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-based simulated fuel containing CsITakamatsu, Yuki*; Ishii, Hiroto*; Oishi, Yuji*; Muta, Hiroaki*; Yamanaka, Shinsuke*; Suzuki, Eriko; Nakajima, Kunihisa; Miwa, Shuhei; Osaka, Masahiko; Kurosaki, Ken*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 17(3/4), p.106 - 110, 2018/12
In order to establish the synthesis method of simulated fuel contacting Cesium (Cs) which is required for the evaluation of physical/chemical characteristics in fuel and release behavior of Cs, sintering tests of the cerium dioxide (CeO) based simulated fuels containing Cesium iodide (CsI) are performed by using spark plasma sintering (SPS) method. The sintered CeO pellets with homogeneous distribution of several micro meter of CsI spherical precipitates were successfully obtained by optimizing SPS conditions.
Muta, Hiroaki*; Nishikane, Ryoji*; Ando, Yusuke*; Matsunaga, Junji*; Sakamoto, Kan*; Harjo, S.; Kawasaki, Takuro; Oishi, Yuji*; Kurosaki, Ken*; Yamanaka, Shinsuke*
Journal of Nuclear Materials, 500, p.145 - 152, 2018/03
Times Cited Count：14 Percentile：78.17(Materials Science, Multidisciplinary)Tanaka, Kosuke; Sato, Isamu; Hirosawa, Takashi; Kurosaki, Ken*; Muta, Hiroaki*; Yamanaka, Shinsuke*
Journal of Nuclear Science and Technology, 52(10), p.1285 - 1289, 2015/10
Times Cited Count：2 Percentile：16.55(Nuclear Science & Technology)Polycrystalline specimens of americium-containing barium plutonate have been prepared by mixing the appropriate amounts of (Pu
Am
)O and BaCO
powders followed by reacting and sintering at 1600 K under the flowing gas atmosphere of dry-air. The sintered specimens had a single phase of orthorhombic perovskite structure and were crack-free. The elastic moduli were determined from the longitudinal and shear sound velocities. The Debye temperature was also determined from the sound velocities and lattice parameter measurements. The thermal conductivity was calculated from the measured density at room temperature, literature values of heat capacity, and thermal diffusivity measured by laser flash method in vacuum. The thermal conductivity of americium-containing barium plutonate was roughly independent of the temperature and was almost the same magnitude as that of BaPuO and BaUO.
image crystalSerizawa, Hiroyuki; Oishi, Yuji*; Kaji, Yoshiyuki; Yamanaka, Shinsuke*
New Research Trends of Fluorite-Based Oxide Materials, p.243 - 262, 2015/01
The image crystal is a shape controllable negative crystal which is sometimes reported by mineralogist. The negative crystals formed in a large single-crystal mass have attracted interest as expensive jewelry because of their mysterious appearance and rarity. Nonetheless, for many scientist, the cavity has been nothing else than a volume defect which occurs in a single crystal by chance. However, the authors found unexpectedly that the image crystal is formed in UO when helium is enclosed in the gas bubble. They also found that the shape of the image crystal changes dramatically with the conditions of helium precipitation, which implies that the shape of the cavity should change depending on the inner pressure. A truncated octahedron-type, an octa-triacontahedron-type and a pentacontahedron-type negative crystal were observed. Recent study clarified that the growth process of the image crystal can be explained by a step free energy model rather than an attachment energy.
Tanaka, Kosuke; Tokushima, Kazuyuki*; Kurosaki, Ken*; Oishi, Yuji*; Muta, Hiroaki*; Yamanaka, Shinsuke*
Journal of Nuclear Materials, 443(1-3), p.218 - 221, 2013/11
Times Cited Count：0 Percentile：0.00(Materials Science, Multidisciplinary)Polycrystalline specimens of barium uranate, BaUO, were prepared and several properties such as the thermal expansion coefficient, elastic moduli, thermal conductivity, and Debye temperature were evaluated.
Serizawa, Hiroyuki; Matsunaga, Junji*; Haga, Yoshinori; Nakajima, Kunihisa; Akabori, Mitsuo; Tsuru, Tomohito; Kaji, Yoshiyuki; Kashibe, Shinji*; Oishi, Yuji*; Yamanaka, Shinsuke*
Crystal Growth & Design, 13(7), p.2815 - 2823, 2013/07
Times Cited Count：5 Percentile：41.90(Chemistry, Multidisciplinary)Since the shape of the negative crystal closely relates to the morphology of the crystal habits, the formation and the growth mechanism is important subject in a field of the physical science. Whereas, the negative crystal formed in a large single crystal mass has been arousing interest as an expensive jewelry because of its mysterious appearance and rarity. However, it is difficult to control the shape of this polyhedral cavity embedded in a solid medium arbitrary. Here we report the recent discovery on the growth process of the negative crystal. We found that precipitated helium forms the negative crystal in UO; the shape changes drastically with the condition of the helium precipitation. The transformation mechanism was discussed in this article. Our investigation implies that the shape of the negative crystal can be arbitrary controlled by controlling the precipitation condition.
Tanaka, Kosuke; Sato, Isamu; Hirosawa, Takashi; Kurosaki, Ken*; Muta, Hiroaki*; Yamanaka, Shinsuke*
Journal of Nuclear Materials, 422(1-3), p.163 - 166, 2012/03
Times Cited Count：10 Percentile：58.67(Materials Science, Multidisciplinary)Polycrystalline specimens of strontium plutonate, SrPuO, have been prepared by mixing the appropriate amounts of PuO and SrCO powders followed by reacting and sintering at 1600 K under the flowing gas atmosphere of dry-air. The sintered specimens had a single phase of orthorhombic perovskite structure and were crack-free. The elastic moduli of SrPuO were determined from the longitudinal and shear sound velocities. The Debye temperature was also determined from the sound velocities and lattice parameter measurements. The thermal conductivity of SrPuO was calculated from the measured density at room temperature, literature values of heat capacity, and thermal diffusivity measured by laser flash method in vacuum.
Tanaka, Kosuke; Osaka, Masahiko; Miwa, Shuhei; Hirosawa, Takashi; Kurosaki, Ken*; Muta, Hiroaki*; Uno, Masayoshi*; Yamanaka, Shinsuke*
Journal of Nuclear Materials, 420(1-3), p.207 - 212, 2012/01
Times Cited Count：6 Percentile：41.82(Materials Science, Multidisciplinary)In order to investigate the effect on fuel thermophysical properties when adding americium and selected fission products to uranium-plutonium mixed fuel, simulated low decontamination MOX fuel with high burn-ups to 250 GWd/t, has been prepared and subjected to characterization tests, elastic moduli measurements, melting temperature measurement.
Osaka, Masahiko; Konashi, Kenji*; Hayashi, Hirokazu; Li, D.*; Homma, Yoshiya*; Yamamura, Tomoo*; Sato, Isamu; Miwa, Shuhei; Sekimoto, Shun*; Kubota, Takumi*; et al.
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 5 Pages, 2011/12
Summer schools for future experts have successfully been completed under Japan Actinide Network (J-ACTINET) for the purpose of development of human resources who are expected to be engaged in every areas of actinide-research/engineering. The first summer school was held in Ibaraki-area in August 2009, followed by the second one in Kansai-area in August 2010. Two summer schools have focused on actual experiences of actinides in actinide-research fields for university students and young researchers/engineers as an introductory course of actinide-researches. Several quasi actinide-handling experiences at the actinide-research fields have attracted attentions of participants at the first school in Ibaraki-area. The actual experiments using actinides-containing solutions have been carried out at the second school in Kansai-area. Future summer schools will be held every year for the sustainable human resource development in various actinide-research fields.
Minato, Kazuo; Konashi, Kenji*; Yamana, Hajimu*; Yamanaka, Shinsuke*; Nagasaki, Shinya*; Ikeda, Yasuhisa*; Sato, Seichi*; Arita, Yuji*; Idemitsu, Kazuya*; Koyama, Tadafumi*
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 5 Pages, 2011/12
Actinide science research is indispensable to maintain sustainable development of innovative nuclear technology. For actinide science research, special facilities with containment and radiation shields are needed to handle actinide materials. The number of facilities for actinide science research has been decreased, especially in universities, due to the high maintenance cost. J-ACTINET was established in 2008 to promote and facilitate actinide science research and to foster many of young scientists and engineers in actinide science. The research program was carried out, through which young researchers were expected to learn how to make experiments with advanced experimental tools and to broaden their horizons. The summer schools and computational science school were held to provide students and young researchers with the opportunities to come into contact with actinide science research. The overseas dispatch program was also carried out.
at temperatures from 300 to 1500 KTanaka, Kosuke; Sato, Isamu; Hirosawa, Takashi; Kurosaki, Ken*; Muta, Hiroaki*; Yamanaka, Shinsuke*
Journal of Nuclear Materials, 414(2), p.316 - 319, 2011/07
Times Cited Count：24 Percentile：84.72(Materials Science, Multidisciplinary)Polycrystalline specimens of barium plutonate, BaPuO, have been prepared by mixing the appropriate amounts of PuO and BaCO followed by reacting and sintering at 1600 K under the flowing gas atmosphere of dry-air. The thermal conductivity of BaPuO was almost the same magnitude as that of BaUO.
Ce
)O
Osaka, Masahiko; Miwa, Shuhei; Kurosaki, Ken*; Uno, Masayoshi*; Yamanaka, Shinsuke*
Journal of Nuclear Materials, 408(3), p.285 - 288, 2011/01
Times Cited Count：3 Percentile：25.23(Materials Science, Multidisciplinary)Oxygen non-stoichiometry in (ThCe)O were investigated from a viewpoint of features of Ce reduction in several oxide solid solutions. Oxygen non-stoichiometry was experimentally determined by means of thermogravimetric analysis as a function of oxygen potential at 1173, 1273 and 1373 K. The similar features of isotherms of oxygen non-stoichiometry in (ThCe)O with those in actinide and/or lanthanide-oxygen dioxides were observed. Oxygen non-stoichiometry in (ThCe)O were compared with those of CeO and (UCe)O. It was concluded that features of Ce reduction have some relationships with defect forms and their transformations in the solid solutions.
Ce)OOsaka, Masahiko; Tanaka, Kosuke; Miwa, Shuhei; Kurosaki, Ken*; Uno, Masayoshi*; Yamanaka, Shinsuke*
Materials Research Society Symposium Proceedings, Vol.1215, p.199 - 203, 2010/10
Oxygen potentials of (ThCe)O were experimentally determined by means of thermogravimetric analysis as a function of non-stoichiometry at 1173 and 1273 K. Oxygen potentials of (ThCe)O at each temperature increased with increase of O/M ratio (= 2-x) and steep increases of the oxygen potentials toward O/M = 2 were observed. These characteristics are typical for non-stoichiometric fluorite-type actinides dioxides. The oxygen potentials of (ThCe)O were similar to those of CeOO when they were plotted as a function of average Ce valence.
Tanaka, Kosuke; Osaka, Masahiko; Kurosaki, Ken*; Muta, Hiroaki*; Uno, Masayoshi*; Yamanaka, Shinsuke*
Materials Research Society Symposium Proceedings, Vol.1215, p.95 - 100, 2010/10
In order to investigate the effect of MAs and FP addition on the oxygen potential of MOX fuels, thermogravimetric analysis (TGA) were carried out. MOX fuels with Am and 26 kinds of fission product elements (FPs), simulating low-decontamination MOX fuel and high burn-up to 250 GWd/t, were prepared by a conventional powder metallurgical route in a glove box. The oxygen potentials for simulating low-decontamination MOX fuels were higher than the fuels without FPs and increased positively with increasing simulated burn-up.
-O ( = Mo or U) ternary compoundsTokushima, Kazuyuki*; Tanaka, Kosuke; Kurosaki, Ken*; Gima, Hiromichi*; Muta, Hiroaki*; Uno, Masayoshi*; Yamanaka, Shinsuke*
Materials Research Society Symposium Proceedings, Vol.1215, p.151 - 156, 2010/10
The thermal diffusivities of CsMoO and CsUO using samples fabricated by hot press and SPS techniques were measured by a laser flash method in the range from room temperature to 823 K for CsMoO and to 900 K for CsUO. The thermal conductivities of these cesium ternary oxides were quite low compared with UO and MOX fuel. This is consistent with previous findings. These results would be useful for evaluating the thermal performance of MOX fuels at the high burn-up region in the fast reactors.
Kurosaki, Ken*; Tanaka, Kosuke; Osaka, Masahiko; Oishi, Yuji*; Muta, Hiroaki*; Uno, Masayoshi*; Yamanaka, Shinsuke*
Proceedings of Joint International Conference of 7th Supercomputing in Nuclear Application and 3rd Monte Carlo (SNA + MC 2010) (USB Flash Drive), 4 Pages, 2010/10
It is important to understand the behavior of fission products and actinides under irradiation. In the present study, the chemical states of fission products and actinides in irradiated oxide fuels were evaluated by both thermodynamic equilibrium calculation and post-irradiation examination.
Adachi, Jun*; Kurosaki, Ken*; Uno, Masayoshi*; Yamanaka, Shinsuke*; Takano, Masahide; Akabori, Mitsuo; Minato, Kazuo
Journal of Nuclear Materials, 384(1), p.6 - 11, 2009/01
Times Cited Count：12 Percentile：61.38(Materials Science, Multidisciplinary)The indentation hardness, Vickers hardness, fracture toughness, and Young's modulus of polycrystalline uranium monontride (UN) at sub-microscale and macroscale were evaluated by an indentation test, Vickers hardness test, and the ultrasonic pulse echo method. The Young's modulus and Vickers hardness were in good agreement with the literature values. The fracture toughness of UN was about three times that of UO. In addition, we revealed the indentation size effect on the indentation hardness of UN.
Katayama, Masahito*; Adachi, Jun*; Kurosaki, Ken*; Uno, Masayoshi*; Miwa, Shuhei; Osaka, Masahiko; Tanaka, Kenya; Yamanaka, Shinsuke*
Materials Research Society Symposium Proceedings, Vol.1043, p.190 - 195, 2008/00
The molecular dynamics (MD) calculation was performed on minor actinides (MA)-containing mixed oxide (MOX) fuels, (U
PuMA
)O (x = 0, 0.016, 0.03, 0.05, 0.1, 0.15), and the lattice parameter, heat capacity and thermal conductivity were evaluated. The calculated thermal conductivity data are comparable in (UPuMA)O at any temperature and any x value, indicating that the thermal conductivity of MA-containing MOX fuels is scarcely influenced by adding MA up to 15 %. The present study shows that the MD calculation can be usefully applied to determine the thermophysical properties of MA-containing MOX fuels.
Osaka, Masahiko; Adachi, Jun*; Kurosaki, Ken*; Uno, Masayoshi*; Yamanaka, Shinsuke*
Journal of Nuclear Science and Technology, 44(12), p.1543 - 1549, 2007/12
Times Cited Count：12 Percentile：62.85(Nuclear Science & Technology)no abstracts in English
with addition of 9% AmMiwa, Shuhei; Osaka, Masahiko; Yoshimochi, Hiroshi; Tanaka, Kenya; Kurosaki, Ken*; Uno, Masayoshi*; Yamanaka, Shinsuke*
Journal of Alloys and Compounds, 444-445, p.610 - 613, 2007/10
Times Cited Count：14 Percentile：60.85(Chemistry, Physical)no abstracts in English
