬광계수법 특성상 소광현상의 영향을 배제하기 위해 건조 등의 최소한의 전처리가 필요 할 것으로 판단되었다. 계측결과를 바탕으로 방사선비상시 피폭환자에 대한 의료적 처치 기준 및 선량평가 절차를 수립하였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권2호
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• pp.22-27
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• 2012

$^{226}Ra$ in groundwater could be analyzed by various methods. LSC (liquid scintillation counter) is used to measure its activity of Ba co-precipitates with Hisafe III scintillation cocktail solution. Counting efficiency was obtained using NIST $^{226}Ra$ standard solution in triplicate and calculated $^{226}Ra$ concentration using the efficiency values. $^{226}Ra$ values of 19 groundwaters having Gross-${\alpha}$ concentrations of more than 5 pCi/L ranged from ND (${\leq}$ 0.1 pCi/L) to 1.18 pCi/L. Geologic settings of the 19 areas are composed of granitic rocks of Pre-Cambrian and Jurassic and Cretaceous, gneiss (schist) of Pre-Cambrian, and volcanic rocks of Cretaceous. No relationship was shown among $^{226}Ra$ a concentrations and in-situ water quality data, and Gross-${\alpha}$, uranium, radon concentrations.