• Proceedings of the Korean Radioactive Waste Society Conference
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• 2016.05a
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• pp.397-398
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• 2016

• 대한방사선방어학회:학술대회논문집
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• 2009.11a
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• pp.64-65
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• 2009

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.105.2-105.2
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• 2007

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2016.05a
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• pp.37-38
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• 2016

• 대한방사선방어학회:학술대회논문집
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• 2010.04a
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• pp.180-181
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• 2010

• Journal of Radiation Protection and Research
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• v.10 no.2
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• pp.96-108
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• 1985

A study for the assessment of natural environmental radiation exposure at a flat and open field of about $10,000m^2$ in area in CNU Daeduk campus has been carried out by means of gamma-ray scintillation spectrometry and thermoluminescence dosimetry for one year period of time from October 1984. The detectors used were 3'${\phi}{\times}$3' NaI(T1) and two different types of LiF TLD, namely, chip sealed in plastic sheet which tightly pressed on two open holes of a metal plate and Teflon disk. Three 24-hour cycles of in-situ spectrometry, and two 3-month and one 1-month cycles of field TL dosimetry were performed. All the spectra measured were converted into exposure rate by means of G(E) opertaion, and therefrom exposure rate due to terrestrial component of environmental radiation was figured out. Exposure rate determined by the spectrometry was, on average, $(10.54{\pm}2.96){\mu}R/hr$, and the rates of $(12.0{\pm}3.4){\mu}R/hr$ and $(11.0{\pm}3.6){\mu}R/hr$ were obtained from chip and disk TLD, respectively. Fluctuations in diurnal variation of the exposure rate measured by the spectrometry were noticeable sometime even in a single cycle of 24 hours. It is concluded that appropriately combined use of TLD with iu-sitn gamma-ray spectrometry system can give more accurate and precise measure of environmental radiation exposure, and further study for more adequate and sensitive TLD for environmental dosimetry, including improvement and elevation of accuracy in data assessment through inter-laboratory or international intercomparison is necessary.

• Journal of Radiation Protection and Research
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• v.34 no.4
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• pp.170-175
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• 2009

For the emergency radiation monitoring using gamma spectrometry, we should sufficiently survey the background spectra as environmental samples with systematic nuclide identification method. In this study, we obtained the gamma ray energy spectrum using a HPGe gamma spectrometry system from an air sample. And we identified nuclide of the gamma ray energy peaks in the spectrum using two methods -1) Half life calculation and 2) survey for cascade coincidence summing peaks using nuclear data. As the results, we produced the nuclide identification results for the air sample.

• Journal of radiological science and technology
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• v.37 no.4
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• pp.261-265
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• 2014

The ${\gamma}$-ray concentration and gross-${\beta}$ activity by age group were measured in the teeth of males and females of the domestic residents. They were divided into 7 age groups from 10s to the age of 70s. The gross-${\beta}$ activity concentration was measured by using the Tennelec XLB measuring instrument filled with P10 gas (argon 90%, methane 10%). The ${\gamma}$-ray was measured through the ${\gamma}$-ray spectroscopic analytical method by using the high purity germanium (HPGe) radiation detector. The range of gross-${\beta}$ activity concentration was measured 0.089 to 0.32 Bq/kg in females and 0.13 to 0.26 Bq/kg in males. From the ${\gamma}$-ray spectroscopic analysis of the teeth, the natural radioactive isotopes of $^{40}K$, $^{208}Tl$, $^{228}Ac$ and $^{234}Th$ were detected and their measured ${\gamma}$-ray activity concentrations were found to be 20.7, 21.9, 3.88 and 5.24 Bq/kg, respectively.

• Journal of Radiation Protection and Research
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• v.34 no.4
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• pp.190-194
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• 2009

Gamma spectral results for macroalgae samples taken from the environment of Ulchin nuclear power plants in Korea (east coast), showed 766 keV peaks, which were identified as $^{95}Nb$ by several research institutes. After the enhancement of liquid radioactive waste disposal facility at Ulchin NPP site, the $^{95}Nb$ amount in the liquid radioactive waste outflow has drastically reduced, but the expected reduction in $^{95}Nb$ specific activity from environmental samples did not actually show up on gamma spectroscopy. Detailed re-investigation revealed that along with 766 keV peak, other peaks (63, 92 and 1001 keV) from $^{234}Th-^{234}mPa$ decay series were also detected on spectroscopy, and that the measured half lives of the four peaks were very close to known half life of $^{234}Th-^{234}mPa$ decay series, which is 24.1 day. The measured gamma yield ratios of 766 keV peak to 1001 peak were very close to known ratio 0.35 for $^{234}mPa$. It is concluded that 766 keV peaks on gamma spectroscopy of Ulchin NPP environmental samples were mainly from $^{234}mPa$, which is one of naturally occurring radionuclides.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.3
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• pp.321-328
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• 2019

The detection performances of the NaI(Tl), $LaBr_3$(Ce) and $CeBr_3$ scintillation detectors, which can be used to rapidly evaluate the major artificial radionuclides deposited on the soil surface in a nuclear accident or radiological emergency, were compared. Detection performance was assessed by calculating the minimum detectable activity (MDA). The detection efficiency of each detector for artificial radionuclides was semi-empirically determined using mathematical modelling and point-like sources having certified radioactivity. The background gamma-ray energy spectrum for MDA evaluation was obtained from relatively wide and flat grassland, and the MDA values of each detector for the major artificial radionuclides that could be released in nuclear accidents were calculated. As a result, the relative MDA values of each detector regarding surface deposition distribution at normal environmental radiation level were evaluated as high in the order of the NaI(Tl), $LaBr_3$(Ce), and $CeBr_3$ detectors. These results were compared based on each detector's intrinsic and measurement environment background, detection efficiency, and energy resolution for the gamma-ray energy region of the radionuclide of interest.