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Abstract  

An on-line method developed for separating plutonium and americium was developed. The method is based on the use of HPLC pump with three analytical chromatographic columns. Plutonium is reduced throughout the procedure to trivalent oxidation state, and is recovered in the various separation steps together with americium. Light lanthanides and trivalent actinides are separated with TEVA resin in thiocyanate/formic acid media. Trivalent plutonium and americium are pre-concentrated in a TCC-II cation-exchange column, after which the separation is performed in CS5A ion chromatography column by using two different eluents. Pu(III) is eluted with a dipicolinic acid eluent, and Am(III) with oxalic acid eluent. Radiochemical and chemical purity of the eluted plutonium and americium fractions were ensured with alpha-spectrometry.

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Abstract  

The influence of aqueous silica of two different physical forms (dissolved ions and SiO2 colloid) on the dissolution of UO2 nuclear fuel material was investigated at 95 °C temperature in autoclaves. It was tested that SiO2 colloids can contribute to the surface degradation or act as carrier for uranium ions during a near field geochemical dissolution process. In the presence of colloids, well-crystallized secondary phases containing U and Si were formed on the surfaces, the latter attacked by the treatment. This was not the case when dissolved Si was used. SiO2 colloids were partly found in their original form on the surfaces after 1000 hours at 95 °C. A surface charge model suggests that this different effects are due to the development of electrostatic interactions between the UO2 and SiO2 surfaces.

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Abstract  

XANES has been recently used for the determination of oxidation states of actinides in environmental samples. To obtain reliable results, however, a sufficiently long counting time at every probing energy and a large number of experimental points per XANES spectrum are required, due to the complex mathematical model used to fit the measured spectrum. This makes micro-mapping difficult, since the time required for data collection becomes unacceptably long. A simplified model for data collection and evaluation is presented. Its effectiveness has been tested by measuring the distribution of Pu oxidation states in a “hot” particle coming from a nuclear weapon test site.

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Summary  

A radioactively contaminated marine sediment core stemming from Irish Sea has been characterized by radiometric and mass spectrometric techniques as for 237Np, 241Am, 239Pu, 240Pu, 241Pu, 137Cs and 154Eu. The data obtained with independent methods in the framework of a QA/QC program as compared with the source term discharges, as well as with those reported in literature, are in good agreement.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: M. Pham, M. Betti, P. Povinec, V. Alfimov, D. Biddulph, J. Gastaud, W. Kieser, J. López Gutiérrez, G. Possnert, J. Sanchez-Cabeza, and T. Suzuki

Abstract  

A certified reference material designed for the determination of 129I in seawater, IAEA-418 (Mediterranean Sea water) is described and the results of certification are presented. The median of 129I concentration with 95% confidence interval was chosen as the most reliable estimates of the true value. The median, given as the certified value, is 2.28 × 108 atom L−1 (95% confidence interval is (2.16–2.73) 108 atom L−1), or 3.19 × 10−7 Bq L−1 (95% confidence interval is (3.02–3.82) × 10−7 Bq L−1). The material is intended to be used for standardization procedures applied in accelerator mass spectrometric laboratories. It is available in 1 L units and may be ordered via IAEA web side (www.iaea.org).

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Journal of Radioanalytical and Nuclear Chemistry
Authors: M. Pham, M. Betti, P. Povinec, M. Benmansour, R. Bojanowski, P. Bouisset, E. Calvo, G. Ham, E. Holm, M. Hult, C. Ilchmann, M. Kloster, G. Kanisch, M. Köhler, J. La Rosa, F. Legarda, M. Llauradó, A. Nourredine, J.-S. Oh, M. Pellicciari, U. Rieth, A. Rodriguez y Baena, J. Sanchez-Cabeza, H. Satake, J. Schikowski, M. Takeishi, H. Thébault, and Z. Varga

Abstract  

A new Reference Material (RM) for radionuclides in mussel (Mytilus galloprovincialis) from the Mediterranean Sea (IAEA-437) is described and the results of the certification process are presented. Four radionuclides (40K, 234U, 238U, and 239+240Pu) have been certified, and information values on massic activities with 95% confidence intervals are given for nine radionuclides (137Cs, 210Pb(210Po), 226Ra, 228Ra, 228Th, 230Th, 232Th, 235U, and 241Am). Results for less frequently reported radionuclides (90Sr, 129I, 238Pu, 239Pu, and 240Pu) are also reported. The RM can be used for quality assurance/quality control of the analysis of radionuclides in mussel samples, for the development and validation of analytical methods and for training purposes. The material is available in 200 g units.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: M. Pham, M. Betti, P. Povinec, M. Benmansour, V. Bünger, J. Drefvelin, C. Engeler, J. Flemal, C. Gascó, J. Guillevic, R. Gurriaran, M. Groening, J. Happel, J. Herrmann, S. Klemola, M. Kloster, G. Kanisch, K. Leonard, S. Long, S. Nielsen, J.-S. Oh, P. Rieth, I. Östergren, H. Pettersson, N. Pinhao, L. Pujol, K. Sato, J. Schikowski, Z. Varga, V. Vartti, and J. Zheng

Abstract  

A new certified reference material (CRM) for radionuclides in sea water from the Irish sea (IAEA-443) is described and the results of the certification process are presented. Ten radionuclides (3H, 40K, 90Sr, 137Cs, 234U, 235U, 238U, 238Pu, 239+240Pu and 241Am) have been certified, and information values on massic activities with 95% confidence intervals are given for four radionuclides (230Th, 232Th, 239Pu and 240Pu). Results for less frequently reported radionuclides (99Tc, 228Th, 237Np and 241Pu) are also reported. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in water samples, for the development and validation of analytical methods and for training purposes. The material is available in 5 L units from IAEA (http://nucleus.iaea.org/rpst/index.htm).

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