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Journal Articles

Structural characterization of Eu-HONTA complexes by IBIL and EXAFS analyses

Watanabe, So; Sano, Yuichi; Okada, Makoto*; Matsuura, Haruaki*; Hagura, Naoto*; Kada, Wataru*

Nuclear Instruments and Methods in Physics Research B, 477, p.60 - 65, 2020/08

 Times Cited Count:0 Percentile:100(Instruments & Instrumentation)

IBIL and EXAFS analyses were applied on strucutral analysis of Eu complex formed in adsorbent developed for extraction chromatography. Those analyses revealed slight structural difference between adsorbent and solvent systems.

Journal Articles

Improvement in flow-sheet of extraction chromatography for trivalent minor actinides recovery

Watanabe, So; Senzaki, Tatsuya; Shibata, Atsuhiro; Nomura, Kazunori; Takeuchi, Masayuki; Nakatani, Kiyoharu*; Matsuura, Haruaki*; Horiuchi, Yusuke*; Arai, Tsuyoshi*

Journal of Radioanalytical and Nuclear Chemistry, 322(3), p.1273 - 1277, 2019/12

 Times Cited Count:0 Percentile:100(Chemistry, Analytical)

Journal Articles

STRAD project for systematic treatments of radioactive liquid wastes generated in nuclear facilities

Watanabe, So; Ogi, Hiromichi*; Arai, Yoichi; Aihara, Haruka; Takahatake, Yoko; Shibata, Atsuhiro; Nomura, Kazunori; Kamiya, Yuichi*; Asanuma, Noriko*; Matsuura, Haruaki*; et al.

Progress in Nuclear Energy, 117, p.103090_1 - 103090_8, 2019/11

 Times Cited Count:0 Percentile:100(Nuclear Science & Technology)

Journal Articles

Ion beam induced luminescence of complexes formed in adsorbent for MA recovery process

Watanabe, So; Katai, Yuya*; Matsuura, Haruaki*; Kada, Wataru*; Koka, Masashi*; Sato, Takahiro*; Arai, Tsuyoshi*

Nuclear Instruments and Methods in Physics Research B, 450, p.61 - 65, 2019/07

 Times Cited Count:1 Percentile:58.8(Instruments & Instrumentation)

Journal Articles

Microanalysis of silica-based adsorbent for effective recovery of radioactive elements

Sano, Yuichi; Watanabe, So; Matsuura, Haruaki*; Nagoshi, Kohei*; Arai, Tsuyoshi*

Journal of Nuclear Science and Technology, 54(10), p.1058 - 1064, 2017/10

 Times Cited Count:3 Percentile:50.46(Nuclear Science & Technology)

For effective recovery of radioactive elements by adsorbents using polymer-immobilized silica (SiO$$_{2}$$-P) supports, the microstructure of SiO$$_{2}$$-P particles impregnated with CMPO as extractants and their change with the crosslinking degree of polymer (CDP) were investigated using STXM and EXAFS analyses; further, their relation with adsorption/elution behavior was discussed. The adsorption/elution tests using adsorbents with a different CDP demonstrated that a higher CDP inhibited the elution of adsorbed metal ions from the adsorbent. The results of STXM and EXAFS analyses suggested that adsorption by CMPO proceeds through the entire area in the adsorbent and the local structure around adsorbed metal ions is similar irrespective of the CDP. Conversely, STXM analyses implied the capture of eluents such as H$$_{2}$$O by polymers with high CDP, which suppresses the prompt elution of adsorbed metal ions from the adsorbent.

Journal Articles

Local structure and distribution of remaining elements inside extraction chromatography adsorbents

Watanabe, So; Sano, Yuichi; Shiwaku, Hideaki; Yaita, Tsuyoshi; Ono, Shimpei*; Arai, Tsuyoshi*; Matsuura, Haruaki*; Koka, Masashi*; Sato, Takahiro*

Nuclear Instruments and Methods in Physics Research B, 404, p.202 - 206, 2017/08

 Times Cited Count:3 Percentile:50.46(Instruments & Instrumentation)

Journal Articles

Microscopic analyses of complexes formed in adsorbent for Mo and Zr separation chromatography

Abe, Ryoji*; Nagoshi, Kohei*; Arai, Tsuyoshi*; Watanabe, So; Sano, Yuichi; Matsuura, Haruaki*; Takagi, Hideaki*; Shimizu, Nobutaka*; Koka, Masashi*; Sato, Takahiro*

Nuclear Instruments and Methods in Physics Research B, 404, p.173 - 178, 2017/08

 Times Cited Count:1 Percentile:80.48(Instruments & Instrumentation)

JAEA Reports

XAFS measurement of simulated waste glass samples (Borosilicate glass including vanadium)

Nagai, Takayuki; Kobayashi, Hidekazu; Sasage, Kenichi; Ayame, Yasuo; Okamoto, Yoshihiro; Shiwaku, Hideaki; Matsuura, Haruaki*; Uchiyama, Takafumi*; Okada, Yukiko*; Nezu, Atsushi*; et al.

JAEA-Research 2016-015, 52 Pages, 2016/11


The local structure of waste elements in simulated waste glasses including V was estimated by using synchrotron XAFS measurement in this study. The results are as follows. (1) V has a high possibility which exists in the glass phase in the case of frit, and V can regard both samples as stable 4 coordination structure. (2) Zn, Ce, Nd, Zr, and Mo exist in the glass phase, and the difference is admitted by the percentage of Ce(III) and Ce(IV) by the composition. (3) Ru is separated from the glass phase as RuO$$_{2}$$ crystalline, both of metal and oxide exist in Rh, and Pd is separated out as metal. (4) It was confirmed that the regularity of the local structure of Zr and Mo in the molten glasses retreats as a result of the XAFS measurement at high temperature. (5) The XAFS measurement of molten glasses were performed at 1200$$^{circ}$$C, so it would be possible to acquire excellent data by improving the shapes of the sample cell.

Journal Articles

Structural investigation of thorium in molten lithium-calcium fluoride mixtures for salt treatment process in molten salt reactor

Numakura, Masahiko*; Sato, Nobuaki*; Bessada, C.*; Okamoto, Yoshihiro; Akatsuka, Hiroshi*; Nezu, Atsushi*; Shimohara, Yasuaki*; Tajima, Keisuke*; Kawano, Hirokazu*; Nakahagi, Takeshi*; et al.

Progress in Nuclear Energy, 53(7), p.994 - 998, 2011/11

 Times Cited Count:10 Percentile:31.54(Nuclear Science & Technology)

X-ray absorption fine structure (XAFS) measurements on thorium fluoride in molten lithium-calcium fluoride mixtures and molecular dynamics (MD) simulation of zirconium and yttrium fluoride in molten lithium-calcium fluoride mixtures have been carried out. In the molten state, coordination number of thorium and inter ionic distances between thorium and fluorine in the first neighbor are nearly constant in all mixtures. However the fluctuation factors (Debye-Waller factor and C$$_3$$ cumulant) increase until $$x$$CaF$$_2$$ = 0.17 and decrease by addition of excess CaF$$_2$$. It means that the local structure around Th$$^{4+}$$ is disordered until $$x$$CaF$$_2$$=0.17 and stabilized over $$x$$CaF$$_2$$ = 0.17. The variation of fluctuation factors is related to the number density of F$$^-$$ in ThF$$_4$$ mixtures and the stability of local structure around Th$$^{4+}$$ increases with decreasing the number density of F$$^-$$ in ThF$$_4$$ mixtures. This tendency is common to those in the ZrF$$_4$$ and YF$$_3$$ mixtures.

Journal Articles

EXAFS analysis of uranium(IV) and thorium(IV) complexes in concentrated CaCl$$_{2}$$ solutions

Uehara, Akihiro*; Fujii, Toshiyuki*; Matsuura, Haruaki*; Sato, Nobuaki*; Nagai, Takayuki; Minato, Kazuo; Yamana, Hajimu*; Okamoto, Yoshihiro

Proceedings in Radiochemistry, 1(1), p.161 - 165, 2011/09

Journal Articles

Ion specific effects on the structure of molten AF-ZrF$$_4$$ systems (A$$^+$$ = Li$$^+$$, Na$$^+$$, and K$$^+$$)

Pauvert, O.*; Salanne, M.*; Zanghi, D.*; Simon, C.*; Reguer, S.*; Thiaudi$`e$re, D.*; Okamoto, Yoshihiro; Matsuura, Haruaki*; Bessada, C.*

Journal of Physical Chemistry B, 115(29), p.9160 - 9167, 2011/07

 Times Cited Count:44 Percentile:22(Chemistry, Physical)

The structure of molten AF-ZrF$$_4$$ system (A$$^+$$=Li$$^+$$, Na$$^+$$, K$$^+$$) is studied using EXAFS spectroscopy with molecular dynamics simulations. From the Zr$$^{4+}$$ solvation shell point of view, we observe a progressive stabilization of the 7-fold and then of the 6-fold coordinated complexes when passing from Li$$^+$$ to Na$$^+$$ and K$$^+$$ as a "counterion". Particular attention is given to the systems consisting of 35 mol% of ZrF$$_4$$. At that particular composition, the ZrF$$_6$$$$^{2-}$$ complex predominates largely whatever the nature of the alkali. The calculated vibrational properties of this complex are in excellent agreement with a previous Raman spectroscopy experiment on molten KF-ZrF$$_4$$. The most important differences are observed for the lifetime of these octahedral units. On a larger scale, an intense first sharp diffraction peak is observed for the Zr$$^{4+}$$-Zr$$^{4+}$$ partial structure factor, which can be attributed to the correlations between the octahedral units formed.

Journal Articles

In situ experimental evidence for a nonmonotonous structural evolution with composition in the molten LiF-ZrF$$_4$$ system

Pauvert, O.*; Zanghi, D.*; Salanne, M.*; Simon, C.*; Rakhamatullin, A.*; Matsuura, Haruaki*; Okamoto, Yoshihiro; Vivet, F.*; Bessada, C.*

Journal of Physical Chemistry B, 114(19), p.6472 - 6479, 2010/05

 Times Cited Count:45 Percentile:22.64(Chemistry, Physical)

The structure of the molten LiF-ZrF$$_4$$ system up to 50 mol% ZrF$$_4$$ was investigated by combining high-temperature nuclear magnetic resonance (NMR) and extended X-ray absorption fine structure (EXAFS) experiments with molecular dynamics (MD) calculations. $$^{91}$$Zr high-temperature NMR experiments give an average coordination of 7 for the zirconium ion on all domains of composition. MD simulations, in agreement with EXAFS experiments at the K-edge of Zr, provide evidence for the coexistence of three different Zr-based complexes, [ZrF$$_6$$]$$^{2-}$$, [ZrF$$_7$$]$$^{3-}$$, and [ZrF$$_8$$]$$^{4-}$$, in the melt.

Journal Articles

X-ray structural analysis of molten PbCl$$_2$$

Okamoto, Yoshihiro; Iwadate, Yasuhiko*; Fukushima, Kazuko*; Matsuura, Haruaki*; Minato, Kazuo

Journal of Physics and Chemistry of Solids, 66(2-4), p.452 - 455, 2005/02

 Times Cited Count:6 Percentile:68.03(Chemistry, Multidisciplinary)

The structure of molten PbCl$$_2$$ was investigated by using X-ray diffrtaction(XRD) and X-ray absorption fine structure(XAFS) analysis techniques. From the fourier transformation analysis if the XRD data, the nearest Pb$$^{2+}$$-Cl$$^-$$ interaction consists of two kinds of interactions; rigid 4-fold tetrahedron and 2-3 loose coordination. The XAFS result shows a local structure is the 4-fold coordination in the melt.

Oral presentation

Development of pyrochemical reprocessing technology based on Co-electrodeposition method, 12; General overview and electrodeposition test

Myochin, Munetaka; Kofuji, Hirohide; Yamana, Hajimu*; Shirai, Osamu*; Yamamura, Tsutomu*; Umesaki, Norimasa*; Matsuura, Haruaki*; Kajinami, Akihiko*; Iwadate, Yasuhiko*; Otori, Norikazu*; et al.

no journal, , 

no abstracts in English

Oral presentation

Mixing behavior of rare earth - alkali chlorides probed by XAFS and MD simulation

Okamoto, Yoshihiro; Yaita, Tsuyoshi; Shiwaku, Hideaki; Matsuura, Haruaki*; Madden, P. A.*

no journal, , 

Mixing behavior of rare earth trichlorides (RECl$$_3$$) with LiCl-KCl eutectic melt was studied by using an X-ray absorption fine structure (XAFS) and a molecular dynamics (MD) simulation techniques. We had confirmed that the local structure of pure RECl$$_3$$ melt changed corresponding to size of RE$$^{3+}$$ ion. On the other hand, it can be concluded that many mixtures show stabilized 6-fold coordination (RECl$$_6$$)$$^{3-}$$ structure in diluted compositions. It suggests that molten RECl$$_3$$ has a simular local structure in diluted composition.

Oral presentation

High-energy XAFS study of molten terbium trichloride mixtures

Numakura, Masahiko; Okamoto, Yoshihiro; Yaita, Tsuyoshi; Shiwaku, Hideaki; Suzuki, Shinichi; Kobayashi, Toru; Akutsu, Kazuhiro; Matsuura, Haruaki*

no journal, , 

The high energy XAFS using K-absorption edge is very effective to obtain information on behavior of small amount of rare earth elements in molten chlorides. In the present study, we performed the XAFS measurement to obtain the local structure change for molten TbCl$$_3$$ and the mixture of 40% TbCl$$_3$$ with LiCl-KCl eutectic, 15% TbCl$$_3$$ with LiCl-KCl eutectic and 1.5% TbCl$$_3$$ with LiCl-KCl eutectic. We found that as the concentration of TbCl$$_3$$ is lower, the coordination number decrease a little and become near 6 but the nearest Tb-Cl distance is almost same. In addition, we found that Debye-Waller factor become very small. We also performed molecular dynamics simulation to obtain the information of structure change. This simulation showed the intense structure change occurs at vicinity of 25% TbCl$$_3$$ with LiCl-KCl eutectic. Its simulation result accorded with this XAFS experiment result.

Oral presentation

Structural analysis of molten TbF$$_3$$-LiF

Numakura, Masahiko*; Bessada, C.*; Ory, S.*; Rakhamatullin, A.*; Akatsuka, Hiroshi*; Nezu, Atsushi*; Yaita, Tsuyoshi; Okamoto, Yoshihiro; Shiwaku, Hideaki; Matsuura, Haruaki*

no journal, , 

To investigate the local structure of molten TbF$$_3$$ - LiF (x[TbF$$_3$$ = 0.2), X-ray absorption fine structure technique (XAFS) was applied using by BL11XU in SPring-8. By several analyses, e.g. X-ray diffraction and differential scanning calorimetry, it had been confirmed that TbF$$_{3}$$ and boron nitride reacted at less than 1073 K even under helium gas flow environment, thus, we focused on the spectrum obtained below 1073 K. According to the curve fitting, the interionic distance obtained from the data of heating between 933 K and 1013 K was shorter than solid state. It would be surely molten state of TbF$$_3$$ - LiF (x[TbF$$_3$$] = 0.2), since the value of distance obtained, i.e. 2.26${AA}$ corresponds to the sum of ionic radii of Tb$$^{3+}$$ and F$$^-$$.

Oral presentation

Integration of minor actinide separation process; EXAFS analysis of rare earth elements absorbed at the surface of various adsorbents

Matsuura, Haruaki*; Nezu, Atsushi*; Arai, Tsuyoshi*; Ono, Shimpei*; Sano, Yuichi; Watanabe, So

no journal, , 

no abstracts in English

Oral presentation

Strucutral analysis of complexes formed in adsorbents for MA recovery

Watanabe, So; Sano, Yuichi; Arai, Tsuyoshi*; Matsuura, Haruaki*; Shimizu, Nobutaka*; Takagi, Hideaki*

no journal, , 

no abstracts in English

Oral presentation

STXM analysis of adsorbent for effective recovery of radioactive elements

Sano, Yuichi; Watanabe, So; Matsuura, Haruaki*; Arai, Tsuyoshi*

no journal, , 

For effective recovery of radioactive elements by adsorbents using polymer-immobilized silica (SiO$$_{2}$$-P) supports, the microstructure of SiO$$_{2}$$-P particles impregnated with CMPO as extractants and their change with the crosslinking degree of polymer (CDP) were investigated using STXM analysis. The results of STXM analysis suggested that the distributions of polymer are spread and impurity molecules such as H$$_{2}$$O are captured by the increase of CDP.

49 (Records 1-20 displayed on this page)