• Title/Summary/Keyword: environmental isotopes

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Determination of a Minimum Detectable Activity through a Measurement of Pu Isotopes in Environmental Samples

  • Lee, M. H.;Jung, E. C.;Song, K.S.
    • Bulletin of the Korean Chemical Society
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    • v.29 no.6
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    • pp.1162-1166
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    • 2008
  • In this paper, several parameters affecting the sensitivity and determining the minimum detectable activity (MDA) for the measurement of the Pu isotopes were investigated. Among the parameters affecting the determination of the MDA values for the Pu isotopes in the environmental samples, amounts of the samples appeared to be crucial factors in decreasing the MDA values. The MDA for the Pu isotopes in the environmental samples were calculated by varying the counting time of the samples and background. The results obtained in this study can be used for an environmental radiation monitoring program regarding the level of concern for a radionuclide beyond which some action may need to be taken.

A STUDY ON THE SIMULTANEOUS MEASUREMENTS OF BETA EMITTING ISOTOPES

  • Lee, Goung-Jin;Kim, Seoung-Pyung
    • Journal of Radiation Protection and Research
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    • v.26 no.3
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    • pp.155-159
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    • 2001
  • Beta radiation is measured for an environmental monitoring purpose or for an internal radiation exposure monitoring of nuclear power plant's worker. In korea, strontium 89 and strontium 90 is measured for an environmental monitoring purpose. Also tritium and carbon 14 contained in urine is measured for an internal radiation exposure monitoring of nuclear power plant's worker. Because above isotopes emits low energy beta radiations having a wide range of energy, very complicated isotope separation preprocess is needed. In this study, two mixed beta emitting isotopes are measured simultaneously using a liquid scintillation counter(LSC) and analyzed by using a developed statistical method. Banded least square method is used to analyze the mixed spectrum, and the goodness-of-fitness test is proposed. Test results show that the developed procedure can be very useful for analyzing a mixed beta emitting isotopes.

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Preliminary studies on the sulfur isotopes and geochemistry of the urban precipitation in Korea

  • Jang, Jae-Ho;Lee, In-Sung;Kim, Gue-Buem
    • Proceedings of the KSEEG Conference
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    • 2003.04a
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    • pp.237-237
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    • 2003
  • Preliminary studies on the seasonal variations in abundance of stable isotopes were carried out on the snow and rainwater samples from urban area. Stable isotopes and other geochemical data as a tool for characterizing the seasonality and source of pollutants were examined in study areas, especially to trace the sources of sulfate in precipitation and to distinguish sulfates of natural and anthropogenic origin. (omitted)

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Establishing of a rapid analytical method on uranium isotopic ratios for the environmental monitoring around nuclear facilities (원자력 시설 주변 환경 감시를 위한 토양 중 우라늄 동위원소 신속 분석법 확립)

  • Park, Ji-Young;Lim, Jong-Myoung;Lee, Hyun-Woo;Lee, Wanno
    • Analytical Science and Technology
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    • v.31 no.3
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    • pp.134-142
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    • 2018
  • The uranium isotopic ratio in environmental samples around nuclear facilities is important because it reveals information regarding illegal activities or anthropogenic pollution. Determination of uranium isotopes, however, is a challenging task requiring much labor and time because of the complex separation procedures and lengthy process. In this study, a rapid determination method for uranium isotopes in environmental samples was developed using. The sample was completely decomposed using the alkali fusion method. The separation procedure using extraction chromatography (UTEVA) was simplified in a single step without any further removal process for Si and major matrix elements. The established method can be completed within 3 h from sample dissolution to ICP-MS measurement. Most matrix elements and uranium isotopes in the soil samples were well separated and purified. Five types of were used to assess the method's accuracy and precision for a rapid uranium analysis method. The analytical accuracy for all CRM samples ranged from 95.1 % to 97.8 %, and the relative standard deviation was below 3.9 %. From the analytical results, one may draw conclusions that the evaluated method for uranium isotopes using alkali-fusion, the extraction chromatography process, and ICP-MS measurements is fast and fairly reliable owing to its recovering efficiencies. Thus, it is expected that the evaluated method can contribute to the improvement of environmental monitoring ability.

Studies on Stream Ecosystem in the Bukhan River using Stable Isotopes (안정동위원소를 이용한 북한강 하천생태계 연구)

  • Kang, Jung-In;Kim, Jae-Gu;Lee, Sang-Don
    • Journal of Wetlands Research
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    • v.13 no.3
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    • pp.515-522
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    • 2011
  • This study examined the epiphytes using stable isotopes. Separated epiphytes should represent the water quality. In study areas, where agricultural paddies were prevailing, biomass of epiphytes can increase nitrogen isotopes(${\delta}^{15}N$) and as a result decrease in carbon isotopes(${\delta}^{13}C$). Naerin stream and Inbuk upper areas showed higher nitrogen isotopes(${\delta}^{15}N$) than in Hangye and Buk stream. Also, stable carbon isotopes(${\delta}^{13}C$) in Naerin stream and Inbuk streams tended to increase than in Hangye and Buk stream. This can indicate the epiphytes can be a good indicator for water quality pollution.

A study on the analysis of uranium isotopes in environmental samples using a kinetic phosphorescence analyzer (반응속도론적 인광 분석기를 이용한 환경 시료 중 우라늄 동위원소 분석에 대한 연구)

  • Lee, Myung-Ho;Park, Ye-Eun;Nam, Jong-Soo;Sohn, Se-Chul;Song, Kyu-Seok
    • Analytical Science and Technology
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    • v.23 no.6
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    • pp.518-523
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    • 2010
  • In this paper, the study of analysis of uranium isotopes in environmental samples with a kinetic phosphorescence analyzer (KPA) was described. After leaching uranium fraction from soil and glass material with microwave acid digestion technology, uranium isotopes were purified with UTEVA column, and then measured using KPA. Linearity and repeatability tests for measurement of uranium isotopes were carried out in the uranium standard solution with KPA. The reliability for analytical method of uranium with KPA was validated by its application to uranium standard solution, ground water, IAEA and NIST reference samples.

A Study on the Environmental Radioactive Strontium Analysis (환경중 방사성 스트론튬 분석 방법 연구)

  • Lee, Goung-Jin;Hwang, Jung-Lae;Chung, Woon-Kwan
    • Journal of Radiation Protection and Research
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    • v.24 no.3
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    • pp.155-160
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    • 1999
  • In the natural, there exist several kinds of radioactive isotopes. From atmospheric weapon tests and then some isotopes are naturally radioactivity above all things, nuclear power plant operation and man-made radioactive isotopes concern steadily growing in the environment. During the fission process of nuclear weapon tests and nuclear power plant operation, more than 200 radioactive isotopes are generated. Among them, $^{90}Sr$ and $^{137}Cs$ has been regarded as very important isotopes due to characteristics. In this paper, a quantitative analysis method of environment low level $^{90}Sr$ is studied. Radioactivity level of the environmental $^{90}Sr$ is very low, and it emits continuous beta spectrum, and $^{90}Sr$ exists together with $^{89}Sr$, $^{90}Y$ and other radioactive isotopes. It very difficult to make the quantitative analysis of $^{90}Sr$. For the analysis of low level radioactive strontium, enrich and chemical separation of strontium from the other radioactive isotopes are needed. For the estimation of strontium recovery ratio, so called SGAT(Strontium Gravimetric Analysis Technique) was generally used among the domestic research groups, and chemical procedures were developed appropriation for the SGAT, Recently, by using ICP(Inductively Coupled atomic Plasma emission spectrophotometer), amounts of stable atoms can be measured easily and accurately to the extend of ppm or ppb. In this paper, new chemical procedures are developed to exploits the ICP technique. New developed method has simpler chemical treatment procedures and then it gives more accurate results compared with the traditional SGAT.

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Comparison between Total Least Squares and Ordinary Least Squares for Linear Relationship of Stable Water Isotopes (완전최소자승법과 보통최소자승법을 이용한 물안정동위원소의 선형관계식 비교)

  • Lee, Jeonghoon;Choi, Hye-Bin;Lee, Won Sang;Lee, Seung-Gu
    • Economic and Environmental Geology
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    • v.50 no.6
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    • pp.517-523
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    • 2017
  • A linear relationship between two stable water isotopes, oxygen and hydrogen, has been used to understand the water cycle as a basic tool. A slope and intercept from the linear relationship indicates what kind of physical processes occur during movement of water. Traditionally, ordinary least squares (OLS) method has been utilized for the linear relationship, but total least squares (TLS) method provides more accurate slope and intercept theoretically because isotopic compositions of both oxygen and hydrogen have uncertainties. In this work, OLS and TLS were compared with isotopic compositions of snow and snowmelt collected from the King Sejong Station, Antarctica and isotopic compositions of water vapor observed by Lee et al. (2013) in the western part of Korea. The slopes from the linear relationship of isotopic compositions of snow and snowmelt at the King Sejong Station were estimated to be 7.00 (OLS) and 7.16(TLS) and the slopes of stable water vapor isotopes were 7.75(OLS) and 7.87(TLS). There was a melting process in the snow near the King Sejong Station and the water vapor was directly transported from the ocean to the study area based on the slope calculations. There is no significant difference in two slopes to interpret the physical processes. However, it is necessary to evaluate the slope differences from the two methods for studies for example, groundwater recharge processes, using the absolute slope values.

Methodological Study on Measurement of Hydrogen Abundance in Hydrogen Isotopes System by Low Resolution Mass Spectrometry

  • Lia, Jin-Ying;Shib, Lei;Hub, Shi-Lin
    • Mass Spectrometry Letters
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    • v.2 no.1
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    • pp.1-7
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    • 2011
  • China's rapid economic growth has resulted in significant environmental side effects. Therefore, China has been interested in reducing her dependence on foreign oil and gas by developing technologies needed for hydrogen, in addition to her increasing energy mix of nuclear and renewable energy form, such as solar and wind power. There are three isotopes of hydrogen, i.e. protium (P or H), deuterium (D), and tritium (T). Both deuterium and tritium are important materials in nuclear fuel cycle industry. Tritium is one of the critical radioactive nuclides. Planning for and implementing contamination control as a part of normal operation and maintenance activities is an important function in any hydrogen facility, especially tritium facility. The development of hydrogen isotopes analysis is the key issues in this area. Mass spectrometry (MS) with medium (about 600) and high resolution (> 1,400) is commercially available; however, the routine analysis of hydrogen isotopes is done with low-resolution MS (< 200) in China. This paper summarizes the progress of MS measurement technology for hydrogen isotope abundance in China, focusing on our lab's research program and technical status. An analyzing method has been introduced for accurate measurement of tritium abundance in the H.D.T system by low resolution MAT-253 MS. The quotient of compression ratio coefficient is determined by building up equipment for laboratory-scale preparation of secondary standard gases and by considering the difference in sensitivity between hydrogen isotopes. The results show that the measured value is reproducible within the relative error range of 0.8% for gas samples of different tritium abundance.