• Title/Summary/Keyword: radionuclides

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Adsorption Characteristics of Cobalt, Strontium, and Cesium on Natural Soil and Kaolin (자연토양 및 카올린에 대한 코발트, 스트론튬, 세슘의 흡착 특성)

  • Cheon, Kyeong Ho;Choi, Jeong-Hak;Shin, Won Sik;Choi, Sang June
    • Journal of Environmental Science International
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    • v.23 no.9
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    • pp.1609-1618
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    • 2014
  • In this study, as a fundamental study for the remediation of the radionuclides-contaminated soil, the adsorption of cobalt, strontium, and cesium on natural soil and kaolin were experimently investigated and adsorption characteristics were evaluated by using several adsorption kinetic and isotherm models. The pseudo-first-order kinetic model (PFOM), pseudo-second-order kinetic model (PSOM), one-site mass transfer model (OSMTM), and two compartment first-order kinetic model (TCFOKM) were used to evaluate the kinetic data and the pseudo-second-order kinetic model was the best with good correlation. The adsorption equilibria of cobalt, strontium, and cesium on natural soil were fitted successfully by Redlich-Peterson and Sips models. For kaolin, the adsorption equilibria of cobalt, strontium, and cesium were fitted well by Redlich-Peterson, Freundlich, and Sips models, respectively. The amount of adsorbed radionuclides on natural soil and kaolin was in the order of cesium > strontium > cobalt. It is considered that these results could be useful to predicting the adsorption behaviors of radionuclides such as cobalt, strontium, and cesium in soil environments.

Radionuclides in Environmental Samples and Sample Concentration of Land in the Analysis in the Method of Direct (직접법에서 환경시료중 육상시료의 방사성 핵종 및 농도 분석)

  • Jang, Eun-Sung;Kim, Jin-Seop
    • Journal of Environmental Science International
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    • v.24 no.3
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    • pp.275-280
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    • 2015
  • In order to measure the Radionuclides and Concentration, the directly grinded land samples (river soil, pine leaves and mugwort) among the environment samples around the nuclear power plant were filled in a 450 mL Marinelli beaker and weighed to obtain the dry mass ratio of the samples. Then the background and land samples were measured for 80,000 sec. The analysis of the collected land samples showed that most of them contained less radiation nuclide than the detection minimum limit in the 'Ministry of Education, Science and Technology Public Notice No. 2010-32.'In others, the natural radionuclides $^{40}K$ were detected. Of the products of nuclear reaction discharged by a nuclear reaction, $^{134}Cs$ and $^{137}Cs$ are more easily detected, and their discharge sources can be traced using the relative ratio. Although the radioactive concentration in the vicinity of Kori Nuclear Power Plant, which is more than 1,100km away from Fukushima, the Japanese nuclear accident site, continuous monitoring is needed as the radionuclides can still be accumulated in the soil or animals and plants.

Therapeutic radionuclides (치료용 방사성동위원소)

  • Choi, Sun-Ju;Hong, Young-Don;Lee, So-Young
    • Nuclear Medicine and Molecular Imaging
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    • v.40 no.2
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    • pp.58-65
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    • 2006
  • Since the development of sophisticated molecular carriers such as octereotides for peptide receptor targeting and monoclonal antibodies against various antigens associated with specific tumor types, radionuclide therapy (RNT) employing open sources of therapeutic agents is promising modality for treatment of tumors. furthermore, the emerging of new therapeutic regimes and new approaches for tumor treatment using radionuclide are anticipated in near future. In targeted radiotherapy using peptides and other receptor based tarrier molecules, the use of radionuclide with high specific activity in formulating the radiopharmaceutical is essential in order to deliver sufficient number of radionuclides to the target site without saturating the target. In order to develop effective radiopharmaceuticals for therapeutic applications, it is crucial to carefully consider the choice of appropriate radionuclides as well as the tarrier moiety with suitable pharmacokinetic properties that could result in good in vivo localization and desired excretion. Up to date, only a limited number of radionuclides have been applied in radiopharmaceutical development due to the constraints in compliance with their physical half-life, decay characteristics, cost and availability in therapeutic applications. In this review article, we intend to provide with the improved understanding of the factors of importance of appropriate radionuclide for therapy with respect to their physical properties and therapeutic applications.

Analysis of ultra-low radionuclide concentrations in water samples with baromembrane method

  • Vasyanovich, Maxim;Ekidin, Aleksey;Trapeznikov, Alexander;Plataev, Anatoly
    • Nuclear Engineering and Technology
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    • v.53 no.1
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    • pp.253-257
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    • 2021
  • This work demonstrates the use of baromembrane method based on reverse osmosis (RO) process. The method is realized on mobile complex, which allows to concentrate and determine ultra-low activity of radionuclides in water cooling ponds of Russian nuclear fuel cycle enterprises. The existence level of radionuclide background creates difficult conditions for identification the contribution of liquid discharges enterprise, as standard monitoring methods have a very high detection level for radionuclides. Traditional methods for determining the background radionuclides concentrations require the selection of at least 500 liters (l) of water, followed by their evaporation to form a dry residue. This procedure with RO membranes requires at least 5 days. It is possible to reduce the time and energy spent on evaporation of hundreds of water liters by pre-concentrating radionuclides in a smaller sample volume with baromembrane method. This approach allows preliminary concentration of water samples from 500 l volume till 20 l volume during several hours. This approach is universal for the concentration of dissolved salts of any heavy metals, other organic compounds and allows the preparation of water countable samples in much shorter time compared to the traditional evaporation method.

Review of Potential Import Restrictions by Japan on Korean Fishery Products - A Focus on Radionuclides Dispute between Korea and Japan - (일본의 한국산 수산물 수입규제 가능성 검토 - 한·일 방사능 분쟁을 중심으로 -)

  • Lim, Byeong-Ho;Hong, Suk-Gu;Yoo, Jin-Hee
    • Korea Trade Review
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    • v.44 no.6
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    • pp.119-134
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    • 2019
  • This study focuses on a recent WTO SPS dispute related to Korea Import Bans and Testing and Certification Requirements for Radionuclides (DS495) in order to learn from the case and take proactive measures to prevent potential import restrictions by Japan on Korean seafood. Korean-Radionuclides (Japan) emphasizes the importance of sufficient scientific evidence, especially scientific information from relevant international organizations, in an effort to take preventive measures towards Japan's restrictions on Korean seafood imports. Japan claims that a novel parasite, Kudoa septempuctata, in Korean flatfish causes food poisoning. As food poisoning is a serious concern, there is a low possibility that Japan's enhanced monitoring measures would be more trade restrictive than required as prescribed in Article 5.6 of the WTO SPS Agreement. In addition, Korea is the biggest exporter of olive flounder to Japan. Hence, the possibility that similar conditions could be established is low in relation to non-discriminatory principles under the WTO SPS Agreement. Accordingly, we should collect relevant scientific evidence, improve domestic sanitary management of fishery products, and seek export diversification so that we prepare for potential import restrictions by Japan and minimize implications.

Numerical Modelling of Radionuclide Migration for the Underground Silo at Near-Field

  • Myunggoo Kang;Jaechul Ha
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.21 no.4
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    • pp.465-479
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    • 2023
  • To ensure the safety of disposal facilities for radioactive waste, it is essential to quantitatively evaluate the performance of the waste disposal facilities by using safety assessment models. This paper addresses the development of the safety assessment model for the underground silo of Wolseong Low-and Immediate-Level Waste (LILW) disposal facility in Korea. As the simulated result, the nuclides diffused from the waste were kept inside the silo without the leakage of those while the integrity of the concrete is maintained. After the degradation of concrete, radionuclides migrate in the same direction as the groundwater flow by mainly advection mechanism. The release of radionuclides has a positive linear relationship with a half-life in the range of medium half-life. Additionally, the solidified waste form delays and reduces the migration of radionuclides through the interaction between the nuclides and the solidified medium. Herein, the phenomenon of this delay was implemented with the mass transfer coefficient of the flux node at numerical modeling. The solidification effects, which are delaying and reducing the leakage of nuclides, were maintained the integrity of the nuclides. This effect was decreased by increasing the half-life and the mass transfer coefficient of radionuclides.

Influence of operation of thermal and fast reactors of the Beloyarsk NPP on the radioecological situation in the cooling pond. Part 1: Surface water and bottom sediments

  • Panov, Aleksei;Trapeznikov, Alexander;Trapeznikova, Vera;Korzhavin, Alexander
    • Nuclear Engineering and Technology
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    • v.54 no.8
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    • pp.3034-3042
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    • 2022
  • The results of radioecological monitoring of the cooling pond Beloyarsk NPP (Russia) have been presented. The influence of waste technological waters of thermal and fast NPP reactors on the content of artificial radionuclides in surface waters and bottom sediments of the Beloyarsk reservoir has been studied. The long-term dynamics of the specific activity of 60Co, 90Sr, 137Cs and 3H in the main components of the freshwater ecosystem at different distances from the source of radionuclide discharge has been estimated. Critical radionuclides (60Co and 137Cs), routes of their entry and periods of maximum discharge of radioisotopes into the cooling pond have been determined. It is shown that the technology of electricity generation at Beloyarsk NPP, based on fast reactors, has a much smaller effect on the flow of artificial radionuclides into the freshwater ecosystem of the reservoir. During the entire period of monitoring studies, the decrease in the specific activity of radionuclides from NPP origin in surface waters was 4.3-74.5 times, in bottom sediments 10-505 times. The maximum discharge of artificial radionuclides into the reservoir was noted during the period of restoration and decontamination work aimed at eliminating emergencies at the AMB thermal reactors of the first stage of the Beloyarsk NPP.

Influence of operation of thermal and fast reactors of the Beloyarsk NPP on the radioecological situation in the cooling pond: Part II, Macrophytes and fish

  • Aleksei Panov ;Alexander Trapeznikov;Vera Trapeznikova ;Alexander Korzhavin
    • Nuclear Engineering and Technology
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    • v.55 no.2
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    • pp.707-716
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    • 2023
  • The influence of waste technological waters of thermal and fast reactors of Beloyarsk NPP (Russia) on the accumulation of 60Co, 90Sr and 137Cs in macrophytes and ichthyofauna of the cooling pond has been studied. Critical radionuclides, routes of their entry into the ecosystem and periods of maximum discharge of radioisotopes into the cooling pond have been determined. It is shown that the technology of electricity generation at the Beloyarsk NPP, based on fast reactors, has a much smaller effect on the release of artificial radionuclides into the environment. Therefore, during the entire period of monitoring studies (1976-2019), the decrease in the specific activity of radionuclides of NPP origin in macrophytes was 13-25800 times, in ichthyofauna 1.5-44.5 times. The maximum discharge of artificial radionuclides into the Beloyarsk reservoir was noted during the period of restoration and decontamination work aimed at eliminating the emergencies at the AMB reactors of NPP. The factors influencing the accumulation of artificial radionuclides in the components of the freshwater ecosystem of the Beloyarsk cooling pond have been determined, including: the physicochemical nature of radioisotopes, their concentration in surface water, the temperature of the aquatic environment, the trophicity of the reservoir, the species of hydrobionts.

Beta particle energy spectra shift due to self-attenuation effects in environmental sources

  • Alton, Thomas Theakston;Monk, Stephen David;Cheneler, David
    • Nuclear Engineering and Technology
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    • v.49 no.7
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    • pp.1483-1488
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    • 2017
  • In order to predict and control the environmental and health impacts of ionizing radiation in environmental sources such as groundwater, it is necessary to identify the radionuclides present. Beta-emitting radionuclides are frequently identified by measuring their characteristic energy spectra. The present work shows that self-attenuation effects from volume sources result in a geometry-dependent shift in the characteristic spectra, which needs to be taken into account in order to correctly identify the radionuclides present. These effects are shown to be compounded due to the subsequent shift in the photon spectra produced by the detector, in this case an inorganic solid scintillator ($CaF_2:Eu$) monitored using a silicon photomultiplier. Using tritiated water as an environmentally relevant, and notoriously difficult to monitor case study, analytical predictions for the shift in the energy spectra as a function of depth of source have been derived. These predictions have been validated using Geant4 simulations and experimental results measured using bespoke instrumentation.

International Trends in Risk Management of Groundwater Radionuclides (지하수 중 자연방사성물질의 위해성 관리에 대한 고찰)

  • 신동천;김예신;문지영;박화성;김진용;박선구
    • Environmental Analysis Health and Toxicology
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    • v.17 no.4
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    • pp.273-284
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    • 2002
  • At present, the health risks associated with the natural radionuclides of ground water have become a concern as potential social problems. However, there are no regulatory actions or control strategies for such risks. Therefore, we have investigated and discussed the risks and associated management strategies for radionuclides in other countries. US EPA has proposed MCL (300 pCi/L) and AMCL (4,000 pCi/L) for radon, and 30 ppb for uranium, 15 pCi/L for gross-alpha and 5 pCi/L for radium as final MCLs. Also, Canada, WHO and European countries have their inherent management levels. Finally, we suggested several criteria for setting guidelines in our countries including exposure related criteria such as geological distribution, occurrence, exposure probability distribution, exposure population and multimedia exposure assessment, acceptable risk, and cost -benefit analysis. The national-scale exposure and risk assessment, and economic analysis should be conducted for producing and aggregating the representative information on these criteria.