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Fukui, Toshiki*; Maki, Takashi*; Miura, Nobuyuki; Tsukada, Takeshi*
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 23(2), p.169 - 173, 2016/12
The basic research programs for the next generation vitrification technology, which are commissioned project from Ministry of Economy, Trade and Industry of Japan, have been implemented from 2014 until 2018 for developing the advanced vitrification technology of low level wastes and high level liquid wastes.
Okamoto, Yoshihiro; Nakada, Masami; Akabori, Mitsuo; Komamine, Satoshi*; Fukui, Toshiki*; Ochi, Eiji*; Nitani, Hiroaki*; Nomura, Masaharu*
Denki Kagaku Oyobi Kogyo Butsuri Kagaku, 81(7), p.543 - 546, 2013/07
Times Cited Count：7 Percentile：17.93(Electrochemistry)The molten state of simulated high-level waste glass and the behavior of ruthenium element in the melt were investigated by using synchrotron radiation based X-ray imaging technique. Melting, generating and moving of bubbles, condensation and sedimentation of ruthenium element were observed dynamically in continuous 12-bit gray-scale images from the CCD camera. X-ray intensity was obtained easily by digitizing gray-scale values in the image. The existence of ruthenium element is emphasized as a black color in the CCD image at X-ray energy higher than the Ru K-absorption edge. Position sensitive imaging X-ray absorption fine structure (XAFS) measurement was also performed to clarify the chemical state of ruthenium element in the melt.
Okamoto, Yoshihiro; Nakada, Masami; Akabori, Mitsuo; Komamine, Satoshi*; Fukui, Toshiki*; Ochi, Eiji*; Nitani, Hiroaki*; Nomura, Masaharu*
Proceedings of 4th Asian Conference on Molten Salt Chemistry and Technology & 44th Symposium on Molten Salt Chemistry, Japan, p.47 - 52, 2012/09
The molten state of the simulated high-level waste glass and the behavior of ruthenium element in the melt were investigated by using synchrotron radiation based X-ray imaging technique. Melting, generating and moving of bubbles, condensation and sedimentation of ruthenium element were observed dynamically in continuous 12-bit gray-scale images from the CCD camera. The existence of ruthenium in the X-ray CCD image was emphasized over the energy of Ru K-absorption edge. X-ray intensity was obtained easily by digitalizing gray-scale values in the image. Position sensitive imaging X-ray absorption fine structure (XAFS) measurement was performed to clarify the chemical state of ruthenium element in the melt.
Okamoto, Yoshihiro; Nakada, Masami; Akabori, Mitsuo; Shiwaku, Hideaki; Komamine, Satoshi*; Fukui, Toshiki*; Ochi, Eiji*; Nitani, Hiroaki*; Nomura, Masaharu*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 11(2), p.127 - 132, 2012/06
Distribution and the chemical state of Ru element in the simulated high-level waste glass were examined by using the synchrotron radiation based X-ray imaging technique. In this technique, a direct X-ray CCD camera is used in place of an ion chamber. Position sensitive X-ray absorption spectra were obtained by analyzing gray scale in images of the X-ray CCD camera. At first, we measured a test sample containing RuO
and Ru metal powder. We successfully obtained information on the Ru distribution in the sample. In addition, the chemical state (oxide or metal ?) of each small Ru-rich spot was evaluated by the corresponding position sensitive XAFS spectrum. The imaging XAFS technique was applied to some simulated high-level waste glass samples. The Ru distribution of the glass sample and their chemical state were confirmed by image analyses. It can be seen that Ru element scattered in the glass sample exists as oxide RuO.
Kanagawa, Akihiro*; Iwatsuki, Jin; Tanaka, Nobuyuki; Onuki, Kaoru; Fukui, Hiroshi*; Nishibayashi, Toshiki*
JAEA-Technology 2007-061, 32 Pages, 2007/12
JAEA-Technology-2007-061.pdf:21.03MB
Separation of hydrogen iodide from HIx solution (HI-I
-HO mixture) is one of the technical issues in the development of thermochemical IS process. Application of pervaporation (PV) to the concentration of HIx solution in the IS process pilot test plant was discussed from the viewpoints of process heat mass balance, conceptual design of the apparatus, and the corrosion resistance of the membrane module. Compared with the electro-electrodialysis system, the PV system enables the downsizing of apparatus by using hollow fiber membranes, although it does not improve the thermal efficiency of IS process. Immersion tests of commercially available Nafion hollow fiber membrane module in the HIx solution at 100
C indicated the necessity of improving the corrosion resistance of bundle materials.
Amamoto, Ippei; Myochin, Munetaka; Fukui, Toshiki*
New Glass, 22(2), p.21 - 26, 2007/06
As the electrolyte [LiCl-KCl] used in the pyrochemical reprocessing process by the electrorefining method will likely be contaminated by the accumulation of various fission products [FPs] after prolonged electrolytic operation, some measures, e.g., its replacement by a virgin electrolyte, etc. are necessary. The constant replacement of electrolyte, however, could lead to the generation of enormous amount of high level radioactive waste [HLW] because the spent electrolyte is a waste salt and is classified as HLW. From the viewpoints of environmental load reduction and economical improvement, it is desirable to have the spent electrolyte purified for recycling by removing its FPs. The FPs precipitation method by converting FPs to insoluble compounds such as phosphates could be one of the potential techniques to remove FPs. Subsequently, it is necessary to immobilise FPs precipitates by vitrification or some other methods. The possibility and potential advantages of the vitrification of FPs phosphates using the iron phosphate glass is introduced in this paper. At the same time, comparisons are made with the borosilicate immobilisation method.
Cs and 
Co in slag made from non-metallic radioactive wastesNakashima, Mikio; Nakashio, Nobuyuki; Kameo, Yutaka; Fukui, Toshiki*; Isobe, Motoyasu*; Otake, Atsushi*; Wakui, Takuji*; Hirabayashi, Takakuni*
Radiochimica Acta, 91(1), p.45 - 51, 2003/01
Times Cited Count：2 Percentile：19(Chemistry, Inorganic & Nuclear)no abstracts in English
Nakashima, Mikio; Fukui, Toshiki*; Nakashio, Nobuyuki; Isobe, Motoyasu*; Otake, Atsushi*; Wakui, Takuji*; Hirabayashi, Takakuni*
Journal of Nuclear Science and Technology, 39(6), p.687 - 694, 2002/06
Times Cited Count：16 Percentile：69.83(Nuclear Science & Technology)no abstracts in English
; Obayashi, Hiroshi; ; *; Fukui, Toshiki*; Arai, Kazuhiro*
JNC TJ6410 2002-013, 38 Pages, 2002/02
JNC-TJ6410-2002-013.pdf:1.18MB
no abstracts in English
Fukui, Toshiki; Nakashio, Nobuyuki; Isobe, Motoyasu; Otake, Atsushi*; Wakui, Takuji*; Hirabayashi, Takakuni*; Nakashima, Mikio
JAERI-Review 2000-033, 82 Pages, 2001/02
JAERI-Review-2000-033.pdf:2.61MB
no abstracts in English
Nakashio, Nobuyuki; Isobe, Motoyasu; Wakui, Takuji*; Iwata, Keiji*; Kibayashi, Tatsuyuki*; Kanazawa, Katsuo; Fukui, Toshiki; Otake, Atsushi*; Nakashima, Mikio; Hirabayashi, Takakuni*
JAERI-Research 2001-001, 19 Pages, 2001/02
JAERI-Research-2001-001.pdf:1.29MB
no abstracts in English
Nakashio, Nobuyuki; Wakui, Takuji*; Otake, Atsushi*; Nakashima, Mikio; Fukui, Toshiki*; Isobe, Motoyasu*
Proceedings of 8th International Conference on Radioactive Waste Management and Environmental Remediation (ICEM '01) (CD-ROM), 4 Pages, 2001/00
no abstracts in English
Fukui, Toshiki; Nakashio, Nobuyuki; Isobe, Motoyasu; Otake, Atsushi*; Wakui, Takuji*; Nakashima, Mikio; Hirabayashi, Takakuni*
Dai-7-Kai Doryoku Enerugi Gijutsu Shimpojiumu Koen Rombunshu (00-11), p.356 - 359, 2000/00
no abstracts in English
Kato, Junya; Miyauchi, Atsushi; Aoshima, Atsushi; Shiotsuki, Masao; Yamashita, Teruo; Nakajima, Masayoshi; Morikawa, Yo; Miura, Akihiko; Fukui, Toshiki*; Yamasaki, Akito*; et al.
no journal, ,
no abstracts in English
Yamashita, Teruo; Miura, Akihiko; Kato, Junya; Shiotsuki, Masao; Ono, Isamu*; Fukui, Toshiki*; Yamasaki, Akito*; Matsumoto, Shiro*
no journal, ,
The objective of this development is to extend vitrification melter life-time to reduce burden of the high level radioactive waste management by applying advanced technologies. The candidate concepts of the long-life melter were studied with evaluation of adopted important advanced technologies such as skull layer conditions and the commutative electrode structure. It was concluded that such technology has a potential to extend melter life as 20 years even in the preliminary studies. Based on the obtained results, after the following fiscal year, evaluation of each component, small scale melter examination, and development and evaluation of simulation tool are carried out.
Kubo, Shinji; Ohashi, Hirofumi; Kanagawa, Akihiro; Kasahara, Seiji; Imai, Yoshiyuki; Fukui, Hiroshi*; Nishibayashi, Toshiki*; Shimazaki, Masanori*; Miyashita, Reiko*; Tago, Yasuhiro*; et al.
no journal, ,
For a stable hydrogen production, essential problems with the closed-cycle operation are declared, and the cycle can ensure these are retained in a steady state in case the H production rate, O production rate and HO supply rate have equivalent values. Process control methods used to maintain the mass balance of the process were devised, involving the installation of accumulators for the total system, techniques to maintain the Bunsen reaction composition and so on. For the plant operation, both controlled and manipulated variables were determined, while computer simulation and the bench scale H production test were used to confirm control methods. For closed cycle operation for water splitting driven by helium gas heat, the method is discussed to allocate heat for the O and H production sections in strict proportion. Finally, the use of computer simulation for the O production system allowed the key to maintaining heat balance within a cascade heat absorption system to be confirmed.
Okamoto, Yoshihiro; Nakada, Masami; Akabori, Mitsuo; Minato, Kazuo; Shiwaku, Hideaki; Komamine, Satoshi*; Fukui, Toshiki*; Nitani, Hiroaki*; Nomura, Masaharu*
no journal, ,
Chemical state analysis of Ru element scattered in an imitative glass matrix was performed by using the Imaging XAFS technique. Information on distribution of Ru element in the matrix was obtained from contrast values of CCD images before and after the Ru K-absorption edge. It is confirmed that the feature of the distributed element can be examined by getting XAFS spectra from the contrast information. We can get two kinds of XAFS spectra corresponding to Ru metal and oxide separately in the Imaging XAFS analysis.
Okamoto, Yoshihiro; Nakada, Masami; Akabori, Mitsuo; Minato, Kazuo; Shiwaku, Hideaki; Yaita, Tsuyoshi; Komamine, Satoshi*; Fukui, Toshiki*; Ochi, Eiji*; Nitani, Hiroaki*; et al.
no journal, ,
Distribution and the chemical state of Ru element in the simulated high-level waste glass were examined by using the synchrotron radiation based X-ray imaging technique. In this technique, a direct X-ray CCD camera is used in place of an ion chamber. Position sensitive X-ray absorption spectra were obtained by analyzing gray scale in images of the X-ray CCD camera. It can be seen that Ru element scattered in the glass sample exists as oxide RuO.
Takano, Masahide; Yamagishi, Isao; Akabori, Mitsuo; Minato, Kazuo; Fukui, Toshiki*; Yoshioka, Masahiro*
no journal, ,
no abstracts in English
Takano, Masahide; Yamagishi, Isao; Akabori, Mitsuo; Minato, Kazuo; Yoshioka, Masahiro*; Ochi, Eiji*; Fukui, Toshiki*; Komamine, Satoshi*
no journal, ,
no abstracts in English
