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Ishii, Yui*; Yamamoto, Arisa*; Sato, Naoki*; Nambu, Yusuke*; Kawamura, Seiko; Murai, Naoki; Ohara, Koji*; Kawaguchi, Shogo*; Mori, Takao*; Mori, Shigeo*
Physical Review B, 106(13), p.134111_1 - 134111_7, 2022/10
Times Cited Count：0 Percentile：0(Materials Science, Multidisciplinary)
BOyamada, Akira*; Inohara, Takao*; Yamamoto, Etsuji; Haga, Yoshinori
Progress in Nuclear Science and Technology (Internet), 5, p.128 - 131, 2018/11
Sato, Hiroyuki; Nishida, Akemi; Ohashi, Hirofumi; Muramatsu, Ken*; Muta, Hitoshi*; Itoi, Tatsuya*; Takada, Tsuyoshi*; Hida, Takenori*; Tanabe, Masayuki*; Yamamoto, Tsuyoshi*; et al.
Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 7 Pages, 2017/04
JAEA, in conjunction with Tokyo City University, The University of Tokyo and JGC Corporation, have started development of a PRA method considering the safety and design features of HTGR. The primary objective of the project is to develop a seismic PRA method which enables to provide a reasonably complete identification of accident scenario including a loss of safety function in passive system, structure and components. In addition, we aim to develop a basis for guidance to implement the PRA. This paper provides the overview of the activities including development of a system analysis method for multiple failures, a component failure data using the operation and maintenance experience in the HTTR, seismic fragility evaluation method, and mechanistic source term evaluation method considering failures in core graphite components and reactor building.
Matsuda, Kosuke*; Muramatsu, Ken*; Muta, Hitoshi*; Sato, Hiroyuki; Nishida, Akemi; Ohashi, Hirofumi; Itoi, Tatsuya*; Takada, Tsuyoshi*; Hida, Takenori*; Tanabe, Masayuki*; et al.
Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 7 Pages, 2017/04
This paper proposes a set of procedures for accident sequence analysis in seismic PRAs of HTGRs that can consider the unique accident progression characteristics of HTGRs. Main features of our proposed procedure are as follows: (1) Systematic analysis techniques including Master Logic Diagrams are used to ensure reasonable completeness in identification of initiating events and classification of accident sequences, (2) Information on factors that govern the accident progression and source terms are effectively reflected to the construction of event trees for delineation of accident sequences, and (3) Frequency quantification of seismically-initiated accident sequence frequencies that involve multiplepipe ruptures are made with the use of the Direct Quantification of Fault Trees by Monte Carlo (DQFM) method by a computer code SECOM-DQFM.
Nakamura, Kazuya*; Yamamoto, Yusuke*; Suzuki, K.*; Takao, Tomoaki*; Murakami, Haruyuki; Natsume, Kyohei; Yoshida, Kiyoshi
IEEE Transactions on Applied Superconductivity, 25(3), p.4200704_1 - 4200704_4, 2015/06
Times Cited Count：0 Percentile：0(Engineering, Electrical & Electronic)Takao, Tomoaki*; Kawahara, Yuzuru*; Nakamura, Kazuya*; Yamamoto, Yusuke*; Yagai, Tsuyoshi*; Murakami, Haruyuki; Yoshida, Kiyoshi; Natsume, Kyohei*; Hamaguchi, Shinji*; Obana, Tetsuhiro*; et al.
IEEE Transactions on Applied Superconductivity, 24(3), p.4800804_1 - 4800804_4, 2014/06
Times Cited Count：3 Percentile：21.82(Engineering, Electrical & Electronic)no abstracts in English
and EuAlNakamura, Ai*; Hiranaka, Yuichi*; Hedo, Masato*; Nakama, Takao*; Miura, Yasunao*; Tsutsumi, Hiroki*; Mori, Akinobu*; Ishida, Kazuhiro*; Mitamura, Katsuya*; Hirose, Yusuke*; et al.
JPS Conference Proceedings (Internet), 3, p.011012_1 - 011012_6, 2014/06
Nakamura, Ai*; Hiranaka, Yuichi*; Hedo, Masato*; Nakama, Takao*; Miura, Yasunao*; Tsutsumi, Hiroki*; Mori, Akinobu*; Ishida, Kazuhiro*; Mitamura, Katsuya*; Hirose, Yusuke*; et al.
Journal of the Physical Society of Japan, 82(10), p.104703_1 - 104703_10, 2013/10
Times Cited Count：34 Percentile：82.04(Physics, Multidisciplinary)
and PuKim, S.-Y.; Takao, Koichiro*; Haga, Yoshinori; Yamamoto, Etsuji; Kawata, Yoshihisa; Morita, Yasuji; Nishimura, Kenji*; Ikeda, Yasuhisa*
Crystal Growth & Design, 10(5), p.2033 - 2036, 2010/04
Times Cited Count：15 Percentile：77.54(Chemistry, Multidisciplinary)Plutonyl(VI) nitrate complexes with N-cyclohexyl-2-pyrrolidone (NCP) and N-neopentyl-2-pyrrolidone (NNpP) were prepared, and their molecular and crystal structures were determined by single crystal X-ray analysis. The obtained compounds have the similar composition, PuO
(NO
)(NRP) (NRP = NCP, NNpP), which are analogous to the corresponding U(VI) complexes. Both PuO(NO)(NRP) complexes show typical structural properties of actinyl(VI) nitrates, i.e., hexagonal-bipyramidal geometry consisting of two NRP molecules and two NO
ions located in trans positions in the equatorial plane of PuO
moiety. These findings provide one of criteria in selection of suitable NRP as a precipitation agent for the spent nuclear fuel reprocessing based on the precipitation method.
Matsukawa, Makoto; Kikuchi, Mitsuru; Fujii, Tsuneyuki; Fujita, Takaaki; Hayashi, Takao; Higashijima, Satoru; Hosogane, Nobuyuki; Ikeda, Yoshitaka; Ide, Shunsuke; Ishida, Shinichi; et al.
Fusion Engineering and Design, 83(7-9), p.795 - 803, 2008/12
Times Cited Count：17 Percentile：72.65(Nuclear Science & Technology)no abstracts in English
Kr from a reprocessing plant over a coastal area; Performance examination of an emergency environmental radiation dose evaluation code system "SIERRA-II"Takeyasu, Masanori; Iida, Takao*; Watanabe, Hitoshi; Takeishi, Minoru; Yamamoto, Asao*
Journal of Radioanalytical and Nuclear Chemistry, 275(1), p.43 - 54, 2008/01
Times Cited Count：1 Percentile：10.01(Chemistry, Analytical)The performance of the computer code system "SIERRA-II" for calculating the environmental radiation dose due to an accident was assessed using the environmental monitoring data around the coastally located Tokai Reprocessing Plant (TRP) when Kr was discharged during its operation. The agreement within a factor of 5 between the calculated and observed air concentrations of Kr in areas of a few km from the TRP was achieved in 57% of the comparison data, and the agreement within a factor of 2 was obtained in 29%, disregarding the internal boundary layer. According to the vertical profile of atmospheric temperatures, the internal boundary layer was modeled in the SIERRA-II and the agreement became better than when the internal boundary layer was not considered.
Yamasaki, Chisato*; Murakami, Katsuhiko*; Fujii, Yasuyuki*; Sato, Yoshiharu*; Harada, Erimi*; Takeda, Junichi*; Taniya, Takayuki*; Sakate, Ryuichi*; Kikugawa, Shingo*; Shimada, Makoto*; et al.
Nucleic Acids Research, 36(Database), p.D793 - D799, 2008/01
Times Cited Count：52 Percentile：71.15(Biochemistry & Molecular Biology)Here we report the new features and improvements in our latest release of the H-Invitational Database, a comprehensive annotation resource for human genes and transcripts. H-InvDB, originally developed as an integrated database of the human transcriptome based on extensive annotation of large sets of fulllength cDNA (FLcDNA) clones, now provides annotation for 120 558 human mRNAs extracted from the International Nucleotide Sequence Databases (INSD), in addition to 54 978 human FLcDNAs, in the latest release H-InvDB. We mapped those human transcripts onto the human genome sequences (NCBI build 36.1) and determined 34 699 human gene clusters, which could define 34 057 protein-coding and 642 non-protein-coding loci; 858 transcribed loci overlapped with predicted pseudogenes.
Yoshikawa, Hiroshi; Sakaki, Hironao; Sako, Hiroyuki; Takahashi, Hiroki; Shen, G.; Kato, Yuko; Ito, Yuichi; Ikeda, Hiroshi*; Ishiyama, Tatsuya*; Tsuchiya, Hitoshi*; et al.
Proceedings of International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS '07) (CD-ROM), p.62 - 64, 2007/10
J-PARC is a large scale facility of the proton accelerators for the multi-purpose of scientific researches in Japan. This facility consists of three accelerators and three experimental stations. Now, J-PARC is under construction, and LINAC is operated for one year, 3GeV synchrotron has just started the commissioning in this October the 1st. The completion of this facility will be next summer. The control system of accelerators established fundamental performance for the initial commissioning. The most important requirement to the control system of this facility is to minimize the activation of accelerator devices. In this paper, we show that the performances of each layer of this control system have been achieved in the initial stage.
Z-type hexaferrite (Ba, Sr)CoFe
O
by high-temperature neutron diffractionTakada, Yukio*; Nakagawa, Takashi*; Tokunaga, Masatoshi*; Fukuta, Yasunari*; Tanaka, Takayoshi*; Yamamoto, Takao*; Tachibana, Takeshi*; Kawano, Shinji*; Ishii, Yoshinobu; Igawa, Naoki
Journal of Applied Physics, 100(4), p.043904_1 - 043904_7, 2006/08
Times Cited Count：71 Percentile：89.19(Physics, Applied)no abstracts in English
Z-type hexaferrite estimated by high-temperature neutron diffractionTakada, Yukio*; Nakagawa, Takashi*; Fukuta, Yasunari*; Tokunaga, Masatoshi*; Yamamoto, Takao*; Tachibana, Takeshi*; Kawano, Shinji*; Igawa, Naoki; Ishii, Yoshinobu
Japanese Journal of Applied Physics, 44(5A), p.3151 - 3156, 2005/05
Times Cited Count：4 Percentile：13.67(Physics, Applied)We investigated the correlation between the thremomagnetic curve of CoZ-Type hexagonal barium ferrite, BaCo
Fe
O and its magnetic moment direction. The thermomagnetic curve shows two significant magnetization slumps at 540K and 680K. High-temperature neutron diffraction experiment and Rietveld analyses indicate that temperature rise from 523 to 573K makes the magnetic moments turn to the c-axis from a direction parallel to the c-plane most significantly.The change in average orientation of the magnetic moments must be induced by the disappearence of the contribution of cobalt to magnetism in this temperature.
Yamamoto, Mikihiko*; Ito, Takao*; Oba, Toshiyuki*
JNC TJ8400 2003-061, 25 Pages, 2003/02
JNC-TJ8400-2003-061.pdf:2.05MB
Gas production resulting from some mechanisms, including metal corrosion and microbial degradation in a geological repository, enables to lead overpressurization of pore pressure and enhanced release of pore water with dissolved radionuclides. In this study, gas injection experiments under three-dimensional confinement pressure, a gas-water capillary pressure test using high speed centrifuge method and high pressure mercury injection test were performed on tuff core samples to clarify flow parameters of gas and water. Results of the gas injection tests under the condition of constant injection pressure and axial flow were described. The water permeability of saturated samples were existing between 8.4 
10
and 8.9 10m
although the gas permeability of dried sample were varied between 2.3 10
and 2.5 10
m depending on gas injection pressure. Gas breakthrough phenomenon after rapid rise in outflow rate of water was indicated rather slow increase of gas outflow than that observed on clay materials. Obtained excess pressure when the breakthrough phenomena occurred were 700 and 1,700 kPa. Grater the gas injection pressure, higher the excess pressure at breakthrough. Threshold pressure obtained from the capillary pressure test was order of 10
kPa which was two order of magnitude lower than the value of clay materials. Based on these experimental results, the gas migration process and the retention curve of the tuff sample indicated typical properties observed on porous media. Thus it is expected that the conventional continuum two-phase flow model will be applied reasonably for the tuff sample.
Mihara, Morihiro; Yamamoto, Mikihiko*; Ito, Takao*; Oba, Toshiyuki*
JNC TJ8400 2003-060, 81 Pages, 2003/02
Gas migration phnomena in potential components of near-field barrier system was investigated.
Kuriyama, Masaaki; Akino, Noboru; Ebisawa, Noboru; Honda, Atsushi; Ito, Takao; Kawai, Mikito; Mogaki, Kazuhiko; Oga, Tokumichi; Ohara, Hiroshi; Umeda, Naotaka; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.424 - 434, 2002/09
Times Cited Count：15 Percentile：67.77(Nuclear Science & Technology)no abstracts in English
Kuriyama, Masaaki; Akino, Noboru; Ebisawa, Noboru; Grisham, L. R.*; Honda, Atsushi; Ito, Takao; Kawai, Mikito; Kazawa, Minoru; Mogaki, Kazuhiko; Ohara, Yoshihiro; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.410 - 423, 2002/09
Times Cited Count：49 Percentile：93.08(Nuclear Science & Technology)no abstracts in English
Oga, Tokumichi; Umeda, Naotaka; Akino, Noboru; Ebisawa, Noboru; Grisham, L. R.*; Hikida, Shigenori*; Honda, Atsushi; Ito, Takao; Kawai, Mikito; Kazawa, Minoru; et al.
Review of Scientific Instruments, 73(2), p.1058 - 1060, 2002/02
Times Cited Count：12 Percentile：55.22(Instruments & Instrumentation)no abstracts in English
