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N. Dacheux - One of the best experts on this subject based on the ideXlab platform.
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selective determination of Polonium by photon electron rejecting alpha liquid scintillation perals system
Analytica Chimica Acta, 2000Co-Authors: C. Veronneau, J. Aupiais, N. DacheuxAbstract:We developed a fast analysis method for the determination of Polonium by alpha liquid scintillation with b‐g rejection in environmental samples. The liquid‐liquid extraction with several extractants like HDEHP, TNOA, TOPO or NDA was applied. Among them, the use of the trioctylamine (TNOA) allows the separation of Polonium from uranium, plutonium and thorium in a mixture containing 3 M H2SO4 and sodium chloride (210 2 to 1 M). The distribution ratio of Polonium is over 10 4 , whereas it is only equal to about 10 1 for U, 310 2 for Th, and 310 3 for Pu. This separation process was applied with success to large volume of aqueous solution (250 ml). The detection limit is below 1 mBq l 1 for 200 ml of solution and for a counting time equal to 1000 min. We also successfully applied this procedure for the Polonium activity measurement in various colorless aqueous solutions. Several difficulties were encountered by using this method to organic matter such as fish or shellfish. A yellow coloration occurs which does not allow a measurement. Moreover, the volatility of Polonium compounds unables the use of conventional dissolution methods for organic matter. These problems are also discussed in this paper. © 2000 Elsevier Science B.V. All rights reserved.
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Selective determination of Polonium by photon electron rejecting alpha liquid scintillation (PERALS (R) System)
Analytica Chimica Acta, 2000Co-Authors: C. Veronneau, J. Aupiais, N. DacheuxAbstract:We developed a fast analysis method for the determination of Polonium by alpha liquid scintillation with beta-gamma rejection in environmental samples. The liquid-liquid extraction with several extractants like HDEHP, TNOA, TOPO or NDA was applied. Among them, the use of the trioctylamine (TNOA) allows the separation of Polonium from uranium, plutonium and thorium in a mixture containing 3 M H2SO4 and sodium chloride (2 x 10(-2) to 1 M). The distribution ratio of Polonium is over 10(4), whereas it is only equal to about 10(-1) for U, 3 x 10(-2) for Th, and 3 x 10(-3) for Pu. This separation process was applied with success to large volume of aqueous solution (250 ml). The detection limit is below 1 mBq l(-1) for 200 ml of solution and for a counting time equal to 1000 min. We also successfully applied this procedure for the Polonium activity measurement in various colorless aqueous solutions.Several difficulties were encountered by using this method to organic matter such as fish or shellfish. A yellow coloration occurs which does not allow a measurement. Moreover, the volatility of Polonium compounds unables the use of conventional dissolution methods for organic matter. These problems are also discussed in this paper.
Gilles Montavon - One of the best experts on this subject based on the ideXlab platform.
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Production of Polonium from bismuth and purification using TBP resin and Sr resin
J.Radioanal.Nucl.Chem., 2020Co-Authors: Ali Younes, Cyrille Alliot, Ali Jafar Sunga, Anne-cécile Bonraisin, Marcel Mokili, Steffen Happel, Aude Bombard, Ferid Haddad, Gilles MontavonAbstract:A method for the production and purification of Polonium from an irradiated bismuth target that minimizes processing time, cost, and generation of radioactive wastes, and increases recovery yield, is proposed. Production is done through two approaches: using a 37-MeV alpha particle beam to produce 210Po, and using a deuteron beam of 16-MeV to produce 210Po, 209Po and 208Po. Separation is performed using TBP-resin, and batch studies were performed to optimize conditions. Bismuth is separated with 7 M HCl, and Polonium is successfully retained on the TBP resin. Polonium was recovered using 8 M HNO3 with a 99% yield.
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A route for Polonium 210 production from alpha-particle irradiated bismuth-209 target
Radiochimica Acta, 2014Co-Authors: Ali Younes, Gilles Montavon, Cyrille Alliot, Marcel Mokili, Ferid Haddad, David Deniaud, Julie ChampionAbstract:A method is proposed for production of Polonium-210 via the 209Bi(α, 3n)210At nuclear reaction. Bombardment of a bismuth-209 target was performed with a 37 MeV alpha-particle beam that leads to the production of astatine-210 (T1/2 = 8.1 h), which decays to Polonium-210. It is purified from the bismuth target matrix by employing liquid-liquid extraction using tributyl phosphate (TBP) in para-xylene from 7 M hydrochloric acid. Back extraction of Polonium-210 was performed by 9 M nitric acid. This method allows to purify a tracer amount of Po-210 (2.6 * 10-13 mol) from macroscopic amount of Bi (2.8 * 10-2 mol).
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Review of chemical and radiotoxicological properties of Polonium for internal contamination purposes.
Chemical research in toxicology, 2012Co-Authors: Eric Ansoborlo, Philippe Bérard, Christophe Den Auwer, Richard Wayne Leggett, F. Ménétrier, Ali Younes, Gilles Montavon, Phillipe MoisyAbstract:The discovery of Polonium (Po) was first published in July, 1898 by P. Curie and M. Curie. It was the first element to be discovered by the radiochemical method. Polonium can be considered as a famous but neglected element: only a few studies of Polonium chemistry have been published, mostly between 1950 and 1990. The recent (2006) event in which 210Po evidently was used as a poison to kill A. Litvinenko has raised new interest in Polonium. 2011 being the 100th anniversary of the Marie Curie Nobel Prize in Chemistry, the aim of this review is to look at the several aspects of Polonium linked to its chemical properties and its radiotoxicity, including (i) its radiochemistry and interaction with matter; (ii) its main sources and uses; (iii) its physicochemical properties; (iv) its main analytical methods; (v) its background exposure risk in water, food, and other environmental media; (vi) its biokinetics and distribution following inhalation, ingestion, and wound contamination; (vii) its dosimetry; and (vii...
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Review of chemical and radiotoxicological properties of Polonium
Chemical Research in Toxicology, 2012Co-Authors: Eric Ansoborlo, Philippe Bérard, F. Ménétrier, Ali Younes, Gilles Montavon, C. Den Auwer, R. Leggett, Phillipe MoisyAbstract:The discovery of Polonium (Po) was first published in July, 1898 by P. Curie and M. Curie. It was the first element to be discovered by the radiochemical method. Polonium can be considered as a famous but neglected element: only a few studies of Polonium chemistry have been published, mostly between 1950 and 1990. The recent (2006) event in which 210Po evidently was used as a poison to kill A. Litvinenko has raised new interest in Polonium. 2011 being the 100th anniversary of the Marie Curie Nobel Prize in Chemistry, the aim of this review is to look at the several aspects of Polonium linked to its chemical properties and its radiotoxicity, including (i) its radiochemistry and interaction with matter; (ii) its main sources and uses; (iii) its physicochemical properties; (iv) its main analytical methods; (v) its background exposure risk in water, food, and other environmental media; (vi) its biokinetics and distribution following inhalation, ingestion, and wound contamination; (vii) its dosimetry; and (viii) treatments available (decorporation) in case of internal contamination.
C. Veronneau - One of the best experts on this subject based on the ideXlab platform.
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selective determination of Polonium by photon electron rejecting alpha liquid scintillation perals system
Analytica Chimica Acta, 2000Co-Authors: C. Veronneau, J. Aupiais, N. DacheuxAbstract:We developed a fast analysis method for the determination of Polonium by alpha liquid scintillation with b‐g rejection in environmental samples. The liquid‐liquid extraction with several extractants like HDEHP, TNOA, TOPO or NDA was applied. Among them, the use of the trioctylamine (TNOA) allows the separation of Polonium from uranium, plutonium and thorium in a mixture containing 3 M H2SO4 and sodium chloride (210 2 to 1 M). The distribution ratio of Polonium is over 10 4 , whereas it is only equal to about 10 1 for U, 310 2 for Th, and 310 3 for Pu. This separation process was applied with success to large volume of aqueous solution (250 ml). The detection limit is below 1 mBq l 1 for 200 ml of solution and for a counting time equal to 1000 min. We also successfully applied this procedure for the Polonium activity measurement in various colorless aqueous solutions. Several difficulties were encountered by using this method to organic matter such as fish or shellfish. A yellow coloration occurs which does not allow a measurement. Moreover, the volatility of Polonium compounds unables the use of conventional dissolution methods for organic matter. These problems are also discussed in this paper. © 2000 Elsevier Science B.V. All rights reserved.
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Selective determination of Polonium by photon electron rejecting alpha liquid scintillation (PERALS (R) System)
Analytica Chimica Acta, 2000Co-Authors: C. Veronneau, J. Aupiais, N. DacheuxAbstract:We developed a fast analysis method for the determination of Polonium by alpha liquid scintillation with beta-gamma rejection in environmental samples. The liquid-liquid extraction with several extractants like HDEHP, TNOA, TOPO or NDA was applied. Among them, the use of the trioctylamine (TNOA) allows the separation of Polonium from uranium, plutonium and thorium in a mixture containing 3 M H2SO4 and sodium chloride (2 x 10(-2) to 1 M). The distribution ratio of Polonium is over 10(4), whereas it is only equal to about 10(-1) for U, 3 x 10(-2) for Th, and 3 x 10(-3) for Pu. This separation process was applied with success to large volume of aqueous solution (250 ml). The detection limit is below 1 mBq l(-1) for 200 ml of solution and for a counting time equal to 1000 min. We also successfully applied this procedure for the Polonium activity measurement in various colorless aqueous solutions.Several difficulties were encountered by using this method to organic matter such as fish or shellfish. A yellow coloration occurs which does not allow a measurement. Moreover, the volatility of Polonium compounds unables the use of conventional dissolution methods for organic matter. These problems are also discussed in this paper.
Ali Younes - One of the best experts on this subject based on the ideXlab platform.
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Production of Polonium from bismuth and purification using TBP resin and Sr resin
J.Radioanal.Nucl.Chem., 2020Co-Authors: Ali Younes, Cyrille Alliot, Ali Jafar Sunga, Anne-cécile Bonraisin, Marcel Mokili, Steffen Happel, Aude Bombard, Ferid Haddad, Gilles MontavonAbstract:A method for the production and purification of Polonium from an irradiated bismuth target that minimizes processing time, cost, and generation of radioactive wastes, and increases recovery yield, is proposed. Production is done through two approaches: using a 37-MeV alpha particle beam to produce 210Po, and using a deuteron beam of 16-MeV to produce 210Po, 209Po and 208Po. Separation is performed using TBP-resin, and batch studies were performed to optimize conditions. Bismuth is separated with 7 M HCl, and Polonium is successfully retained on the TBP resin. Polonium was recovered using 8 M HNO3 with a 99% yield.
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A route for Polonium 210 production from alpha-particle irradiated bismuth-209 target
Radiochimica Acta, 2014Co-Authors: Ali Younes, Gilles Montavon, Cyrille Alliot, Marcel Mokili, Ferid Haddad, David Deniaud, Julie ChampionAbstract:A method is proposed for production of Polonium-210 via the 209Bi(α, 3n)210At nuclear reaction. Bombardment of a bismuth-209 target was performed with a 37 MeV alpha-particle beam that leads to the production of astatine-210 (T1/2 = 8.1 h), which decays to Polonium-210. It is purified from the bismuth target matrix by employing liquid-liquid extraction using tributyl phosphate (TBP) in para-xylene from 7 M hydrochloric acid. Back extraction of Polonium-210 was performed by 9 M nitric acid. This method allows to purify a tracer amount of Po-210 (2.6 * 10-13 mol) from macroscopic amount of Bi (2.8 * 10-2 mol).
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Review of chemical and radiotoxicological properties of Polonium for internal contamination purposes.
Chemical research in toxicology, 2012Co-Authors: Eric Ansoborlo, Philippe Bérard, Christophe Den Auwer, Richard Wayne Leggett, F. Ménétrier, Ali Younes, Gilles Montavon, Phillipe MoisyAbstract:The discovery of Polonium (Po) was first published in July, 1898 by P. Curie and M. Curie. It was the first element to be discovered by the radiochemical method. Polonium can be considered as a famous but neglected element: only a few studies of Polonium chemistry have been published, mostly between 1950 and 1990. The recent (2006) event in which 210Po evidently was used as a poison to kill A. Litvinenko has raised new interest in Polonium. 2011 being the 100th anniversary of the Marie Curie Nobel Prize in Chemistry, the aim of this review is to look at the several aspects of Polonium linked to its chemical properties and its radiotoxicity, including (i) its radiochemistry and interaction with matter; (ii) its main sources and uses; (iii) its physicochemical properties; (iv) its main analytical methods; (v) its background exposure risk in water, food, and other environmental media; (vi) its biokinetics and distribution following inhalation, ingestion, and wound contamination; (vii) its dosimetry; and (vii...
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Review of chemical and radiotoxicological properties of Polonium
Chemical Research in Toxicology, 2012Co-Authors: Eric Ansoborlo, Philippe Bérard, F. Ménétrier, Ali Younes, Gilles Montavon, C. Den Auwer, R. Leggett, Phillipe MoisyAbstract:The discovery of Polonium (Po) was first published in July, 1898 by P. Curie and M. Curie. It was the first element to be discovered by the radiochemical method. Polonium can be considered as a famous but neglected element: only a few studies of Polonium chemistry have been published, mostly between 1950 and 1990. The recent (2006) event in which 210Po evidently was used as a poison to kill A. Litvinenko has raised new interest in Polonium. 2011 being the 100th anniversary of the Marie Curie Nobel Prize in Chemistry, the aim of this review is to look at the several aspects of Polonium linked to its chemical properties and its radiotoxicity, including (i) its radiochemistry and interaction with matter; (ii) its main sources and uses; (iii) its physicochemical properties; (iv) its main analytical methods; (v) its background exposure risk in water, food, and other environmental media; (vi) its biokinetics and distribution following inhalation, ingestion, and wound contamination; (vii) its dosimetry; and (viii) treatments available (decorporation) in case of internal contamination.
Hiroshi Sekimoto - One of the best experts on this subject based on the ideXlab platform.
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Polonium evaporation and adhesion experiments for the development of Polonium filter in lead bismuth cooled reactors
Progress in Nuclear Energy, 2008Co-Authors: Toru Obara, Terumitsu Miura, Takeru Koga, Hiroshi SekimotoAbstract:Fundamental experiments were performed to determine the adhesion characteristics of Polonium to different metals and to develop a filter for Polonium evaporated from neutron-irradiated LBE. The results of the first experiments suggested that adhesion characteristics are almost the same for stainless steel and nickel metal. The results of the preliminary experiments for a Polonium filter suggested that stainless steel mesh with thin wires could effectively collect Polonium evaporated from neutron-irradiated LBE. In the experiments, stainless steel wire mesh was used, but from the results of adhesion experiment, it is expected that the same effect can be obtained with wire mesh made of other kinds of metal.
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Polonium evaporation and adhesion experiments for the development of Polonium filter in lead–bismuth cooled reactors
Progress in Nuclear Energy, 2007Co-Authors: Toru Obara, Terumitsu Miura, Takeru Koga, Hiroshi SekimotoAbstract:Fundamental experiments were performed to determine the adhesion characteristics of Polonium to different metals and to develop a filter for Polonium evaporated from neutron-irradiated LBE. The results of the first experiments suggested that adhesion characteristics are almost the same for stainless steel and nickel metal. The results of the preliminary experiments for a Polonium filter suggested that stainless steel mesh with thin wires could effectively collect Polonium evaporated from neutron-irradiated LBE. In the experiments, stainless steel wire mesh was used, but from the results of adhesion experiment, it is expected that the same effect can be obtained with wire mesh made of other kinds of metal.
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Investigation of Polonium Decontamination from Stainless Steel Surfaces Using the Baking Method
Nuclear Technology, 2006Co-Authors: Terumitsu Miura, Toru Obara, Hiroshi SekimotoAbstract:Polonium contamination on material surfaces has been considered one of the problems in the use of lead-bismuth eutectic (LBE) as a coolant and/or target in nuclear systems. Neutron-irradiated LBE contains Polonium and can contaminate material surfaces of the primary loop in nuclear systems. Some methods for removal of Polonium from neutron-irradiated LBE have been investigated. In this paper, the theory and the effectiveness of the baking method for Polonium decontamination of a material surface contaminated by neutron-irradiated LBE are described. Theoretical investigation of the baking method was performed using Langmuir's equation. The effectiveness of the baking method was investigated by baking experiments using Type 316 stainless steel plates contaminated by neutron-irradiated LBE. The experimental results indicated that the baking method is effective for Polonium decontamination when the baking temperature is more than 500°C in a vacuum condition (0.4 Pa). The effective temperature for Polonium decontamination of Type 316 plates differed from that of quartz glass plates previously reported. Comparing the experimental results and calculations of the evaporation rate of Polonium compound by Langmuir's equation showed that the difference in effective temperatures was due to the different chemical forms of Polonium, i.e., elemental Polonium and lead polonide.
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fundamental study of Polonium contamination by neutron irradiated lead bismuth eutectic
Journal of Nuclear Materials, 2005Co-Authors: Toru Obara, Terumitsu Miura, Hiroshi SekimotoAbstract:As a fundamental study of Polonium contamination by neutron irradiated LBE, it was investigated to remove Polonium surface contamination by baking method. The baking experiments were performed using quartz glass plates contaminated by material evaporated from neutron irradiated LBE liquid. The contaminated quartz glass plates were baked in vacuum (2 Pa) at various temperatures. The experimental results clearly show that Polonium evaporated from LBE can be removed by baking samples at temperatures 300 °C and above. It is of note that the decrease in the weight of deposited materials baked at 300 °C differed from that observed at 400 °C or higher temperatures. At temperature of 300 °C, no change in weight was observed. The mass of Polonium in the LBE samples was so small that no weight change could be observed by release of Polonium. Thus, it might show that only the Polonium among the adherent materials was removed by baking at 300 °C without removing other adhered material. The method is rather simple, so it is easy to apply the method for practical application. One of the expected applications may be the removal of Polonium contamination in a primary loop before maintenance work of the loop. Also it shows that this method can be used to avoid the release of Polonium from contaminated material, in case of an accident, by keeping the contaminated material at low temperature.
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Fundamental study of Polonium contamination by neutron irradiated lead–bismuth eutectic
Journal of Nuclear Materials, 2005Co-Authors: Toru Obara, Terumitsu Miura, Hiroshi SekimotoAbstract:As a fundamental study of Polonium contamination by neutron irradiated LBE, it was investigated to remove Polonium surface contamination by baking method. The baking experiments were performed using quartz glass plates contaminated by material evaporated from neutron irradiated LBE liquid. The contaminated quartz glass plates were baked in vacuum (2 Pa) at various temperatures. The experimental results clearly show that Polonium evaporated from LBE can be removed by baking samples at temperatures 300 °C and above. It is of note that the decrease in the weight of deposited materials baked at 300 °C differed from that observed at 400 °C or higher temperatures. At temperature of 300 °C, no change in weight was observed. The mass of Polonium in the LBE samples was so small that no weight change could be observed by release of Polonium. Thus, it might show that only the Polonium among the adherent materials was removed by baking at 300 °C without removing other adhered material. The method is rather simple, so it is easy to apply the method for practical application. One of the expected applications may be the removal of Polonium contamination in a primary loop before maintenance work of the loop. Also it shows that this method can be used to avoid the release of Polonium from contaminated material, in case of an accident, by keeping the contaminated material at low temperature.