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Tokumitsu, Shun*; Matsumiya, Masahiko*; Sasaki, Yuji
Separation and Purification Technology, 382(Part 2), p.135631_1 - 135631_9, 2026/02
Times Cited Count：0Saga, Kaname; Ban, Yasutoshi
Solvent Extraction and Ion Exchange, 18 Pages, 2026/00
Times Cited Count：0 Percentile：0.00(Chemistry, Multidisciplinary)Hotoku, Shinobu; Ban, Yasutoshi; Konda, Miki; Kitatsuji, Yoshihiro
JAEA-Technology 2025-009, 33 Pages, 2025/11
JAEA-Technology-2025-009.pdf:1.9MB
High-level liquid waste (HLLW) produced from reprocessing of spent nuclear fuels contains heat generating nuclides such as Sr-90, Y-90, Cs-137, Ba-137m, and Am-241. Separation and recovery of these nuclides lead to reduce the volume and toxicity of high-level waste. Furthermore, the recovered nuclides and elements could be utilized as resources after purification. In this test, Sr separation by extraction chromatography using Sr resin and Pb resin, Cs separation by co-precipitation using ammonium phosphomolybdate (AMP), and Am separation by solvent extraction using alkyl diamideamine (ADAAM) were carried out, cold tests were performed for the separation of Cs and Sr in a nitric acid solution. Based on the results, hot tests were performed using dissolution solutions of spent fuel at the Nuclear Fuel Cycle Safety Engineering Research Facility (NUCEF), and each component contained in the separated solution was analyzed. In the Sr separation by extraction chromatography, most of Sr was separated from other elements using 8 mol/L nitric acid for absorption and 0.02 mol/L nitric acid for elution. In the separation of Cs, more than 99.9% of Cs was selectively co-precipitated by adding AMP to the HLLW, in which nitric acid concentration was adjusted to 3.1 mol/L. In solvent extraction of Am by ADAAM, 81.4% of Am-241 was recovered by a single stage batch experiment. Since Sr, Cs, and Am were properly separated and recovered from HLLW, the effectiveness of the present separation method was successfully demonstrated.
Toigawa, Tomohiro; Tsubata, Yasuhiro; Kumagai, Yuta; Ban, Yasutoshi
Progress in Nuclear Science and Technology (Internet), 8, p.286 - 290, 2025/09
We propose a simple process simulation methodology that uses readily available information about radiation impact. A process simulation was conducted for a minor actinides (MA) separation process while considering the degradation of extraction ability by radiolysis. The simulation provided a processing limit of MA and enabled the evaluation of radiation stability.
Sasaki, Yuji; Kaneko, Masashi; Ban, Yasutoshi; Suzuki, Hideya*
Journal of Nuclear Science and Technology, 61(7), p.883 - 893, 2024/07
Times Cited Count：5 Percentile：64.60(Nuclear Science & Technology)The mutual separation of Am and Cm is conducted using an alkyl-diamide amine (ADAAM) extractant. ADAAM exhibits extremely high separation factor with respect to Am and Cm separation (5.9) in a nitric acid-
-dodecane system. The batch-wise multistage extractions are performed using a system containing 0.2 M ADAAM and 1.5 M nitric acid. In this multistage extraction, an organic solvent give 96.5% and 1.06% yields of Am and Cm. After the mutual separation of Am and Cm, an additional extraction step is included to reduce the volumes of these aqueous and organic phases. Taking these steps, Am and Cm can be recovered in just two or three stages in the aqueous phases.
Micheau, C.; Ueda, Yuki; Motokawa, Ryuhei; Akutsu, Kazuhiro*; Yamada, Norifumi*; Yamada, Masako*; Moussaoui, S. A.*; Makombe, E.*; Meyer, D.*; Berthon, L.*; et al.
Journal of Molecular Liquids, 401, p.124372_1 - 124372_12, 2024/05
Times Cited Count：4 Percentile：57.85(Chemistry, Physical)Sasaki, Yuji; Kaneko, Masashi; Ban, Yasutoshi; Kinoshita, Ryoma; Matsumiya, Masahiko*; Shinoku, Kota*; Shiroishi, Hidenobu*
Analytical Sciences, 39(9), p.1575 - 1583, 2023/09
Times Cited Count：3 Percentile：22.76(Chemistry, Analytical)Extraction of Rh from HCl can be performed by NTAamide(C6) (hexahexyl-nitrilotriacetamide) and other related compounds into n-dodecane. We use ion-pair extraction of anionic species of Rh-chloride and protonated extractant. Rh behave as anion in hydrochloric acid and the tertiary nitrogen atom in extractant may be protonated to produce the quaternary amine in acidic condition. From the present work, the maximum distribution ratio of Rh(III) is 16. The D(Rh) values are changeable during preparation of the aqueous solutions because different Rh-Cl-H
O complexes are formed in HCl media and show the slow exchange rate between Cl and HO. Using the UV spectrum, Rh-chloride solution having the peak of spectrum at 504 nm can be extracted effectively, where RhCl
(HO)
and RhCl
(H
O)
exist mainly from DFT calculation. Stoichiometry of one-one complex of Rh and NTAamide is obtained from slope analysis, and 85 mM of concentrated Rh ion can be extracted.
Arai, Yoichi; Watanabe, So; Hasegawa, Kenta; Okamura, Nobuo; Watanabe, Masayuki; Takeda, Keisuke*; Fukumoto, Hiroki*; Ago, Tomohiro*; Hagura, Naoto*; Tsukahara, Takehiko*
Nuclear Instruments and Methods in Physics Research B, 542, p.206 - 213, 2023/09
Times Cited Count：1 Percentile：17.76(Instruments & Instrumentation)Narita, Hirokazu*; Maeda, Motoki*; Tokoro, Chiharu*; Suzuki, Tomoya*; Tanaka, Mikiya*; Shiwaku, Hideaki; Yaita, Tsuyoshi
RSC Advances (Internet), 13(25), p.17001 - 17007, 2023/06
Times Cited Count：3 Percentile：20.66(Chemistry, Multidisciplinary)no abstracts in English
Simonnet, M.; Sasaki, Yuji; Yaita, Tsuyoshi
Solvent Extraction and Ion Exchange, 41(7), p.857 - 867, 2023/00
Times Cited Count：5 Percentile：28.09(Chemistry, Multidisciplinary)Simonnet, M.; Sittel, T.*; We
ling, P.*; Geist, A.*
Energies (Internet), 15(20), p.7724_1 - 7724_10, 2022/10
Times Cited Count：8 Percentile：30.49(Energy & Fuels)Matsutani, Takafumi; Sasaki, Yuji; Katsuta, Shoichi*
Analytical Sciences, 37(11), p.1603 - 1609, 2021/11
Times Cited Count：9 Percentile：40.51(Chemistry, Analytical)We investigated the chemical behavior of lanthanides (Ln) using diglycolamide extractant with multistage extraction. We obtained the breakthrough curves for light and middle Ln. Our study reveals that the metal extraction limit depends on their 
values and metal concentrations used in the experiments. From the multistage extractions of 15 aqueous phases and 15 organic phases, three curves (extraction curves, back-extraction curves, and separation curves) were obtained by changing the nitric acid concentration. As an example, under a condition of the separation curve experiment (aqueous phase: 0.5 M HNO
, organic phase: 0.1 M TDDGA (
-tetradecyl-diglycolamide) in -dodecane), a recovery of more than 99% of Sm in the organic phase with less than 1% Nd can be obtained.
Simonnet, M.; Kobayashi, Toru; Shimojo, Kojiro; Yokoyama, Keiichi; Yaita, Tsuyoshi
Inorganic Chemistry, 60(17), p.13409 - 13418, 2021/09
Times Cited Count：30 Percentile：90.38(Chemistry, Inorganic & Nuclear)Sasaki, Yuji; Morita, Keisuke; Matsumiya, Masahiko*; Ono, Ryoma*; Shiroishi, Hidenobu*
JOM, 73(4), p.1037 - 1043, 2021/04
Times Cited Count：4 Percentile：22.62(Materials Science, Multidisciplinary)The separation of Dy from Nd is studied from the viewpoint of recycling Dy from Nd magnets. Both metals are lanthanide elements, which means their mutual separation is difficult because of their similar chemical behaviors. All lanthanide elements can be extracted easily by using tetradodecyl-diglycolamide (TDdDGA) extractants, and it has a relatively high separation factor (SF) between Dy and Nd (SF over 10). In the present study, by performing eight extraction steps with the organic phase (0.1M TDdDGA in dodecane), ten steps with an aqueous phase (0.7 M HNO with metals), and six steps with another aqueous phase (0.7 M HNO without metals), approximately 99% Dy was recovered into the organic phase with 1% co-extraction of Nd.
Sasaki, Yuji; Morita, Keisuke; Kitatsuji, Yoshihiro; Ito, Keisuke*; Yoshizuka, Kazuharu*
Solvent Extraction Research and Development, Japan, 28(2), p.121 - 131, 2021/00
Times Cited Count：3 Percentile：11.42(Chemistry, Multidisciplinary)High concentration of Cs is present in high-level radioactive waste. It is well-known that Cs is an alkali element and difficult to extract completely into an organic phase. Crown ether compounds are widely available for Cs extractants; DtBuDB18C6 (di-
-butyl-dibenzo-18crown6), was used in this study. Organic solvents used for the industrial applications, such as -dodecane and 1-octanol, have low solubility concerning the compound; other solvents were employed and tested. In this study, ketone-, ether-, and ester-type solvents showed high solubility for DtBuDB18C6 and DtBuDB18C6, when dissolved in ketones and alcohols, exhibited relatively high Cs distribution ratios ((Cs)), closely to 10.
Toigawa, Tomohiro; Murayama, Rin*; Kumagai, Yuta; Yamashita, Shinichi*; Suzuki, Hideya; Ban, Yasutoshi; Matsumura, Tatsuro
UTNL-R-0501, p.24 - 25, 2020/12
This report summarizes the results obtained in FY2019 at Electron Linac Facility of University of Tokyo. The radiolysis process of a diglycolamide extractant, which is expected to be used in the separation process of minor actinides (MA), in dodecane and octanol solutions was investigated by pulse radiolysis. As a result, it was suggested that by adding alcohol, the decomposition process of the diglycolamide extractant was different from the decomposition processes in the single solvent of dodecane considered that the decomposition occurred via a radical cation species of the extractant.
Sasaki, Yuji; Nakase, Masahiko*
Petorotekku, 43(11), p.782 - 787, 2020/11
As analog compounds of DGA (diglycolamide), MIDOA(methylimino-diacetamide) and TDGA(thia-diglycolammide) are used for the extractants of platinum group metals. These extractants can be extracted noble metals and oxyanions, which followed by HSAB theory. The high concentration of these metals can be also extracted by these compounds. The research of metal-complex structures gives the information on the ability and role for complex-formation, which will be useful for the development of novel extractants.
-dodecane by methylimino-dioctylacetamide (MIDOA))Sasaki, Yuji
Separation Science and Technology, 55(4), p.708 - 715, 2020/00
Times Cited Count：6 Percentile：20.98(Chemistry, Multidisciplinary)Methylimino-di-n-octylacetamide (MIDOA) was used to extract 57 metals from HCl into -dodecane. MIDOA is a tridentate ligand with one N donor and two carbonyl O donors and can extract soft acid metals and metal oxonium anions. In the present work, Fe(III), Zr(IV), Ga(III), Mo(VI), Tc(VII), Pd(II), Cd(II), In(III), Sn(IV), W(VI), Re(VII), Os(III), Ir(III), Pt(IV), Au(III), Hg(II), Bi(III), and U(VI) had distribution ratios above 10 when using 0.1 M MIDOA/n-dodecane and 3 M HCl. The amount of metal ion (Mo(VI), Tc(VII), Re(VII), Pd(II), Pt(IV), and Au(III)) extracted from HCl was greater than that obtained using HNO.
Simonnet, M.; Suzuki, Shinichi; Miyazaki, Yuji*; Kobayashi, Toru; Yokoyama, Keiichi; Yaita, Tsuyoshi
Solvent Extraction and Ion Exchange, 38(4), p.430 - 440, 2020/00
Times Cited Count：23 Percentile：63.78(Chemistry, Multidisciplinary)Simonnet, M.; Miyazaki, Yuji*; Suzuki, Shinichi; Yaita, Tsuyoshi
Solvent Extraction and Ion Exchange, 37(1), p.81 - 95, 2019/00
Times Cited Count：10 Percentile：31.92(Chemistry, Multidisciplinary)