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Aratani, Kenta; Takiya, Hiroaki; Koda, Yuya; Ishiyama, Masahiro; Tezuka, Masashi; Mizui, Hiroyuki
Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 5 Pages, 2019/05
The prototype advanced thermal reactor FUGEN is the heavy water-moderated, boiling light water-cooled, pressure tube-type reactor, and has progressing the decommissioning since 2008. The most of facilities such as turbine system have the system structure and the operating conditions similar to those of BWR, although FUGEN has the characteristic structure of reactor core and the heavy water treatment facilities. In Japan, the knowledge and findings from FUGEN decommissioning activities are very important and valuable to perform BWR decommissioning in future, because the decommissioning of FUGEN is research and development as the first decommissioning of real-scale reactor. In the first phase of FUGEN decommissioning activities, the dismantlement project of reactor core cooling system started. By 2017, the low-level contaminated equipment such as the condensers of turbine system and the main-steam pipes of main-steam system was dismantled, and the management data was accumulated. The knowledge and findings from the 10 years of dismantlement experience will be reflected to the future dismantlement of higher contaminated facilities.
Strasser, P.*; Abe, Mitsushi*; Aoki, Masaharu*; Choi, S.*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; et al.
EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01
Times Cited Count:13 Percentile:99.06(Quantum Science & Technology)Ueno, Yasuhiro*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; Ito, Takashi; Iwasaki, Masahiko*; et al.
Hyperfine Interactions, 238(1), p.14_1 - 14_6, 2017/11
Times Cited Count:3 Percentile:86.59(Physics, Atomic, Molecular & Chemical)Strasser, P.*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; Ito, Takashi; Iwasaki, Masahiko*; et al.
Hyperfine Interactions, 237(1), p.124_1 - 124_9, 2016/12
Times Cited Count:7 Percentile:90.97(Physics, Atomic, Molecular & Chemical)Yamamoto, Shunya; Hakoda, Teruyuki; Yoshikawa, Masahito
JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 129, 2015/03
no abstracts in English
Yamamoto, Shunya; Hakoda, Teruyuki; Miyashita, Atsumi; Yoshikawa, Masahito
Materials Research Express (Internet), 2(2), p.026401_1 - 026401_8, 2015/02
Times Cited Count:4 Percentile:14.59(Materials Science, Multidisciplinary)The effects of deposition temperature and film thickness on the structural and gasochromic properties of tungsten trioxide films used for the optical detection of diluted cyclohexane have been investigated. The tungsten trioxide films were prepared on SiO substrates by magnetron sputtering, with the deposition temperature ranging from 300 to 550C in an Ar and O gas mixture. The gasochromic properties of the films, coated with a catalytic Pt layer, were examined by exposing them up to 5% cyclohexane in N gas. We found that (001)-oriented monoclinic tungsten trioxide films, with a columnar structure, grew at deposition temperatures between 400 and 450C. The gasochromic characterization of the tungsten trioxide films revealed that (001)-oriented tungsten trioxide films, with cauliflower-like surface morphology, were appropriate for the optical detection of cyclohexane.
Hiraishi, Masatoshi*; Iimura, Soshi*; Kojima, Kenji*; Yamaura, Junichi*; Hiraka, Haruhiro*; Ikeda, Kazutaka*; Miao, P.*; Ishikawa, Yoshihisa*; Torii, Shuki*; Miyazaki, Masanori*; et al.
Nature Physics, 10(4), p.300 - 303, 2014/04
Times Cited Count:103 Percentile:95.46(Physics, Multidisciplinary)Hakoda, Teruyuki; Yamamoto, Shunya; Aritani, Hirofumi*; Yoshikawa, Masahito
JAEA-Review 2013-059, JAEA Takasaki Annual Report 2012, P. 127, 2014/03
Reduction of noble metal ions and subsequent production of noble metal particles in a solution has been performed as a radiation-induced precipitation (RIP) method using high energy ionizing radiation. Electron beams with energies below 300 keV have shorter penetration range and can irradiate at higher dose rates. Application of such low energy EBs to the RIP method has a possibility of producing film matters consisting of noble metal particles on the surface of the solution. In the present study, this possibility was examined using a few ten keV EBs for PtCl ion solutions. Black-colored film matters were produced on the surface of the sample solution after EB irradiation. Lower concentrations of ethanol such as 0.5v% accelerated the formation of Pt films on the sample solution. The films had network structure consisting of connected Pt particles with sizes of 2-5 nm.
Yamamoto, Shunya; Hakoda, Teruyuki; Yoshikawa, Masahito
JAEA-Review 2013-059, JAEA Takasaki Annual Report 2012, P. 123, 2014/03
no abstracts in English
Hakoda, Teruyuki; Igarashi, Hidetoshi*; Isozumi, Yukihiro*; Yamamoto, Shunya; Aritani, Hirofumi*; Yoshikawa, Masahito
Journal of Physics and Chemistry of Solids, 74(2), p.200 - 204, 2013/02
Times Cited Count:3 Percentile:16.73(Chemistry, Multidisciplinary)The gasochromic property of dehydrogenation-catalyst loaded tungsten trioxide (M/WO) powders was examined in exposure to gaseous cyclohexane under different kinds and contents of catalysts, catalyst temperatures, and cyclohexane concentrations. The change in the intensity of visible lights reflected from the M/WO powders was in situ obtained using a portable visible-light spectrometer. The catalyst of Pt was a catalyst initiating dehydrogenation and the change of reflected light intensity at lower temperatures in comparison with the catalysts of Pd and Rh. Among 0.1, 0.5, and 1wt% Pt/WO powders, the 0.5wt% Pt/WO powders demonstrated large change of reflected lights. The heating of 0.5wt% Pt/WO powders at temperatures higher than 130C was required to visually detect cyclohexane at a concentration of 1v%, lower than the combustion lower limit (1.3v%).
Sakoda, Masahito*; Kubota, Kazuhiro*; Tanaka, Shuhei*; Matsuoka, Eiichi*; Sugawara, Hitoshi*; Matsuda, Tatsuma; Haga, Yoshinori
Journal of the Physical Society of Japan, 81(Suppl.B), p.SB011_1 - SB011_4, 2012/12
Times Cited Count:2 Percentile:10.8(Physics, Multidisciplinary)Isozumi, Yukihiro; Hakoda, Teruyuki; Yamamoto, Shunya; Aritani, Hirofumi*; Yoshikawa, Masahito
Radioisotopes, 61(6), p.289 - 296, 2012/06
In the present study, the reduction of PtCl ions and subsequent formation of Pt particles were examined for a few tens keV EB irradiation of PtCl ion solution in the presence of 1-20wt% ethanol as an OH radical scavenger. As a result, the reduction of PtCl ions proceeded in whole solution by irradiating only the topmost surface layer of the solution, and these Pt particles with sizes of 2-5 nm would be produced as primary particles through reduction of PtCl ions. Moreover, these Pt particles were observed to have hydrogen dissociation activity and oxidation activity.
Yoshimura, Kimio; Hakoda, Teruyuki; Yamamoto, Shunya; Yoshikawa, Masahito
Journal of Physics and Chemistry of Solids, 73(5), p.696 - 698, 2012/05
Times Cited Count:4 Percentile:19.69(Chemistry, Multidisciplinary)Tungsten trioxide powder with loading 0.1wt% platinum (Pt/WO) was prepared for opticaldetection of organic hydrides such as cyclohexane, decalin by impregnation with PtCl and subsequent calcination in N gas at 500C. The SEM observation of Pt/WO shows that the Pt particles with mean diameters of 80-100 nm were on the surface of the WO powder. The Pt/WO showed coloration for 13% cyclohexane at higher 100C and for 1.3% cyclohexane at 200C. The in-situ XRD results of the Pt/WO in coloring/bleaching change indicate that the coloring of Pt/WO was caused by transformation of WO to tungsten bronze. The analysis of reacted gas demonstrates that Pt on WO produces only hydrogen and benzene through dehydrogenation of cyclohexane over 100C. It was founded that the Pt/WO has potential of optical detection of organic hydrides by heating at higher 100C.
Sakoda, Masahito*; Tanaka, Shuhei*; Matsuoka, Eiichi*; Sugawara, Hitoshi*; Harima, Hisatomo*; Honda, Fuminori*; Settai, Rikio*; Onuki, Yoshichika; Matsuda, Tatsuma; Haga, Yoshinori
Journal of the Physical Society of Japan, 80(8), p.084716_1 - 084716_5, 2011/08
Times Cited Count:8 Percentile:50.77(Physics, Multidisciplinary)Yoshimura, Kimio; Hakoda, Teruyuki; Sugimoto, Masaki; Yamamoto, Shunya; Yoshikawa, Masahito
Radiation Physics and Chemistry, 80(4), p.587 - 590, 2011/04
Times Cited Count:2 Percentile:18.29(Chemistry, Physical)no abstracts in English
Yoshimura, Kimio; Hakoda, Teruyuki; Yamamoto, Shunya; Yoshikawa, Masahito
Applied Surface Science, 257(9), p.4428 - 4431, 2011/02
Times Cited Count:5 Percentile:25.35(Chemistry, Physical)no abstracts in English
Hakoda, Teruyuki; Yamamoto, Shunya; Kawaguchi, Kazuhiro; Yamaki, Tetsuya; Kobayashi, Tomohiro*; Yoshikawa, Masahito
Applied Surface Science, 257(5), p.1556 - 1561, 2010/12
Times Cited Count:13 Percentile:50.83(Chemistry, Physical)Carbon-based films having nitrogen species on their surface were prepared on a glassy-carbon (GC) substrate as a non-platinum cathode catalyst for polymer electrolyte fuel cells by depositing cobalt and carbon in the presence of N gas using a pulse laser deposition method and then removing metal Co by HCl-washing treatment. The oxygen reduction reaction (ORR) activity was electrochemically determined using a rotating disk electrode system where the film samples on the GC substrate were replaceable. The ORR activity increased with elevating temperature of the GC substrate during the deposition. A carbon-based film prepared at 600C in the presence of 66.7 Pa N showed the highest ORR activity among the tested samples; its ORR potential was 0.66 V (vs. NHE). This film was composed of amorphous carbons doped with pyridine-type nitrogen atoms on its surface.
Yamamoto, Shunya; Hakoda, Teruyuki; Kawaguchi, Kazuhiro; Yamaki, Tetsuya; Yoshikawa, Masahito
no journal, ,
no abstracts in English
Kawaguchi, Kazuhiro; Takahiro, Katsumi*; Yamamoto, Shunya; Hakoda, Teruyuki; Yoshikawa, Masahito
no journal, ,
no abstracts in English
Hakoda, Teruyuki; Yamamoto, Shunya; Kawaguchi, Kazuhiro; Yamaki, Tetsuya; Kobayashi, Tomohiro*; Yoshikawa, Masahito
no journal, ,
no abstracts in English