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Sasaki, Yuji; Kaneko, Masashi; Ban, Yasutoshi; Suzuki, Hideya*
Journal of Nuclear Science and Technology, 61(7), p.883 - 893, 2024/07
Times Cited Count：3 Percentile：54.24(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.
Kinoshita, Ryoma; Sasaki, Yuji; Kaneko, Masashi; Matsumiya, Masahiko*; Shinoku, Kota*; Shiroishi, Hidenobu*
Hydrometallurgy, 222, p.106159_1 - 106159_12, 2023/10
Times Cited Count：1 Percentile：16.17(Metallurgy & Metallurgical Engineering)Solvent extraction is conducted using a total of 20 metals revealing high stability constants with Cl and hexahexyl-nitrilotriacetamide (NTAamide(C6)) extractant. The metals used here may behave as anions at high Cl concentrations, and NTAamide(C6), which contains a tertiary N atom, is protonated under acidic conditions. Most of the metal ions in this study display higher distribution ratios (D(M)) from HCl than those from HNO
, and exhibit 1:1 stoichiometries with NTAamide. Following the experimental results, the association constants and distribution coefficients of the group 12 elements are calculated via ion-pair extraction modeling using density functional theory calculations, and the simulations of D yield calculated values with the same trend as that of the measured values.
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：2 Percentile：15.43(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.
Suzuki, Hideya*; Ban, Yasutoshi
Analytical Sciences, 39(8), p.1341 - 1348, 2023/08
Times Cited Count：4 Percentile：57.53(Chemistry, Analytical)The Japan Atomic Energy Agency (JAEA) has proposed the Solvent Extraction from Liquid waste using Extractants of CHON-type for Transmutation (SELECT) process by solvent extraction as a new separation technology to recover minor actinides (MA) from high-level liquid waste (HLLW) produced by spent fuel reprocessing. The MA separation in the SELECT process comprises the batch recovery of MA and rare earths (RE) from HLLW, MA/RE separation, and Am/Cm separation. Three highly practical extractants are used in the MA separation. Furthermore, this flow configuration facilitates the preparation of nitric acid concentrations in the aqueous phase. However, the separation factor between Cm and Nd in the MA/RE separation is small (
= 2.5), requiring many extraction stages for continuous extraction in a mixer-settler. Therefore, this study investigated the separation of only Am from an aqueous nitric acid solution containing MA (Am and Cm) and RE using an organic phase mixed with two extractants alkyl diamideamine with 2-ethylhexyl alkyl chains (ADAAM(EH)) and hexa-n-octylnitrilotriacetamide (HONTA) used in the SELECT process. Under high-concentration nitric acid conditions, Am and La, Ce, Pr, Nd (light lanthanides) were extracted in the ADAAM(EH) + HONTA mixed solvent, whereas Cm, medium, and heavy lanthanides, and Y were partitioned in the aqueous phase. Subsequently, only light lanthanides could be back extracted from the ADAAM(EH) + HONTA mixture solvent containing Am and light lanthanides in low nitric acid concentrations. Furthermore, Am could be easily stripped with 0.2 M or 5 M nitric acid. This method does not require the mutual separation of Cm and Nd, which have low separation factors. Am can be efficiently separated by one extraction and two back-extractions, reducing the number of steps in the SELECT process.
Kaneko, Masashi; Suzuki, Hideya; Matsumura, Tatsuro
Inorganic Chemistry, 57(23), p.14513 - 14523, 2018/12
Times Cited Count：23 Percentile：79.08(Chemistry, Inorganic & Nuclear)We elucidated the separation mechanism between Am(III) and Cm(III) ions by using two different types of diamide ligands, diglycolamide (DGA) and alkylated diamide amine (ADAAM), by means of the density functional theory technique and electron density analysis. The molecular geometries and formation reactions of the metal-ligand complexes were modeled by using [M(DGA)]
and [M(ADAAM)(NO)(HO)]. We successfully reproduced Cm(III) selectivity over Am(III) with DGA and Am(III) selectivity over Cm(III) with ADAAM. Furthermore, we analyzed the bonding properties between the metal ion and the diamide-type ligands by using model complexes, [M(DGA)] and [M(ADAAM)(NO)(HO)], and revealed the differences in terms of the bond dissociation energy and the metal 5f-orbital participation in the covalency between the Am(III) and the Cm(III) complexes. It was suggested that the differences were key factors to understand the Am(III)/Cm(III) selectivity.
Sasaki, Yuji; Morita, Keisuke; Ito, Keisuke; Suzuki, Shinichi; Shiwaku, Hideaki; Takahashi, Yuya*; Kaneko, Masaaki*; Omori, Takashi*; Asano, Kazuhito*
Proceedings of International Nuclear Fuel Cycle Conference (GLOBAL 2017) (USB Flash Drive), 4 Pages, 2017/09
no abstracts in English
Ogura, K.*; Asano, Masaharu; Yasuda, Nakahiro*; Yoshida, Masaru
Nuclear Instruments and Methods in Physics Research B, 185(1-4), p.222 - 227, 2001/12
Times Cited Count：33 Percentile：89.04(Instruments & Instrumentation)no abstracts in English
Kaneko, Masashi; Watanabe, Masayuki; Suzuki, Hideya; Matsumura, Tatsuro
no journal, ,
Japan Atomic Energy Agency has developed separation reagents between Am and Cm ions, which are minor actinides, to achieve partitioning and transmutation strategy. We aim to elucidate the Am/Cm separation mechanism by various reagents at a molecular level to design a novel extraction reagent. This study focused on the Am/Cm separation with diglycolamide (DGA) and alkyl-diacetoamidamine (ADAAM) reagents by using density functional theory. We modeled the complex formation reactions by referring to reported single crystal structures and solvent extraction experiments. As the result, we succeeded in reproducing the Am/Cm separation behaviors with DGA and ADAAM reagents. Moreover, the electronic state analyses of the extracted complexes indicated that a difference in chemical bonding property of 5f-electrons between Am and Cm differentiates the Am/Cm selectivity.
Osugi, Takeshi
no journal, ,
no abstracts in English
Kaneda, Yoshihisa*; Haga, Kazuko*; Shibata, Masahito*; Kuranaga, Mebae*; Kikuchi, Michio*; Yamamoto, Takeshi*; Kato, Jun; Osugi, Takeshi; Kuroki, Ryoichiro
no journal, ,
Solidified cement and alkali activated materials was made, and used for dissolution test to obtain basic data of solidification on the waste caused by the contaminated water treatment at Fukushima Daiichi Nuclear Power Station.
Kikuchi, Michio*; Yamamoto, Takeshi*; Otsuka, Taku*; Kawato, Takaya*; Kaneda, Yoshihisa*; Shibata, Masahito*; Haga, Kazuko*; Taniguchi, Takumi; Osugi, Takeshi; Kuroki, Ryoichiro
no journal, ,
Summary of the study which is for characterization of Solidified cement and alkali activated materials was carried out due to obtain the data available for applicability evaluation low-temperature solidification on the waste caused by the contaminated water treatment at Fukushima Daiichi Nuclear Power Station.
Suzuki, Hideya*; Ban, Yasutoshi; Tsubata, Yasuhiro; Tsutsui, Nao; Toigawa, Tomohiro; Kurosawa, Tatsuya*; Shibata, Mitsunobu*; Kawasaki, Tomohiro*; Matsumura, Tatsuro
no journal, ,
The Japan Atomic Energy Agency (JAEA) has been studying partitioning technology. Recently, JAEA proposed a new liquid-liquid extraction technology called SELECT process to separate minor actinide (MA) from high-level liquid waste for transmutation. In this process, new extractants (HONTA, ADAAM) with highly practical and high extraction ability for MA was developed. A mixed solvent of HONTA and ADAAM was tested for mutual separation of MA and rare earth elements (RE). In this test, separation of MA and RE was achieved with very high yield. Furthermore, Americium (Am) and Curium (Cm) were separated efficiently with high separation factor values.
Kato, Jun; Imaizumi, Ken*; Osugi, Takeshi; Sone, Tomoyuki; Kuroki, Ryoichiro; Kikuchi, Michio*; Yamamoto, Takeshi*; Otsuka, Taku*; Kaneda, Yoshihisa*; Osawa, Norihisa*
no journal, ,
Solidified cement and Alkali Activated Materials (AAM) containing simulated carbonated slurry was prepared, and the amount of Hydrogen gas generation on gamma-ray irradiation was determined. The obtained data was compared with the data of solidified material without any content of waste, and the effect for Hydrogen gas generation with the material containing simulated carbonated slurry was evaluated.
Taniguchi, Takumi; Namiki, Masahiro*; Osugi, Takeshi; Sone, Tomoyuki; Kuroki, Ryoichiro; Kikuchi, Michio*; Yamamoto, Takeshi*; Otsuka, Taku*; Kaneda, Yoshihisa*; Osawa, Norihisa*; et al.
no journal, ,
no abstracts in English
Kakuda, Ayaka; Osone, Osamu*; Hiraki, Yoshihisa; Osugi, Takeshi; Sone, Tomoyuki; Kuroki, Ryoichiro; Kudo, Isamu*; Elakneswaran, Y.*; Sato, Tsutomu*
no journal, ,
no abstracts in English
Kikuchi, Michio*; Yamamoto, Takeshi*; Otsuka, Taku*; Kawato, Takaya*; Kaneda, Yoshihisa*; Shibata, Masahito*; Haga, Kazuko*; Osugi, Takeshi; Sone, Tomoyuki; Kuroki, Ryoichiro
no journal, ,
In order to obtain data to be used in the evaluation of the applicability of low temperature processing to carbonate slurry generated by contaminated water treatment at Fukushima Daiichi Nuclear Power Station, the basic properties of the solidified cement and alkali activated material blended simulated carbonated slurry were evaluated. An overview of the study and some of the results obtained are reported here.
Hiraki, Yoshihisa
no journal, ,
no abstracts in English
Hiraki, Yoshihisa; Kakuda, Ayaka; Saito, Toshimitsu*; Sone, Tomoyuki; Elakneswaran, Y.*; Sato, Tsutomu*; Osugi, Takeshi; Kuroki, Ryoichiro
no journal, ,
no abstracts in English
Sasaki, Yuji; Kaneko, Masashi; Ban, Yasutoshi; Suzuki, Hideya*
no journal, ,
Am and Cm as minor actinides, have the similar chemical behavior, thus both metals are, in general, hard to separate. On the other hand, separation of Am with long-lived radionuclide to transmute from Cm to emit neutrons by spontaneous fission has been requesting. Although the mutual separation by solvent extraction is a tough work, ADAAM (Alkyl DiAmide AMine) developed in JAEA show high separation factor of Am/Cm of around 6 at HNO-n-dodecane system. We focus on basic research on solvent extraction using ADAAM and investigate the physical properties, i.e., polarity and viscosity, and separation factors of Am/Cm variated in combination with water-soluble masking agent of An, and will show the information at the meeting.
Sakamoto, Ryo*; Kaneda, Yoshihisa*; Kobayashi, Yutaro*; Haga, Kazuko*; Taniguchi, Takumi; Kuroki, Ryoichiro; Okada, Takashi; Yoshida, Yukihiko; Osugi, Takeshi
no journal, ,
no abstracts in English
