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Suzuki, Ryota*; Kobayashi, Yoshinori*; Kuno, Yoshinori*; Yamada, Taichi; Yamazaki, Keiichi*; Yamazaki, Akiko*
International Journal on Artificial Intelligence Tools, 25(5), p.1640005_1 - 1640005_19, 2016/10
Times Cited Count：1 Percentile：10.56(Computer Science, Artificial Intelligence)To meet the demands of an aging society, research on intelligent/robotic wheelchairs have been receiving a lot of attention. In elderly care facilities, care workers are required to communicate with the elderly in order to maintain both their mental and physical health. While this is regarded as important, having a conversation with someone on a wheelchair while pushing it from behind in a traditional setting would interfere with their smooth and natural conversation. So we are developing a robotic wheelchair system which allows companions and wheelchair users to move in a natural formation. This paper reports on an investigation to learn the patterns of human behavior when the wheelchair users and their companions communicate while walking together. The ethnographic observation reveals a natural formation of positioning for both companions and wheelchair users. Based on this investigation, we propose a multiple robotic wheelchair system which can maintain desirable formations for communication between wheelchairs.
Sasao, Eiji; Suzuki, Keiichi*; Yamada, Nobuto*; Kuboshima, Koji*
Proceedings of 12th SEGJ International Symposium (USB Flash Drive), 4 Pages, 2015/11
We performed investigation of a fault with thick and clay-altered damaged zone in granitic rock using cosmic ray muons at the Mizunami Underground Research Laboratory. Geology of the Laboratory consists of sedimentary rock and underlying granite with unconformable contact at the 170 meters below ground level (G.L.). A vertical fault with a thick, clay-altered damaged zone is present in the granite. The muon telescopes were settled at the G.L.-200 and -300 meters to estimate densities of granite and fault. Densities of granite, fault and sedimentary rock are calculated as 3.38, 2.88 and 1.99 g/cm
, respectively. The obtained density is obviously higher than absolute value, though the reason of such difference is not clear at the moment. If the density of granite is assumed to be 2.6 g/cm, then the densities of fault and sedimentary rock are re-calculated as 2.2 and 1.5 g/cm. This result indicates that cosmic ray muons have good potential to detect geological structure.
Takamatsu, Kuniyoshi; Takegami, Hiroaki; Ito, Chikara; Suzuki, Keiichi*; Onuma, Hiroshi*; Hino, Ryutaro; Okumura, Tadahiko*
Annals of Nuclear Energy, 78, p.166 - 175, 2015/04
Times Cited Count：10 Percentile：64.26(Nuclear Science & Technology)In our study, we focused on a nondestructive inspection method by which cosmic-ray muons could be used to observe the internal reactor from outside the RPV and the CV. We conducted an observation test on the HTTR to evaluate the applicability of the method to the internal visualization of a reactor. We also analytically evaluated the resolution of existing muon telescopes to assess their suitability for the HTTR observation, and were able to detect the major structures of the HTTR based on the distribution of the surface densities calculated from the coincidences measured by the telescopes. Our findings suggested that existing muon telescopes could be used for muon observation of the internal reactor from outside the RPV and CV.
Takegami, Hiroaki; Takamatsu, Kuniyoshi; Ito, Chikara; Hino, Ryutaro; Suzuki, Keiichi*; Onuma, Hiroshi*; Okumura, Tadahiko*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 13(1), p.7 - 16, 2014/03
One of the important problems for controlling of the Fukushima Daiichi Nuclear Power Plant is removing of fuel debris. As this preparation, the nondestructive inspection method for grasping the position of fuel debris is required. Therefore, we focused on a nondestructive inspection method using cosmic-ray muons. In this study, the applicability of this method for internal visualization of reactor was confirmed by preliminary test of internal visualization of High Temperature Engineering Test Reactor (HTTR). By using cosmic-ray muons, major components in the HTTR, such as concrete wall and reactor core, can be observed from the outside of a containment vessel. From the results, it appears that the inspection method with muons is a candidate method for searching the fuel debris in a reactor. Based on the results, we also proposed some improvements of this system for inspection at the Fukushima Daiichi Nuclear Power Station.
Takegami, Hiroaki; Terada, Atsuhiko; Noguchi, Hiroki; Kamiji, Yu; Ono, Masato; Takamatsu, Kuniyoshi; Ito, Chikara; Hino, Ryutaro; Suzuki, Keiichi*; Onuma, Hiroshi*; et al.
JAEA-Research 2013-032, 25 Pages, 2013/12
JAEA-Research-2013-032.pdf:3.56MB
We focused on a non-destructive inspection method using cosmic-ray muons as a candidate method for observation of internal the reactor from the outside of a reactor building. In this study, the applicability of this method for the reactor investigation was confirmed by a preliminary examination with High Temperature Engineering Test Reactor (HTTR). From the results of this examination, it appears that high density structures, such as the core and concrete walls, were able to observe by using muon telescope with coincidence method from the outside of the pressure vessel. Furthermore, we proposed some improvements of this muon inspection system for on-site investigation at the Fukushima Daiichi NPS.
Suzuki, Keiichi*; Onuma, Hiroshi*; Takegami, Hiroaki; Takamatsu, Kuniyoshi; Hino, Ryutaro; Okumura, Tadahiko*
Shadan Hojin Butsuri Tansa Gakkai Dai-129-Kai (Heisei-25-Nendo Shuki) Gakujutsu Koenkai Koen Rombunshu, p.131 - 134, 2013/10
In the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, the nuclear fuel had melted down due to loss of coolant and had already become debris. The debris would fall to the bottom of the CV. To remove the debris for future decommission is necessary; however the area and the size are unclear. On the other hand, cosmic ray muons are absorbed extremely in the debris because of the high density of uranium and plutonium. The inner structure of the nuclear reactor may be visualized with muons penetrating easily throught such the high-density material, as a non-contact or -destructive inspection. In this study, the muons through the HTTR were measured and visualizing the internal structure was attempted. As a result, high density areas were recognized at the same position as that of the reactor pressure vessel (RPV); therefore, the technical possibility with muons could be demonstrated. In the near future, new R&Ds will be promoted toward the practical use.
Suzuki, Keiichi*; Nishiyama, Eiichiro*
JNC TJ7410 2005-002, 79 Pages, 2003/03
JNC-TJ7410-2005-002.PDF:19.85MB
no abstracts in English
*
JNC TJ7420 2000-007, 28 Pages, 2000/03
JNC-TJ7420-2000-007.pdf:11.92MB
no abstracts in English
Suzuki, Kazuyuki; Nakamura, Yoshinobu; Hikita, Keiichi; Kogawa, Takayuki; Hayashi, Shinichiro
no journal, ,
The reprocessing plant dissolves Spent Fuels and it is a process to attract U and Pu after the removal of the Fission Products. Because dissolver is a tank with boiling nitric acid, there is it in the severe corrosion environment. Corrosion environment of the heat transfer surface is the severest. Therefore, the dissolver is made in High Chrome Nickel Steel in consideration of corrosion resistance. This paper reports a supersonic wave measurement method and corrosion rate of the dissolver.
Hikita, Keiichi; Uchida, Naoki; Suzuki, Kazuyuki; Mitani, Hironobu; Hata, Katsuro; Hayashi, Shinichiro; Yudo, Mitsuhiro*; Sakai, Hideaki*
no journal, ,
TRP dissolver deposits dissolver sludge which consists of zircaloy swarf with shearing operation and undissolved fission products such as Mo, Ru, Rh and Pd with dissolution operation. We have developed dissolver cleaning device which can be introduced through a ventilation pipe to inside dissolver.
Hata, Katsuro; Suzuki, Kazuyuki; Miyoshi, Ryuta; Sugai, Eiji; Hikita, Keiichi; Nakamura, Yoshinobu; Hayashi, Shinichiro
no journal, ,
The pulse filter of the clarification process used the sintered metal powder filter at Tokai reprocessing plant. It is known that the sintered metal powder filter is easy to be clogged up by sludge. Therefore, we examined the filtration performance of the sintered laminated wire mesh filter which might substitute for the sintered metal powder filter.
Kikuchi, Hideki; Suzuki, Kazuyuki; Sugai, Eiji; Hikita, Keiichi; Otani, Takehisa; Samoto, Hirotaka; Hayashi, Shinichiro
no journal, ,
About 6t the Fugen MOX type B fuels, whose Pu content rate is about 1.7%, were reprocessed on Tokai Reprosessing Plant(TRP) to the present. It was required to control plutonium(Pu) concentration of dissolution liquor because of the higher Pu content of the MOX fuels. There operational method to control Pu concentration by dilution has be established. And the amount of Pu, which was transferred to the highly radioactive liquid waste system with the residue from the clarification process, was investigated.
Takamatsu, Kuniyoshi; Takegami, Hiroaki; Ito, Chikara; Hino, Ryutaro; Suzuki, Keiichi*; Akiyama, Mitsuru*
no journal, ,
no abstracts in English
Takamatsu, Kuniyoshi; Takegami, Hiroaki; Ito, Chikara; Hino, Ryutaro; Suzuki, Keiichi*; Akiyama, Mitsuru*
no journal, ,
Cosmic ray muons can pass through large structures such as industrial plants and buildings including foundation. Engineering Advancement Association of Japan (ENAA) and Kawasaki Geological Engineering (KGE) have developed an exploration system using cosmic ray muons for detecting underground cavities which have a potential to bring about disasters. Japan Atomic Energy Agency (JAEA) has started an applicability test of this technology to the Fukushima Dai-ichi Nuclear Power Plants together with ENAA and KGE in October, 2012. In the test, core internal structures of the High Temperature Engineering Test Reactor (HTTR) will be visualized to obtain practical data on resolution and measuring time necessary for improving the system.
Yamada, Nobuto; Sasao, Eiji; Kuboshima, Koji*; Suzuki, Keiichi*
no journal, ,
JAEA and KGE perform the joint research on cosmic ray muons applying detection of sub-surface geological structure such as fault, using the research gallery of the Mizunami Underground Research Laboratry. We set the detectors of cosmic ray muons in the underground gallery to assess its applicability for estimating geological structure in deep underground. We estimate the geological structure by the number of cosmic ray muons observed from November 2013 to August 2014 and confirm that we can observe the substantial number of cosmic ray muons to estimate the geological structure in the research gallery of granite at G.L.-300m.
Yamada, Nobuto; Suzuki, Keiichi*; Kanazawa, Sunao*; Tsuge, Takashi*
no journal, ,
To evaluate the distribution of geological discontinuity such as fractures around the underground gallery is one of the important factors to conduct high level radioactive waste disposal, but it is difficult to evaluate them enough only by geological survey such as boring investigations. We carried out GPR to obtain the distribution of fractures exist nearby the underground gallery of granite in Mizunami Underground Research Laboratory, and understand that we can detect them by GPR.
Yamada, Nobuto; Sasao, Eiji; Suzuki, Keiichi*; Kuboshima, Koji*; Kanazawa, Sunao*
no journal, ,
JAEA and KGE perform the joint research on cosmic ray muons applying detection of sub-surface geological structure such as fault, using the research gallery of the Mizunami Underground Research Laboratory. We set the detectors of cosmic ray muons in the underground gallery to evaluate its applicability for estimating geological structure in deep underground. We estimate the geological structure by the number of cosmic ray muons observed from November 2013 to August 2014 and confirm that we can observe the substantial number of cosmic ray muons to estimate the geological structure in the research gallery of granite at -300m underground.
