• Journal of Korean Society for Atmospheric Environment
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• v.16 no.5
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• pp.453-467
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• 2000

The aim of this research is to collect and characterize fine particles (FPM:$\leq$2.5${\mu}{\textrm}{m}$) and coarse particles (CPM: 2.5~10${\mu}{\textrm}{m}$) using a low volume air sampler provided by the IAEA, at urban (Taejon) and rural area(Wonju) for a period of about two years(April 1996 to May 1998) and to promote a use of nuclear analytical techniques for air pollution studies. For the collection of airborne particulate matter (PM(sub)10), the Gent stacked filter unit sampler and polycarbonate membrane filters were employed. The concentration of trace elements in collected APM samples were determined byu instrumental Neutron Activation Analysis. For validation of the analytical data, internal quality control were implemented by using both the comparison of the analytical results of standard reference materials(NIST SRM 1648) and interlaboratory comparison for proficiency test (NAT-3). The standard uncertainty was less than 15% and Z-score of two samples were within $\pm$1. The monitoring of (PM(sub)10) mass concentration and elemental concentrations were carried out weekly. The average mass concentration of (PM(sub)10) in urban and rural areas were 59.2$\pm$36.5$\mu\textrm{g}$/㎥ and 41.4$\pm$23.7$\mu\textrm{g}$/㎥, respectively. To investigate the emission source, the enrichment factors were calculated for the fine and coarse particle fractions at two sites, respectively and these values were classified for anthropogenic and soil origin elements.

• Journal of Radiation Protection and Research
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• v.15 no.2
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• pp.17-25
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• 1990

Rats were ingested in drinking water 600mg/L of cadmium chloride solution during 3 months, then the distribution of Cd in major organs and hair were determined by neutron activation analysis. The results were as followings. 1. After administration for 24 hours using $^{115m}Cd$ as tracer, the distribution of blood was 0.03%, kidney 2.99% and liver 3.50% to determine with whole body counter. 2. Cd metal was rapidly excreted with kidney through blood and their accumulation appeared in liver and hair. 3. The comparative data to determine using neutron activation analysis. the content of cadmium of major organs in rats ingested of $CdCl_2$ during 3 month were shown to increase significantly both hair and liver. Above facts, hair samples were able to use as the diagnostic index to evaluate the accumulation of cadmium in liver.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.3
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• pp.265-272
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• 1989

The objective of this study was to investigate the contents of some minerals in vegetable foods by a highly sensitive Neutron Activation Analysis. Chinese Chives, Amaranth, Mugwort, Ginger, Garlic, Root of bellflower, Cultured Duduk, Wild Duduk and Cortinellus-edodes were chosen as experimental materials for this study. The contents of potassium, copper, molybdenum, and bromum were 7099.1mg%, 104.8 ppm, 45.4ppm and 40.4ppm in Chinese Chives. Chinese Chives, Amaranth and Mugwort were more abundant with iron, coppr and cobalt other than vegetable foods. The ratio of sodium to potassium for Chinese Chives was 1 to 796, for Mugwort : 1 to 147 and for Garlic : 1 to 148. As the Neutron Activation Analysis Technique was able to detect gold, samarium, bromum, lanthanum and scandium from vegetable foods, this technique is very useful to analyse the infinitestimal elements in foods.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.390-395
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• 2002

Concentrations of minerals (Ca, K, Mg, Na, Se, Zn, Fe, and Mn) in 50 different Korean foodstuffs were determined through neutron activation analysis. To check the accuracy of this method, the U.S. NIST standard reference materials were analyzed. Anchovy, sesame, perilla, and laver were found to contain relatively higher concentrations of Ca, Mg, Fe, and Zn than the other foodstuffs.

• Nuclear Engineering and Technology
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• v.40 no.1
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• pp.93-98
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• 2008

Several adhesive tapes have been studied in terms of their suitability for securing gold wires into positions for neutron flux measurements in the reactor core and irradiation facilities surrounding the core of the Open Pool Australian Light water (OPAL) reactor. Gamma ray spectrometry has been performed on each irradiated tape in order to identify and quantify activated components. Numerous metallic impurities have been identified in all tapes. Calculations relating to both the effective neutron shielding properties of the tapes and the error in measurement of the $^{198}Au$ activity caused by superfluous activity due to residual tape have been made. The most important identified effects were the prolonged cooling times required before safe enough levels of radioactivity to allow handling were reached, and extra activity caused by residual tape when measured with an ionisation chamber. Knowledge of the most suitable tape can allow a minimal contribution due to these effects, and the use of gamma spectrometry in preference to ionisation chamber measurements of the flux wires is shown to make all systematic errors due to the tape completely negligible.

• Nuclear Engineering and Technology
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• v.43 no.6
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• pp.583-592
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• 2011

The radiological characteristics for waste classification were assessed for neutron-activated decommissioning wastes from a CANDU reactor. The MCNP/ORIGEN2 code system was used for the source term analysis. The neutron flux and activation cross-section library for each structural component generated by MCNP simulation were used in the radionuclide buildup calculation in ORIGEN2. The specific activities of the relevant radionuclides in the activated metal waste were compared with the specified limits of the specific activities listed in the Korean standard and 10 CFR 61. The time-average full-core model of Wolsong Unit 1 was used as the neutron source for activation of in-core and ex-core structural components. The approximated levels of the neutron flux and cross-section, irradiated fuel composition, and a geometry simplification revealing good reliability in a previous study were used in the source term calculation as well. The results revealed the radioactivity, decay heat, hazard index, mass, and solid volume for the activated decommissioning waste to be $1.04{\times}10^{16}$ Bq, $2.09{\times}10^3$ W, $5.31{\times}10^{14}\;m^3$-water, $4.69{\times}10^5$ kg, and $7.38{\times}10^1\;m^3$, respectively. According to both Korean and US standards, the activated waste of the pressure tubes, calandria tubes, reactivity devices, and reactivity device supporters was greater than Class C, which should be disposed of in a deep geological disposal repository, whereas the side structural components were classified as low- and intermediate-level waste, which can be disposed of in a land disposal repository. Finally, this study confirmed that, regardless of the cooling time of the waste, 15% of the decommissioning waste cannot be disposed of in a land disposal repository. It is expected that the source terms and waste classification evaluated through this study can be widely used to establish a decommissioning/disposal strategy and fuel cycle analysis for CANDU reactors.

• Journal of Environmental Health Sciences
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• v.28 no.3
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• pp.64-71
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• 2002

Hair provides important information about the body's mineral status. Therefore, we have studied the trace elemental distribution in human hair under different inhalation and ingestion environment using neutron activation analysis (NAA). NAA is a powerful analytical method which can be used successfully to determine trace elements in environmental and biological materials. Total diet and six different herbal medicine were analysed to study ingestion environment. Airborne dust in foundry was analysed and compared with outdoor dust to study inhalation environment. Human hairs of common person, herbal medicine taker and foundry worker were analysed to estimate the trace elemental distribution of people under different inhalation and ingestion environment. Analytical results show that herbal medicines contain higher micronutrients such as Ca, Mg, Mn and Cu that total diet and airborne dust in foundry has high Cr. The concentration of Ca, Mg and Mn in hair of herbal medicine taker is two times higher than in hair of common person and Cr con-centration in hair of foundry worker is about three times higher than in hair of common person. These results show that NAA can be used importantly to monitor human health through biological and environmental samples.

• Korean Journal of Food Science and Technology
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• v.3 no.3
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• pp.144-149
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• 1971

The sensitive technique of activation analysis is well suited for this study since the elements such as As, Br, and Se in tobaccoes are expected to be high concentration. As, Br, and Hg were determined by Bethge destruction method and subsequent neutron activation analysis. $^{77m}Se$ was also by non-destruction activation analysis. The quantities of the element determined in Korean tobaccoes are given as follows in ppm: As, 0.65 ppm. Hg, 0.74 ppm. Se, 1.18 ppm. Br, 7.1 ppm. From the date given it seems that Korean tobaccoes and foreign tobaccoes contained considerably high concentration of selenium and mercury.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.462-468
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• 2022

The selection and effective utilization of peak-fitting software for conventional gamma-ray spectrum analysis is significant for accurate determination of the mass fraction of elements, particularly in complex peak regions. Majority of the peak-fitting programs can derive similar peak characteristics for singlet peaks, but very few programs can deconvolute multi-peaks in a complex region. The deconvolution of multi-peaks requires special peak-fitting functions, such as left and right-skew distributions. In the this study, 843.76 keV (²⁷Mg) peak area from the complex region (840 keV-850 keV) determined and compared using four different peak-fitting programs, namely, GammaVision, Genie2000, HyperLab, and HyperGam. The 843.76 keV peak interfered with 841.63 keV (^152mEu) and 846.81 keV (⁵⁶Mn). The total Mg concentration was determined through k₀-instrumental neutron activation analysis by applying the isotopic interference correction factor ²⁷Al(n,p)²⁷Mg through the simultaneous determination of Al concentration. HyperLab and HyperGam peak-fitting programs reported consistent peak areas, and resultant concentrations agreed with the certified values of matrix-certified reference materials.

• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1708-1717
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• 2023

The grade analysis of lead-zinc ore is the basis for the optimal development and utilization of deposits. In this study, a method combining Prompt Gamma Neutron Activation Analysis (PGNAA) technology and machine learning is proposed for lead-zinc mine borehole logging, which can identify lead-zinc ores of different grades and gangue in the formation, providing real-time grade information qualitatively and semi-quantitatively. Firstly, Monte Carlo simulation is used to obtain a gamma-ray spectrum data set for training and testing machine learning classification algorithms. These spectra are broadened, normalized and separated into inelastic scattering and capture spectra, and then used to fit different classifier models. When the comprehensive grade boundary of high- and low-grade ores is set to 5%, the evaluation metrics calculated by the 5-fold cross-validation show that the SVM (Support Vector Machine), KNN (K-Nearest Neighbor), GNB (Gaussian Naive Bayes) and RF (Random Forest) models can effectively distinguish lead-zinc ore from gangue. At the same time, the GNB model has achieved the optimal accuracy of 91.45% when identifying high- and low-grade ores, and the F₁ score for both types of ores is greater than 0.9.