Simultaneous determination of insoluble fluoride-forming and high field-strength element abundances in rock samples by ICP-QMS through isotope dilution-internal standardisation

Kagami, Saya; Yokoyama, Tetsuya*

Geostandards and Geoanalytical Research, 45(4), p.679 - 699, 2021/12

AA2020-0580.pdf:1.27MB

https://doi.org/10.1111/ggr.12394

We developed a new method for the determination of the mass fractions of insoluble fluoride-forming elements (IFFEs) and high field strength elements (HFSEs) in rock samples by ICP-QMS. Unlike conventional methods in which the two elemental groups were measured separately using two solutions prepared from distinct sample aliquots, the new technique prepares a solution by acid digestion from a single sample aliquot, then divide the solution into two fractions that are dedicated to the measurement of IFFEs and HFSEs, respectively. The problem regarding the incorporation of IFFEs/HFSEs into insoluble fluorides during HF digestion was overcome by adjusting the Ca-Al-Mg composition of the sample before acid digestion. The acceptable compositional range was Ca/(Ca+Al) 0.43 and Mg/(Mg+Al) 0.40 when the sample was decomposed on a hot plate, while more restricted condition of Ca/(Ca+Al) 0.40, Mg/(Mg+Al) 0.40, and Al/(Mg+Ca) 1.7 was required for the digestion under high pressure and temperature using Teflon bomb. This method achieved the repeatabilities of 4% for most IFFEs and HFSEs, and yielded the mass fractions of most IFFEs and HFSEs that were consistent with the data obtained by conventional methods within 5%. The method is applicable not only to precious samples but also to heterogeneous samples containing accessory minerals enriched in IFFEs/HFSEs.

Research plan on geosphere stability for long-term isolation of radioactive waste (Scientific program for fiscal year 2020)

Ishimaru, Tsuneari; Ogata, Nobuhisa; Shimada, Koji; Kokubu, Yoko; Niwa, Masakazu; Asamori, Koichi; Watanabe, Takahiro; Sueoka, Shigeru; Komatsu, Tetsuya; Yokoyama, Tatsunori; et al.

JAEA-Review 2020-010, 46 Pages, 2020/07

JAEA-Review-2020-010.pdf:1.89MB

This report is a plan of research and development (R&D) on geosphere stability for long-term isolation of high-level radioactive waste (HLW) in Japan Atomic Energy Agency (JAEA), in fiscal year 2020. The objectives and contents in fiscal year 2020 are described in detail based on the JAEA 3rd Medium- and Long-term Plan (fiscal years 2015-2021). In addition, the background of this research is described from the necessity and the significance for site investigation and safety assessment, and the past progress. The plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.

Research plan on geosphere stability for long-term isolation of radioactive waste (Scientific program for fiscal year 2019)

Ishimaru, Tsuneari; Ogata, Nobuhisa; Hanamuro, Takahiro; Shimada, Akiomi; Kokubu, Yoko; Asamori, Koichi; Niwa, Masakazu; Shimada, Koji; Watanabe, Takahiro; Sueoka, Shigeru; et al.

JAEA-Review 2019-010, 46 Pages, 2019/09

JAEA-Review-2019-010.pdf:2.45MB

This report is a plan of research and development (R&D) on geosphere stability for long-term isolation of high-level radioactive waste (HLW) in Japan Atomic Energy Agency, in fiscal year 2019. The objectives and contents in fiscal year 2019 are described in detail based on the outline of 7 years plan (fiscal years 2015-2021). Background of this research is clarified with the necessity and the significance for site investigation and safety assessment, and the past progress in this report. In addition, the plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.

Research plan on geosphere stability for long-term isolation of radioactive waste (Scientific Program for fiscal year 2018)

Ishimaru, Tsuneari; Ogata, Nobuhisa; Shimada, Akiomi; Asamori, Koichi; Kokubu, Yoko; Niwa, Masakazu; Watanabe, Takahiro; Saiga, Atsushi; Sueoka, Shigeru; Komatsu, Tetsuya; et al.

JAEA-Review 2018-020, 46 Pages, 2019/01

JAEA-Review-2018-020.pdf:1.25MB

This report is a plan of research and development (R&D) on geosphere stability for long-term isolation of high-level radioactive waste (HLW) in Japan Atomic Energy Agency, in fiscal year 2018. The objectives and contents in fiscal year 2018 are described in detail based on the outline of 7 years plan (fiscal years 2015-2021). Background of this research is clarified with the necessity and the significance for site investigation and safety assessment, and the past progress in this report. In addition, the plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.

Development of a new continuous dissolution apparatus with a hydrophobic membrane for superheavy element chemistry

Oe, Kazuhiro*; Attallah, M. F.*; Asai, Masato; Goto, Naoya*; Gupta, N. S.*; Haba, Hiromitsu*; Huang, M.*; Kanaya, Jumpei*; Kaneya, Yusuke*; Kasamatsu, Yoshitaka*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 303(2), p.1317 - 1320, 2015/02

https://doi.org/10.1007/s10967-014-3469-3

A new technique for continuous dissolution of nuclear reaction products transported by a gas-jet system was developed for superheavy element (SHE) chemistry. In this technique, a hydrophobic membrane is utilized to separate an aqueous phase from the gas phase. With this technique, the dissolution efficiencies of short-lived radionuclides of Mo and W were measured. Yields of more than 80% were observed for short-lived radionuclides at aqueous-phase flow rates of 0.1-0.4 mL/s. The gas flow-rate had no influence on the dissolution efficiency within the studied flow range of 1.0-2.0 L/min. These results show that this technique is applicable for on-line chemical studies of SHEs in the liquid phase.

Sulfate complexation of element 104, Rf, in HSO/HNO mixed solution

Li, Z.*; Toyoshima, Atsushi; Asai, Masato; Tsukada, Kazuaki; Sato, Tetsuya; Sato, Nozomi; Kikuchi, Takahiro; Nagame, Yuichiro; Schdel, M.; Pershina, V.*; et al.

Radiochimica Acta, 100(3), p.157 - 164, 2012/03

https://doi.org/10.1524/ract.2012.1898

Anionic fluoro complex of element 105, Db

Kasamatsu, Yoshitaka*; Toyoshima, Atsushi; Asai, Masato; Tsukada, Kazuaki; Li, Z.; Ishii, Yasuo; Tome, Hayato*; Sato, Tetsuya; Kikuchi, Takahiro; Nishinaka, Ichiro; et al.

Chemistry Letters, 38(11), p.1084 - 1085, 2009/10

https://doi.org/10.1246/cl.2009.1084

We report on the characteristic anion-exchange behavior of the superheavy element dubnium (Db) with atomic number Z = 105 in HF/HNO solution at the fluoride ion concentration [F] = 0.003 M. The result clearly demonstrates that the fluoro complex formation of Db is significantly different from that of the group-5 homologue Ta in the 6th period of the periodic table while the behavior of Db is similar to that of the lighter homologue Nb in the 5th period.

Extraction behavior of rutherfordium into tributylphosphate from hydrochloric acid

Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Ishii, Yasuo; Tome, Hayato; Sato, Tetsuya; Nishinaka, Ichiro; Ichikawa, Takatoshi; Ichikawa, Shinichi; et al.

Radiochimica Acta, 95(1), p.1 - 6, 2007/01

https://doi.org/10.1524/ract.2007.95.1.1

no abstracts in English

Fluoride complexation of element 104, rutherfordium

Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko; Nishinaka, Ichiro; Hirata, Masaru; Yaita, Tsuyoshi; Ichikawa, Shinichi; Nagame, Yuichiro; et al.

Journal of the American Chemical Society, 126(16), p.5219 - 5224, 2004/04

https://doi.org/10.1021/ja031824u

Fluoride complexation of element 104, rutherfordium (Rf), produced in the Cm(O,5n)Rf reaction has been studied by anion-exchange chromatography on an atom-at-a-time scale. The anion-exchangechromatographic behavior of Rf was investigated in 1.9-13.9 M hydrofluoric acid together with those of the group-4 elements Zr and Hf produced in the O-induced reactions on Ge and Gd targets, respectively. It was found that the adsorption behavior of Rf on anion-exchange resin is quite different from those of Zr and Hf, suggesting the influence of relativistic effect on the fluoride complexation of Rf.

Anion-exchange behavior of Rf in HCl and HNO solutions

Haba, Hiromitsu; Tsukada, Kazuaki; Asai, Masato; Goto, Shinichi*; Toyoshima, Atsushi; Nishinaka, Ichiro; Akiyama, Kazuhiko; Hirata, Masaru; Ichikawa, Shinichi; Nagame, Yuichiro; et al.

Journal of Nuclear and Radiochemical Sciences, 3(1), p.143 - 146, 2002/06

https://doi.org/10.14494/jnrs2000.3.143

We have investigated the sorption behavior of element 104 rutherfordium (Rf) on an anion exchange resin from HCl and HNO solutions. In the HCl experiments, the distribution coefficients of Rf increase with an increase of HCl concentration from 7.0 M to 11.5 M, indicating that anionic species such as [Rf(OH)Cl] or [RfCl] are formed. This sorption behavior of Rf is typical of the group-4 elements Zr and Hf, and is quite different from that of the pseudo-homologue Th. It is also noted that the distribution coefficients decrease in the order Rf, Zr, Hf at 9.0 M HCl, which is consistent with the expected order of ionic radii. On the other hand, Rf appears to behave like Zr and Hf in 8 M HNO not like Pu and Th.