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Journal Articles

Anion-exchange separation of americium and the lanthanides using a single column

Miyamoto, Yutaka; Yasuda, Kenichiro

Journal of Nuclear and Radiochemical Sciences (Internet), 18, p.13 - 15, 2018/07

A sequential separation technique using an anion-exchange column developed in the previous works have the potential to completely separate picograms of Am from the lanthanides using mixtures of acetic acid, hydrochloric acid, and nitric acid as the eluents, without any functional ligands or special columns. This experimental result implies that ultra-trace actinides, including Am, Pu, U, and Th in environmental samples can be sequentially separated by combination of these mixed-media eluents and an anion exchange column.

Journal Articles

Accurate sensitive analytical technique of ultra-trace plutonium in the IAEA environmental samples

Miyamoto, Yutaka; Yasuda, Kenichiro; Suzuki, Daisuke; Esaka, Fumitaka; Magara, Masaaki

KEK Proceedings 2017-6, p.292 - 298, 2017/11

Our updated analytical techniques of ultra-trace plutonium in the IAEA environmental samples by ICP-MS were mentioned. Some careful techniques to accurately determine ultra-trace plutonium in the range of femto-grams to pico-grams were introduced. The uncertainties of analytical results were estimated according to the GUM concept. Our trials of determination of sub-femto grams americium in an environmental sample were also mentioned.

Journal Articles

Analysis of plutonium isotope ratios including $$^{238}$$Pu/$$^{239}$$Pu in individual U-Pu mixed oxide particles by means of a combination of alpha spectrometry and ICP-MS

Esaka, Fumitaka; Yasuda, Kenichiro; Suzuki, Daisuke; Miyamoto, Yutaka; Magara, Masaaki

Talanta, 165, p.122 - 127, 2017/04

 Times Cited Count:4 Percentile:47.81(Chemistry, Analytical)

The isotope ratios of $$^{238}$$Pu/$$^{239}$$Pu, $$^{240}$$Pu/$$^{239}$$Pu, $$^{241}$$Pu/$$^{239}$$Pu, and $$^{242}$$Pu/$$^{239}$$Pu were measured for individual Pu and U-Pu mixed oxide particles by a combination of alpha spectrometry and inductively coupled plasma mass spectrometry (ICP-MS). As a consequence, we were able to determine the $$^{240}$$Pu/$$^{239}$$Pu, $$^{241}$$Pu/$$^{239}$$Pu, and $$^{242}$$Pu/$$^{239}$$Pu isotope ratios with ICP-MS after particle dissolution and chemical separation of uranium, plutonium and americium with UTEVA resins. Furthermore, $$^{238}$$Pu/$$^{239}$$Pu isotope ratios were able to be calculated by using both the $$^{238}$$Pu/( $$^{239}$$Pu+$$^{240}$$Pu) activity ratios that had been measured through alpha spectrometry and the $$^{240}$$Pu/$$^{239}$$Pu isotope ratios determined through ICP-MS. Therefore, the combined use of alpha spectrometry and ICP-MS is useful in determining plutonium isotope ratios, including $$^{238}$$Pu/$$^{239}$$Pu, in individual U-Pu mixed oxide particles.

Journal Articles

Automatic sequential separation with an anion-exchange column for ultra-trace analysis of Pu, U, Th, Pb, and lanthanides in environmental samples

Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki

Journal of Radioanalytical and Nuclear Chemistry, 309(1), p.303 - 308, 2016/07

 Times Cited Count:1 Percentile:76.09(Chemistry, Analytical)

The technique of sequential separation for U, Th, Pb, lanthanides and Pu using a single anion-exchange column and mixed acids media were developed. An automatic system utilizing a small column and pressurized gas was assembled for this sequential separation. By adjusting the eluent chemical composition for Pu separation, this separation technique has been achieved. Some pieces of tree ring sample were digested, and ultra-trace U and Pu in the samples were separated by this system. The analytical results of U and Pu measured by mass spectrometry will be mentioned.

Journal Articles

Determination of plutonium isotope ratios in individual uranium-plutonium mixed particles with inductively coupled plasma mass spectrometry

Esaka, Fumitaka; Suzuki, Daisuke; Miyamoto, Yutaka; Magara, Masaaki

Journal of Radioanalytical and Nuclear Chemistry, 306(2), p.393 - 399, 2015/11

 Times Cited Count:4 Percentile:43.49(Chemistry, Analytical)

An analytical technique was developed by a combination of single particle dissolution, chemical separation of uranium, plutonium and americium with extraction chromatography using UTEVA resins and measurement with inductively coupled plasma mass spectrometry (ICP-MS). This method was applied to plutonium isotope ratio analysis of individual U-Pu particles with U/Pu ratios ranging from 1 to 70. Consequently, $$^{240}$$Pu/$$^{239}$$Pu, $$^{241}$$Pu/$$^{239}$$Pu and $$^{242}$$Pu/$$^{239}$$Pu isotope ratios were successfully determined, while it was impossible to determine $$^{238}$$Pu/$$^{239}$$Pu ratios due to the high process blank values on m/z 238.

Journal Articles

Chemical separation of ultra-trace multi-elements in environmental samples

Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki

KEK Proceedings 2015-4, p.44 - 48, 2015/11

We developed an automatic system for sequential separation with an anion-exchange column to simply and quickly separate less than pico-grams of ultra-trace U, Th, Pb, the lanthanide, and Pu in an environmental sample without foreign contamination. The objective sequential separation of ultra-trace multi-elements succeeded by choosing the HCl-HF mixture based acetic acid for Th separation and the HCl-diluted HF mixture for Pu separation. The objective elements in a multi-elements mixture were completely separated for 6 h 15 min by use of the automatic system and the optimized separation condition.

Journal Articles

Accurate purification age determination of individual uranium-plutonium mixed particles

Miyamoto, Yutaka; Suzuki, Daisuke; Esaka, Fumitaka; Magara, Masaaki

Analytical and Bioanalytical Chemistry, 407(23), p.7165 - 7173, 2015/09

 Times Cited Count:5 Percentile:61.62(Biochemical Research Methods)

Age of individual uranium-plutonium mixed particles with various U/Pu atomic ratios were determined by inductively-coupled plasma mass spectrometry. Micron-sized particles were prepared from U and Pu certified reference materials. The Pu reference was stored for 4-6 years since the last purification. The Pu purification age was obtained from the $$^{241}$$Am/$$^{241}$$Pu ratio which was calculated from the product of three measured ratios of Pu and Am isotopes in the eluted fractions. Am, U and Pu in a sample solution were sequentially separated a small anion-exchange column. The $$^{241}$$Am/$$^{241}$$Pu ratio was accurately determined by spiking pure $$^{243}$$Am to the sample solution. The determined age of particles with various U/Pu ratios was in good agreement with the expected age with high accuracy and high precision.

Journal Articles

Sequential separation of ultra-trace U, Th, Pb, and lanthanides using a simple automatic system

Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki

Analyst, 140(13), p.4482 - 4488, 2015/07

 Times Cited Count:3 Percentile:78.55(Chemistry, Analytical)

Uranium, Thorium, lead, and the lanthanides were automatically and sequentially separated with a single anion-exchange column. This separation was achieved using eluents consisting of simple and highly pure acid mixture of HCl, HNO$$_3$$, acetic acid, and HF. This simple, automatic system is driven with pressurized nitrogen gas, and controlled by a computer program. For an evaluation examination, a reference powdered rock sample was separated by using this system. Abundances of objective elements, including 0.23 ng of lutetium, were accurately determined without corrections of chemical recovery yield or subtraction of processing blank. This separation technique saves time and effort for chemical processing, and it is useful for ultra-trace quantitative and isotopic analyses of elements in small environmental samples.

Journal Articles

Direct isotope ratio analysis of individual uranium-plutonium mixed particles with various U/Pu ratios by thermal ionization mass spectrometry

Suzuki, Daisuke; Esaka, Fumitaka; Miyamoto, Yutaka; Magara, Masaaki

Applied Radiation and Isotopes, 96, p.52 - 56, 2015/02

 Times Cited Count:10 Percentile:12.68(Chemistry, Inorganic & Nuclear)

Isotope ratios of uranium and plutonium in individual U-Pu mixed particles with various U/Pu ratios were determined by thermal ionization mass spectrometry with a continuous heating method without chemical separation. Prior to the measurements, micron-sized U-Pu mixed particles with U/Pu ratios of 1, 5, 10, 18 and 70 were produced by using certified reference materials CRM U-010 (1%$$^{235}$$U enriched, NBL) and SRM 947 (NBS) solutions. As a result of isotope ratio analysis, accurate values for U and Pu ratios, except for $$^{238}$$Pu/$$^{239}$$Pu, were successfully determined for the particles with all U/Pu ratios. Although some pre-treatment such as chemical separation would need for accurate determination of $$^{238}$$Pu/$$^{239}$$Pu isotope analysis, it was shown that this analytical technique has a potential of powerful tool for nuclear safeguards and forensics.

Journal Articles

Plutonium age determination from $$^{240}$$Pu/$$^{236}$$U ratios in individual particles by ICP-MS without prior chemical separation

Esaka, Fumitaka; Suzuki, Daisuke; Miyamoto, Yutaka; Magara, Masaaki

Microchemical Journal, 118, p.69 - 72, 2015/01

 Times Cited Count:5 Percentile:64.48(Chemistry, Analytical)

The determination of the time elapsed since the last purification of plutonium with chemical separation gives important information for monitoring nuclear activities related to reprocessing and nuclear weapon production. Although methods for the analysis of plutonium solutions have been extensively studied, few studies were conducted for the measurement of individual particles. In this work, a simple technique was developed for age determination of individual plutonium particles by a combination of single particle dissolution and measurement by inductively coupled plasma mass spectrometry (ICP-MS) without prior chemical separation. The analytical results of individual plutonium particles having an age of 5.98 y indicated that the use of $$^{240}$$Pu/$$^{236}$$U ratios allowed for the determination of accurate ages, though that of $$^{238}$$Pu/$$^{234}$$U and $$^{239}$$Pu/$$^{235}$$U ratios was not suitable because of the contamination of natural uranium during the process of sample preparation.

Journal Articles

Size distribution of radioactive particles collected at Tokai, Japan 6 days after the nuclear accident

Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki

Journal of Environmental Radioactivity, 132, p.1 - 7, 2014/06

 Times Cited Count:17 Percentile:29.49(Environmental Sciences)

Airborne radioactive particles released by the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in 2011 were collected with a cascade low-pressure impactor at the Japan Atomic Energy Agency (JAEA) in Tokai. Size-fractionated samples were collected twice, in the periods of March 17 - April 1, 2011, and May 9-13, 2011. These size-fractionated samplings were carried out in the earliest days at a short distance from the FDNPPs. Radioactivity of short-lived nuclides (several ten days of half-life) were determined as well as $$^{134}$$Cs and $$^{137}$$Cs. The elemental composition of size-fractionated samples was also measured. In the first collection, the activity median aerodynamic diameter (AMAD) of $$^{rm 129m}$$Te, $$^{134}$$Cs, $$^{136}$$Cs and $$^{137}$$Cs was 1.5-1.6$$mu$$m, while the diameter of $$^{131}$$I was 0.45$$mu$$m.

Journal Articles

Precise age determination of a single plutonium particle using inductively coupled plasma mass spectrometer

Miyamoto, Yutaka; Esaka, Fumitaka; Suzuki, Daisuke; Magara, Masaaki

Radiochimica Acta, 101(11), p.745 - 748, 2013/11

 Times Cited Count:8 Percentile:29.95(Chemistry, Inorganic & Nuclear)

Age-dating of single plutonium particles with diameters of 1 $$mu$$m was demonstrated using eight particles. The precision and accuracy of the Pu age were improved through the addition of an $$^{243}$$Am spike to the sample solutions and by the trace chemical separation of the Pu and Am. The determined age in this work was in good agreement with the expected age with high accuracy and precision. The age with this technique was more precise than that determined using the common technique without an Am spike.

Journal Articles

Research and development on waste management for the Fukushima Daiichi NPS by JAEA

Koma, Yoshikazu; Ashida, Takashi; Meguro, Yoshihiro; Miyamoto, Yasuaki; Sasaki, Toshiki; Yamagishi, Isao; Kameo, Yutaka; Terada, Atsuhiko; Hiyama, Toshiaki; Koyama, Tomozo; et al.

Proceedings of International Nuclear Fuel Cycle Conference; Nuclear Energy at a Crossroads (GLOBAL 2013) (CD-ROM), p.736 - 743, 2013/09

Fukushima Daiichi Nuclear Power Station (F1NPS), TEPCO, was severely damaged with the hydrogen explosions caused by losing their cooling functions due to the earthquake and the tsunami occurred on March 11, 2011. Radioactive wastes generated from the current FINPS and future their decommission and demolition are greater huge amount than those from general reactors and nuclear fuel facilities. Toward accomplishing safe and reasonable management of the wastes, great effort of R&Ds has been strongly required and performed in bringing together the knowledge and experience of all of Japan. This report outlines the current status of the R&Ds performed in JAEA.

Journal Articles

Analysis of individual particles containing nuclear materials in environmental samples

Esaka, Fumitaka; Magara, Masaaki; Suzuki, Daisuke; Miyamoto, Yutaka; Kimura, Takaumi

Hyomen Kagaku, 34(3), p.125 - 130, 2013/03

Analysis of individual particles containing nuclear materials in environmental samples gives important information on the origins. This paper describes analytical techniques of individual particles containing nuclear materials such as uranium and plutonium. A scanning electron microscope (SEM) combined with an X-ray detector, solid track detectors, and secondary ion mass spectrometry (SIMS) were used to identify particles containing uranium and/or plutonium in environmental samples. Isotope ratios for these particles were successfully determined with SIMS, thermal ionization mass spectrometry (TIMS) or inductively coupled plasma mass spectrometry (ICPMS). The complementary use of these methods is effective to characterize individual particles rapidly, precisely and accurately.

Journal Articles

Sequential anion-exchange separation of trace U, Th, Pb and lanthanides in environmental samples

Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki; Kimura, Takaumi; Usuda, Shigekazu*

Proceedings in Radiochemistry, 1(1), p.209 - 212, 2011/09

Nano grams of U, Th, Pb and lanthanides in a geological reference rock were sequentially separated with a single anion-exchange column. Mixture of acetic acid, HCl and HNO$$_{3}$$ were used as the eluents for this separation. The recovery of these key elements was more than 95%, and there was no fractionation among the recoveries of each lanthanide element. Alkaline metals, alkaline earth metals and Fe were effectively eliminated from the key elements. By using this technique, it is possible to simplify the complicated traditional processes without any special ligands, columns and equipments.

Journal Articles

QA/QC activities and estimation of uncertainty for ultra-trace analysis of uranium and plutonium in safeguards environmental samples

Usuda, Shigekazu*; Magara, Masaaki; Esaka, Fumitaka; Yasuda, Kenichiro; Kokubu, Yoko; Lee, C. G.; Miyamoto, Yutaka; Suzuki, Daisuke; Inagawa, Jun; Sakurai, Satoshi; et al.

Journal of Nuclear and Radiochemical Sciences, 11(2), p.A5 - A9, 2011/01

In the analysis of IAEA safeguards environmental samples, isotope ratios of ultra-trace amounts of uranium and plutonium in samples taken from nuclear facilities are determined to detect undeclared nuclear materials and activities. In order to keep and enhance the reliability of the measurement results, validation of analytical methods and estimation of measurement uncertainty in such ultra-trace analysis should be properly done in accordance with worldwide standards. In this paper, the current activities on achievement of QA/QC (quality assurance and quality control) and estimation of measurement uncertainty in the ultra-trace analysis at a clean chemistry laboratory (CLEAR) of JAEA are reported.

Journal Articles

Feasibility study of isotope ratio analysis of individual uranium-plutonium mixed oxide particles with SIMS and ICP-MS

Esaka, Fumitaka; Magara, Masaaki; Suzuki, Daisuke; Miyamoto, Yutaka; Lee, C. G.; Kimura, Takaumi

Mass Spectrometry Letters, 2(4), p.80 - 83, 2011/00

In this study, we applied secondary ion mass spectrometry (SIMS) and inductively coupled plasma mass spectrometry (ICP-MS) to the isotope ratio analysis of individual U-Pu mixed oxide particles. In the analysis of individual U-Pu particles prepared from mixed solution of uranium and plutonium standard reference materials, accurate $$^{235}$$U/$$^{238}$$U, $$^{240}$$Pu/$$^{239}$$Pu and $$^{242}$$Pu/$$^{239}$$Pu isotope ratios were obtained with both methods. However, accurate analysis of $$^{241}$$Pu/$$^{239}$$Pu isotope ratio was impossible, due to the interference of the $$^{241}$$Am peak to the $$^{241}$$Pu peak. In addition, it was indicated that the interference of the $$^{238}$$UH peak to the $$^{239}$$Pu peak has a possibility to prevent accurate analysis of plutonium isotope ratios. These problems would be avoided by a combination of ICP-MS and chemical separation of uranium, plutonium and americium in individual U-Pu particles.

Journal Articles

Isotope ratio analysis of individual sub-micrometer plutonium particles with inductively coupled plasma mass spectrometry

Esaka, Fumitaka; Magara, Masaaki; Suzuki, Daisuke; Miyamoto, Yutaka; Lee, C. G.; Kimura, Takaumi

Talanta, 83(2), p.569 - 573, 2010/12

 Times Cited Count:16 Percentile:44.33(Chemistry, Analytical)

In the present work, an analytical technique by a combination of chemical separation and inductively coupled plasma mass spectrometry (ICP-MS) is developed and applied to isotope ratio analysis of individual sub-micrometer plutonium particles. The ICP-MS results for individual plutonium particles prepared from a standard reference material (NIST SRM-947) indicate that the use of a desolvation system for sample introduction improves the precision of isotope ratios. In addition, the accuracy of the $$^{241}$$Pu/$$^{289}$$Pu isotope ratio is much improved, owing to the chemical separation of plutonium and americium. In conclusion, the performance of the proposed ICP-MS technique is sufficient for the analysis of individual plutonium particles.

Journal Articles

Sequential separation of U, Th, Pb and lanthanides with a single anion-exchange column

Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki; Kimura, Takaumi; Usuda, Shigekazu*

Journal of Nuclear and Radiochemical Sciences, 10(2), p.7 - 12, 2009/12

With combination of a single anion-exchange column and mixed-media of CH$$_{3}$$COOH and other acids (HCl and/or HNO$$_{3}$$), 50 ng of U, Th, Pb, and lanthanides were sequentially separated. All of the elements were recovered more than 95%, and the decontamination factor was more than 100. This separation technique reduces separation time and simplified the complicated traditional processes without any special reagents and equipments.

Journal Articles

Adsorption of Db and its homologues Nb and Ta, and the pseudo-homologue Pa on anion-exchange resin in HF solution

Tsukada, Kazuaki; Haba, Hiromitsu*; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko*; Kasamatsu, Yoshitaka; Nishinaka, Ichiro; Ichikawa, Shinichi; Yasuda, Kenichiro; Miyamoto, Yutaka; et al.

Radiochimica Acta, 97(2), p.83 - 89, 2009/02

 Times Cited Count:19 Percentile:15.82(Chemistry, Inorganic & Nuclear)

Anion-exchange chromatography of element 105, dubnium (Db), produced in the $$^{248}$$Cm($$^{19}$$F, 5n)$$^{262}$$Db reaction is investigated together with the homologues Nb and Ta, and the pseudo-homologue Pa in 13.9 M hydrofluoric acid (HF) solution. The distribution coefficient (K$$_{d}$$) of Db on an anion-exchange resin is successfully determined by running cycles of the 1702 chromatographic column separations. The result clearly indicates that the adsorption of Db on the resin is significantly different from that of the homologues and that the adsorption of anionic fluoro complexes of these elements decreases in the sequence of Ta $$approx$$ Nb $$>$$ Db $$geq$$ Pa.

130 (Records 1-20 displayed on this page)