Development plan for coupling technology between high temperature gas-cooled reactor HTTR and hydrogen production facility, 1; Overview of the HTTR heat application test plan to establish high safety coupling technology

Nomoto, Yasunobu; Mizuta, Naoki; Morita, Keisuke; Aoki, Takeshi; Okita, Shoichiro; Ishii, Katsunori; Kurahayashi, Kaoru; Yasuda, Takanori; Tanaka, Masato; Isaka, Kazuyoshi; et al.

Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 7 Pages, 2023/05

Neutron reflectivity study on the nanostructure of PMMA chains near substrate interfaces based on contrast variation accompanied with small molecule sorption

Shimokita, Keisuke*; Yamamoto, Katsuhiro*; Miyata, Noboru*; Nakanishi, Yohei*; Shibata, Motoki*; Takenaka, Mikihito*; Yamada, Norifumi*; Seto, Hideki*; Aoki, Hiroyuki; Miyazaki, Tsukasa*

Soft Matter, 19(11), p.2082 - 2089, 2023/03

https://doi.org/10.1039/D2SM01482C

Neutron reflectivity study on the suppression of interfacial water accumulation between a polypropylene thin film and Si substrate using a silane-coupling agent

Shimokita, Keisuke*; Yamamoto, Katsuhiro*; Miyata, Noboru*; Arima-Osonoi, Hiroshi*; Nakanishi, Yohei*; Takenaka, Mikihito*; Shibata, Motoki*; Yamada, Norifumi*; Seto, Hideki*; Aoki, Hiroyuki; et al.

Langmuir, 38(41), p.12457 - 12465, 2022/10

https://doi.org/10.1021/acs.langmuir.2c01599

Effective extraction of Pt(IV) as [PtCl] from hydrochloric acid using a simple urea extractant

Ueda, Yuki; Morisada, Shintaro*; Kawakita, Hidetaka*; Wenzel, M.*; Weigand, J. J.*; Oto, Keisuke*

Separation and Purification Technology, 277, p.119456_1 - 119456_8, 2021/12

https://doi.org/10.1016/j.seppur.2021.119456

no abstracts in English

Performance tests of catalysts for the safe conversion of hydrogen inside the nuclear waste containers in Fukushima Daiichi

Reinecke, E.-A.*; Takenaka, Keisuke*; Ono, Hitomi*; Kita, Tomoaki*; Taniguchi, Masashi*; Nishihata, Yasuo; Hino, Ryutaro; Tanaka, Hirohisa*

International Journal of Hydrogen Energy, 46(23), p.12511 - 12521, 2021/03

https://doi.org/10.1016/j.ijhydene.2020.08.262

The safe decommissioning as well as decontamination of the radioactive waste resulting from the nuclear accident in Fukushima Daiichi represents a huge task for the next decade. At present, research and development on long-term safe storage containers has become an urgent task with international cooperation in Japan. One challenge is the generation of hydrogen and oxygen in significant amounts by means of radiolysis inside the containers, as the nuclear waste contains a large portion of sea water. The generation of radiolysis gases may lead to a significant pressure build-up inside the containers and to the formation of flammable gases with the risk of ignition and the loss of integrity. In the framework of the project "R&D on technology for reducing concentration of flammable gases generated in long-term waste storage containers" funded by the Japanese Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT), the potential application of catalytic recombiner devices inside the storage containers is investigated. In this context, a suitable catalyst based on the so-called intelligent automotive catalyst for use in a recombiner is under consideration. The catalyst is originally developed and mass-produced for automotive exhaust gas purification, and is characterized by having a self-healing function of precious metals (Pd, Pt and Rh) dissolved as a solid solution in the perovskite type oxides. The basic features of this catalyst have been tested in an experimental program. The test series in the REKO-4 facility has revealed the basic characteristics of the catalyst required for designing the recombiner system.

Research on hydrogen safety technology utilizing the automotive catalyst

Ono, Hitomi*; Takenaka, Keisuke*; Kita, Tomoaki*; Taniguchi, Masashi*; Matsumura, Daiju; Nishihata, Yasuo; Hino, Ryutaro; Reinecke, E.-A.*; Takase, Kazuyuki*; Tanaka, Hirohisa*

E-Journal of Advanced Maintenance (Internet), 11(1), p.40 - 45, 2019/05

https://www.jsm.or.jp/ejam/Vol.11No.1/AA/AA155/AA155.html

Total recovery of gold, palladium, and platinum using lignophenol derivative

Parajuli, D.; Khunathai, K.*; Adhikari, C. R.*; Inoue, Katsutoshi*; Oto, Keisuke*; Kawakita, Hidetaka*; Funaoka, Masamitsu*; Hirota, Koichi

Minerals Engineering, 22(13), p.1173 - 1178, 2009/10

https://doi.org/10.1016/j.mineng.2009.06.003

Spectroscopic analysis for extraction of Pt(IV) with amide and urea type extractants

Ueda, Yuki; Sugita, Tsuyoshi; Okamura, Hiroyuki; Shimojo, Kojiro; Naganawa, Hirochika; Morisada, Shintaro*; Kawakita, Hidetaka*; Oto, Keisuke*

no journal, , 

Platinum group metals (PGMs) are indispensable metals in modern industries and are used for example as active components in automobile gas catalysts, jewellery goods, electronic devices and dental materials. In order to meet the growing demand, high efficient receptors for liquid-liquid extraction of the respective anionic chloro-complexes are required in order to enhance capable winning from either pour geological deposits or complex secondary sources within the Urban Mining. The ligand containing urea or amide groups can form the hydrogen bond with anionic species. The novel urea or amide containing extractants were synthesized and its extraction behavior and mechanism were investigated in this work.

Extraction of Pt(IV) from HCl solutions with amide and urea substituted extractants

Ueda, Yuki; Morisada, Shintaro*; Kawakita, Hidetaka*; Omi, Kentaro*; Fujita, Mitsuharu*; Weigand, J.*; Shimojo, Kojiro; Naganawa, Hirochika; Oto, Keisuke*

no journal, , 

Platinum group metals (PGMs) are indispensable metals in modern industries and are used for example as active components in automobile gas catalysts, jewelry goods, electronic devices and dental materials. In order to meet the growing demand, high efficient extraction reagents for liquid-liquid extraction of the respective anionic chloro-complexes are required in order to enhance capable winning from either pour geological deposits or complex secondary sources within the Urban Mining. The ligand containing urea or amide groups can form the hydrogen bond with anionic species. The novel urea or amide incorporating extraction reagents were synthesized and its extraction behavior and mechanism were investigated in this work.

Anion-exchange behavior of Nb, Ta, and Pa in HF/HNO solution for understanding chemical species of Db

Adachi, Sadia*; Sueki, Keisuke*; Toyoshima, Atsushi*; Tsukada, Kazuaki; Haba, Hiromitsu*; Komori, Yukiko*; Yokokita, Takuya*; Mori, Taiki*

no journal, , 

Anion exchange behavior of group-5 elements, Nb, Ta, and their pseudo homologue Pa in HF and HF/HNO solution was investigated to understand chemical properties of Db. Adsorption behavior of Db is clearly different from that of Ta and is similar to those of Nb and Pa. In the present study, anion exchange experiments of Nb, Ta and Pa were carried out with HF/HNO aqueous solution as basic experiments for estimating the species of Db fluoride complex. Adsorption behavior was investigated by changing the fluoride ion concentration for each HNO concentration. Based on the observed distribution coefficients of these elements, we discuss the formation reaction of the anionic fluoride complex and chemical species of Db.