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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.
Arai, Yoichi; Watanabe, So; Ono, Shimpei; Nakamura, Masahiro; Shibata, Atsuhiro; Nakamura, Fumiya*; Arai, Tsuyoshi*; Seko, Noriaki*; Hoshina, Hiroyuki*; Hagura, Naoto*; et al.
International Journal of PIXE, 29(1&2), p.17 - 31, 2019/00
The spent PUREX solvent containing U and Pu is generated from the reprocessing process of spent nuclear fuel. The nuclear material removal is important for the safe storage or disposal of the spent solvent. Our previous study revealed that the adsorbent with the iminodiacetic acid (IDA) functional group is one of the most promising materials for designing the nuclear material recovery process. Accordingly, an IDA-type adsorbent was synthesized by using graft polymerization technology or a chemical reaction to improve the adsorption rate and capacity. The synthesized IDA-type adsorbent was characterized by micro particle-induced X-ray emission (PIXE) and extended X-ray absorption fine structure (EXAFS) analyses. The micro-PIXE analysis revealed that Zr was adsorbed on the whole synthesized adsorbents and quantified the microamount of adsorbed Zr. Moreover, EXAFS suggested that Zr in the aqueous solution and solvent can be trapped by the IDA group with different mechanisms.
Nishihara, Tetsuo; Yan, X.; Tachibana, Yukio; Shibata, Taiju; Ohashi, Hirofumi; Kubo, Shinji; Inaba, Yoshitomo; Nakagawa, Shigeaki; Goto, Minoru; Ueta, Shohei; et al.
JAEA-Technology 2018-004, 182 Pages, 2018/07
Research and development on High Temperature Gas-cooled Reactor (HTGR) in Japan started since late 1960s. Japan Atomic Energy Agency (JAEA) in cooperation with Japanese industries has researched and developed system design, fuel, graphite, metallic material, reactor engineering, high temperature components, high temperature irradiation and post irradiation test of fuel and graphite, high temperature heat application and so on. Construction of the first Japanese HTGR, High Temperature engineering Test Reactor (HTTR), started in 1990. HTTR achieved first criticality in 1998. After that, various test operations have been carried out to establish the Japanese HTGR technologies and to verify the inherent safety features of HTGR. This report presents several system design of HTGR, the world-highest-level Japanese HTGR technologies, JAEA's knowledge obtained from construction, operation and management of HTTR and heat application technologies for HTGR.
Takahashi, Yukio*; Kadono, Toshiharu*; Yamamoto, Shimpei*; Singh, V. R.*; Verma, V.*; Ishigami, Keisuke*; Shibata, Goro*; Harano, Takayuki*; Takeda, Yukiharu; Okane, Tetsuo; et al.
Physical Review B, 90(2), p.024423_1 - 024423_5, 2014/07
Times Cited Count:11 Percentile:44.44(Materials Science, Multidisciplinary)Tachibana, Yukio; Nishihara, Tetsuo; Sakaba, Nariaki; Ohashi, Hirofumi; Sato, Hiroyuki; Ueta, Shohei; Aihara, Jun; Goto, Minoru; Sumita, Junya; Shibata, Taiju; et al.
JAEA-Technology 2009-063, 155 Pages, 2010/02
This report describes full scope of the feasible future test plan mainly using the HTTR. The test items cover fuel performance and radionuclide transport, core physics, reactor thermal hydraulics and plant dynamics, and reactor operations, maintenance, control, etc. The test results will be utilized for realization of Japan's commercial Very High Temperature Reactor (VHTR) system, GTHTR300C.
Magori, Shimpei*; Kira, Erika*; Shibata, Satoshi*; Umehara, Yosuke*; Kochi, Hiroshi*; Hase, Yoshihiro; Tanaka, Atsushi; Sato, Shusei*; Tabata, Satoshi*; Kawaguchi, Masayoshi*
Molecular Plant-Microbe Interactions, 22(3), p.259 - 268, 2009/03
Times Cited Count:104 Percentile:92.65(Biochemistry & Molecular Biology)Legume plants tightly control the development and number of symbiotic root nodules. In , this regulation required in the shoots, suggesting that a long-distance communication between the shoots and the roots may exist. To better understand its molecular basis, we isolated and characterized a novel hypernodulating mutant of named (). Reciprocal grafting with wild type showed that hypernodulation is determined by the root genotype. Moreover, grafting a shoot onto a rootstock did not exhibit any obvious additive effects on the nodule number. These observations indicate that a shoot factor and a root factor participate in the same genetic pathway which governs the long-distance signaling of nodule number control. may function downstream of and the gene product might serve as a receptor or mediator of unknown mobile signal molecules that are transported from the shoots to the roots.
Takahashi, Yuichi*; Shibata, Shimpei*; Yokoyama, Jun*; Hashimoto, Hirofumi*; Yokobori, Shinichi*; Yamagishi, Akihiko*; Kawaguchi, Yuko*; Gusev, O.*; Narumi, Issei; Sato, Katsuya; et al.
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Ono, Shimpei; Kawanobe, Takayuki*; Watahiki, Hiromi; Shibata, Atsuhiro; Nomura, Kazunori
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Ono, Shimpei; Arai, Yoichi; Watanabe, So; Seko, Noriaki*; Kasai, Noboru*; Hoshina, Hiroyuki*; Shibata, Atsuhiro; Nomura, Kazunori
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Ono, Shimpei; Arai, Yoichi; Watanabe, So; Seko, Noriaki*; Kasai, Noboru*; Hoshina, Hiroyuki*; Shibata, Atsuhiro; Nomura, Kazunori
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Ono, Shimpei; Ichige, Yoshiaki; Shibata, Atsuhiro; Sato, Takehiko; Takeuchi, Masayuki
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no abstracts in English