Verma, V.*; Sakamoto, Shoya*; Ishikawa, Koichiro*; Singh, V. R.*; Ishigami, Keisuke*; Shibata, Goro; Kadono, Toshiharu*; Koide, Tsuneharu*; Kuroda, Shinji*; Fujimori, Atsushi*
Physica B; Condensed Matter, 642, p.414129_1 - 414129_5, 2022/10
Tanaka, Hirohisa*; Masaki, Sayaka*; Aotani, Takuro*; Inagawa, Kohei*; Iwata, Sogo*; Aida, Tatsuya*; Yamamoto, Tadasuke*; Kita, Tomoaki*; Ono, Hitomi*; Takenaka, Keisuke*; et al.
SAE Technical Paper 2022-01-0534 (Internet), 10 Pages, 2022/03
Sasaki, Yuji; Morita, Keisuke; Matsumiya, Masahiko*; Ono, Ryoma*; Shiroishi, Hidenobu*
JOM, 73(4), p.1037 - 1043, 2021/04
The separation of Dy from Nd is studied from the viewpoint of recycling Dy from Nd magnets. Both metals are lanthanide elements, which means their mutual separation is difficult because of their similar chemical behaviors. All lanthanide elements can be extracted easily by using tetradodecyl-diglycolamide (TDdDGA) extractants, and it has a relatively high separation factor (SF) between Dy and Nd (SF over 10). In the present study, by performing eight extraction steps with the organic phase (0.1M TDdDGA in dodecane), ten steps with an aqueous phase (0.7 M HNO with metals), and six steps with another aqueous phase (0.7 M HNO without metals), approximately 99% Dy was recovered into the organic phase with 1% co-extraction of Nd.
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
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.
Takeda, Tetsuaki*; Inagaki, Yoshiyuki; Aihara, Jun; Aoki, Takeshi; Fujiwara, Yusuke; Fukaya, Yuji; Goto, Minoru; Ho, H. Q.; Iigaki, Kazuhiko; Imai, Yoshiyuki; et al.
High Temperature Gas-Cooled Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.5, 464 Pages, 2021/02
As a general overview of the research and development of a High Temperature Gas-cooled Reactor (HTGR) in JAEA, this book describes the achievements by the High Temperature Engineering Test Reactor (HTTR) on the designs, key component technologies such as fuel, reactor internals, high temperature components, etc., and operational experience such as rise-to-power tests, high temperature operation at 950C, safety demonstration tests, etc. In addition, based on the knowledge of the HTTR, the development of designs and component technologies such as high performance fuel, helium gas turbine and hydrogen production by IS process for commercial HTGRs are described. These results are very useful for the future development of HTGRs. This book is published as one of a series of technical books on fossil fuel and nuclear energy systems by the Power Energy Systems Division of the Japan Society of Mechanical Engineers.
Sumida, Kazuki; Sakuraba, Yuya*; Masuda, Keisuke*; Kono, Takashi*; Kakoki, Masaaki*; Goto, Kazuki*; Zhou, W.*; Miyamoto, Koji*; Miura, Yoshio*; Okuda, Taichi*; et al.
Communications Materials (Internet), 1, p.89_1 - 89_9, 2020/11
Nakano, Masanao; Fujii, Tomoko; Nemoto, Masashi; Tobita, Keiji; Kono, Takahiko; Hosomi, Kenji; Nishimura, Shusaku; Matsubara, Natsumi; Maehara, Yushi; Narita, Ryosuke; et al.
JAEA-Review 2019-048, 165 Pages, 2020/03
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2018 to March 2019. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co., Inc. (the trade name was changed to Tokyo Electric Power Company Holdings, Inc. on April 1, 2016) in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and exceeded the normal range of fluctuation in the monitoring, were evaluated.
Sasaki, Yuji; Ban, Yasutoshi; Morita, Keisuke; Matsumiya, Masahiko*; Ono, Ryoma*; Shiroishi, Hidenobu*
Solvent Extraction Research and Development, Japan, 27(1), p.63 - 67, 2020/00
Mutual separation technique of Dy and Nd in Nd magnet is studied. Dy is more valuable than Nd, then Dy might be isolated and reused. Lanthanide elements can be extracted thoroughly by diglycolamide (DGA) extractants, we use this reagent for the recovery and isolation of Dy. Tetradodecyl-DGA (TDdDGA) has relatively high separation factors(SF) between Dy and Nd (SF=17-18) in HNO extraction system, counter-current extraction using TDdDGA was applied for their mutual separation. From the present study, using the condition, four extraction stages, organic phase: 0.1M TDdDGA in n-dodecane, aqueous phase: 0.3M HNO, 92% Dy can be recovered with 0.7% co-extraction of Nd.
Kurihara, Momo*; Yasutaka, Tetsuo*; Aono, Tatsuo*; Ashikawa, Nobuo*; Ebina, Hiroyuki*; Iijima, Takeshi*; Ishimaru, Kei*; Kanai, Ramon*; Karube, Jinichi*; Konnai, Yae*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 322(2), p.477 - 485, 2019/11
We assessed the repeatability and reproducibility of methods for determining low dissolved radiocesium concentrations in freshwater in Fukushima. Twenty-one laboratories pre-concentrated three of 10 L samples by five different pre-concentration methods (prussian-blue-impregnated filter cartridges, coprecipitation with ammonium phosphomolybdate, evaporation, solid-phase extraction disks, and ion-exchange resin columns), and activity of radiocesium was measured. The z-scores for all of the Cs results were within 2, indicating that the methods were accurate. The relative standard deviations (RSDs) indicating the variability in the results from different laboratories were larger than the RSDs indicating the variability in the results from each separate laboratory.
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
Nakano, Masanao; Fujita, Hiroki; Mizutani, Tomoko; Nemoto, Masashi; Tobita, Keiji; Kono, Takahiko; Hosomi, Kenji; Hokama, Tomonori; Nishimura, Tomohiro; Matsubara, Natsumi; et al.
JAEA-Review 2018-025, 171 Pages, 2019/02
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2016 to March 2017. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Electric Power Company Holdings, Inc. in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and were exceeded the normal range of fluctuation in the monitoring, were evaluated.
Satou, Yukihiko; Sueki, Keisuke*; Sasa, Kimikazu*; Yoshikawa, Hideki; Nakama, Shigeo; Minowa, Haruka*; Abe, Yoshinari*; Nakai, Izumi*; Ono, Takahiro*; Adachi, Koji*; et al.
Geochemical Journal, 52(2), p.137 - 143, 2018/00
Ono, Takahiro*; Iizawa, Yushin*; Abe, Yoshinari*; Nakai, Izumi*; Terada, Yasuko*; Satou, Yukihiko; Sueki, Keisuke*; Adachi, Koji*; Igarashi, Yasuhito*
Bunseki Kagaku, 66(4), p.251 - 261, 2017/04
no abstracts in English
Ishigami, Keisuke*; Yoshimatsu, Kohei*; Toyota, Daisuke*; Takizawa, Masaru*; Yoshida, Teppei*; Shibata, Goro*; Harano, Takayuki*; Takahashi, Yukio*; Kadono, Toshiharu*; Verma, V. K.*; et al.
Physical Review B, 92(6), p.064402_1 - 064402_5, 2015/08
Saito, Toru; Okubo, Toshikazu*; Izumi, Keisuke*; Okawa, Yoshinao*; Kobayashi, Norihiro*; Yamazaki, Toru; Kawano, Katsumi; Isono, Takaaki
Teion Kogaku, 50(8), p.400 - 408, 2015/08
Aramid fiber-reinforced plastic (AFRP) has been developed as a structural material that has the advantages of light weight and high strength. In this study, tensile tests were carried out to measure the tensile properties of AFRP rod on the market for reinforcement of concrete at room temperature, 77 K and 4.2 K. Especially at cryogenic temperatures, it is difficult to perform a tensile test of the bar because the specimen slips through the jig grip. To prevent the rod from slipping, tensile tests were carried out with some filling conditions. The applicable and appropriate tensile test conditions were established by modifying the jig grip, treating the surface of the rod and using cryogenic epoxy infill to grip the rod. They were more than 1100 MPa. Additionally, the AFRP rod included a temperature dependence in which the Young's modulus increased as the test temperature decreased. It was confirmed that the Young's modulus increased because aramid fiber was more dominant than epoxy.
Ochi, Yoshihiro; Nagashima, Keisuke; Maruyama, Momoko; Tsubouchi, Masaaki; Yoshida, Fumiko; Kono, Nanase; Mori, Michiaki; Sugiyama, Akira
Optics Express (Internet), 23(11), p.15057 - 15064, 2015/06
We have developed a 1 kHz repetition picosecond laser system dedicated for intense terahertz (THz) pulse generation. The system comprises a chirped pulse amplification laser equipped with a Yb:YAG thin-disk amplifier. At room temperature, the Yb:YAG thin-disk regenerative amplifier provides pulses having energy of over 10 mJ and spectral bandwidth of 1.2 nm. The pulse duration achieved after passage through a diffraction grating pair compressor was 1.3 ps. By employing this picosecond laser as a pump source, THz pulses having a peak frequency of 0.3 THz and 4 J of energy were generated by means of optical rectification in an Mg-doped LiNbO crystal.
Nakayasu, Akio*; Doke, Ryosuke*; Niizato, Tadafumi; Urabe, Atsushi*; Ono, Eisuke*
Joho Chishitsu, 25(4), p.189 - 203, 2014/12
Various uncertainties exist in the data using in the research of geomorphology and geology. When the development process of the geological environment is restored using the data with these uncertainties, the result of the model or simulation inevitably includes uncertainties derived from the uncertainties of data. Especially, in the geological environment model dealing with chronological change of the site (Site Evolution Model) which consists from various kinds of data, the quality assessment/control in each data is important. In this study, the factors of the uncertainties occurred in the process of data acquisition for the estimation of uplift rate, which is one of the data for drawing the topographic evolution, are analyzed by using Evidential Support Logic (ESL). The result of this study is assumed to be used as a tool for extracting the factor of uncertainties in the planning of the investigation, and for controlling the quality of results in the implementation of the investigation.
Takahashi, Yukio*; Kadono, Toshiharu*; Yamamoto, Shimpei*; Singh, V. R.*; Verma, V.*; Ishigami, Keisuke*; Shibata, Goro*; Harano, Takayuki*; Takeda, Yukiharu; Okane, Tetsuo; et al.
Physical Review B, 90(2), p.024423_1 - 024423_5, 2014/07
Shibata, Goro*; Yoshimatsu, Kohei*; Sakai, Enju*; Singh, V. R.*; Verma, V.*; Ishigami, Keisuke*; Harano, Takayuki*; Kadono, Toshiharu*; Takeda, Yukiharu; Okane, Tetsuo; et al.
Physical Review B, 89(23), p.235123_1 - 235123_5, 2014/06
Hayashi, Kentaro*; Katayanagi, Nobuko*; Fumoto, Tamon*; Hasegawa, Toshihiro*; Ono, Keisuke*; Katata, Genki
Nogyo Kankyo Gijutsu Kenkyojo Heisei 25 Nendo Kenkyu Seika Joho, 30 (Internet), 2 Pages, 2014/03
no abstracts in English