• 제목/요약/키워드: Radionuclides

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The Prediction Methods of Iodine-129 release rate : Model Development

  • Park, Jin-Beak;Lee, Kun-Jai;Kang, Duck-Won;Shin, Sang-Woon;Park, Kyung-Rok
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1995년도 추계학술발표회논문집(2)
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    • pp.879-884
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    • 1995
  • The results of performance assessment analyses have shown that the long-lived radionuclides such as I-129 control the potential individual dose impact to the public. I-129 is difficult-to-measure(DTM) in low-level waste because it is non-gamma emitting radionuclides and exists at extremely low concentrations in radioactive waste generated by nuclear reactors. In this study, computer modeling technique to predict release rate of I-129 is developed to provide another tools far performance assessment of land disposal facilities and characteristics of radwaste. Model suggested in this study will give conservative values of I-129 release rate far determination of radwaste characteristics. More detailed approach is implemented to account for release conditions of fuel source-nuclides. 1-131 concentration measured from reactor coolant and released fraction from tramp fuel have dominant roles in calculating release rate of I-129 with fuel defect conditions.

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5-Bromo-Ph4-BTPhen Ligand for Selective Removal of Strontium and Cobalt From Water

  • Jang, Jiseon;Harwood, Laurence M.;Cowell, Joe;Afsar, Ashfaq;Lee, Dae Sung
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2018년도 춘계학술논문요약집
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    • pp.183-183
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    • 2018
  • In this study, 5-bromo-2,9-bis(5,6-diphenyl-1,2,4-triazin-3-yl)-1,10-phenanthroline (5-bromo-Ph4-BTPhen) was synthesized and evaluated for its ability to remove major radionuclides ($Cs^+$, $Sr^{2+}$, and $Co^{2+}$). The synthesized ligand removed both $Sr^{2+}$ and $Co^{2+}$ from $1mg\;L^{-1}$ aqueous solutions with extraction efficiencies of up to 99% at neutral and alkaline pH. The $Sr^{2+}$ and $Co^{2+}$ removal efficiencies decreased as a consequence of the higher bonding strengths of competing metal ions to the N-donor atoms in the cavity of the ligand; competing divalent ions affected the $Sr^{2+}$ and $Co^{2+}$ removal efficiencies more than monovalent ions.

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Decontamination of spent ion exchange resins contaminated with iron-oxide deposits using mineral acid solutions

  • Tokar, E.A.;Matskevich, A.I.;Palamarchuk, M.S.;Parotkina, Yu.A.;Egorin, A.M.
    • Nuclear Engineering and Technology
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    • 제53권9호
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    • pp.2918-2925
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    • 2021
  • The efficiency of decontamination of model spent ion exchange resins, contaminated with magnetite and hematite, with mineral acid solutions, and using electro-decontamination, was evaluated. It has been shown that effective hematite dissolution occurs in concentrated mineral acid solutions. However, the use of direct current increases the decontamination efficiency of spent ion exchange resins contaminated with hematite. It is determined that with increasing voltage and acid concentration, the dissolution efficiency of hematite deposits increases and can exceed 99%. It has been shown that hematite dissolution is accompanied by secondary adsorption of radionuclides due to ion exchange, which can be removed with sodium nitrate solutions.

Long term activity measurement of the primary circuit water on the LVR-15 research reactor

  • Ladislav Viererbl;Vit Klupak;Hana Assmann Vratislavska
    • Nuclear Engineering and Technology
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    • 제56권4호
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    • pp.1250-1253
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    • 2024
  • Activity measurement of the primary circuit water of fission reactors is one method that can provide early detection of a damaged fuel assembly in the reactor core. This is an important aspect in the safe operation of the reactor and for radiation protection of staff. Radionuclides in the primary circuit water are produced by the activation of stable nuclides and the fission of fissile nuclides, mainly the isotope 235U. In the LVR-15 research reactor, measurement of the activity of the primary circuit water has been regularly undertaken since 1996. A water sample is taken from the primary circuit every week and the activities are measured four days later using gamma spectrometry. The results of these long-term measurements from 1996 to 2022 are presented. The activity time dependences of the individual radionuclides are discussed in relation to fuel assembly damage and for events connected to contamination of the water by objects inserted into the primary circuit during experiments carried out near the reactor core.