Toigawa, Tomohiro; Peterman, D. R.*; Meeker, D. S.*; Grimes, T. S.*; Zalupski, P. R.*; Mezyk, S. P.*; Cook, A. R.*; Yamashita, Shinichi*; Kumagai, Yuta; Matsumura, Tatsuro; et al.
Physical Chemistry Chemical Physics, 23(2), p.1343 - 1351, 2021/01
The candidate An(III)/Ln(III) separation ligand hexa--octylnitrilo-triacetamide (HONTA) was irradiated under envisioned SELECT (Solvent Extraction from Liquid waste using Extractants of CHON-type for Transmutation) process conditions using a solvent test loop in conjunction with cobalt-60 gamma irradiation. We demonstrate that HONTA undergoes exponential decay with increasing gamma dose to produce a range of degradation products which have been identified and quantified by HPLC-ESI-MS/MS techniques. The combination of HONTA destruction and degradation product ingrowth, particularly dioctylamine, negatively impacts the extraction and back-extraction of both americium and europium ions. The loss of HONTA was attributed to its reaction with the solvent (-dodecane) radical cation of (HONTA + R) = (7.61 0.82) 10 M s obtained by pulse radiolysis techniques. However, when this ligand is bound to either americium or europium ions, the observed -dodecane radical cation kinetics increase by over an order of magnitude. This large reactivity increase to additional reaction pathways occurring upon metal-ion binding. Lastly nanosecond time-resolved measurements showed that both direct and indirect HONTA radiolysis yielded the short-lived (100 ns) HONTA radical cation as well as a longer-lived (s) HONTA triplet excited state. These HONTA species are important precursors to the suite of HONTA degradation products observed.
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.
Arai, Yoichi; Watanabe, So; Ono, Shimpei; Nomura, Kazunori; Nakamura, Fumiya*; Arai, Tsuyoshi*; Seko, Noriaki*; Hoshina, Hiroyuki*; Hagura, Naoto*; Kubota, Toshio*
Nuclear Instruments and Methods in Physics Research B, 477, p.54 - 59, 2020/08
Arai, Yoichi; Watanabe, So; Ono, Shimpei; Nomura, Kazunori; Nakamura, Fumiya*; Arai, Tsuyoshi*; Seko, Noriaki*; Hoshina, Hiroyuki*; Kubota, Toshio*
QST-M-23; QST Takasaki Annual Report 2018, P. 59, 2020/03
Simonnet, M.; Miyazaki, Yuji*; Suzuki, Shinichi; Yaita, Tsuyoshi
Solvent Extraction and Ion Exchange, 37(1), p.81 - 95, 2019/00
Nagano, Tetsushi; Naganawa, Hirochika; Suzuki, Hideya; Toshimitsu, Masaaki*; Mitamura, Hisayoshi*; Yanase, Nobuyuki*; Grambow, B.
Analytical Sciences, 34(9), p.1099 - 1102, 2018/09
A previously reported emulsion flow (EF) extraction system does not include a device for refining used solvent. Therefore, the processing of large quantities of wastewater by using the EF extractor alone could lead to the accumulation of wastewater components into the solvent and diminished extraction performance. In the present study, we have developed a solvent-washing-type EF system, which is equipped with a unit for washing used solvent to prevent accumulation, and successfully applied it for treating uranium-containing wastewater.
Do, V. K.; Yamamoto, Masahiko; Taguchi, Shigeo; Kuno, Takehiko; Surugaya, Naoki
Current Analytical Chemistry, 14(2), p.111 - 119, 2018/00
A direct coupling of two-phase flow solvent extraction microfluidics with ICP-MS for element-selective analysis is successfully established. Two-phase flow in microchannels of two combined glass chips for continuous extraction and back-extraction is stabilized through balancing the pressure by using an external coiled tube that functions as a flow resistor. The difference of fluid flow rate between microchannels and ICP-MS is adjusted by a proposed interface system including T-junction mixer and a switching valve. An online measurement of rhenium is successfully demonstrated. The calibration curve for Re is carried out in the range of 1 g/L to 20 g/L. The limit of detection is 0.2 g/L with a needed sample volume of one milliliter. Total time including extraction, back-extraction, and measurement is less than one hour. The development of the online coupling is a first step towards future applications to the selective measurement of highly radioactive elements.
Sasaki, Yuji; Morita, Keisuke; Saeki, Morihisa*; Hisamatsu, Shugo; Yoshizuka, Kazuharu*
Hydrometallurgy, 169, p.576 - 584, 2017/05
The novel tridentate extractant including soft donor has developed and examined. The extractant, tetraoctyl-thiodiglycolamide (TDGA), is analogous structure to tetraoctyl-diglycolamide (TODGA) and methylimino-dioctylacetamide (MIDOA), but with sulfur donor instead of ether oxygen or nitrogen atoms of TODGA or MIDOA. From the present work, TDGA can extract silver, palladium, gold, and mercury from acidic solutions to n-dodecane. In addition to these results, the distribution ratios of hard and soft acid metals by using TDGA, TODGA, and MIDOA are compared, where the metal-complexations with each donor atom are investigated. 1H-NMR and IR studies for the metal-TDGA complexes indicate the role on donor atoms, S and N, of TDGA.
Sasaki, Yuji; Yoshimitsu, Ryo*; Nishihama, Shohei*; Shimbori, Yuma*; Shiroishi, Hidenobu*
Separation Science and Technology, 52(7), p.1186 - 1192, 2017/03
The new extractant, biuret(C8), is synthesized and tested for the solvent extraction of hard acid metals like actinides and soft acid metals. This compound has the similar central frame to malonamide but with 2-NH introduced into the central frame, then both amidic oxygen and nitrogen atoms may bond with metals. From the present work, not only hard acid metals, but also soft acid metals can be extracted by biuret(C8) from nitric or perchloric acids to n-dodecane. The extractability for biuret(C8) is compared with other representative extractants, malonamide, TODGA and MIDOA. It is clear that the distribution ratio(D) of U and Pu by biuret(C8) is similar to those for malonamide, but with lower values than those for TODGA and MIDOA, and D for soft acid metals and oxonium anions show higher values than those for TODGA and malonamide and lower than those for MIDOA.
Zhao, Y.; Koizumi, Satoshi*; Kondo, Tetsuo*
JPS Conference Proceedings (Internet), 8, p.033002_1 - 033002_6, 2015/09
Tsutsui, Nao; Ban, Yasutoshi; Hakamatsuka, Yasuyuki; Urabe, Shunichi; Matsumura, Tatsuro
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1153 - 1157, 2015/09
,-Dialkylamides are promising alternative extractants to tri--butyl phosphate in the reprocessing of spent nuclear fuels, but the two-phase separation between their organic and aqueous phases has not been evaluated quantitatively. ,-Di(2-ethylhexyl)-2,2-dimethylpropanamide (DEHDMPA) in -dodecane were agitated with uranyl nitrate-containing nitric acid, and their turbidities and their uranium distribution ratios were measured with respect to the time for the quantitative evaluation. Increasing DEHDMPA, uranium, and nitric acid concentrations enhanced turbidities. Although turbidities decreased with respect to the time, uranium distribution ratios slightly changed, indicating the observed turbidities did not affect these uranium distribution ratios significantly. Therefore, DEHDMPA may act as suitable extractant for uranium in nitric acid from two-phase separation viewpoint, and turbidity may be an indicator for extractant performance evaluation.
Morita, Yasuji; Kubota, Masumitsu*
JAERI-Review 2005-041, 35 Pages, 2005/09
Research and development on Partitioning in JAERI are reviewed in the present report from the beginning to the development of the 4-Group Partitioning Process and its test with real high-level liquid waste (HLLW). In the 3-Group Partitioning Process established in around 1980, elements in HLLW are separated into 3 groups of transuranium element group, Sr-Cs group and the other element group. The 4-Group Partitioning Process subsequently developed contains the separation of Tc-platinum group metals additionally. The process was tested to demonstrate its performance with real concentrated HLLW. Until then, various separation methods for various elements were studied and selection and optimization of the separation methods were carried out to establish the process. Review of the experience, findings and results is very important and valuable for future study on partitioning. The present report is prepared from this point of view.
Imaizumi, Hirobumi; Ban, Yasutoshi; Sato, Makoto; Asakura, Toshihide; Morita, Yasuji
JAERI-Research 2005-025, 94 Pages, 2005/09
Washing properties of n-butylamine compounds, which are decomposable by burning or electrolysis, for dibutylphosphoric acid (DBP) and Zr in real and simulated degraded solvents have been investigated. In experiments with simulated degraded solvents, basic properties of n-butylamine compounds for washing DBP and Zr were examined and optimum condition was obtained. It was confirmed from the simulated degraded solvent washing tests that 0.25 mol/dm n-butylamine oxalate of pH 2 could effectively remove Zr from the degraded solvent and the solution of pH 4 was effective for DBP, 95% removal of Zr and DBP were obtained by batch washing. The validity of n-butylamine as a degraded solvent wash reagent was shown by the washing test for real degraded solvent that was performed by continuous counter current flow using a miniature mixer-settler. The present study was carried out as a part of the joint study "Research and Development of Process Elements in an Advanced Aqueous Reprocessing" between Japan Nuclear Cycle Development Institute and JAERI.
Yamaguchi, Isoo*; Suzuki, Shinichi; Sasaki, Yuji; Yamagishi, Isao; Matsumura, Tatsuro; Kimura, Takaumi
JAERI-Tech 2005-037, 56 Pages, 2005/07
For the development of the reprocessing of spent nuclear fuels, the solvent extraction using the mixer-settler equipment is greatly available. This method has the advantages of the treatment of the large mass of materials and continuous operations. In case of the application of the mixer-settler devise, the precise calculation using the distribution ratio of metals in order to determine the metal concentration at each stage is indispensable. This calculation is performed in the development of ARTIST process. The metal concentration in each stage of ARTIST process is calculated by the simulation using excel software equipped with counter-current equations. This method is not taken into consideration of the change of acid concentration, therefore, we developed the new method to calculate the metal concentration even after acidity change. This method can calculate not only the metal concentration at each extraction step but also at each stage of mixer-settler. Using this calculation, we evaluated the optimum condition of solvent extraction in ARTIST process.
Sasaki, Yuji; Sugo, Yumi; Suzuki, Shinichi; Kimura, Takaumi
Analytica Chimica Acta, 543(1-2), p.31 - 37, 2005/07
The detailed study of extraction capacity of diglycolamide (DGA) with and without DHOA, N,N'-dihexyloctanamide as a modifier, was performed by using the novel analytical method for the determination of the limit of metal concentration in the organic phase (LOC). The effect on modifier was studied and it is confirmed that LOC increases with DHOA concentration. It is noteworthy that LOC reaches to the stoichiometric value, which is obtained by the extraction reaction, by using 0.1M TODGA mixed with more than 0.5M DHOA into n-dodecane. Without modifier, relation of the different DGA compounds with LOC was investigated, and it is clear that LOC using N,N,N',N'-tetradodecyl-diglycolamide (TDdDGA), whose extractant can suppress the third phase, reaches to the stoichiometric value. From this work, it is obvious that the application of the condition without the third phase formation, e.g., enough concentration of modifier coexisted and DGA with long alkyl chain, is important to attain the stochiometric LOC value.
Apichaibukol, A.; Sasaki, Yuji; Morita, Yasuji
Solvent Extraction and Ion Exchange, 22(6), p.997 - 1011, 2004/12
no abstracts in English
Suzuki, Hideya*; Sasaki, Yuji; Sugo, Yumi; Apichaibukol, A.; Kimura, Takaumi
Radiochimica Acta, 92(8), p.463 - 466, 2004/08
The promising extractant for the partitioning of HLLW, TODGA, was used and investigated for the extraction of Sr(II) and separation from Am(III). Both metal ions can be extracted by TODGA based on the extraction reaction accompanying the neutral HNO as well as the counter anion, NO. The mixture of TODGA and monoamide can reduce the distribution ratio of Sr(II), compared to the D(Sr) without monoamide, this solvent may extract only Am(III) with holding Sr(II) in the aqueous phase. After extraction of An by TODGA and monoamide, Sr(II) remaining in HLLW can be extracted by using enough high concentration of TODGA at the next step. Because of its high D value, Sr(II) can be coextracted with An by TODGA. It was observed that D(Sr) decrease with an increase of HNO from 3M to 6M HNO at the same TODGA concentration, while Am(III) has still high D values at least until 6M HNO. By using 6M HNO of aqueous phase, An and Sr(II) can be separated after coextraction.
Shimada, Asako; Yaita, Tsuyoshi; Narita, Hirokazu; Tachimori, Shoichi; Kimura, Takaumi; Okuno, Kenji*; *
Solvent Extraction Research and Development, Japan, 11, p.1 - 10, 2004/04
The distribution ratio () of Am(III) and lighter Ln(III) in the extraction with -dimethyl--diphenylpyridine-2,6-dicarboxyamide(DMDPhPDA) from HNO solutions were determined. The D's increased with an increase of HNO concentration. Additionally, separation of Am(III) from Ln(III) were confirmed for all the HNO concentration range (S.F.=(D/D)). From 4 M HNO solution with 0.5 M DMDPhPDA CHCl solution, the 's of Am(III), Eu(III) and Nd(III) were 1.3, 0.25 and 0.24, respectively. This result suggests that Am(III) can be separated from Eu and Nd in the higher HNO concentration region than that has been reported so far. These 's value and the S.F. were reproduced in the extraction from the metal concentration range from 10 M order to 10 M.
Shimada, Asako; Yaita, Tsuyoshi; Narita, Hirokazu; Tachimori, Shoichi; Okuno, Kenji*
Solvent Extraction and Ion Exchange, 22(2), p.147 - 161, 2004/03
The distribution ratios of lanthanides with -dimethyl--diphenylpyridine-2,6-dicarboxyamide(DMDPhPDA) from 1-5M nitric acid solutions were determined and the extraction mechanism was discussed on the basis of the slope analyses of acid and ligand concentration dependencies and lanthanide patterns (variation of the distribution ratio as a function of ionic radius). The lanthanide extractions were explained through two mechanisms from the standpoint of the formation of the extracted complex as follows: (1) the formation of inner-sphere complex with two DMDPhPDA molecules for light lanthanides in the extraction from HNO less than 3M, and (2) the formation of outer-sphere complex with the third DMDPhPDA molecules in addition to the inner-sphere complex in the extraction of light lanthanides from HNO more than 3M, and those of heavy lanthanides from 1-5M HNO solutions. Nitric acid concentration is more influential than the ligand concentration in the formation of outer-sphere complex.
Ishioka, Noriko; Izumo, Mishiroku; Hashimoto, Kazuyuki; Kobayashi, Katsutoshi; Matsuoka, Hiromitsu; Sekine, Toshiaki
JAERI-Tech 2001-095, 23 Pages, 2002/01
no abstracts in English