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Onishi, Takashi; Koyama, Shinichi; Mimura, Hitoshi*
Nihon Ion Kokan Gakkai-Shi, 31(3), p.43 - 49, 2020/10
Nakamura, Shota*; Hyodo, Kazushi*; Matsumoto, Yuji*; Haga, Yoshinori; Sato, Hitoshi*; Ueda, Shigenori*; Mimura, Kojiro*; Saiki, Katsuyoshi*; Iso, Kosei*; Yamashita, Minoru*; et al.
Journal of the Physical Society of Japan, 89(2), p.024705_1 - 024705_5, 2020/02
Times Cited Count:2 Percentile:19.65(Physics, Multidisciplinary)Suzuki, Yoshitaka; Kitagawa, Tomoya*; Namekawa, Yoji*; Matsukura, Minoru*; Nishikata, Kaori; Mimura, Hitoshi*; Tsuchiya, Kunihiko
Transactions of the Materials Research Society of Japan, 43(2), p.75 - 80, 2018/04
no abstracts in English
Onishi, Takashi; Tanaka, Kosuke; Koyama, Shinichi; Ou, L. Y.*; Mimura, Hitoshi*
NEA/NSC/R(2017)3, p.463 - 469, 2017/11
no abstracts in English
Suzuki, Yoshitaka; Ishida, Takuya*; Suzuki, Yumi*; Matsukura, Minoru*; Kurosaki, Fumio*; Nishikata, Kaori; Mimura, Hitoshi*; Tsuchiya, Kunihiko
JAEA-Technology 2016-027, 24 Pages, 2016/12
The research and development (R&D) on the production of Mo/Tc by (n,) method has been carried out in the Neutron Irradiation and Testing Reactor Center. The Mo production by (n,) reaction is a simple and easy method, and it also is advantageous from viewpoints of nuclear proliferation resistance and waste management. However, it is difficult to produce the Tc solution with high radioactive concentration because the specific radioactivity of Mo by this method is extremely low. Up to now, various Mo absorbents such as Polyzirconium Compound (PZC) and Polytitanium Compound (PTC) have been developed with high Mo adsorption efficiency. It is necessary for utilization to the generator of these absorbents to evaluate the effect of elements containing these absorbents and to assure the quality of Tc solution. In this report, the status of R&D of the Mo adsorbents was investigated. The alumina as Mo adsorbent, which uses in medical Mo/Tc generator, was focused and Mo adsorption/desorption properties of three kinds of alumina was evaluated by different properties such as crystal structure and specific surface.
Onishi, Takashi; Koyama, Shinichi; Mimura, Hitoshi*
Progress in Nuclear Energy, 82, p.69 - 73, 2015/07
Times Cited Count:6 Percentile:43.95(Nuclear Science & Technology)no abstracts in English
Mimura, Hitoshi*; Yamagishi, Isao
Zeoraito, 31(4), p.115 - 124, 2014/12
Massive tsunami caused by the Great East Japan Earthquake attacked the Fukushima Daiichi Nuclear Power Plant and caused the nuclear accident of level 7 to overturn the safety myth of nuclear power generation. The domestic worst accident does not yet reach the convergence, and many inhabitants around the power plant are forced to double pains of earthquake disaster and nuclear accident. At present, large amounts of high-activity-level water over 500,000 tons are stored in Fukushima NPP-1 site, which is a serious obstacle to take measures for the nuclear accident. For the decontamination of high-activity-level water containing seawater, the circulating injection cooling system using packed columns with inorganic ion-exchangers is operated and the cold shutdown is accomplished. However, the advancement of operating system and the safety management of secondary solid wastes are very important subject. In this paper, the adsorption properties and solidification characteristics are compared for Cs and Sr selective adsorbents mainly composed of zeolites and the enhancement of adsorption properties are reported. Especially, naturally occurring zeolites abundant in Japan have high selectivity towards Cs, and also have excellent functions of gas trapping and self sintering for stable solidification. Zeolites are thus expected for the treatment and disposal of contaminated water in future. This paper also reports the present situation of safety management of solid wastes and the development of stable solidification methods, and summarizes the future subjects considering the safety disposal.
Onishi, Takashi; Koyama, Shinichi; Masud, R. S.*; Kawamura, Takuya*; Mimura, Hitoshi*; Niibori, Yuichi*
Nihon Ion Kokan Gakkai-Shi, 25(4), p.220 - 227, 2014/11
no abstracts in English
Sasaki, Yuji; Tsubata, Yasuhiro; Kitatsuji, Yoshihiro; Sugo, Yumi; Shirasu, Noriko; Ikeda, Yasuhisa*; Kawasaki, Takeshi*; Suzuki, Tomoya*; Mimura, Hitoshi*; Usuda, Shigekazu*; et al.
JAEA-Research 2014-008, 220 Pages, 2014/06
The researches on Development of mutual separation technology of minor actinides by the novel hydrophilic and lipophilic diamide compounds, entrusted to Japan Atomic Energy Agency by the Ministry of Education, Culture, Sports, Science and Technology of Japan, from 2010 to 2012 are summarized. This project was composed of three themes, those are (1) Development of total recovery of MA+Ln: basic researches for new extractant, DOODA, (2) Development of mutual separation of Am/Cm/Ln: basic researches of Ln-complex, solvent extraction, and extraction chromatography, and (3) Evaluation of separation technique: process simulation. For topic (1), we summarized the information on characteristic of DOODA extractant. For topic (2), we summarized the information on structures of Ln-complexes, solvent extraction and chromatography. For topic (3), we summarized the information on conditions of mixer-settler and evaluation of each fraction separated.
Onishi, Takashi; Koyama, Shinichi; Mimura, Hitoshi*
Proceedings of International Waste Management Symposia 2013 (WM2013) (CD-ROM), 7 Pages, 2013/02
As part of a development of nuclides separation process by using highly-functional xerogels, xerogels including insoluble ferrocyanide compounds were prepared for separation of Pt group metals. Adsorption and elution behaviors of Pt group metals were investigated in simulated high level radioactive liquid waste. Removal of sulfur from recovered palladium was also conducted by a thermal decomposition and digestion method.
Osaka, Masahiko; Tanaka, Kosuke; Sekine, Shinichi; Akutsu, Yoko; Suzuki, Tatsuya*; Mimura, Hitoshi*
Journal of Nuclear Materials, 427(1-3), p.384 - 388, 2012/08
Times Cited Count:4 Percentile:31.05(Materials Science, Multidisciplinary)Morphology-controlled synthesis of Mo compounds from a nitric acid solution by microwave heating was investigated for effective utilizations of Mo fission product from a high level nuclear waste. The microwave heating method was revealed to greatly accelerate crystallization and crystal growth of the synthesized powder. Addition of a small amount of Zr stabilized synthesis of a hexagonal-MoO powder. Furthermore, the microwave heating with Zr-addition has synthesized a specific urchin-like shaped hexagonal-MoO crystal having a good crystallinity. The present methods would be useful for effective utilization of Mo from high level nuclear waste in terms of their practicability and ability to the morphology control.
Nishiura, Masaya*; Toba, Shiori*; Takao, Daisuke*; Miyashiro, Daisuke*; Sakakibara, Hitoshi*; Matsuo, Tatsuhito; Kamimura, Shinji*; Oiwa, Kazuhiro*; Yagi, Naoto*; Iwamoto, Hiroyuki*
Journal of Structural Biology, 178(3), p.329 - 337, 2012/06
Times Cited Count:3 Percentile:8.41(Biochemistry & Molecular Biology)We report the first X-ray diffraction patterns recorded from single axonemes of eukaryotic flagella with a diameter of only 0.2 m, by using the technique of cryomicrodiffraction. A spermatozoon isolated from Drosophila melanogaster, was mounted straight in a glass capillary, quickly frozen and its 800-m segment was irradiated end-on with intense synchrotron radiation X-ray microbeams (diameter, 2 m) at 74 K. Well-defined diffraction patterns were recorded, consisting of a large number of isolated reflection spots. The patterns had features of an 18-fold rotational symmetry as expected from the axonemal structure. The diffraction patterns were compared with the results of model calculations based on a published electron micrograph of the Drosophila axoneme. The comparison provided information on the native state of axoneme, including estimates of axonemal diameter and interdoublet spacing.
Yamagishi, Isao; Mimura, Hitoshi*; Idemitsu, Kazuya*
Nihon Genshiryoku Gakkai-Shi ATOMO, 54(3), p.166 - 170, 2012/03
no abstracts in English
Mimura, Hitoshi*; Yamagishi, Isao
Nihon Ion Kokan Gakkai-Shi, 23(1), p.6 - 20, 2012/02
Large amounts of seawater contaminated with radioactive cesium accumulated in the nuclear accident of Fukushima NPP1. As of December, 2011, the circulating injection cooling system is effectively operated and the cold shutdown is completed, while the amounts of high-activity-level water are estimated to be over 200,000 m in future. However, at present, the treatment and disposal methods for the solid wastes (zeolites, insoluble ferrocyanides and crystalline silicotitanate) are not yet decided. In particular, there is no experience in the treatment and disposal of high decontamination solid materials such as insoluble ferrocyanides and crystalline silicotitanate. Hence the development of effective treatment and disposal methods are very urgent and important subjects. This special issue deals with the characterization and adsorption properties of selective adsorbents for high decontamination of cesium and the subjects for the treatment and disposal of solid wastes.
Koyama, Shinichi; Suzuki, Tatsuya*; Ozawa, Masaki*; Kurosawa, Kiyoko*; Fujita, Reiko*; Mimura, Hitoshi*; Okada, Ken*; Morita, Yasuji; Fujii, Yasuhiko*
Procedia Chemistry, 7, p.222 - 230, 2012/00
Times Cited Count:2 Percentile:70.03(Chemistry, Analytical)Adv.-ORIENT cycle strategy has been proposed as a basic concept for trinitarian research on separation, transmutation and utilization of nuclides and elements based on FBR fuel cycle. Validation of principal separation method and related safety research were performed from 2006 through 2011 as Phase I program. First, more than 90% of Cs could be recovered from the actual spent fuel [IXC(I) step]. The next is the adsorption of the platinum group metals (PGM), lanthanides, Am and Cm were separated by using a tertiary pyridine-type resin (TPR) as ion exchange steps [IXC(II, III, IV) steps]. The separated PGM metals will be supplied to the electrochemical extraction [CEE step]. As experiment for safety issues, Hastelloy-B at RT and Ta at 90C were confirmed their anti-corrosive in highly concentrated HCl media. Thermo-chemical stability for TPR was verified. Issues to be solved for next phase based on the final results of phase I program.
Tomiyama, Shin*; Mimura, Hitoshi*; Niibori, Yuichi*; Yamagishi, Isao; Morita, Yasuji
Proceedings of 11th OECD/NEA Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation (Internet), 10 Pages, 2012/00
The immobilization of Cs has been studied by the calcination of the Cs-form of various kinds of mordenites. In this study, the effect of various parameters such as calcining temperature and time, components in mordenites, conditions for cold and hot pressing, on the immobilization of Cs in ceramic products are evaluated by using X-ray diffractometry (XRD), density balance (Archimedes' method), scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). Results showed that recrystallization to the stable ceramic solid forms of CsAlSiO was achieved only in calcination of Synthetic Mordenite-C which contains Ti and Fe as binder. The Cs-form mordenites were pelletized into a disk by cold isostatic pressing and the density of the solid forms increased with calcining temperature and time.
Koyama, Shinichi; Yamagishi, Isao; Suzuki, Tatsuya*; Ozawa, Masaki*; Fujita, Reiko*; Okada, Ken*; Tatenuma, Katsuyoshi*; Mimura, Hitoshi*; Fujii, Yasuhiko
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 8 Pages, 2011/12
Effective separation of MA and LLFP, transmutation and utilization were the main directions of Advanced OREINT Cycle project. Study for each integrant technology was concluded as first trial of the project. TPR enabled to separate MA/Ln and then Am/Cm precisely from spent fuel in HCl and HNO media. CEE method could separate the light PGM and Tc by HCl media. Recovery of Cs from simulated HLLW coul be achieved more than 90 %. In addition, the perspective for next phase was proposed.
Osaka, Masahiko; Miwa, Shuhei; Tanaka, Kosuke; Akutsu, Yoko; Ikeda, Kaoru*; Mimura, Hitoshi*; Suzuki, Tatsuya*; Usuki, Toshiyuki; Yano, Toyohiko*
Annals of Nuclear Energy, 38(12), p.2661 - 2666, 2011/10
Times Cited Count:2 Percentile:17.88(Nuclear Science & Technology)Novel concepts for effective utilization of molybdenum (Mo) from nuclear waste and magnesium silicates from hazardous asbestos wastes are proposed. A fast reactor cycle scheme that incorporates each material is described in the present paper. Basic studies on some fundamental technologies for the present cycle are given. Basic separation aspects for Mo by using LIX63 micro capsules and tertiary pyridine resin were investigated. A simple chemical synthesis route for Mo precursor powder from Mo containing HNO solution was tested. Effects of impurities in recovered Mo on sintering behavior were experimentally investigated.
Utsumi, Yuki*; Sato, Hitoshi*; Kurihara, Hidenao*; Maso, Hiroyuki*; Hiraoka, Koichi*; Kojima, Kenichi*; Tobimatsu, Komei*; Okochi, Takuo*; Fujimori, Shinichi; Takeda, Yukiharu; et al.
Physical Review B, 84(11), p.115143_1 - 115143_7, 2011/09
Times Cited Count:12 Percentile:45.97(Materials Science, Multidisciplinary)We have studied conduction-band (CB) electronic states of a typical valence-transition compound YbInCu by means of temperature-dependent hard X-ray photoemission spectroscopy (HX-PES), soft X-ray absorption spectroscopy (XAS), and soft X-ray photoemission spectroscopy (SX-PES) of the valence band. We have described the valence transition in YbInCu in terms of the charge transfer from the CB to Yb 4 states.
Koyama, Shinichi; Suzuki, Tatsuya*; Mimura, Hitoshi*; Fujita, Reiko*; Kurosawa, Kiyoko*; Okada, Ken*; Ozawa, Masaki
Progress in Nuclear Energy, 53(7), p.980 - 987, 2011/09
Times Cited Count:5 Percentile:37.62(Nuclear Science & Technology)Individual basic researches of separation step were performed in the Advanced ORIENT Cycle project. High separation selectivity for Cs and Sr by novel nano adsorbents AMP-SG (D) and D18C6-MC were confirmed, respectively. TPR well adsorbed Pd and Tc in dilute HCl condition. Formation of rare metal fission product RMFP-deposit Pt electrodes from SHLLW was verified, and it was confirmed that high catalytic reactivity on electrolytic production of hydrogen. As experiment for engineering feasibility, Hastelloy-B at RT and Ta at 90C were confirmed their anti-corrosive in highly concentrated HCl media. Thermo-chemical stability for TPR was verified in either HCl or HNO media toward its practical use in the separation process. Issues to be solved for optimization based on the results of lab-scale experiment have revealed in this study.