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Furuta, Takuya; Sato, Tatsuhiko; Han, M. C.*; Yeom, Y. S.*; Kim, C. H.*; Brown, J. L.*; Bolch, W. E.*
Physics in Medicine & Biology, 62(12), p.4798 - 4810, 2017/06
Times Cited Count:15 Percentile:53.46(Engineering, Biomedical)A new function to treat tetrahedral-mesh geometry, a type of polygon-mesh geometry, was implemented in the Particle and Heavy Ion Transport code Systems (PHITS). Tetrahedral-mesh is suitable to describe complex geometry including curving shapes. In addition, construction of three-dimensional geometry using CAD software becomes possible with file format conversion. We have introduced a function to create decomposition maps of tetrahedral-mesh objects at the initial process so that the computational time for transport process can be reduced. Owing to this function, transport calculation in tetrahedral-mesh geometry can be as fast as that for the geometry in voxel-mesh with the same number of meshes. Due to adaptability of tetrahedrons in size and shape, dosimetrically equivalent objects can be represented by tetrahedrons with much fewer number of meshes compared with the voxels. For dosimetric calculation using computational human phantom, significant acceleration of the computational speed, about 4 times, was confirmed by adopting the tetrahedral mesh instead of the voxel.
Myagmarjav, O.; Ikeda, Ayumi*; Tanaka, Nobuyuki; Kubo, Shinji; Nomura, Mikihiro*
International Journal of Hydrogen Energy, 42(9), p.6012 - 6023, 2017/03
Times Cited Count:21 Percentile:49.80(Chemistry, Physical)Noguchi, Hiroki; Takegami, Hiroaki; Kamiji, Yu; Tanaka, Nobuyuki; Iwatsuki, Jin; Kasahara, Seiji; Kubo, Shinji
Proceedings of 8th International Topical Meeting on High Temperature Reactor Technology (HTR 2016) (CD-ROM), p.1029 - 1038, 2016/11
JAEA has been conducting R&D on the IS process for nuclear-powered hydrogen production. We have constructed a 100 NL/h-H-scale test apparatus made of industrial materials. At first, we investigated performance of components in this apparatus. In this paper, the test results of H
SO
decomposition, HI distillation, and HI decomposition were shown. In the H
SO
section, O
production rate is proportional to H
SO
feed rate and SO
decomposition ratio was estimated about 80%. In HI distillation section, we confirmed to acquire a concentrated HI solution over azeotropic HI composition in the condenser. In HI decomposition section, H
could be produced stably by HI decomposer and decomposition ratio was about 18%. The H
SO
decomposer, the HI distillation column, and the HI decomposer were workable. Based on the results added to that shown in Series I, we conducted a trial continuous operation and succeeded it for 8 hours.
Zheng, X.; Ito, Hiroto; Tamaki, Hitoshi; Maruyama, Yu
Journal of Nuclear Science and Technology, 53(3), p.333 - 344, 2016/03
Times Cited Count:12 Percentile:71.76(Nuclear Science & Technology)Yamaguchi, Isoo*; Morita, Yasuji; Fujiwara, Takeshi; Yamagishi, Isao
JAERI-Tech 2005-054, 61 Pages, 2005/09
The HLW-79Y-4T type transportation cask for liquid radioactive fuel material (commonly called "Cendrillon") was imported from France and modified for Japanese regulation in order to obtain high-level radioactive liquid waste (HLW) for partitioning tests in JAERI by transportation from Tokai Establishment of Japan Nuclear Fuel Cycle Development Institute. The cask was used for the HLW transportation five times from 1982 to 1990. After that, it was kept and maintained for next transportation of HLW from facilities outside JAERI. Finally, we decided to decompose the cask because HLW can be obtained in JAERI Tokai. For the decomposition, radiation dose and contamination by radioactivity was first measured and then the methods to reduce those levels were determined. The cask was decomposed after the decontamination to separate the part that has high radiation level. The separated part was put in a vessel specially prepared. The present report describes those procedures for the decomposition of the transportation cask.
Okada, Taku; Utsumi, Wataru; Kaneko, Hiroshi*; Yamakata, Masaaki*; Shimomura, Osamu
Physics and Chemistry of Minerals, 29(7), p.439 - 445, 2002/08
Times Cited Count:18 Percentile:54.59(Materials Science, Multidisciplinary)An experimental technique to make real-time observations at high pressure and temperature of the diamond forming process in candidate material of mantle fluids as a catalyst has been established for the first time. In situ X-ray diffraction experiments using synchrotron radiation have been performed upon a mixture of brucite (Mg(OH)) and graphite as starting material. Brucite decomposes into periclase (MgO) and H
O at 3.6 GPa and 1050
C while no periclase is formed after the decomposition of brucite at 6.2 GPa and 1150
C, indicating that the solubility of the MgO component in H
O greatly increases with increasing pressure. The conversion of graphite to diamond in aqueous fluid has been observed at 7.7 GPa and 1835
C. Time-dependent X-ray diffraction profiles for this transformation have been successfully obtained.
Kurata, Yuji; Tachibana, Katsumi; Suzuki, Tomio
Nihon Kinzoku Gakkai-Shi, 65(4), p.262 - 265, 2001/04
no abstracts in English
Watanabe, Kazuo; Inagawa, Jun
Analyst, 121, p.623 - 625, 1996/05
Times Cited Count:11 Percentile:43.70(Chemistry, Analytical)no abstracts in English
; ; ; ; Machi, Sueo
Journal of Nuclear Science and Technology, 12(6), p.362 - 369, 1975/06
Times Cited Count:20no abstracts in English
Myagmarjav, O.; Ikeda, Ayumi*; Nomura, Mikihiro*; Kubo, Shinji
no journal, ,
The thermal decomposition of hydrogen iodide (HI) to produce hydrogen in a membrane reactor was investigated using the separation characteristics of a silica membrane with the aim of improving the one-pass decomposition rate of HI decomposition reaction in the thermochemical IS process. The silica membranes were prepared by a counter diffusion chemical vapor deposition (CVD) of hexyltrimethoxysilane (HTMOS) using alumina porous support. The membrane reactor phenomenon was evaluated using determined H production rate from HI decomposition at 400
C. It was found from experiments that produced H
rate was approximately 1.5 mL min
in permeated site. Hydrogen was successfully produced and extracted from the HI decomposition membrane reactor with a utilization of the HTMOS silica membrane. The HTMOS silica membrane was effective for the HI decomposition at higher reaction temperature of 400
C in the membrane reactor.