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Journal Articles

Advanced analysis technology for new material and product development

Sasaki, Hirokazu*; Nishikubo, Hideo*; Nishida, Shinsuke*; Yamazaki, Satoshi*; Nakasaki, Ryusuke*; Isomatsu, Takemi*; Minato, Ryuichiro*; Kinugawa, Kohei*; Imamura, Akihiro*; Otomo, Shinya*; et al.

Furukawa Denko Jiho, (138), p.2 - 10, 2019/02

no abstracts in English

Journal Articles

Mutual separation of trivalent lanthanide and actinides by hydrophilic and lipophilic multidentate diamides

Sasaki, Yuji; Morita, Keisuke

Progress in Nuclear Science and Technology (Internet), 5, p.27 - 32, 2018/12

no abstracts in English

Journal Articles

Conceptual plant system design study of an experimental HTGR upgraded from HTTR

Ohashi, Hirofumi; Goto, Minoru; Ueta, Shohei; Sato, Hiroyuki; Fukaya, Yuji; Kasahara, Seiji; Sasaki, Koei; Mizuta, Naoki; Yan, X.; Aoki, Takeshi*

Proceedings of 9th International Topical Meeting on High Temperature Reactor Technology (HTR 2018) (USB Flash Drive), 6 Pages, 2018/10

Conceptual design study of an experimental HTGR is performed to upgrade the plant system from Japanese High Temperature engineering Test Reactor (HTTR) to a commercial HTGR. Safety systems of HTTR are upgraded to demonstrate the commercial HTGR concept, such as a passive reactor cavity cooling system, a confinement, etc. An intermediate heat exchanger (IHX) is replaced by a steam generator (SG) for a process heat supply to demonstrate the technology for a commercial use. This paper describes the conceptual design study results of the plant system of the experimental HTGR.

Journal Articles

New precise measurement of muonium hyperfine structure interval at J-PARC

Ueno, Yasuhiro*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Keiichi*; Ito, Takashi; Iwasaki, Masahiko*; et al.

Hyperfine Interactions, 238(1), p.14_1 - 14_6, 2017/11

 Times Cited Count:1 Percentile:17.79

Journal Articles

Reduction and resource recycling of high-level radioactive wastes through nuclear transmutation; Isolation techniques of Pd, Zr, Se and Cs in simulated high level radioactive waste using solvent extraction

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

Journal Articles

Extraction and separation of Se, Zr, Pd, and Cs including long-lived radionuclides

Sasaki, Yuji; Morita, Keisuke; Suzuki, Shinichi; Shiwaku, Hideaki; Ito, Keisuke; Takahashi, Yuya*; Kaneko, Masaaki*

Solvent Extraction Research and Development, Japan, 24(2), p.113 - 122, 2017/06

The solvent extraction of Se, Zr, Pd, and Cs from nitric acid into 1-octanol (OC) and dodecane has been performed. These elements include long-lived radionuclides in spent nuclear fuels, so a simple separation method is indispensable for the development of the treatment of high-level liquid radioactive waste. It was found that Se can be extracted using phenylenediamine, Zr can be extracted using tetraoctyl diglycolamide and di-2-ethylhexyl phosphoric acid, and Pd can be extracted using (methylimino)bis(dioctylacetamide) and hexaoctylnitrilotriacetamide. These elements can be recovered in over 90% yield by these extractants from nitric acid into OC. A distribution ratio of Cs of greater than 1 can be obtained using di-t-butyldibenzo-18-crown-6. It is clear that 90% recovery of Cs can be achieved using an extraction solvent with ten times the volume of the aqueous phase.

Journal Articles

Precious metal extraction by N,N,N',N'-tetraoctyl-thiodiglycolamide and its comparison with N,N,N',N'-tetraoctyl-diglycolamide and methylimino-N,N'-dioctylacetamide

Sasaki, Yuji; Morita, Keisuke; Saeki, Morihisa*; Hisamatsu, Shugo; Yoshizuka, Kazuharu*

Hydrometallurgy, 169, p.576 - 584, 2017/05

 Times Cited Count:4 Percentile:39.18(Metallurgy & Metallurgical Engineering)

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.

Journal Articles

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

 Times Cited Count:1 Percentile:82.74(Chemistry, Multidisciplinary)

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.

Journal Articles

New muonium HFS measurements at J-PARC/MUSE

Strasser, P.*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Keiichi*; Ito, Takashi; Iwasaki, Masahiko*; et al.

Hyperfine Interactions, 237(1), p.124_1 - 124_9, 2016/12

 Times Cited Count:3 Percentile:10.17

Journal Articles

Separation of Ru(III), Rh(III) and Pd(II) from nitric acid solutions using ion-exchange resins bearing carboxylic betaine

Suzuki, Tomoya; Morita, Keisuke; Sasaki, Yuji; Matsumura, Tatsuro

Separation Science and Technology, 51(17), p.2815 - 2822, 2016/09

 Percentile:100(Chemistry, Multidisciplinary)

To understand the adsorption properties of styrene-divinylbenzene copolymer functionalized with ${it N,N,N}$-trimethylglycine, AMP03, the adsorption behaviors for platinoid ions (Ru(III), Rh(III), and Pd(II)) were examined. Furthermore, we performed adsorption experiments using sample solutions with adding triethylamine, thiourea, and ${it N,N,N}$-trimethylglycine. Based on the adsorption data obtained in this study, we performed chromatographic experiments. The results indicated that all platinoid ions in the feed solution completely adsorbed on AMP03, and almost 80% of the adsorbed platinoid ions were recovered. These results show that AMP03 has the potential to recover Ru(III), Rh(III), and Pd(II) from high-level liquid waste.

JAEA Reports

Study on radionuclide analysis of rubble and plants for decommissioning of Fukushima Daiichi Nuclear Power Station

Seki, Kotaro; Sasaki, Takayuki*; Akimoto, Yuji*; Tokunaga, Takahito; Tanaka, Kiwamu; Haraga, Tomoko; Ueno, Takashi; Ishimori, Kenichiro; Hoshi, Akiko; Kameo, Yutaka

JAEA-Technology 2016-013, 37 Pages, 2016/07

JAEA-Technology-2016-013.pdf:2.09MB

In this study, based on the simple and rapid analytical method established from the wastes from research facilities, we created analytical schemes which is applicable to rubble and plants collected at Fukushima Daiichi, then transported to Nuclear Science Research Institute of JAEA. We examined the applicability, and confirmed quantifiability of radioactivity concentration with high recovery rate without being affected by fission products such as $$^{90}$$Sr and $$^{137}$$Cs.

Journal Articles

Recovery of Rhodium(III) from nitric acid solutions using adsorbent functionalized with ${it N,N,N}$-trimethylglycine

Suzuki, Tomoya; Morita, Keisuke; Sasaki, Yuji; Matsumura, Tatsuro

Bulletin of the Chemical Society of Japan, 89(5), p.608 - 616, 2016/05

 Times Cited Count:3 Percentile:71.91(Chemistry, Multidisciplinary)

In a previous study, we found that AMP03 adsorbs Rh(III) from the HNO$$_{3}$$ solution with pH = 1.7 - 2.2. In this study, to understand the Rh(III) adsorption properties of AMP03 and clarify conditions for efficient recovery, we investigated the adsorption behaviors of Rh(III) from the HNO$$_{3}$$ solution. As a result, it was found that Rh(III) is effectively adsorbed from aqueous solution containing low H$$^{+}$$ and high NO$$_{3}$$$$^{-}$$ concentration. Considering the adsorption mechanism of Rh(III), we found that Rh$$^{3+}$$ in aqueous solution is adsorbed with two betaine groups in AMP03 and three NO$$_{3}$$$$^{-}$$.

Journal Articles

Masking effects for Mo, Re, Pd and Ru by S and N-donor reagents through MIDOA and NTAamide extraction

Sasaki, Yuji; Morita, Keisuke; Shimazaki, Shoma*; Tsubata, Yasuhiro; Ozawa, Masaki*

Solvent Extraction Research and Development, Japan, 23(2), p.161 - 174, 2016/05

We examined the masking effects of 16 water-miscible reagents, on the extraction of Mo, Re, Ru, and Pd. The extractants, methylimino-dioctylacetamide (MIDOA) and hexaoctyl-nitrilotriacetamide (NTAamide(C8)), show significantly high distribution ratios for these metals, were employed in this study. Masking effects were observed as a decrease of distribution ratio with an increase of masking agent concentration in these extraction systems. The results showed that Pd and Ru can be masked by similar reagents including N- or S- donor atoms, which suppressed the extraction into the organic phase. In contrast, distribution ratio of Mo was only slightly masked by the above mentioned reagents. The masking of Mo was achieved using complexing agents having a central N(CH$$_{2}$$C(P)=O)$$_{2}$$ framework that is important for this purpose. A masking agent for Re was not found in this study.

Journal Articles

Silver extraction by $$N,N,N',N'$$-tetraoctyl-thiodiglycolamide

Sasaki, Yuji; Suzuki, Tomoya; Morita, Keisuke; Yoshizuka, Kazuharu*

Hydrometallurgy, 159, p.107 - 109, 2016/01

 Times Cited Count:2 Percentile:69.48(Metallurgy & Metallurgical Engineering)

The novel tridentate extractant including soft donor has developed and examined. The extractant, tetraoctyl-thiodiglycolamide (S-DGA), is analogous structure to tetraoctyl-diglycolamide (TODGA), but with sulfur donor instead of ether oxygen of TODGA. S-DGA has unique property to extract silver from acidic solutions to n-dodecane with relatively high D values. We investigated the extraction behavior of Ag in various acids, HNO$$_{3}$$, H$$_{2}$$SO$$_{4}$$, and HClO$$_{4}$$.

Journal Articles

The Effect of alkyl substituents on actinide and lanthanide extraction by diglycolamide compounds

Sasaki, Yuji; Sugo, Yumi; Morita, Keisuke; Nash, K.*; Nash, K. L.*

Solvent Extraction and Ion Exchange, 33(7), p.625 - 641, 2015/10

 Times Cited Count:28 Percentile:17.19(Chemistry, Multidisciplinary)

The effect of alkyl substituents at amidic N atoms in diglycolamide (DGA) compounds on solvent extraction was investigated. The solubility in water and n-dodecane, loading capacity, and distribution ratio (D) of lanthanides and actinides for various DGA compounds were monitored. DGA derivatives with short alkyl chains, for example methyl and ethyl groups, are highly water soluble, while DGA derivatives with long alkyl chains are highly soluble in n-dodecane. The loading capacity correlats with their alkyl chain lengths. The results of masking effect and solubility tests indicate that TEDGA(tetraethyl-diglycolamide) is the best actinide masking agent among the water-soluble DGA derivatives. Actinide extractions were performed using ten DGA compounds in six diluents (nitrobenzene, 1,2-dichloroethane, 1-octanol, chloroform, toluene, and n-dodecane), in which it was observed that DGA derivatives with shorter alkyl chains show higher D values.

Journal Articles

Investigation of single-cycle separation process based on forward and backward extractions of actinides and fission products

Sasaki, Yuji; Tsubata, Yasuhiro; Shirasu, Noriko; Morita, Keisuke; Suzuki, Tomoya

Nippon Genshiryoku Gakkai Wabun Rombunshi, 14(3), p.202 - 212, 2015/09

We have been developing the new partitioning method of high-level radioactive waste by single-cycle extraction process. This process is composed of extraction of actinides (An) and fission products (FP, e.g., Pd, Ru, Mo and Tc), and mutual separation by back-extraction. The extractant employed in this process is required to extract soft, hard acid metals and oxonium anions simultaneously. The NTAamide (hexaoctyl-nitrilotriacetamide) is one of the candidate extractants. After extraction of An and FP, the mutual separation by back-extraction should be set up. Pd and Ru extracted by NTAamide can be back-extracted by complexing agents such as thiourea, systeine, diethylenetriamine, and trisaminoethylamine, and the back-extraction of Mo can be performed by methylimino-diethylacetamide (MIDEA), NTAamide(C2) and iminodimethylphosphoric acid, and Re can be done by aqueous phase with high pH.

Journal Articles

Concept for the single cycle process based on mutual separation by reverse extraction of actinides and fission products

Sasaki, Yuji; Tsubata, Yasuhiro; Shirasu, Noriko; Morita, Keisuke; Suzuki, Tomoya

Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1653 - 1656, 2015/09

The concept for the new partitioning method of high-level radioactive waste (HLW) by single-cycle extraction process has been investigated. This process is based on extraction of actinides (An) and fission products (FP), and mutual separation by reverse extraction. Solo extractant and several stripping reagents will be utilized in this process. The extractant employed in this process is required to extract soft (platinum metals), hard acid metals(An), and oxonium anions (Mo, Tc) simultaneously. NTAamide is one of the candidate extractants. After extraction of An and FP by NTAamide(C8), the mutual separation among these metals by reverse extraction will be followed using the suitable water-miscible reagents. The extraction of An and FP, and the masking effect by some water-miscible reagents has been studied.

Journal Articles

A Study on adsorption properties of ion-exchange resins bearing ${it N,N,N}$-trimethylglycine to Ru(III), Rh(III) and Pd(II) for developing separation techniques from high-level liquid waste

Suzuki, Tomoya; Shimazaki, Shoma*; Morita, Keisuke; Sasaki, Yuji; Ozawa, Masaki*; Matsumura, Tatsuro

Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1539 - 1543, 2015/09

To understand the adsorption behaviors of ion-exchange resin bearing ${it N,N,N}$-trimethylglycine groups (AMP03), adsorption experiments using HNO$$_{3}$$ solutions containing Ru(III), Rh(III), and Pd(II) have been performed. AMP03 strongly adsorbed Pd(II), and Ru(III) and Rh(III) were moderately adsorbed. To control the adsorption abilities of AMP03 for the Ru(III), Rh(III) and Pd(II), adsorption experiments using sample solutions with added thiourea (TU), triethylamine (TEA), and betaine anhydrous were performed. The adsorption abilities for Ru(III) and Rh(III) greatly increased with the addition of TEA, whereas the ability to adsorb Pd(II) was not significantly affected. The addition of TU or betaine anhydrous remarkably decreased the adsorption ability for Pd(II), and contrastingly slight changes in the abilities to adsorb Ru and Rh were also observed. These results show that AMP03 has a significant potential for separation of platinoid elements from HNO$$_{3}$$ solution.

Journal Articles

Studies on the extraction of soft acid metal species using MIDOA and analogous compounds

Sasaki, Yuji; Saeki, Morihisa; Sugo, Yumi; Ikeda, Yasuhisa*; Kawasaki, Takeshi*; Suzuki, Tomoya*; Ohashi, Akira*

Solvent Extraction Research and Development, Japan, 22(1), p.37 - 45, 2015/05

 Times Cited Count:5 Percentile:64.07(Chemistry, Multidisciplinary)

An extractant, methylimino-bis-${it N,N'}$-dioctylacetamide (MIDOA), was used for the extraction of soft acid metals. It was found that MIDOA can extract not only Cr(VI), Mo(VI), W(VI), Tc(VII) and Re(VII), whose metals can form the oxonium anions due to their high oxidation states, but also other metal cations, like Nb(V), Ta(V) and Pd(II). Analogous compounds, imino-bis-${it N,N'}$-dioctylacetamide (IDOA) and methylimino-bis-${it N,N'}$-di-2-ethylhexylacetamide (MIDEHA), are synthesized and compared for their extractability. It is clear that these extractants have almost same or lower $$D$$ values than those for MIDOA. In order to examine the effect on extractability with different donor atoms, TODGA (${it N,N,N',N'}$-tetraoctyl-diglycolamide) and TDGA (${it N,N,N',N'}$-tetraoctyl-tyiodiglycolamide) having oxygen and sulfur donor are employed. The comparison of their extractabilities suggests that the trend of Pd and Re extraction is N $$>$$ S $$>$$ O and N $$>$$ O $$>$$ S, respectively.

Journal Articles

Efficient adsorption of Rh(III) from HNO$$_{3}$$ solution on ion-exchange resin bearing ${it N,N,N}$-trimethylglycine by adding N donor ligands and desorption using thiourea

Suzuki, Tomoya; Morita, Keisuke; Sasaki, Yuji

Chemistry Letters, 44(2), p.152 - 153, 2015/02

 Times Cited Count:2 Percentile:84.79(Chemistry, Multidisciplinary)

To recover Rh(III) from HNO$$_{3}$$ solution, adsorption experiments have been performed using an ion-exchange resin bearing an ${it N,N,N}$-trimethylglycine group (AMP03). AMP03 was found to exhibit relatively high adsorption ability for Rh(III) for [HNO$$_{3}$$]$$_{rm surp}$$ $$<$$ 0.02 M ([HNO$$_{3}$$]$$_{rm surp}$$ denotes HNO$$_{3}$$ concentration in the supernatant), and the ${it K$_{d}$}$ values increase significantly with the addition of triethylamine or tris(2-aminoethyl)amine to 0.12 M HNO$$_{3}$$ solutions. In contrast, the addition of thiourea leads to a decrease in the ${it K$_{d}$}$ values; i.e., a masking effect on Rh(III) was observed. These results show that AMP03 has a significant potential for effectively recovering Rh from HNO$$_{3}$$ solution.

310 (Records 1-20 displayed on this page)