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Maeda, Tsuyoshi
Hoken Butsuri (Internet), 54(4), p.220 - 221, 2019/12
no abstracts in English
Maeda, Tsuyoshi; Endo, Yuya; Uezu, Yasuhiro
Hoken Butsuri (Internet), 54(3), p.177 - 180, 2019/10
no abstracts in English
Bendo, A.*; Maeda, Tomoyoshi*; Matsuda, Kenji*; Lervik, A.*; Holmestad, R.*; Marioara, C. D.*; Nishimura, Katsuhiko*; Nunomura, Norio*; Toda, Hiroyuki*; Yamaguchi, Masatake; et al.
Philosophical Magazine, 99(21), p.2619 - 2635, 2019/07
Times Cited Count：26 Percentile：82.72(Materials Science, Multidisciplinary)
CMaeda, Toshikatsu; Chiba, Noriaki; Tateishi, Tsuyoshi*; Yamaguchi, Tetsuji
Nihon Genshiryoku Gakkai Wabun Rombunshi, 12(2), p.158 - 164, 2013/06
no abstracts in English
Maeda, Hiroki*; Ishiguro, Yuki*; Honda, Takashi*; Jung, J.-S.*; Michimura, Shinji*; Inami, Toshiya; Kimura, Tsuyoshi*; Wakabayashi, Yusuke*
Journal of the Ceramic Society of Japan, 121(3), p.265 - 267, 2013/03
Times Cited Count：5 Percentile：30.43(Materials Science, Ceramics)Structural deformation of a magnetocapacitive material SmMnO was studied by X-ray diffraction measurement in a magnetic field. This antiferromagnetic material shows a jump in dielectric constant at 9 K only when a magnetic field of a few tesla is applied. In-field X-ray diffraction measurements clarified that there is no sudden change in structure that involves atomic displacement within the c-plane in Pbnm notation, while the antiferromagnetic phase transition at 60 K gives rise to a noticeable rotation of the MnO
octahedra. This rotation occurs to maximize the energy gain through the exchange interaction.
Ishimi, Akihiro; Katsuyama, Kozo; Maeda, Koji; Nagamine, Tsuyoshi; Asaka, Takeo; Furuya, Hirotaka
Journal of Nuclear Science and Technology, 49(12), p.1144 - 1155, 2012/12
Times Cited Count：8 Percentile：52.49(Nuclear Science & Technology)no abstracts in English
Ichikawa, Shoichi; Haga, Hiroyuki; Kikukawa, Kiyohide*; Fukasaku, Hironobu*; Kurosawa, Yoichi*; Katsuyama, Kozo; Maeda, Koji; Nagamine, Tsuyoshi
JAEA-Technology 2011-020, 32 Pages, 2011/07
JAEA-Technology-2011-020.pdf:6.56MB
Disassembling technique of the driver fuel assembly irradiated in the experimental fast reactor JOYO has been established at Fuel Monitoring Facility in JAEA. This technique made it possible to remove the fuel pins from the driver fuel assembly without the fuel pin sectioning. After disassembling the fuel assembly, some selected fuel pins can be reassembled into the new irradiation vehicle for the continuous irradiation at JOYO. This technique enables us to obtain the irradiation data of high burn-up fuel and high neutron dose material.
Imai, Yoshinori*; Takahashi, Hideyuki*; Kitagawa, Kentaro*; Matsubayashi, Kazuyuki*; Nakai, Noriyuki*; Nagai, Yuki; Uwatoko, Yoshiya*; Machida, Masahiko; Maeda, Atsutaka*
Journal of the Physical Society of Japan, 80(1), p.013704_1 - 013704_4, 2011/01
Times Cited Count：36 Percentile：81.82(Physics, Multidisciplinary)no abstracts in English
Katsuyama, Kozo; Ishimi, Akihiro; Maeda, Koji; Nagamine, Tsuyoshi; Asaka, Takeo
Journal of Nuclear Materials, 401(1-3), p.86 - 90, 2010/06
Times Cited Count：4 Percentile：30.63(Materials Science, Multidisciplinary)The helium releases were investigated in FBR fuel pins irradiated to high burn-up. The released amounts of helium gas increased with the increase of burn-up, but their data were scattered in the region of high burn-up region. This was understood to be caused by the differences of 
Am contents among fuel pellets, because this nuclide generates 
Cm which undergoes alpha decay at a short half life.
Katsuyama, Kozo; Maeda, Koji; Nagamine, Tsuyoshi; Furuya, Hirotaka
Nuclear Technology, 169(1), p.73 - 80, 2010/01
Times Cited Count：3 Percentile：24.08(Nuclear Science & Technology)Three-dimensional X-ray CT (computer tomography) images were successfully taken of a fast breeder reactor fuel assembly which had been irradiated to high burn-up. The interior and outside of the fuel assembly can be clearly observed on any cross section from any angle. Using these images, it is possible to analyze the deformation of fuel pins, abnormalities in the fuel assembly, and microstructural change in the fuel pins. 127 central void sizes were tentatively analyzed as a function of linear heat rating. Compared with conventional non-destructive and destructive post irradiation examination (PIEs), this X-ray CT technique has great advantages including the number of PIE data acquisitions in a short time, reduced PIE costs, reduced radioactive waste generation, and physical protection of nuclear materials.
-Co films with giant tunnel magnetoresistanceMatsumoto, Yoshihiro; Sakai, Seiji; Takagi, Yasumasa*; Nakagawa, Takeshi*; Yokoyama, Toshihiko*; Shimada, Toshihiro*; Mitani, Seiji*; Naramoto, Hiroshi*; Maeda, Yoshihito
Chemical Physics Letters, 470(4-6), p.244 - 248, 2009/03
Times Cited Count：17 Percentile：51.33(Chemistry, Physical)Electronic and spin states of the codeposited C-Co films with large tunnel magnetoresistance (TMR) effect were investigated with the X-ray absorption and magnetic circular dichroism (MCD) spectroscopies. It is revealed that a C-Co compound generated in the C-Co films shows the clear MCD signal attributed to the spin-polarized Co 3d states hybridized with C 
orbitals. The magnetic response of these Co 3d-derived states agrees well with temperature dependence of the observed MR ratios of the granular C-Co films. This suggests the incorporation of the spin-polarized Co 3d-derived states of the C-Co compound into the observed TMR effect.
Maeda, Seiichiro; Takashita, Hirofumi; Okawa, Tsuyoshi; Higuchi, Masashi*; Abe, Tomoyuki
JNC TN8400 2003-019, 185 Pages, 2003/08
JNC-TN8400-2003-019.pdf:11.78MB
We are studying on an in-core breeding concept as a candidate for a practical FBR fuel cycle system attainable in an early stage on the premise that sodium coolant and mixed oxide fuel should be adopted, since the technical issues with these combination are most advanced and common with the fuel cycle for a LWR-MOX system. An enhancement of fuel volume fraction using thick fuel pins enables the in-core breeding. The fuel material flow can be greatly lessened by minimizing amount of the blanket with the in-core breeding core. The low material flow leads to significant reduction of the fuel cycle cost. We investigated a 3500 MWth large-scale core adjusting several conditions presented in JNC's feasibility study program for a commercialized FBR system in this study. These were shown in this study that a discharged burnup averaged over the core and the blanket could reach approximately 130 GWd/t (core averaged about 150 GWd/t) within the maximum fast neutron fluence about 5
10
/cm
, that the small reactivity loss with burnup easily enabled long operation and that stable power distribution during operation significantly improved hydraulic property in this type core. We investigated measures to reduce sodium void reactivity, because core height enlargement to enhance neutron efficiency caused the increase of sodium void reactivity.We also investigated feasibility of a high breeding type core with low burnup considering a variety of FBR introducing scenarios and a trade-off correlation between breeding performance and burnup extension. The performance in this core design at core disruption accidents is not revealed enough. Further investigation should be made in detail to confirm that the in-core breeding concept could be accepted in a safety aspect.
bulk samples and formation of columner defects on high-Tc supercoductorOkayasu, Satoru; Sasase, Masato; Hojo, Kiichi; Chimi, Yasuhiro; Iwase, Akihiro; Ikeda, Hiroshi*; Yoshizaki, Ryozo*; Kambara, Tadashi*; Sato, H.*; Hamatani, Yutaro*; et al.
Physica C, 382(1), p.104 - 107, 2002/10
Times Cited Count：28 Percentile：75.41(Physics, Applied)no abstracts in English
Ura, Tamaki*; Takamasa, Tomoji*; Nishimura, Hajime*; Aoki, Taro*; Ueno, Michio*; Maeda, Toshio*; Nakamura, Masato*; Shimazu, Shunsuke*; Tokunaga, Sango*; Shibata, Yozo*; et al.
JAERI-Tech 2001-049, 154 Pages, 2001/07
JAERI-Tech-2001-049.pdf:11.24MB
JAERI has studied on design and operation of a nuclear powered submersible research vessel, which will navigate under sea in the Arctic Ocean, as a part of the design study of advanced marine reactors. This report describes operation conditions and an operating system of the vessel those were discussed by the specialists of hull design, sound positioning, ship motions and oceanography, etc. The design conditions on ship motions for submersible vessels were surveyed considering regulations in our country, and ship motions were evaluated assuming the observation activities in the Arctic Ocean. A submarine transponder system and an on ice communication buoy system were examined as a positioning and communication system supposing the activity under ice. Procedures to secure safety of nuclear powered submersible research vessel were discussed based on the investigation of accidents. These results were reflected to the concept of the nuclear powered submersible research vessel, and subjects fto be settled in the next step were clarified.
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JNC TN9400 2001-077, 114 Pages, 2001/06
JNC-TN9400-2001-077.pdf:4.32MB
Bundle duct interaction (BDI) caused by expansion of fuel pin bundle is a main factor to limit the fuel lifetime. Therefore, it is important for the design of fast reactor fuel assembly to understand the fuel pin deformation behavior under BDI condition. In order to understand the fuel pin deformation behavior under BDI condition, out-of-pile compression tests were conducted for FBR fuel pin bundle by use of X-ray CT equipment. In these compression tests, two kinds of fuel pin bundles were conducted. 0ne was the fuel pin bundle with the short wire-pitch and the other was the fuel pin bundle with the short wire-pitch and large diameter claddings. The general discussions were also performed based on the results of out-of-pile compression tests obtained by use of X-ray CT equipment in the previous work. Following results were obtained. (1)The occurrence of the pin-to-duct contact depends on the wire-pitch. In the fuel pin bundle with large wire-pitch, the pin-to-duct contact occurred at the early stage of BDI. The reason of this result is due to the low bowing rigidity of the fuel pins with long wire-pitch. (2)The value of the ovalation stiffness strongly depends on the geometry of cladding (diameter, thickness) and especially on wire-pitch. This result in this work revealed that the occurrence of the pin-to-duct contact depends on the value of the ovalation stiffness. (3)The occurrence of wire dispersion and dispersive displacement of pins depends on the wire-pitch strongly. In the fuel pin bundle with the long wire-pitch, the occurrence of the above-mentioned suppression mechanism to BDI is remarkable. (4)The suppression mechanism to BDI of the fuel pin bundle with the long wire-pitch is elastic oval deformation of cladding, wire dispersion and dispersive displacement of pins. 0n the other hand, the elastic and plastic oval deformation of cladding is the major suppression mechanism to BDI in the fuel pin bundle with the short wire-pitch. (5)The appearance ...
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JNC TN9400 2001-022, 130 Pages, 2000/10
JNC-TN9400-2001-022.pdf:9.09MB
Bundle duct interaction (BDI) caused by expansion of fuel pin bundle becomes one of the main limiting factors for fuel life times. Then, it is important for the design of fast reactor fuel assembly to understand the BDI behavior in detail. In order to understand the BDI behavior, out of pile compressive tests were conducted for FFTF type bundle by use of X-ray CT equipment. In these compressive tests, two type bundles with different accuracy of initial wire position were conducted. The objective of this test is to evaluate the influence of the initial error from standard position of wire at the same axial position. The locations of the pins and the duct flats are analyzed from CT image data. Quantitative evaluation was performed at the CT image dada and discussed the bundle deformation status under BDI condition. Following results are obtained. (1)The accuracy of initial wire position is strongly depends on the pin-to-duct contact behavior. In the case of bundle with large error from standard position, pin to-duct contact is delayed. (2)The BDI mitigation of the bundle with small error from standard wire position is following: The elastic ovality is the dominant deformation in mild BDI condition, then the wire dispersion and pin dispersion are occurred in severe BDI condition. (3)The BDI mitigation of the bundle with large error from standard wire position is following: The elastic ovality and local bowing of pins with large error from standard wire position are occurred in mild BDI condition, then pin dispersion is occurred around pins with large error from standard wire position, finally wire dispersion is occurred in severe BDI condition. (4)The existence of pins with large error from standard wire position is effective to delay the pin-to-duct contact, but the existence of these pins is possible to contact of pin-to-pin.
; ; ; Matsumoto, Shinichiro
JNC TN9410 2000-009, 65 Pages, 2000/09
JNC-TN9410-2000-009.pdf:4.36MB
In order to evaluate irradiation behavior of(U, Pu) C and (U, Pu) N fuel using fast reactor, (U, Pu) C and (U, Pu) N fuel pins were irradiated in JOYO for the fist time in Japan. In this study, one (U, Pu) C fuel pin and two (U, Pu) N fuel pins were irradiated to maximum burn up about 40GWd/t. Post irradiation examination of (U, Pu) C and (U, Pu) N fuel pins started in Fuel Monitoring Facility (FMF) at JNC from October 1999, and it ended in March, 2000. The results of non-destructive post irradiation examination reported in this document. Main results are shown in the following. (1)The soundness of all (U,Pu) C and (U,Pu) N fuel pins were confirmed from the non-destructive examination result. (2)The fuel stack elongation of (U,Pu) C and (U,Pu) N is bigger than it of the MOX fuel for fast reactor. (3)The singular behavior from the gamma ray scanning measurement in the stack area was not confirmed. The migration of Cs137 to lower insulator pellet and outside of the pellet was confirmed in (U,Pu) N B9NO2 pin. In (U,Pu) C fuel, the migration of Cs137 was not confirmed. (4)In (U,Pu) C B9CO1 pin and (U,Pu) N B9NO2 pin in which the gap width was small, diameter of cladding increase around 50 
m in the stack area which originates for FCMI was confirmed. In (U,Pu) N B9NO1 pin in which the gap width was wide, the ovality which originates from the relocation of the pellet was confirmed. (5)Fission gas release rate of (U,Pu) N were 3.3% and 5.2%, and the low value compared to the MOX fuel was shown.
Maeda, Koji; Nagamine, Tsuyoshi; ; Mitsugi, Takeshi; Matsumoto, Shinichiro
Dai-3-Kai Shoshago Shiken Ni Kansuru Nikkan Semina, 0 Pages, 1999/00
None
SrCaCuOy containing columnar defects*; Hanaguri, T.*; *; Maeda, A.*; Sasase, Masato; Hojo, Kiichi; Steel, D. G.*; Lee, J. U.*; Hofman, D. J.*
Physical Review B, 59(17), p.11568 - 11574, 1999/00
Times Cited Count：8 Percentile：45.66(Materials Science, Multidisciplinary)no abstracts in English
*; *; Maeda, A.*; Asaoka, Hidehito; Takei, Humihiko*; *; *; *; *; *; et al.
Journal of the Physical Society of Japan, 65(10), p.3266 - 3273, 1996/00
Times Cited Count：16 Percentile：71.32(Physics, Multidisciplinary)no abstracts in English
