Radiation-induced effects on the extraction properties of hexa--octylnitrilo-triacetamide (HONTA) complexes of americium and europium

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

https://doi.org/10.1039/D0CP05720G

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.

Microscopic analyses on Zr adsorbed IDA chelating resin by PIXE and EXAFS

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

https://doi.org/10.1016/j.nimb.2019.10.028

Quantitative analysis of Cs extraction by some dialkoxycalix[4]arene-crown-6 extractants

Simonnet, M.; Miyazaki, Yuji*; Suzuki, Shinichi; Yaita, Tsuyoshi

Solvent Extraction and Ion Exchange, 37(1), p.81 - 95, 2019/00

https://doi.org/10.1080/07366299.2019.1575002

Online coupling of two-phase flow solvent extraction microfluidics with inductively coupled plasma mass spectrometry

Do, V. K.; Yamamoto, Masahiko; Taguchi, Shigeo; Kuno, Takehiko; Surugaya, Naoki

Current Analytical Chemistry, 14(2), p.111 - 119, 2018/00

https://doi.org/10.2174/1573411013666170421121927

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.

Solvent extraction of metal ions using a new extractant, biuret(C8)

Sasaki, Yuji; Yoshimitsu, Ryo*; Nishihama, Shohei*; Shimbori, Yuma*; Shiroishi, Hidenobu*

Separation Science and Technology, 52(7), p.1186 - 1192, 2017/03

https://doi.org/10.1080/01496395.2017.1284863

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.

Application of turbidity measurement for evaluation of two-phase separation in ,-dialkylamides-nitric acid systems

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.

Washing properties of n-butylamine oxalate in degraded solvent (Joint study between JNC and JAERI)

Imaizumi, Hirobumi; Ban, Yasutoshi; Sato, Makoto; Asakura, Toshihide; Morita, Yasuji

JAERI-Research 2005-025, 94 Pages, 2005/09

JAERI-Research-2005-025.pdf:13.61MB

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.

A method for the determination of extraction capacity and its application to -tetraalkylderivatives of diglycolamide-monoamide/n-dodecane media

Sasaki, Yuji; Sugo, Yumi; Suzuki, Shinichi; Kimura, Takaumi

Analytica Chimica Acta, 543(1-2), p.31 - 37, 2005/07

https://doi.org/10.1016/j.aca.2005.04.061

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.

Extraction and separation of Am(III) and Sr(II) by N,N,N',N'-tetraoctyl-3-oxapentanediamide (TODGA)

Suzuki, Hideya*; Sasaki, Yuji; Sugo, Yumi; Apichaibukol, A.; Kimura, Takaumi

Radiochimica Acta, 92(8), p.463 - 466, 2004/08

https://doi.org/10.1524/ract.92.8.463.39276

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.

Extraction studies of lanthanide(III) ions with -dimethyl--diphenylpyridine-2,6-dicarboxyamide(DMDPhPDA) from nitric acid solutions

Shimada, Asako; Yaita, Tsuyoshi; Narita, Hirokazu; Tachimori, Shoichi; Okuno, Kenji*

Solvent Extraction and Ion Exchange, 22(2), p.147 - 161, 2004/03

https://doi.org/10.1081/SEI-120030392

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.