• Analytical Science and Technology
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• v.14 no.3
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• pp.212-220
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• 2001

This study was performed to establish the analytical method of radium and radon in various environmental samples with the ${\gamma}$-ray spectrometry. The major problem in the measurements of low level ${\gamma}$-ray, such as environmental radioactivity, is the fluctuation of ${\gamma}$-ray background spectrum. To overcome this problem, a nitrogen gas was filled up in the detector chamber to reduce the background counts due to airborne radioactivities, i.e., $^{214}Pb$ and $^{214}Bi$, the daughters of $^{222}Rn$ in air. When nitrogen gas flowed around the detector, peak counts of ${\gamma}$-rays from the daughters of $^{222}Rn$ decreased about 80% below 1 MeV and about 20~50% above 1 MeV. The use of nitrogen purging results in approximately tenfold increment of sensitivity.

• Analytical Science and Technology
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• v.13 no.6
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• pp.693-698
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• 2000

The object of this series of experiments was aimed for the systematic and long-term radioactivity monitoring through indirect search of C-14 concentration level changes in the natural conditions around the operating nuclear facilities. The result of environmental radioactivity level through tree-ring analysis is increased after operating nuclear facilities and such a level can be proved to relate power generation closely. The measured result of ${\delta}^{13}C$ through the treatment of cellulose can be showed the level -30‰. This figure is very different from one which is measured the -17‰ of air sample by passive air sampling and -8‰ of air sample by active air sampling. And these differences can be assumed as isotope fractionation by photosynthesis, but the problem is more study as needed.

• Journal of radiological science and technology
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• v.44 no.3
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• pp.247-252
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• 2021

As the number of single-person households increases, the consumption of bottled water is increasing. In addition, as the public's interest in radioactivity increases, interest in the field of living radioactivity is also increasing. Since drinking water is an essential element in our daily life, it must be safe from radioactivity. In this study, gamma radiation of drinking spring water was measured and internal exposure dose evaluation was performed to determine its harmfulness. K-40 and uranium-based radioactivity analysis was performed through a high-purity germanium detector, and as a result, drinking water was detected somewhat higher than that of mixing water. Since there is no regulation on the natural radioactivity concentration in Korea, it was compared with the U.S. Environmental Protection Agency Drinking Water Regulations and World Health Organization standard. As a result, there were some items that exceeded standards. Internal exposure was evaluated according to the effective dose formula of ICRP 119. As the result was derived that a maximum of 1.17 mSv per year could be received. This result means that the dose limit for the general public may be exceeded, and it was judged that it is necessary to set an appropriate standard value and present a recommendation value through continuous monitoring in the future.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.24-31
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• 2004

In order to decommission safely nuclear power plant, it is necessary for the procedure of residual radioactivity investigation in site to provide detailed guidance for planning, implementing, and evaluating environmental and facility radiological surveys conducted to demonstrate compliance with a dose or risk-based regulation. This study presents the procedure of residual radioactivity investigation in decommissioning site - Historical Site Assessment, Scoping Survey, characterization Survey, Remedial Action Support Survey, Final Status Survey - on the basis of MARSSIM(Multi-Agency Radiation Survey and Site Investigation Manual) and investigation cases of decommissioned or decommissioning nuclear power plant.

• Journal of Environmental Science International
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• v.12 no.6
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• pp.677-688
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• 2003

The purpose of this study was to predict occurrence of earthquakes in Korea by measuring the concentration of radon radioactivity in the air and in the underground water. Two monitoring systems of radon concentration detection in the air were installed in Seoul, East Coast area, whereas of radon concentration in the underground water in Kyungju area during December, 1999 to June, 2001. The distribution of radon concentration in the air in Seoul is as follows Winter(10.10 $\pm$ 2.81 Bq/㎥), autumn(8.41 $\pm$ 1.35 Bq/㎥), summer(5.83 $\pm$ 0.05 Bq/㎥) and spring (5.34 $\pm$ 0.44 Bq/㎥), whereas the distribution of radon in the air in the East Coast area showed some difference as follows : autumn (14.08 $\pm$ 5.75 Bq/㎥), Summer (12.04 $\pm$ 0.53 Bq/㎥), Winter (12.02 $\pm$ 1.40 Bq/㎥) and spring (8.93 $\pm$ 0.91 Bq/㎥). In the meanwhile, the distribution of radon in the water is as follows : spring (123.59 $\pm$ 16.36count/10min), Winter (93.95 $\pm$ 79.69counter/10min), autumn (68.96 $\pm$ 37.53counter/10min) and spring (34.45 $\pm$ 9.69counter/10min). The daily range of the density of radon concentration in Seoul and East Coast area was between 5.51 Bq/㎥ - 9.44 Bq/㎥, 7.15 Bq/㎥ - 15.27 Bq/㎥, respectively. Correlation of the distributions of radon concentrations in the air and in underground water with earthquake showed considerable variations of radon concentration before the occurrence of the earthquake. The results suggested that radon radioactivity seemed to be helpful for the prediction of the occurrence of earthquake.

• Journal of the Korean Society of Radiology
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• v.8 no.6
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• pp.293-299
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• 2014

Compton suppression device is a device by using the Compton scattering reaction and suppress the Compton continuum portion of the spectrum, so can be made more clear analysis of gamma ray peak in the Compton continuum region. Measurements above background occurs or, radioactivity counts of radioactivity concentration value of $^{40}K$ nuclides $^{137}Cs$ and natural radioactivity artificial radioactivity detected from the surface soil sample, unwanted non-target analysis and interference peak who dotted line you know the calibration of the measurement energy is allowed to apply the (Compton suppression) non-suppressed spectrum inhibition spectrum and (Compton Unsuppression) the background to the measured value of the activity concentration value of the standard-ray source is detected relative to the peak of By measuring according to the different distances cause $^{137}Cs$, and comparative analysis of the Monte Carlo simulation, in order to obtain a detection capability for efficient, looking at the Compton inhibitor, as the CSF value increases with increase in the distance, more It was found that the background due to Compton continuum of the measured spectrum suppression mode Compton unrestrained mode can know that the Compton suppression many were made, using a $^{137}Cs$ is reduced.

• Korean Journal of Environmental Agriculture
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• v.6 no.1
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• pp.7-16
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• 1987

A study was undertaken to investigate the absorption, translocation and metabolism of carbofuran in rice paddies. Ring-3-$^{14}C-carbofuran$ applied onto the paddy soil surface was rapidly absorbed and translocated into rice plants. Within 2 days after treatment, it was observed that carbofuran reached shoot tips and accumulated. More than 15% of total radioactivity was recovered in rice plant from 3 to 20 days after treatment. In organic soluble fraction of rice plant extract, 3-hydroxycarbofuran was the major metabolite recording 43% and 4% of total organic soluble radioactivity in shoot and root at 20 days respectively. 3-Ketocarbofuran and phenolic metabolites including carbofuran phenol, 3-hydroxycarbofuran phenol and 3-ketocarbofuran phenol were also detected in the organic soluble fractions. Some glycosidic conjugates of carbofuran metabolites were found in water soluble fraction of rice plant extract and 3-hydroxycarbofuran was the most abundant aglycone. Radioactivity in paddy soil was rapidly decreased until 3 days after treatment and then maintained almost constant level. A significant portion (42∼56 %) of the total radioactivity remained in soil as nonextractable residue from 5 to 20 days after treatment. The nonextractable radioactivity was mainly located in soil organic matter distributing in humin, fulvic acid and humic acid fractions with the decreasing order. Evolution of $^{14}CO_2$ from ring cleavage of $3-^{14}C-carbofuran$ was negligible recording only 1.8% of total radioactivity during 20 days after treatment.

• Nuclear Engineering and Technology
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• v.10 no.1
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• pp.13-25
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• 1978

The present paper deals with the measurement of the environmental radioactivity at the Kori nuclear Power Plant site area for the Period of six years from December 1970 to December 1976. Gross alpha activity was measured in samples of airborne particulate. Gross beta measurement was performed on soil, water, airborne perticulate, pine needle, precipitation, fallout (gummed acetate paper) and various foodstuffs. Radioactivities of strontium-90 and cesium-l37 were determined by means of radiochemical analyses in samples of spinach, cabbage, barley, rice in terrestrial food, sea eel, shell fish, dulse, green laver in marine product and milk, and of fallout (cloumn), Furthermore, tritum was also analyzed in water sample of well, stream and sea by electrical enrichment.

• Nuclear Engineering and Technology
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• v.5 no.3
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• pp.240-248
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• 1973

The present report concerns measurement of environmental radioactivity in the Ko-ri nuclear power plant site area. Gross beta measurements have been performed on soil, water, pine needle, and fallout samples collected during the period of December 1970-November 1972. Radioactivities of Strontium-90 and Cesium-137 have been measured by radiochemical analyses on samples of vegetables and marine products collected in 1972. Apparent seasonal variations and overall decrease by the year was also observed from the results of soil, pine needle, and fallout sample measurements respectively.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.519-520
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• 2018