• 방사성폐기물학회지
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• 제14권4호
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• pp.331-341
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• 2016

국내 유통중인 다양한 형태의 원료물질 또는 공정부산물들에 대한 물리적, 화학적 및 방사선적 특성을 평가하기 위해 약 220여 개, 총 16 종의 표본 시료를 선정하였다. 해당 시료들에 대하여 $LaBr_3$ 섬광검출기를 이용한 에너지 스펙트럼 측정과 에너지 분산형 X-선 형광 분광기를 이용한 U, Th, K와 물질의 주요 성분 분석을 수행하였다. 그리고 HPGe 검출기를 이용하여 $^{234}Th$, $^{234m}Pa$ 및 $^{214}Bi$ 등의 우라늄 붕괴계열 핵종들과 $^{228}Ac$, $^{212}Pb$ 및 $^{208}Tl$ 등의 토륨 붕괴계열 핵종들 그리고 $^{40}K$ 등의 방사능농도를 분석함으로써 원료물질 및 공정부산물의 특성에 관한 기초자료를 수집하였다. 추가적으로 ROI구간별 계수율과 원소성분함량, 방사능농도와 같은 특성변수들 간의 상관관계를 분석함으로써 스크리닝 장비를 이용한 방사능 농도 분포 유추 가능성을 평가하였다. 본 연구에서 구축된 특성 데이터베이스는 천연방사성핵종 분석을 위한 절차 및 방법을 수립하는데 유용한 정보를 제공하고, 천연방사성핵종 분석에 대한 정확성 및 재현성을 향상시킬 수 있을 것으로 판단된다.

• Journal of Radiation Protection and Research
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• 제41권3호
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• pp.291-300
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• 2016

Background: It is necessary to assess radiation dose to workers due to inhalation of airborne particulates containing naturally occurring radioactive materials (NORM) to ensure radiological safety required by the Natural Radiation Safety Management Act. The objective of this study is to develop an internal dose assessment procedure for workers at industries using raw materials containing natural radionuclides. Materials and Methods: The dose assessment procedure was developed based on harmonization, accuracy, and proportionality. The procedure includes determination of dose assessment necessity, preliminary dose estimation, airborne particulate sampling and characterization, and detailed assessment of radiation dose. Results and Discussion: The developed dose assessment procedure is as follows. Radioactivity concentration criteria to determine dose assessment necessity are $10Bq{\cdot}g^{-1}$ for $^{40}K$ and $1Bq{\cdot}g^{-1}$ for the other natural radionuclides. The preliminary dose estimation is performed using annual limit on intake (ALI). The estimated doses are classified into 3 groups ( < 0.1 mSv, 0.1-0.3 mSv, and > 0.3 mSv). Air sampling methods are determined based on the dose estimates. Detailed dose assessment is performed using air sampling and particulate characterization. The final dose results are classified into 4 different levels ( < 0.1 mSv, 0.1-0.3 mSv, 0.3-1 mSv, and > 1 mSv). Proper radiation protection measures are suggested according to the dose level. The developed dose assessment procedure was applied for NORM industries in Korea, including coal combustion, phosphate processing, and monazite handing facilities. Conclusion: The developed procedure provides consistent dose assessment results and contributes to the establishment of optimization of radiological protection in NORM industries.

• Journal of Radiation Protection and Research
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• 제43권4호
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• pp.160-169
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• 2018

Background: This study aims to develop an integrated optical system that can simultaneously or selectively measure the signals obtained from radioluminescence (RL), thermoluminescence (TL), and optically stimulated luminescence (OSL), which are luminescence phenomena of materials stimulated by radioactivity, heat, and light, respectively. The luminescence mechanism of various materials could be investigated using the glow curves of the luminescence materials. Materials and Methods: RL/TL/OSL integrated measuring system was equipped with a X-ray tube (50 kV, $200{\mu}A$) as an ionizing radiation source to irradiate the sample. The sample substrate was used as a heating source and was also designed to optically stimulate the sample material using various light sources, such as high luminous blue light emitting diode (LED) or laser. The system measured the luminescence intensity versus the amount of irradiation/stimulation on the sample for the purpose of measuring RL, TL and OSL sequentially or by selectively combining them. Optical filters were combined to minimize the interference of the stimulation light in the OSL signal. A long-pass filter (420 nm) was used for 470 nm LED, an ultraviolet-pass filter (260-390 nm) was used for detecting the luminescence of the sample by PM tube. Results and Discussion: The reliability of the system was evaluated using the RL/OSL characteristics of $Al_2O_3:C$ and the RL/TL characteristics of LiF:Mg,Cu,Si, which were used as dosimetry materials. The RL/OSL characteristics of $Al_2O_3:C$ showed relatively linear dose-response characteristics. The glow curve of LiF:Mg,Cu,Si also showed typical RL/OSL characteristics. Conclusion: The reliability of the proposed system was verified by sequentially measuring the RL characteristics of radiation as well as the TL and OSL characteristics by concurrent thermal and optical stimulations. In this study, we developed an integrated measurement system that measures the glow curves of RL/TL/OSL using universal USB-DAQs and the control program.

• 한국식품위생안전성학회지
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• 제36권3호
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• pp.248-256
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• 2021

건조 수산가공식품의 안전성 확보를 위해 2020년 경기도 내 유통 중인 건조 수산가공식품 12품목 120건을 수거하여 방사능(¹³¹I, ¹³⁴Cs, ¹³⁷Cs) 및 중금속(납, 카드뮴, 비소, 수은) 함량을 분석하였다. 모든 시료에서 자연 방사성 핵종 중 하나인 ⁴⁰K만 검출되었으며, 인공 방사성 물질인 ¹³¹I, ¹³⁴Cs, ¹³⁷Cs는 최소검출가능농도(MDA) 이하의 값을 나타내었다. 중금속의 평균 함량[평균±표준편차(최소값-최대값)]은 생물로 환산하였을 때 납 0.066±0.065(N.D.-0.332) mg/kg, 카드뮴 0.200±0.406(N.D.-2.941) mg/kg, 비소 3.630±3.170(0.371-15.007) mg/kg, 수은 0.009±0.011(0.0005-0.0621) mg/kg 이었으며, 수산물에서 중금속 기준이 있는 제품의 경우 모두 기준 규격 이내로 나타났다. 국내산 제품과 수입산 제품의 중금속 함량은, 조개의 카드뮴과 새우의 수은 함량에서만 유의적인 차이를 나타내었다(P<0.05). 본 연구 결과, 유통 중인 건조 수산가공식품에서 방사능 및 중금속은 안전한 수준인 것으로 판단되나, 식품 중 특히 수산물에서 방사능 오염에 대한 국민의 우려가 크기 때문에 국민들의 불안감 해소를 위해 방사능 검사는 지속적으로 필요할 것으로 생각된다. 또 향후 건조 수산가공식품 중에서도 건조된 형태로 직접 섭취 가능한 제품의 중금속 관리 기준 설정을 위한 기초 자료로 활용할 수 있을 것이다.

• 분석과학
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• 제21권6호
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• pp.474-479
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• 2008

중국의 주요 황사발원지로 알려진 오도스 사막, 알라샨 사막, 타클라마칸 사막 및 황토고원의 표층퇴적물에 분포되어 있는 우라늄계열의 $^{226}Ra$, 토륨계열의 $^{228}Ac$과 비 계열인 $^{40}K$과 같은 지각중 대표적인 자연방사성핵종의(naturally occurring radioactive nuclide: NORN) 방사능 특성을 조사하였다. 감마선 분광법을 이용하여 NORN의 비방사능(specific activity: SA, Bq/kg)을 측정하고 비방사능 비(specific activity ratio: SAR)를 산출하여 발원지에 따른 자연방사능 특성을 분석하였다. 발원지에 따른 세 핵종의 SA값은 $^{226}Ra$의 경우 세 사막지대에서는 평균 17.9~21.9 Bq/kg으로 매우 유사한 값을 가지는 반면 황토고원에서는 평균 35.0 Bq/Kg으로 큰 차이를 나타내고 있었다. $^{228}Ac$의 경우는 오도스 사막과 알라샨 사막에서는 평균 27.1~27.2 Bq/kg으로 거의 같은 값을 가지며 타클라마칸 사막에서는 31.7 Bq/kg 그리고 황토고원에서는 49.0 Bq/kg으로 큰 차이를 나타내고 있었다. $^{40}K$의 경우는 636~943 Bq/kg 으로 네 곳의 발원지에서 특별한 차이를 나타내지 않았다. $^{226}Ra/^{228}Ac$의 평균 SAR 값에서 네 곳의 발원지에서 0.708-0.721로 거의 일정하게 나타났고 $^{226}Ra/^{40}K$과 $^{228}Ac/^{40}K$의 평균 SAR 값을 보면, 오도스와 알라샨 사막은 각각 0.0209-0.0213과 0.0287-0.0320으로 유사한 값을 나타내고 있으나 타클라마칸 사막과 황토고원 표층시료들에서의 평균 SAR 값을 보면, 0.0353, 0.0506과 0.0493, 0.0773으로 상당한 차이를 나타낸다.

• Journal of Radiation Protection and Research
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• 제41권2호
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• pp.133-140
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• 2016

Backgrounds: The accident at Fukushima Daiichi Nuclear Power Plant (NPP), March 2011, caused serious radioactive contamination over wide area in east Japan. Therefore, it is important to know the effect of the accident and the status of NPP. Materials and Methods: This paper provides a review on the status of radiation dose and radioactive contamination caused by the accident on the basis of publicized information. Results and Discussion: Monitoring of radiation dose and exposure dose of residents has been conducted extensively by the governments and various organizations. The effective dose of general residents due to the accident proved to be less than a mSv both for external and internal dose. The equivalent committed dose of thyroid was evaluated to be a few mSv in mean value and less than 50 mSv even for children. Monitoring of radioactivity concentration has been carried out on food ingredients, milk and tap water, and actual meal. These studies indicated the percentage of foods above the regulation standard was over 10% in 2011 but decreasing steadily with time. The internal dose due to foods proved to be tens of ${\mu}Sv$ and much less than that due to natural $^{40}K$ even in the Fukushima area and decreasing steadily, although high level concentration is still observed in wild plants, wild mushrooms, animals and some kind of fishes. Conclusion: According to extensive studies, not only the effect of the accident but also the pathway and countermeasures against radioactive contamination have been revealed, and they are applied very effectively for restoration of environment and reconstruction of the area.

• 자원환경지질
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• 제33권3호
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• pp.195-204
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• 2000

order to investigate physical characteristics and element concentrations of sediments, coastal bottom sediments were collected at 20 stations in the vicinity of Youngkwang Nuclear Power Plant. After air drying of samples in the laboratory. article size distribution was examined by Master sizer (X-350F), radio-activity by HPGe ${\gamma}$-spectrphotometer, and element concentrations by ICP-AES and AAS. According to particle size analysis , sediments are mainly composed of silt fraction weith 23% of sand, 65% of silt and 12% of clay on average. Most sediments are derived from muddy environment that silt dominates with the characteristics of 5.3${\varsigma}$ mean particle size, poorly sorted, very fine skewed and lepto-kurtic. Only two sediments are well sorted with sandy silt owing to wind, winnowing action, tide and current andits complex reactions. Element concentrations in the coastal bottom sediments are relatively high at finer sediment and show significant relationship with grain size. Index of geoaccumulation by heavy metals at every sampling station is classified as practically unpolluted. The radioactivities of the sediments were measured for 15 isotope elements, and 2 elements of K-40 and Cs-137 were detected in most sediments. The K-40 is the natural nuclide and the artificial nuclide of Cs-137 was thought to be derived from the fallout of past nuclear weapon test. The results of correlation coefficient between grain size and radioactivity shows that the activity of Cs-137 significantly increases in finer grain.

• Bulletin of the Korean Chemical Society
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• 제29권3호
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• pp.595-598
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• 2008

Emodin (3-methyl-1,6,8-trihydroxyanthraquinone) is a natural chemotherapeutic compound with diverse biological properties including an antitumor activity. Emodin, a specific inhibitor of the protein tyrosine kinase, has a number of cellular targets in related to it. Its inhibition activity affects the mammalian cell cycle regulation in specific oncogene. Practically, it has been proven to inhibit HER-2/neu tyrosine kinase expressing breast cancer cells as an anticancer agent. 2-[123I]iodoemodin has been synthesized and evaluated human breast cancer cells (MDA-MB-231, MCF-7, fibroblast as a control) which express basal levels of HER-2/neu tyrosine kinase to investigate its suitability as a breast cancer imaging agent and 2-iodoemodin has been synthesized as a standard compound. The radiochemical yield of the 2-[123I]iodoemodin was about 72% and its radiochemical purity was over 97% after purification. The radioactivity of the 2-[123I]iodoemodin was increased in a time dependent manner in both cell lines and the ratio of MDA-MB-231 and MCF7 to fibroblast was 2.9 and 1.7, respectively.

• Journal of Radiation Protection and Research
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• 제15권2호
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• pp.75-85
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• 1990

Kalsruhe원자력 연구소(KfK) 주변의 방사능 측정자료로부터 피폭선량을 계산하였다. 식물성 식품의 섭취가 가장 중요한 피폭 경로였고, 식품중의 자연방사성 동위원소인 K-40 과 Pb-210이 주요 피폭원이었다. 인공방사능에의한 피폭은 대부분 지표에 침척된 Cs-134 와 Cs-137으로부터 방출되는 감마선 때문이었다. KfK주변환경에서의 유효선량당량은 ICRP의 권고제한치보다 훨씬 적은 값이었다.

• Clinical and Experimental Reproductive Medicine
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• 제16권2호
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• pp.131-138
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• 1989

The present study was designed to develop a new method for the determination of estrogen receptor in porcine uterus using frozen sections. Cryostat sections were incubated with $^3H$-estradiol($^3H$-$E_2$) in the presence or absence of diethylstilbestrol(DES) and the radioactivity of 3H-E2 bound to estrogen receptor(ER) was detected. The level of specific estrogen receptor was determined by Scatchard analysis. The highest ratio of specific binding against total binding was achieved in 3 sec. tions(5mm x 5mm) which was corresponded to lOO${\mu}$/ml protein concentration. Optimal binding was obtained during incubation with $^3H$-$E_2$ for 30 minutes at 23$^{\circ}C$ after treatment of sections with acetone for 20 seconds. Three time-washing of sections was proved to be appropriate for the removal of unbound 3H-E2. 200-fold molar excess of DES was substituted for the binding of $^3H$-$E_2$ to ER sufficiently(binding efficiency of 54.8%). ER was saturated with 4nM of $^3H$-$E_2$ and its dissociation constant was 0.1nM. ER assay using frozen sections(Histological radioreceptor assay, HRRA) was significantly correlated with radioreceptor assay for estradiol(RRA, 0.976 , p