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Li, C.*; Fang, W.*; Yu, H. Y.*; Peng, T.*; Yao, Z. T.*; Liu, W. G.*; Zhang, X.*; Xu, P. G.; Yin, F.*
Materials Science & Engineering A, 892, p.146096_1 - 146096_11, 2024/02
Times Cited Count:0 Percentile:0.02(Nanoscience & Nanotechnology)Senzaki, Tatsuya; Arai, Yoichi; Yano, Kimihiko; Sato, Daisuke; Tada, Kohei; Ogi, Hiromichi*; Kawanobe, Takayuki*; Ono, Shimpei; Nakamura, Masahiro; Kitawaki, Shinichi; et al.
JAEA-Testing 2022-001, 28 Pages, 2022/05
In preparation for the decommissioning of Laboratory B of the Nuclear Fuel Cycle Engineering Laboratory, the nuclear fuel material that had been stored in the glove box for a long time was moved to the Chemical Processing Facility (CPF). This nuclear fuel material was stored with sealed by a polyvinyl chloride (PVC) bag in the storage. Since it was confirmed that the PVC bag swelled during storage, it seems that any gas was generated by radiolysis of the some components contained in the nuclear fuel material. In order to avoid breakage of the PVC bag and keep it safety for long time, we began the study on the stabilization treatment of the nuclear fuel material. First, in order to clarify the properties of nuclear fuel material, radioactivity analysis, component analysis, and thermal analysis were carried out. From the results of thermal analysis, the existence of organic matter was clarified. Then, ion exchange resin with similar thermal characteristics was selected and the thermal decomposition conditions were investigated. From the results of these analyzes and examinations, the conditions for thermal decomposition of the nuclear fuel material contained with organic matter was established. Performing a heat treatment of a small amount of nuclear fuel material in order to confirm the safety, after which the treatment amount was scaled up. It was confirmed by the weight change after the heat treatment that the nuclear fuel material contained with organic matter was completely decomposed.
Kitagawa, Yoshihiro; Shirahama, Takuma*; Kisohara, Naoyuki; Tsuboi, Akihiko
Dai-96-Kai Reza Kako Gakkai Koen Rombunshu (Internet), p.91 - 96, 2022/01
Laser scanning quenching is a locally and rapidly heat-treated process and has an advantage of no coolant required. Compared with conventional technique such as induction quenching, the region of laser quenching is about 0.50.7mm in depth and it needs to be expanded for more applications or durability. For this purpose, the temperature distributions and transitions in materials during laser irradiation have been revealed by using a 3D heat transfer computer code, micro-structural observation and hardness transitions in depth direction. The results indicate the laser irradiation with low power and low scan speed condition allows deeper quenching area, but it also suggests the hardness of the deepest quenching area is degraded due to slow temperature decreasing rate after laser heat scanning. Multiple times continuous irradiation have been proposed and studied to resolve this hardness degradation, and maximum quenching depth of 1.4mm is obtained under three times irradiation and controlling its power and scan speed properly.
Tomota, Yo*; Wang, Y.*; Omura, Takahito*; Sekido, Nobuaki*; Harjo, S.; Kawasaki, Takuro; Gong, W.*; Taniyama, Akira*
Tetsu To Hagane, 106(5), p.262 - 271, 2020/05
Times Cited Count:0 Percentile:0(Metallurgy & Metallurgical Engineering)Wang, Y.*; Tomota, Yo*; Omura, Takahito*; Morooka, Satoshi; Gong, W.*; Harjo, S.
Acta Materialia, 184, p.30 - 40, 2020/02
Times Cited Count:28 Percentile:86.1(Materials Science, Multidisciplinary)Shibata, Akinobu*; Takeda, Yasunari*; Park, N.*; Zhao, L.*; Harjo, S.; Kawasaki, Takuro; Gong, W.*; Tsuji, Nobuhiro*
Scripta Materialia, 165, p.44 - 49, 2019/05
Times Cited Count:30 Percentile:84.98(Nanoscience & Nanotechnology)Yaita, Tsuyoshi; Honda, Mitsunori; Shimoyama, Iwao; Ito, Kenichi*; Mampuku, Yuzo*; Tsuji, Takuya; Matsumura, Daiju
Nihon Genshiryoku Gakkai-Shi ATOMO, 59(8), p.483 - 487, 2017/08
no abstracts in English
Shimoyama, Iwao; Honda, Mitsunori; Kogure, Toshihiro*; Baba, Yuji; Hirao, Norie*; Okamoto, Yoshihiro; Yaita, Tsuyoshi; Suzuki, Shinichi
Photon Factory News, 35(1), p.17 - 22, 2017/05
We introduce Cs-free mineralization (CFM) for Cs removal and reuse of radioactive-contaminated soil in Fukushima and report recent work conducted in the BL27A beamline in Photon Factory. In this work, we investigated compositional and structural changes of Cs-sorbed weathered biotite (WB) before and after heating treatment with addition of NaCl-CaCl salts under low-pressure condition, to study Cs desorption mechanism from clay minerals. X-ray fluorescence spectroscopy clarified that almost all Cs and K were removed with the salts at 700 C. On the other hand, Ca increased with heating temperature. X-ray diffraction and transmission electron microscopy analysis clarified that phase transitions from WB to some Ca-rich silicate minerals, e.g., augite, were caused by the heating treatment with the salt. Based on these results, CFM is proposed for Cs removal utilizing the mechanism in which large monovalent cations are discharged with accompanying the phase transition. We also discuss the role of Cl in this reaction showing chemical bonding change of Cl observed using X-ray absorption spectroscopy in the early stage of the chemical reaction.
Iwamoto, Naoya*; Azarov, A.*; Oshima, Takeshi; Moe, A. M. M.*; Svensson, B. G.*
Journal of Applied Physics, 118(4), p.045705_1 - 045705_8, 2015/07
Times Cited Count:6 Percentile:26.86(Physics, Applied)Wakai, Eiichi; Sato, Michitaka*; Okubo, Nariaki; Sawai, Tomotsugu; Shiba, Kiyoyuki; Jitsukawa, Shiro
Nihon Kinzoku Gakkai-Shi, 69(6), p.460 - 464, 2005/06
Times Cited Count:1 Percentile:16.26(Metallurgy & Metallurgical Engineering)no abstracts in English
Oshima, Takeshi
Hoshasen To Sangyo, (105), p.12 - 18, 2005/03
no abstracts in English
Kudo, Yusuke; Sakasai, Akira; Hamada, Kazuya; Takano, Katsutoshi*; Nakajima, Hideo; Okuno, Kiyoshi; Matsukawa, Makoto; Tamai, Hiroshi; Ishida, Shinichi
Journal of Nuclear Materials, 329-333(Part1), p.634 - 638, 2004/08
Times Cited Count:3 Percentile:23.51(Materials Science, Multidisciplinary)Japan Atomic Energy Research Institute (JAERI) has a plan to construct a tokamak fusion device called JT-60SC in which superconducting magnet system will be used. The objectives of this study are to clarify applicability of conventional austenitic stainless steel wire for the SS316LN to the conduit material of the Nb3Sn cable-in-conduit conductor for the central solenoid (CS) of JT-60SC. Tensile properties, fracture toughness and fatigue crack growth rate of both as-weld and aged (923 K 240 hours) weld metals were evaluated at 4 K. The measured tensile properties of aged weld metal satisfied the requirement of JT-60SC. Fatigue crack growth property was enough to ensure the required operation cycles of 9.0 10e4. However, fracture toughness of aged weld metal could not be validated due to unstable crack extension. It was concluded that improvement of fracture toughness after aging was required to ensure the structural integrity of the CS conduit.
Wakai, Eiichi; Taguchi, Tomitsugu; Yamamoto, Toshio*; Kato, Yoshiaki; Takada, Fumiki
Materials Transactions, 45(8), p.2638 - 2640, 2004/08
Times Cited Count:1 Percentile:12.41(Materials Science, Multidisciplinary)no abstracts in English
Kokawa, Hiroyuki*; Shimada, Masayuki*; Wang, Z.*; Sato, Yutaka*; Sato, Yoshihiro*; Kiuchi, Kiyoshi
JAERI-Tech 2003-014, 22 Pages, 2003/03
no abstracts in English
Oi, Akihiko; Oshima, Takeshi; Yoshikawa, Masahito; Lee, K. K.; Iwami, Motohiro*; Ito, Hisayoshi
Materials Science Forum, 389-393, p.831 - 834, 2002/05
no abstracts in English
Hosono, F.*; Iwaki, G.*; Kikuchi, Kenichi*; Ishida, Shinichi; Ando, Toshinari*; Kizu, Kaname; Miura, Yushi; Sakasai, Akira
IEEE Transactions on Applied Superconductivity, 12(1), p.1037 - 1040, 2002/03
Times Cited Count:6 Percentile:38.85(Engineering, Electrical & Electronic)no abstracts in English
Oshima, Takeshi; Uedono, Akira*; Abe, Hiroshi; Chen, Z. Q.*; Ito, Hisayoshi; Yoshikawa, Masahito; Abe, Koji*; Eryu, Osamu*; Nakashima, Kenshiro*
Physica B; Condensed Matter, 308-310, p.652 - 655, 2001/12
Times Cited Count:6 Percentile:37.48(Physics, Condensed Matter)Co-implantation of Al(2E18/cm3) and C(1E18/cm3) into 6H-SiC and subsequent thermal annealing up to 1650 C werer carried out. Vacancy-type defects in the implanted layer were studied by monoenergetic positron beams. The mean size of vacancy-type defects in as-implanted samples is found to be close to the size of divacancy. Although vacancy clsters near a surface region were created by 1000 C-annealing, clustering is suppressed in a deep region.The mean size of vacancys decrease by annealing above 1000 C, and major vacancy defects annealed out after annealing at 1400 C. No significant difference in defect annealing between only Al- and co-implanted samles was observed.This result suggests that electrical activation of Al is enhanced by the site competition mechanism.
Saito, Tamotsu; Baba, Shinichi; Eto, Motokuni
JAERI-Research 99-070, p.21 - 0, 2000/01
no abstracts in English
Narumi, Kazumasa; Yamamoto, Shunya; Naramoto, Hiroshi
Materials Research Society Symposium Proceedings, Vol.587, p.O8.4.1 - O8.4.6, 2000/00
no abstracts in English
Narumi, Kazumasa; Yamamoto, Shunya; Naramoto, Hiroshi
JAERI-Review 99-025, TIARA Annual Report 1998, p.155 - 157, 1999/10
no abstracts in English