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Pu
Am
)O
(z = 0.05, 0.10, and 0.15)Yokoyama, Keisuke; Watanabe, Masashi; Tokoro, Daishiro*; Sugimoto, Masatoshi*; Morimoto, Kyoichi; Kato, Masato; Hino, Tetsushi*
Nuclear Materials and Energy (Internet), 31, p.101156_1 - 101156_7, 2022/06
Times Cited Count：3 Percentile：68.71(Nuclear Science & Technology)In current nuclear fuel cycle systems, to reduce the amount of high-level radioactive waste, minor actinides (MAs) bearing MOX fuel is one option for burning MAs using fast reactor. However, the effects of Am content in fuel on thermal conductivity are unclear because there are no experimental data on thermal conductivity of high Am bearing MOX fuel. In this study, The thermal conductivities of near stoichiometric (UPuAm)O solid solutions(z = 0.05, 0.10, and 0.15) have been measured between room temperature (RT) and 1473 K. The thermal conductivities decreased with increasing Am content and satisfied the classical phonon transport model ((A+BT)
) up to about 1473 K. A values increased linearly with increasing Am content because the change in ionic radius affects the conduction of the phonon due to the solid solution in U
and Am
. B values were independent of Am content.
Goto, Sho; Aoki, Kenji; Morimoto, Kenji; Tsuboi, Masatoshi; Isozaki, Naohiko; Furukawa, Ryuichi; Kitagawa, Osamu; Fukaya, Yasuhiro*
Nihon Hozen Gakkai Dai-17-Kai Gakujutsu Koenkai Yoshishu, p.517 - 520, 2021/07
no abstracts in English
Yasuda, Satoshi; Tamura, Kazuhisa; Terasawa, Tomoo; Yano, Masahiro; Nakajima, Hideaki*; Morimoto, Takahiro*; Okazaki, Toshiya*; Agari, Ryushi*; Takahashi, Yasufumi*; Kato, Masaru*; et al.
Journal of Physical Chemistry C, 124(9), p.5300 - 5307, 2020/03
Times Cited Count：14 Percentile：60.14(Chemistry, Physical)Confinement of hydrogen molecules at graphene-substrate interface has presented significant importance from the viewpoints of development of fundamental understanding of two-dimensional material interface and energy storage system. In this study, we investigate H confinement at a graphene-Au interface by combining selective proton permeability of graphene and the electrochemical hydrogen evolution reaction (electrochemical HER) method. After HER on a graphene/Au electrode in protonic acidic solution, scanning tunneling microscopy finds that H nanobubble structures can be produced between graphene and the Au surface. Strain analysis by Raman spectroscopy also shows that atomic size roughness on the graphene/Au surface originating from the HER-induced strain relaxation of graphene plays significant role in formation of the nucleation site and H storage capacity.
Tanaka, Taiki*; Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Haba, Hiromitsu*; Boll, R. A.*; Brewer, N. T.*; Van Cleve, S.*; Dean, D. J.*; Ishizawa, Satoshi*; et al.
Physical Review Letters, 124(5), p.052502_1 - 052502_6, 2020/02
Times Cited Count：19 Percentile：81.08(Physics, Multidisciplinary)Isozaki, Naohiko; Morimoto, Kenji; Furukawa, Ryuichi; Tsuboi, Masatoshi; Yada, Yuji; Miyoshi, Ryuta; Uchida, Toyomi; Ikezawa, Kazumi*; Kurosawa, Kenji*
Nihon Hozen Gakkai Dai-16-Kai Gakujutsu Koenkai Yoshishu, p.225 - 228, 2019/07
Highly active liquid waste, which is generated by the reprocessing of spent nuclear fuel, is stored in storage tank of Tokai Reprocessing Plant until it is vitrified. The waste solution in the tank is periodically agitated to avoid the precipitation of insoluble residues during the storage. Three way valves and ball valves have been located at the tank for agitation. Radiation dose rate at the valve location is high and operator's radiation exposure become a problem. Therefore, measures to reduce radiation exposure are performed and reported in this presentation.
= 100 with a multireflection time-of-flight mass spectrographIto, Yuta*; Schury, P.*; Wada, Michiharu*; Arai, Fumiya*; Haba, Hiromitsu*; Hirayama, Yoshikazu*; Ishizawa, Satoshi*; Kaji, Daiya*; Kimura, Sota*; Koura, Hiroyuki; et al.
Physical Review Letters, 120(15), p.152501_1 - 152501_6, 2018/04
Times Cited Count：60 Percentile：93.36(Physics, Multidisciplinary)Masses of 
Es, 
Fm and the transfermium nuclei 
Md, and 
No, produced by hot- and cold-fusion reactions, in the vicinity of the deformed 
neutron shell closure, have been directly measured using a multi-reflection time-of-flight mass spectrograph. The masses of Es and 
Md were measured for the first time. Using the masses of 
Md as anchor points for 
decay chains, the masses of heavier nuclei, up to 
Bh and 
Mt, were determined. These new masses were compared with theoretical global mass models and demonstrated to be in good agreement with macroscopic-microscopic models in this region. The empirical shell gap parameter 
derived from three isotopic masses was updated with the new masses and corroborate the existence of the deformed neutron shell closure for Md and Lr.
Tanaka, Taiki*; Narikiyo, Yoshihiro*; Morita, Kosuke*; Fujita, Kunihiro*; Kaji, Daiya*; Morimoto, Koji*; Yamaki, Sayaka*; Wakabayashi, Yasuo*; Tanaka, Kengo*; Takeyama, Mirei*; et al.
Journal of the Physical Society of Japan, 87(1), p.014201_1 - 014201_9, 2018/01
Times Cited Count：18 Percentile：74.47(Physics, Multidisciplinary)Excitation functions of quasielastic scattering cross sections for the 
Ca + 
Pb, 
Ti + Pb, and Ca + 
Cm reactions were successfully measured by using the gas-filled recoil-ion separator GARIS. Fusion barrier distributions were extracted from these data, and compared with the coupled-channels calculations. It was found that the peak energies of the barrier distributions for the Ca + Pb and Ti + Pb systems coincide with those of the 2n evaporation channel cross sections for the systems, while that of the Ca + Cm is located slightly below the 4n evaporation ones. This results provide us helpful information to predict the optimum beam energy to synthesize superheavy nuclei.
Maeda, Seiichiro; Oki, Shigeo; Otsuka, Satoshi; Morimoto, Kyoichi; Ozawa, Takayuki; Kamide, Hideki
Proceedings of International Conference on Fast Reactors and Related Fuel Cycles; Next Generation Nuclear Systems for Sustainable Development (FR-17) (USB Flash Drive), 10 Pages, 2017/06
The next generation fast reactor is being investigated in Japan, aiming at several targets such as "safety", "reduction of environmental burden" and "economic competitiveness". As for the safety aspect, FAIDUS concept is adopted to avoid re-criticality in core destructive accidents. The uranium-plutonium mixed oxide fuel, in which minor actinide elements are included, will be applied to reduce the amount and potential radio-toxicity of radioactive wastes. The high burn-up fuel is pursued to reduce fuel cycle cost. The candidate concept of the core and fuel design, which could satisfy various design criteria by design devisals, has been established. In addition, JAEA is investigating material properties and irradiation behavior of MA-MOX fuel. JAEA is developing the fuel design code especially for the fuel pin with annular pellets of MA-bearing MOX. Furthermore, JAEA is developing oxide dispersion strengthened (ODS) ferritic steel cladding for the high burnup fuel.
-PuO-ZrO pseudo-ternary systemMorimoto, Kyoichi; Hirooka, Shun; Akashi, Masatoshi; Watanabe, Masashi; Sugata, Hiromasa*
Journal of Nuclear Science and Technology, 52(10), p.1247 - 1252, 2015/10
Times Cited Count：4 Percentile：33.25(Nuclear Science & Technology)As a part of decommissioning plan of the damaged reactors at Fukushima Daiichi Nuclear Power Plant, some strategies for removing of debris from the reactors are discussed. In these considerations, it is necessary to predict a melt progression during the severe accident based on theoretical evidences. Melting temperature is one of the most important thermal characteristics to analyse a melt progression during the severe accident. In this study, the melting temperatures of specimens of U, Pu and Zr mixed oxide prepared as simulated debris were measured by the thermal arrest technique. From the results of this measurement, the influences of Pu
and Zr contents on the melting temperature of the simulated debris were evaluated.
Kato, Masato; Hirooka, Shun; Ikusawa, Yoshihisa; Takeuchi, Kentaro; Akashi, Masatoshi; Maeda, Koji; Watanabe, Masashi; Komeno, Akira; Morimoto, Kyoichi
Proceedings of 19th Pacific Basin Nuclear Conference (PBNC 2014) (USB Flash Drive), 12 Pages, 2014/08
Uranium and plutonium mixed oxide (MOX) fuel has been developed for Japan sodium-cooled fast reactors. Science based fuel technologies have been developed to analyse behaviours of MOX pellets in the sintering process and irradiation conditions. The technologies can provide appropriate sintering conditions, irradiation behaviour analysis results and so on using mechanistic models which are derived based on theoretical equations to represent various properties.
and zircaloy-2Hirooka, Shun; Kato, Masato; Morimoto, Kyoichi; Komeno, Akira; Uchida, Teppei; Akashi, Masatoshi
Journal of Nuclear Materials, 437(1-3), p.130 - 134, 2013/06
Times Cited Count：5 Percentile：38.62(Materials Science, Multidisciplinary)Ono, Shinya*; Inoue, Kei*; Morimoto, Masahiro*; Arae, Sadanori*; Toyoshima, Hiroaki*; Yoshigoe, Akitaka; Teraoka, Yuden; Ogata, Shoichi*; Yasuda, Tetsuji*; Tanaka, Masatoshi*
Surface Science, 606(21-22), p.1685 - 1692, 2012/11
Times Cited Count：8 Percentile：35.38(Chemistry, Physical)
1-tetrahydrocannabinolic acid (THCA) synthase, the enzyme controlling the psychoactivity of 
Shoyama, Yoshinari*; Tamada, Taro; Kurihara, Kazuo; Takeuchi, Ayako*; Taura, Futoshi*; Arai, Shigeki; Blaber, M.*; Shoyama, Yukihiro*; Morimoto, Satoshi*; Kuroki, Ryota
Journal of Molecular Biology, 423(1), p.96 - 105, 2012/10
Times Cited Count：82 Percentile：89.24(Biochemistry & Molecular Biology)1-tetrahydrocannabinolic acid (THCA) synthase catalyzes the oxidative cyclization of cannabigerolic acid (CBGA) into THCA, the precursor of the primary psychoactive agent 1-tetrahydrocannabinol in . The structure-function relationship of THCA synthase was investigated by X-ray structure determination (2.75 
resolution) and mutational analysis. Specific amino acid residues were identified in the active site of THCA synthase that are involved in the oxidative cyclization of the CBGA substrate.
and zircalloy-2Kato, Masato; Uchida, Teppei; Hirooka, Shun; Akashi, Masatoshi; Komeno, Akira; Morimoto, Kyoichi
Materials Research Society Symposium Proceedings, Vol.1444, p.91 - 96, 2012/09
Times Cited Count：1 Percentile：56.78(Materials Science, Multidisciplinary)
and zircalloy-2Hirooka, Shun; Akashi, Masatoshi; Uchida, Teppei; Morimoto, Kyoichi; Kato, Masato
Materials Research Society Symposium Proceedings, Vol.1444, p.97 - 101, 2012/09
Times Cited Count：0 Percentile：0.11(Materials Science, Multidisciplinary)Ono, Shinya*; Inoue, Kei*; Morimoto, Masahiro*; Arae, Sadanori*; Toyoshima, Hiroaki*; Yoshigoe, Akitaka; Teraoka, Yuden; Ogata, Shoichi*; Yasuda, Tetsuji*; Tanaka, Masatoshi*
Shingaku Giho, 111(114), p.23 - 27, 2011/07
The initial oxidation on high-index silicon surfaces with (113) and (120) orientations at 820 K has been investigated by real-time X-ray photoemission spectroscopy (Si 2p and O 1s) using 687 eV photons. The time evolutions of the Si
(n=1-4) components in the Si 2p spectrum indicate that the Si
state is suppressed on high-index surfaces compared with Si(001). The O 1s state consists of two components, a low-binding-energy component (LBC) and a high-binding-energy component (HBC). It is suggested that the O atom in strained Si-O-Si contributes to the LBC component. The reaction rates are slower on high-index surfaces compared with that on Si(001).
Ioki, Kimihiro*; Barabash, V.*; Cordier, J.*; Enoeda, Mikio; Federici, G.*; Kim, B. C.*; Mazul, I.*; Merola, M.*; Morimoto, Masaaki*; Nakahira, Masataka*; et al.
Fusion Engineering and Design, 83(7-9), p.787 - 794, 2008/12
Times Cited Count：19 Percentile：76.01(Nuclear Science & Technology)This paper presents recent results of ITER activities on Vacuum Vessel (VV), blanket, limiter, and divertor. Major results can be summarized as follows. (1) The VV design is being developed in more details considering manufacturing and assembly methods, and cost. Incorporating manufacturing studies being performed in cooperation with parties, the regular VV sector design has been nearly finalized. (2) The procurement allocation of blanket modules among 6 parties was fixed and the blanket module design has progressed in cooperation with parties. Fabrication of mock-ups for prequalification testing is under way and the tests will be performed in 2007-2008. (3) The divertor activities have progressed with the aim of launching the procurement according to the ITER project schedule.
Taguchi, Chiho; Taura, Futoshi*; Tamada, Taro; Shoyama, Yoshinari; Shoyama, Yukihiro*; Tanaka, Hiroyuki*; Kuroki, Ryota; Morimoto, Satoshi*
Acta Crystallographica Section F, 64(3), p.217 - 220, 2008/03
Times Cited Count：3 Percentile：36.02(Biochemical Research Methods)Yamauchi, Michinori*; Ochiai, Kentaro; Morimoto, Yuichi*; Wada, Masayuki*; Sato, Satoshi; Nishitani, Takeo
Radiation Protection Dosimetry, 116(1-4), p.542 - 546, 2005/12
Times Cited Count：3 Percentile：24.22(Environmental Sciences)no abstracts in English
Ioki, Kimihiro*; Akiba, Masato; Barabaschi, P.*; Barabash, V.*; Chiocchio, S.*; Daenner, W.*; Elio, F.*; Enoeda, Mikio; Ezato, Koichiro; Federici, G.*; et al.
Journal of Nuclear Materials, 329-333(1), p.31 - 38, 2004/08
Times Cited Count：14 Percentile：66.09(Materials Science, Multidisciplinary)The preparation of the procurement specifications is being progressed for key components. Progress has been made in the preparation of the procurement specifications for key nuclear components of ITER. Detailed design of the vacuum vessel (VV) and in-vessel components is being performed to consider fabrication methods and non-destructive tests (NDT). R&D activities are being carried out on vacuum vessel UT inspection with waves launched at an angle of 20 or 30 degree, on flow distribution tests of a two-channel model, on fabrication and testing of FW mockups and panels, on the blanket flexible support as a complete system including the housing, on the blanket co-axial pipe connection with guard vacuum for leak detection, and on divertor vertical target prototypes. The results give confidence in the validity of the design and identify possibilities of attractive alternate fabrication methods.
