• Journal of Food Hygiene and Safety
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• v.33 no.6
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• pp.488-494
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• 2018

To ensure food-safety of mushrooms from radioactive contamination, edible mushroom samples distributed in Gyeonggi province in Korea were collected according to species and country of origin. A total of 284 mushrooms, belonging to 10 species (Lentinula edodes, Pleurotus ostreatus, Pleurotus eryngii, Agaricus bisporus, Flammulina velutipes, Phellinus linteus, Inonotus Obliquus (Chaga), Auricularia auricula-judae, Ganoderma lucidum and Tricholoma matsutake) were subjected to radioactivity testing. The concentration of artificial radionuclides, 131I, 134Cs, and 137Cs, was analyzed using gamma-ray spectrometry. 131I and 134Cs were not detected more than MDA value from all samples. Among 204 domestic mushrooms, however, 137Cs were detected in 0.21~2.58 Bq/kg from six cases (3 Lentinula edodes, 1 Ganoderma lucidum and 2 Tricholoma matsutake), whereas 137Cs were detected in 0.21~53.79 Bq/kg from 38 cases (22 Inonotus Obliquus(Chaga), 14 Phellinus linteus, 1 Lentinula edodes and 1 Tricholoma matsutake) among 80 imported mushrooms. In addition, average concentration of 137Cs in 10 Chaga mushroom-processed products was more than twice as much as dried Chaga mushroom, and maximum concentration was 123.79 Bq/kg. Results suggest that radioactivity monitoring system for imported mushrooms and mushroom-processed products should be continuously intensified to secure food-safety in Korea.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.239-240
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• 2004

작년 2월에 착공식을 가진 월성의 WTRF (Wolsung Tritium Removal Facility)에서 2005년 후반기부터 매년 $2.6{\times}10^{16}$ Bq(7 MCi) 이상의 삼중수소가 생산될 예정이므로 이제 우리나라에서도 삼중수소를 활용하는 연구를 본격적으로 할 수 있게 되었다. 현재 우리나라는 삼중수소를 전량, 수입하여 37 MBq (1 mCi) 혹은 $3.7{\times}10^{10}$ Bq (1 Ci)미만의 매우 적은 양으로 생물, 생화학, 농학 및 의약품 합성연구 등의 연구에 이용하오 있는 정도이고, 삼중수소의 활용에 관한 국내의 연구는 거의 전무한 상태이다.(중략)

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.407-417
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• 2004

This study is to verify radiation detection method by using $\alpha$-spectroscopy and ${\gamma}$-spectroscopy for concretes and components which will be generated during the decommissioning of the uranium conversion plant. Components and inside walls of the building were contaminated with natural uranium materials. Some parts of the stainless steel pipes and concretes of the walls were sampled and analyzed their alpha and gamma activities respectively. Alpha and gamma activities are well matched each other in the range of high activity region to 0.01 Bq/g and gamma activities are over estimated comparing alpha activities corresponded in below 0.005 Bq/g region for the natural uranium of AUC sample. The $^{238}U$ originated from natural products of conversion process could be distinguished by measuring $^{214}Pb$ or $^{214}Bi$ and $^{234}Th$ or $^{234m}Pa$. Uranium contaminations mainly are in the wall surface of the plant. Decontamination process of generating wastes which can be reached tp background level gamma activities measured by gamma spectroscopy can also be used to conservative assessment data.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.1
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• pp.1-7
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• 2005

Anion exchange chromatography and HDEHP extraction chromatography using DTPA-lactic acid as an eluent were applied in series for the separation of $^{241}$Am and $^{244}$Cm in radwaste samples. The separated elements were determined by electrodeposition at the sodium hydrogen sulfate-sodium sulfate buffer solution followed by alpha-spectrometry. The recovery yields of $^{241}$Am and $^{244}$Cm were 85.2$\pm$$15.3\%$, respectively, from the synthetic solution of spent nuclear fuel sample. The amounts of 241Am and 2440m determined in radwaste sample solutions of condensate bottoms were at the range of 1.5-1.9 Bq/g and -1.7 Bq/g, respectively.

• Journal of the Korea Convergence Society
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• v.11 no.8
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• pp.71-76
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• 2020

This study measured radioactive surface contamination in general public restrooms in hospitals and in dedicated toilets for nuclear medicine. The measurement method was measured using Berthold (LB 124, Germany) at the entrance to the restroom, inside the restroom, around the restroom, in the urinal, and around the urinal. As a result of the use of the restroom, there was no dedicated place waiting for patients who received radioisotopes in one of the three hospitals. As a result of measuring the restroom for exclusive use of radioisotopes, all measurement sites in the radioiodine therapy room were the highest, and the results of measuring the public restrooms showed background level contamination at all hospitals except hospital B. However, it was measured as 8.073 Bq/㎠ and 6.426 Bq/㎠ in the urinals in the public restroom on the first floor of the B hospital. Therefore, it is recommended to explain the dangers of radiation exposure to patients and provide a place for patients to wait. In addition, a plan should be sought to prevent patients from receiving radioisotopes from using unnecessary movements and general public restrooms.

• Journal of Radiation Protection and Research
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• v.19 no.3
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• pp.199-208
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• 1994

The derived intervention levels in Korean foodstuffs were estimated using the dynamic ingestion pathway model which was developed considering Korean environment. The derived intervention levels were estimated from the intervention level of dose based on the thyroid committed dose equivalent of infant in the case of I-131, and the whole body committed dose equivalent for age groups and 13 kinds foodstuffs in the cases of Cs-137 and Sr-90. The derived intervention levels were shown as a considerable variation with deposition time and radionuclide. The adult was the most important age group in the estimation of derived intervention levels for Cs-137 and Sr-90. In the adult, the derived intervention levels for rice were 2390 and 47 Bq/kg for Cs-137 and Sr-90 in the case of deposition in summer, respectively, and 198 and 79 Bq/kg in the case of deposition in winter, respectively.

• Journal of Soil and Groundwater Environment
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• v.16 no.5
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• pp.53-66
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• 2011

Groundwater which infiltrated in recharge areas discharges in the forms of evapotranspiration, baseflow to streams, groundwater abstraction and eventually flows into the sea. This study characterized radon-222 concentration and electrical conductivity (EC) in coastal groundwater discharge, well groundwater, Ilkwang Stream water, and seawater in the coastal area of Busan Metropolitan City and subsequently estimated groundwater discharge rate to the sea. The median value of Rn-222 concentration is highest in well groundwater (18.36 Bq/L), and then decreases in the order of coastal groundwater discharge (15.92 Bq/L), Ilkwang Stream water (1.408 Bq/L), and seawater (0.030 Bq/L). The relationship between Rn-222 concentration and EC values is relatively strong in well groundwater and then in seawater. However, the relationship is not visible between coastal groundwater discharge and Ilkwang Stream water. The groundwater discharge rate to the sea is estimated as $3,130m^3$/day by using radon mass budget model and $16,788m^3$/day by using Darcy's law.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.3
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• pp.334-341
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• 2016

Objectives: This study is aimed at examining radon exposure in offices and the factors that can influence the concentrations. Methods: Indoor radon concentrations in a total of 30 places were measured from January 18 to 21, 2016, targeting six buildings in Seoul with different completion years. The measurement was conducted according to the radon measurement guidelines for indoor air suggested by the Ministry of Environment. Results: As a result of comparing each average concentration, underground area concentration was $42.850{\pm}22.501Bq/m^3$, and that of the ground floors was $27.850{\pm}12.232Bq/m^3$, which was lower than the concentration in the underground areas and statistically significant (p=0.045). As a result of comparing the concentration according to whether or not outside air entered, the average concentration for ventilated areas was $24.876{\pm}11.833Bq/m^3$, and the average concentration for enclosed areas was $47.892{\pm}19.375Bq/m^3$. The concentration in ventilated areas was lower at a statistically significant level (p=0.001). Finally, as a result of the multiple regression analysis for evaluating the factors influencing radon concentration, only ventilation was significant (p=0.007). Conclusions: As a result of measuring radon in office buildings, there was no place that exceeding the recommended standard of the US EPA, but the concentration in poorly ventilated areas was measured to be high. An effort to manage radon concentration and reduce it through the improvement of ventilation systems, repeated measurement is necessary in the future.

• Journal of Radiation Protection and Research
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• v.20 no.2
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• pp.123-128
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• 1995

The concentration of Cs-137 and Sr-90 has been analyzed in soils around Taejon region. A correalation was found between the concentration of Cs-137 and the organic matter content. The mean value of Cs-137 was 14.37Bq/kg-dry and that of Sr-90 was 7.95Bq/kg-dry in undisturbed soils around Taejon region. The concentration ratio of Cs-137/Sr-90 was 1.99. The distribution of Cs-137 and Sr-90 was similar to cumulative fallout level and had been more affected by nuclear weapons test than by the chernobyl accident.

• Ocean and Polar Research
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• v.38 no.2
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• pp.139-148
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• 2016

The activity concentrations of $^{210}Po$ and $^{210}Pb$ within phytoplankton-zooplankton-anchovy-mackerel in the coastal water of the Jeju Island were determined to understand their distribution and bio-accumulation along the trophic level. In the surface water, the total activity concentrations of $^{210}Po$ and $^{210}Pb$ were $0.83{\pm}0.004mBq\;kg^{-1}$ and $1.27{\pm}0.03mBq\;kg^{-1}$. And the dissolved activity concentration of $^{210}Po$ and $^{210}Pb$ were $0.75{\pm}0.06mBq\;kg^{-1}$ and $1.22{\pm}0.09mBq\;kg^{-1}$ respectively. In the phytoplankton, the concentration factor (CF) of $^{210}Po$ and $^{210}Pb$ were $1.5{\times}10^5$ and $2.6{\times}10^4$ shows $^{210}Po$ is 5 times higher compared to $^{210}Pb$. The similar CF factor in the zooplankton of $^{210}Po$ was derived as $1.4{\times}10^5$. The CF of $^{210}Po$ in anchovy was increased twice compared to that in plankton. This is the evidence that there is $^{210}Po$ bio-magnification in the trophic level of plankton-anchovy. However the $^{210}Po$ activity concentration in the muscle tissue of mackerel was one-hundred times lower than that in anchovy. This reflects that in the trophic level of anchovy-mackerel, the bio-accumulation of $^{210}Po$ is decreased. The activity concentrations of $^{210}Po$ in the internal organs of anchovy and mackerel were 8 to 38 times higher than those in muscle tissues. In phytoplankton-zooplankton-anchovy, the CF of $^{210}Pb$ was decreased five times along the trophic level in order. In anchovy-mackerel it was decreased by 30-70%.