• Title/Summary/Keyword: radionuclides

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Radiation Dosimetry for Radionuclide Therapy (동위원소 치료 관련 방사선 흡수선량평가)

  • Kim, Eun-Hee
    • 대한핵의학회:학술대회논문집
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    • 2001.05a
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    • pp.4-10
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    • 2001
  • The radionuclide therapy is a protocol for tumor control by administering radionuclides as the cytotoxic agents. Radionuclides concentrated at the site of cancerous lesion are expected to kill the cancerous cells with minimal injury to the normal tissue. The efficacy of every radionuclide treatment can be evaluated by examining the toxicity to the lesion differentiated from that to the normal tissue. Radiation dosimetry is the procedure of quantitating the energy absorbed by target volumes of interest. Dosimetric information plays an indicator of the expected radiation damage and thus the therapeutic efficacy. This paper summarizes the dosimetric aspects in radionuclide therapy in terms of radionuclides of use, radiation dosimetry methodology and considerations for each treatment in practical use.

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PRIMORDIAL RADIONUCLIDES DISTRIBUTION AND DOSE EVALUATION IN UDAGAMANDALAM REGION OF NILGIRIS IN INDIA

  • Manikandan, N.Muguntha;Selvasekarapandian, S.;Sivakumar, R.;Meenakshisundaram, V.;Raghunath, V.M.
    • Journal of Radiation Protection and Research
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    • v.26 no.3
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    • pp.183-190
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    • 2001
  • The activity concentration of primordial radionuclides i.e., $^{238}U$ series, $^{232}Th$ series and $^{40}K$, in soil samples collected from Udagamandalam environment, have been measured by employing NaI (Tl) Gamma ray Spectrometer. The absorbed gamma dose rate has also been simultaneously measured by using both Environmental Radiation Dosimeter at each soil sampling location (ambient gamma dose) as well as from the gamma dose derived from the activity concentration of the primordial radionuclides. The results of activity concentration of each radio nuclides in soil, absorbed dose rate in air due to soil activity and possible cosmic radiation at each location along with human effective dose equivalent for Udagamandalam environment are presented and discussed.

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고분자 물질을 사용한 토양 중 방사성 핵종의 고정화

  • 원휘준;김계남;김민길;오원진
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.09a
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    • pp.293-297
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    • 2003
  • A series of laboratory experiments was conducted to investigate the fixation characteristics of poly(vinylalcohol)-poly(methacrylic acid)(PVA-PMAA) mixed solution on the soluble (equation omitted)-radionuclides. Using the potentiometric titration technique, it was found out that the PVA and PMAA in a solution form intermacromolecular complex. The mobilized portion of each radionuclide by water from sand surface treated with a fixative was measured by ${\gamma}$-ray spectroscopy, The mobilized portion of minor radionuclides such as $^{241}$ Am, $^{154}$ Eu, $^{155}$ Eu and $^{144}$ Ce were higher than those of $^{134}$ Cs and $^{137}$ Cs. The capability of PVA-PMAA system was better among the candidate solutions for the fixation of total (equation omitted)-radioactivity, $^{134,137}$Cs which is composed of more than 85 % of total ${\gamma}$-radioactivity could be fixed effectively by the PVA-PMAA solution.

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Soil Washing에 의한 세슘과 코발트 오염 토양 복원기술 개발

  • 김계남;원휘준;오원진;김민길
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.04a
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    • pp.337-339
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    • 2003
  • The technology removing radionuclides from soil using soil washing was studied. The main radionuclides contaminated in the soil are Cs$^{137}$ and Co$^{60}$ . It is suitable that scrubbing time is 4 hours and a mixing ratio of soil weight and washing solution volume is 1:10. more than two times continuous scrubbing method with 0.5 M oxalic acid was needed to remove Cs$^{137}$ and Co$^{60}$ from soil more than 70%. Radionuclides removal efficiencies of recycling washing solutions recycled with strong acid resins until 5 times are similar to that of 0.5 M oxalic acid.

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Fixation of $\gamma$-Radionuclides by the PVA-PMAA System

  • Won, Hui-Jun;Ahn, Byung-Gil;Jung, Chong-Hun;Kim, Gye-Nam;Oh, Won-Zin
    • Nuclear Engineering and Technology
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    • v.32 no.3
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    • pp.205-213
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    • 2000
  • A series of laboratory experiments was conducted to investigate the fixation characteristics of poly(vinylalcohol)-poly(methacrylic acid)(PVA-PMAA) mixed solution on the soluble ${\gamma}$- radionuclides. Using the potentiometric titration technique, it was found out that the PVA and PMAA in a solution form intermacromolecular complex. The mobilized portion of each radionuclide by water from sand surface treated with a fixative was measured by ${\gamma}$-ray spectroscopy. The mobilized portion of minor radionuclides such as 241Am, 154Eu, 155Eu and 144Ce were higher than those of 134Cs and 137Cs. The capability of PVA-PMAA system was better among the candidate solutions for the fixation of total ${\gamma}$-radioactivity. 134,137Cs which is composed of more than 85 % of total ${\gamma}$-radioactivity could be fixed effectively by the PVA-PMAA solution.

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Radionuclide Transport Mediated by Pseudo-Colloid in the fractured Rock Media : Model Development

  • Baik, Min-Hoon;Hahn, Phil-Soo
    • Proceedings of the Korean Nuclear Society Conference
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    • 1995.05b
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    • pp.769-774
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    • 1995
  • In this study, a transport model was developed in order to analyze and predict the transport behaviors of radionuclides mediated by pseudo-colloid in the fractured rock media. It was resulted that the transport of Pu-239 was faster than Ni-63 because pseudo-colloid formation constant of Pu-239 was greater than that of Ni-63. Also, the effect of pseudo-colloid formation on the transport of a radionuclide was shown to be very significant when the apparent pseudo colloid formation constant, $K_{ap}(m^{3}/kg)$, was greater than 100. Thus, it can be concluded that acceleration of radionuclide migration may be occurred because the pseudo-colloid formation of radionuclides increases the amount of mobile components in the solution and consequently decreases the amount of radionuclides adsorbed on the stationary solid medium.

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A Pathway Analysis Model for Determining Acceptable Levels of Contamination of Radionuclides in Soil (토양의 방사능오염 허용기준치 설정을 위한 피폭경로모델)

  • Lee, Chang-Woo;Kim, Kug-Chan;Lee, Jeong-Ho
    • Journal of Radiation Protection and Research
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    • v.15 no.2
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    • pp.67-74
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    • 1990
  • A methodology for calculating acceptable levels of contamination of radionuclides in soil for unrestricted use was described. Pathways of exposure include direct radiation from ground surfaces, ingestion of contaminated food and inhalation of resuspended radionuclides. Results calculated using site-specific data for Korean environment were discussed and compared with those estimated by other guidelines.

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Estimation of Effective Dose to Residents Due to Hypothetical Accidents During Dismantling of Steam Generator

  • Kyeong-Ju Lee;Chang-Lak Kim
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.21 no.2
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    • pp.183-191
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    • 2023
  • The potential impact of hypothetical accidents that occur during the immediate and deferred dismantling of the Kori Unit 1 steam generator has been comprehensively evaluated. The evaluation includes determining the inventory of radionuclides in the Steam Generator based on surface contamination measurements, assuming a rate of release for each accident scenario, and applying external and internal exposure dose coefficients to assess the effects of radionuclides on human health. The evaluation also includes calculating the atmospheric dispersion factor using the PAVAN code and analyzing three years of meteorological data from Kori NPP to determine the degree of diffusion of radionuclides in the atmosphere. Overall, the effective dose for residents living in the Exclusion Area Boundary (EAB) of Kori NPP is predicted, an it is found that the maximum level of the dose is 0.034% compared to the annual dose limit of 1 mSv for the general public. This implies that the potential impact of hypothetical accidents on human health discussed above is within acceptable limits.

Radioactivity concentrations of natural radionuclides in fine dust of Jeju, Korea

  • Chung-Hun Han;Sohyeon Lim;Hee-Jung Im
    • Analytical Science and Technology
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    • v.36 no.4
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    • pp.191-197
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    • 2023
  • Radioactivity concentrations for natural radionuclides were determined from fine dust samples collected in Jeju, Korea according to atmospheric events (Asian dust, haze, fog-mist, and non-event), and radium equivalent activity was calculated. The mean atmospheric radioactivity concentrations for 238U, 232Th, and 40K in 127 fine dust samples were 0.49, 0.24, and 7.23 µBq m-3, respectively, and the radium equivalent activity was 33.25 Bq kg-1. The mean concentrations of 238U and 232Th in the fine dust during the Asian dust period were 1.31 and 1.60 µBq m-3, respectively, above the global average, while the values for the other three atmospheric events were lower. The ratio of 232Th/238U radioactivity during the Asian dust period was 1.22, higher than the ratio for the other three atmospheric events.

Evaluation of the Safty for the Disposal of High-level Nuclear Waste in the Granite (화강암지역에 고준위 원자력 폐기물 처리에 대한 안정성 평가)

  • Oh, Chang Whan
    • Economic and Environmental Geology
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    • v.29 no.2
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    • pp.215-225
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    • 1996
  • All the radionuclides in high-level nuclear waste will decay to harmless levels eventually but for some radionuclides decay is so slow that their radiation remains dangerous for times on the order of tens or hundreds of thousands of years. At the present time, the most favorite disposal plan for high-level radioactive waste is a mined geological disposal in which canister enclosing stable solid form of radioactive waste is placed in mined cavities locating hundred meters below the surface. The chief hazard in such disposal is dissolution of radionuclides from the waste in the groundwater that will eventually carry the dissolved radionuclides to surface environments. The hazard from possible escape of the radionuclides through groundwater can be delayed by engineered and geologic barriers. The engineered barriers can become useless by unexpected geologic catastrophe such as volcanism, earthquake, and tectonic movement and by fraudulent work such as careless construction, improperly welded canisters within the first few decades or centuries. As a result, dangerously radioactive waste which is still intensively radioactive is directly exposed to attack by moving groundwater. All the more, it is almost impossible to control repositories for times more than 10,000 years. Therefore, naturally controlled geologic, barriers whose properties will not be changed within 10,000 years are important to guarantee the safety of repositories of high-level radioactive waste. In Sweden and France, the suitability of granite for the mined geological disposal of high-level waste has been studied intensively. According to the research in Sweden and France, granites has the following physio-chemical characteristics which can delay the transportation of radionuclide by groundwater. First, the permeabilities of granites decreases as the depth increases and is $10^{-8}{\sim}10^{-12}m/s$ at depth below 300 m. Second, groundwater at depth below 300 m has pH=7-9 and reducing condition (Eh=-0.1~0.4). This geochemical condition is desirable to prevent both canister and solid waste from corrosion. Third most radionuclides are not transported by low solubilities and some radionuclide with high solubility such as Cs and Sr are retarded by absorption of geologic media through which ground water flows. Therefore, if high-level waste is disposed at depth below 300 m in the granite body which has a low permeability and is geologically stable more than 10,000 years, the safety of repositories from the hazard due to radionuclide escape can guaranteed for more than 10,000 years.

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