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Naoe, Takashi; Teshigawara, Makoto; Futakawa, Masatoshi; Mizutani, Haruki; Muramatsu, Toshiharu; Yamada, Tomonori; Ushitsuka, Yuji*; Tanaka, Nobuatsu*; Yamasaki, Kazuhiko*
Proceedings of 8th International Congress on Laser Advanced Materials Processing (LAMP 2019) (Internet), 5 Pages, 2019/05
Laser cutting is one of the options in the disposal of radio-active waste, such as spallation neutron target vessel in J-PARC, etc. Due to unique characteristic of laser, such as non-contact system, it is more easily to provide remote-controlled system in comparison with conventional one, such as mechanical cutting machine, etc. However, a demerit of laser cutting is the sputter and fume caused by laser cutting, resulting in contamination with radio-active materials its surroundings. Recently it was developed that the spatter suppression technique by controlling laser beam profile in laser welding process. In order to apply this suppression technique to laser cutting, first of all, we attempted to observe the phenomenon at melting area during laser cutting using a high-speed video camera in order to make the physical model. The result showed that the appearance of fume and sputter were independently confirmed in the time evolution.
Hayashi, Katsuhiko; Kishi, Hirokazu; Kabayashi, Yasushi*; Takebe, Atsuji*; Fujiyama, Tetsuo*; Hiramoto, Masayuki*; Mizutani, Kazuhiko*; Morita, Atsushi*
JAEA-Research 2010-059, 92 Pages, 2011/03
JAEA-Research-2010-059.pdf:3.71MB
In this study, the first investigation is the order of the multi-tunnels excavation. The second is the strain-softening model for multi-tunnels which is based on test data at Horonobe site. As results of first investigation, we showed as 2 dimensional analyses that it was desirable to excavate the tunnel of the remote distance at first and excavate the tunnel between these tunnels next, and it is necessary for the examination that reflected a real plan, such as evacuation machine and actual multi tunnel layout. As the results of second investigation, we also showed the more reliable EDZ by using the strain-softening model that is based on test data at Horonobe site. Furthermore, we standardized the design method (draft) for the practical use by referring the past studies of multi tunnel design method.
Hayashi, Katsuhiko; Kishi, Hirokazu; Kabayashi, Yasushi*; Takebe, Atsuji*; Fujiyama, Tetsuo*; Hiramoto, Masayuki*; Mizutani, Kazuhiko*; Morita, Atsushi*
JAEA-Research 2009-056, 86 Pages, 2010/02
JAEA-Research-2009-056.pdf:9.96MB
In this study, the effect of constitutive models such as strain softening of rock masses for EDZ, and the stress relief ratio used for multi tunnels analysis were conducted. As the result, it is necessary to confirm mechanical behavior of in situ rock and it is important to choose suitable constitutive models, and it is possible for all tunnels in multi tunnels model to have same stress relief ratio.
Hayashi, Katsuhiko; Kobayashi, Yasushi; Hiramoto, Masayuki*; Mizutani, Kazuhiko*; Morita, Atsushi*
JAEA-Research 2009-016, 127 Pages, 2009/08
JAEA-Research-2009-016.pdf:5.23MB
"Study on configuration of analytical domain of the multi tunnels model" and "Remainders on an elasto-plastic FEM (Finite Element Method) analysis" in case of the full width of pillar become plastic on simplified model" are studied as "The study on the enhanced reliability of elasto-plastic FEM". In addition, "The effect of rock support and consolidation of the host rock to control the plastic region" was conducted as "The study on the mechanical stability of tunnels". As the results, it was seen that the analytical domain should be assigned 3-5W (W: width of multi tunnels) for a horizontal side from the endmost tunnel and 3-4W for below of the tunnels. It was found reasonable and proper on the elasto-plastic FEM analysis that the analysis domain must be large enough not to have plastic deformation in all analysis of domains under the condition in which the full width of pillar has plastic deformation. It was also found that the ground support suppresses the plasticity domain as the ground support effect. It was acknowledged that the auxiliary construction method by improvement of the ground has the suppression effect of the plasticity domain applying to the multi tunnels.
Hiramoto, Masayuki; Kobayashi, Yasushi; Nakama, Shigeo; Mizutani, Kazuhiko*; Morita, Atsushi*
JAEA-Research 2008-001, 84 Pages, 2008/03
JAEA-Research-2008-001.pdf:13.19MB
In this study, the following studies on the design method of multi-tunnels were performed. Study on the outbreak behavior of EDZ (Chapter 2) Study on the stability evaluation of the pillars (Chapter 3) In Chapter 2, analysis was carried out for "multi-tunnels model" that modeled the gallery group of a disposal panel scale. As a result, it is important to use multi-tunnels models for prediction evaluation of EDZ, because the outbreak behavior of EDZ was different from the model of the H12 report. In Chapter 3, a stability evaluation method of pillars was considered from two viewpoints of "pillar strength" and "pillar load" based on the similar structures. As a result, if numerical analysis by the multi-tunnels model was carried out, pillar strength and pillar load was estimated adequately. Therefore, a stability evaluation method of the pillars in a disposal institution was suggested.
Inoue, Hiroyuki*; Yoshino, Naoto; Miyanomae, Shunichi*; Mizutani, Kazuhiko*; Noda, Kenji*
JNC TJ8400 2004-005, 161 Pages, 2004/02
JNC-TJ8400-2004-005.pdf:18.59MB
In this study, the laboratory mechanical tests of sedimentary soft rock sampled at HORONOBE area in HOKKAIDO prefecture were conducted in order to build the confidence of OKUBO model for long term deformation of sedimentary rock. And the stability of rock around tunnel in building under the condition assumed the underground of HORONOBE area was examined by numerical simulation using information of boring data obtained before 2002 year. As a result, authors could obtain many values of parameter in OKUBO model under various conditions. These conditions have the difference of temperature and water saturation. In addition, the life time in creep predicted by OKUBO model could be compared with the real one. And numerical simulations, assuming various conditions such as stiffness of buffer material and yielding of support, had been carried out to evaluate the long-term stability of rock surrounding buffer material. Results show the decreasing tendency of time dependency of rock.
Kitamura, Toshikatsu; Togawa, Orihiko; Aramaki, Takafumi; Suzuki, Takashi; Mizutani, Yoshihiko*; Kabuto, Shoji*; Sudo, Kazuhiko*
JNC TN7200 2001-001, p.31 - 34, 2002/01
no abstracts in English
Kitamura, Toshikatsu; Aramaki, Takafumi; Mizutani, Yoshihiko*; Togawa, Orihiko; Mizushima, Toshihiko; Kabuto, Shoji*; Sudo, Kazuhiko*
JAERI-Conf 2000-019, p.26 - 29, 2001/02
no abstracts in English
Katayama, Yoshinori; Mizutani, Takeshi; Utsumi, Wataru; Shimomura, Osamu; Tsuji, Kazuhiko*
Physica Status Solidi (B), 223(2), p.401 - 404, 2001/01
Times Cited Count：18 Percentile：66.81(Physics, Condensed Matter)no abstracts in English
Gottdang, A.*; Klein, M.*; Mous, D. J. W.*; Kitamura, Toshikatsu; Mizutani, Yoshihiko*; Suzuki, Takashi; Aramaki, Takafumi; Togawa, Orihiko; Kabuto, Shoji*; Sudo, Kazuhiko*
AIP Conference Proceedings 576, p.403 - 406, 2001/00
no abstracts in English
Ueta, Shohei; Aihara, Jun; Mizutani, Yoshitaka; Ohashi, Hirofumi; Sakaba, Nariaki; Tachibana, Yukio; Kunitomi, Kazuhiko
no journal, ,
Clean Burn High Temperature Gas-cooled Reactor (CBHTR) is loaded with the coated fuel particle having a fuel kernel made with solid solution of plutonium dioxide (PuO
) and yttrium stabilized zirconia (YSZ) as the inert matrix. To establish the fundamental technique of fabrication of PuO-YSZ coated fuel particle, research plans on fabrications of the fuel kernel by sol-gel process and of multi-ceramics coatings by chemical vapor deposition are reported.
