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Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.
Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07
This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.
Kato, Chiaki; Yamagishi, Isao; Sato, Tomonori; Yamamoto, Masahiro*
Zairyo To Kankyo, 70(12), p.441 - 447, 2021/12
Zeolite particles have been used in a Cs adsorption vessel for purification of contaminated water in Fukushima Dai-ich Nuclear Power Station (1F). The used Cs adsorption vessels were kept in storage space on 1F site. The risk of localized corrosion of stainless steel used in the vessel was worried. To evaluate the risk of localized corrosion, using specially designed electrochemical testing apparatus was used under gamma-ray irradiation test. And, real size mock-up test conducted. The results showed the potential change caused by creation of HO by water radiolysis decreased by zeolite particles and the enrichment of chloride ion concentration in the vessel do not propagate during dry up procedure of Cs adsorption vessel. These data indicate the risk of localized corrosion of Cs adsorption vessel may stay at considerably low level.
Yoshida, Hisao*; Yamamoto, Akira*; Hosokawa, Saburo*; Yamazoe, Seiji*; Kikkawa, Soichi*; Hara, Kenji*; Nakamura, Mitsutaka; Kamazawa, Kazuya*; Tanaka, Tsunehiro*
Topics in Catalysis, 64(9-12), p.660 - 671, 2021/08
Times Cited Count:2 Percentile:12.08(Chemistry, Applied)Takayanagi, Tomohiro; Ono, Ayato; Ueno, Tomoaki*; Horino, Koki*; Togashi, Tomohito; Yamamoto, Kazami; Kinsho, Michikazu; Koizumi, Isao*; Kawamata, Shunsuke*
JPS Conference Proceedings (Internet), 33, p.011020_1 - 011020_6, 2021/03
We are developing a new kicker power supply for J-PARC 3-GeV RCS (Rapid-Cycling Synchrotron) using the next generation power semiconductor SiC-MOSFET with high withstand voltage, low loss, and superior high frequency characteristics. The three major circuits adopted for the RCS kicker power supply, the thyratron switch, the PFN circuit of coaxial cable type, and the end clipper for reflection wave absorption, has been realized with a single modular circuit board based on the LTD circuit. The new kicker power supply realizes stable operation, miniaturization and energy saving by using power semiconductors. The required high voltage can be output by stacking the 800V/2kA modular circuit board in series. The details of circuit design and the results of achieving an output of half 20kV/2kA against the target specification of 40kV/2kA are presented here.
Yamazoe, Seiji*; Yamamoto, Akira*; Hosokawa, Saburo*; Fukuda, Ryoichi*; Hara, Kenji*; Nakamura, Mitsutaka; Kamazawa, Kazuya*; Tsukuda, Tatsuya*; Yoshida, Hisao*; Tanaka, Tsunehiro*
Catalysis Science & Technology, 11(1), p.116 - 123, 2021/01
Times Cited Count:5 Percentile:35.71(Chemistry, Physical)Kato, Chiaki; Sato, Tomonori; Nakano, Junichi; Ueno, Fumiyoshi; Yamagishi, Isao; Yamamoto, Masahiro
Nihon Genshiryoku Gakkai Wabun Rombunshi, 14(3), p.181 - 188, 2015/09
In relation to the consideration for long-term storage of spent Cs adsorption vessels containing zeolites in the Fukushima Daiichi Nuclear Power Station, corrosion of the vessel material in the spent Cs adsorption vessel is one of important issues. We performed electrochemical tests of stainless steel (SUS 316L) in the zeolites containing artificial seawater under -ray irradiation. The spontaneous potential () and critical pitting potential (), of SUS 316L were measured to understand the corrosion resistance of the stainless steel in this study. The rest potential of the stainless steel increased with increasing time after -ray irradiation. The , defined as the steady rest potential, increased with increasing dose rate, while increasing was suppressed by contact with the zeolites. Concentration of HO in bulk water increased with increasing dose rate. The concentration increasing was suppressed by contact with the zeolites due to decomposition of HO. There was good relationship between and the concentration of HO. The of SUS 316L contacted with the zeolites decreased with increasing Cl ion concentration and is slightly smaller than the in the bulk water. The contact with the zeolites causes the suppressant of increasing under the irradiation. The contact with the zeolite can reduce probability in the localized corrosion for SUS 316L.
Kato, Chiaki; Sato, Tomonori; Ueno, Fumiyoshi; Yamagishi, Isao; Yamamoto, Masahiro
Zairyo To Kankyo 2015 Koenshu (CD-ROM), p.83 - 86, 2015/05
In relation to the consideration for long-term storage of spent Cs adsorption vessels containing zeolites in the Fukushima Daiichi Nuclear Power Station, corrosion of the vessel material in the spent Cs adsorption vessel is one of important issues. We performed electrochemical tests of stainless steel (SUS 316L) in the zeolites containing artificial seawater under gamma-ray irradiation. The spontaneous potential (ESP) and critical pitting potential (VC), of SUS316L were measured to understand the corrosion resistance of the stainless steel in this study. The rest potential of the stainless steel increased with increasing time after gamma-ray irradiation. The ESP, defined as the steady rest potential, increased with increasing dose rate, while increasing ESP was suppressed by contact with the zeolites. Concentration of HO in bulk water increased with increasing dose rate. The concentration increasing was suppressed by contact with the zeolites due to decomposition of HO. There was good relationship between ESP and the concentration of HO. The VC of SUS316L contacted with the zeolites decreased with increasing Cl ion concentration and is slightly smaller than the VC in the bulk water. The contact with the zeolites causes the suppressant of increasing ESP under the irradiation. The contact with the zeolites can reduce probability in the localized corrosion for SUS316L.
Mitamura, Hiroyuki*; Watanuki, Ryuta*; Kaneko, Koji; Onozaki, Norimichi*; Amo, Yuta*; Kittaka, Shunichiro*; Kobayashi, Riki*; Shimura, Yasuyuki*; Yamamoto, Isao*; Suzuki, Kazuya*; et al.
Physical Review Letters, 113(14), p.147202_1 - 147202_5, 2014/10
Times Cited Count:18 Percentile:75.45(Physics, Multidisciplinary)Yoshimoto, Masahiro; Saha, P. K.; Yamazaki, Yoshio; Kawase, Masato; Saeki, Riuji; Hayashi, Naoki; Yamamoto, Kazami; Hotchi, Hideaki; Ishiyama, Tatsuya; Kinsho, Michikazu; et al.
Journal of Physics; Conference Series, 417, p.012073_1 - 012073_6, 2013/03
Times Cited Count:4 Percentile:75.99The HBC foil are installed in the J-PARC RCS for the charge-exchange H beam injection. In order to examine the characteristics of the HBC foils, beam studies for the HBC foil were carried out from the viewpoint of foil's life time and the beam survival rate due to foils. According to the compromise between charge-exchange efficiency and foil scattering beam loss, we optimized the foils thickness for user operation. The long-term observation during the user operation as well as the HBC foil endurance test for its life time evaluation was carried out. Even after one year was operation, there was no deterioration of the stripping foil.
Shiga, Hideaki*; Taki, Junichi*; Washiyama, Koshin*; Yamamoto, Jumpei*; Kinase, Sakae; Okuda, Koichi*; Kinuya, Seigo*; Watanabe, Naoto*; Tonami, Hisao*; Koshida, Kichiro*; et al.
PLOS ONE (Internet), 8(2), p.e57671_1 - e57671_8, 2013/02
Times Cited Count:18 Percentile:68.96(Multidisciplinary Sciences)Kawahara, Hirotaka; Yamamoto, Masaya; Tomita, Etsuo; Takamatsu, Misao
JAEA-Technology 2012-030, 50 Pages, 2012/09
In the experimental fast reactor Joyo, in-vessel observation results showed that 6 pins which were connected between the handling head and the wrapper tube joint of the instrumented test subassembly (MARICO-2) were disconnected. Therefore, in order to confirm whether the disconnected 6 pins will influence reactor's safety or not, loose parts behavior in the reactor vessel was evaluated.
Nakayama, Masashi; Amano, Kenji; Tokiwa, Tetsuya; Yamamoto, Yoichi; Oyama, Takuya; Amano, Yuki; Murakami, Hiroaki; Inagaki, Daisuke; Tsusaka, Kimikazu; Kondo, Keiji; et al.
JAEA-Review 2012-035, 63 Pages, 2012/09
The Horonobe Underground Research Laboratory Project is planned to extend over a period 20 years. The investigations will be conducted in three phases, namely "Phase 1: Surface-based investigations", "Phase 2: Construction Phase" (investigations during construction of the underground facilities) and "Phase 3: Operation phase"(research in the underground facilities). This report summarizes the results of the investigations for the 2011 fiscal year (2011/2012). The investigations, which are composed of "Geoscientific research" and "R&D on geological disposal technology", were carried out according to "Horonobe Underground Research Laboratory Project Investigation Program for the 2011 Fiscal year". The results of these investigations, along with the results which were obtained in other departments of Japan Atomic Energy Agency (JAEA), are properly offered to the implementations and the safety regulations. For the sake of this, JAEA has proceeded with the project in collaboration with experts from domestic and overseas research organisations.
Amano, Yuki; Yamamoto, Yoichi; Nanjo, Isao; Murakami, Hiroaki; Yokota, Hideharu; Yamazaki, Masanori; Kunimaru, Takanori; Oyama, Takahiro*; Iwatsuki, Teruki
JAEA-Data/Code 2011-023, 312 Pages, 2012/02
In the Horonobe Underground Research Laboratory (URL) Project, ground water from boreholes, river water and precipitation have been analyzed for the environmental monitoring since the fiscal year 2001. This report shows the data set of water chemistry since the fiscal year 2001 to the fiscal year 2010.
Yoshimoto, Masahiro; Yamazaki, Yoshio; Hayashi, Naoki; Yamamoto, Kazami; Saeki, Riuji; Hotchi, Hideaki; Saha, P. K.; Harada, Hiroyuki; Kawase, Masato; Ishiyama, Tatsuya; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.3927 - 3929, 2010/05
The ()ybrid type thick ()oron-doped ()arbon (HBC) stripping foils are installed and used for the beam injection at the 3GeV RCS (Rapid Cycling Synchrotron) in J-PARC (Japan Proton Accelerator Research Complex). Up to now, the performance deterioration of the stripping foils can not be seen after the long beam irradiation for the 120kW user operation and 300kW high power beam demonstration at the RCS. In order to examine the characteristic of the HBC foils, various beam studies were carried out. The beam-irradiated spot at the foil was measured by scanning the foil setting position, the charge exchange efficiency was evaluated with various thickness foils, and the effect of the SiC fibers supporting the foil mounting was checked with different mounting foils. Beam study results obtained with using the HBC foils will be presented. In addition, the trends of outgas from the stripping foils and the deformations of the foils during the beam irradiation will be reported.
Saha, P. K.; Hotchi, Hideaki; Harada, Hiroyuki; Yoshimoto, Masahiro; Yamamoto, Kazami; Yamazaki, Yoshio; Sugai, Isao*
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.3921 - 3923, 2010/05
The beam loss caused by the nuclear scattering together with the multiple Coulomb scattering at the stripping foil is one main concern of the uncontrolled beam losses in RCS of the J-PARC. In order to have a realistic understanding, a systematic study with both experiment and simulation has been carried out recently. A total of seven targets with different thicknesses were used and the measured beam losses were found to be consistent with the simulation. Such a realistic understanding becomes very useful in order to optimized the size and thickness of the stripping foil in connection with the RCS power upgrade scenario not only with the present injection beam energy of 181 MeV but also for the near future upgrade with 400 MeV.
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Endo, Satoru*; Tomita, Jumpei*; Tanaka, Kenichi*; Yamamoto, Masayoshi*; Fukutani, Satoshi*; Imanaka, Tetsuji*; Sakaguchi, Aya*; Amano, Hikaru; Kawamura, Hidehisa*; Kawamura, Hisao*; et al.
Radiation and Environmental Biophysics, 47(3), p.359 - 365, 2008/07
Times Cited Count:5 Percentile:21.13(Biology)Dolon village located about 60 km from the border of the Semipalatinsk Nuclear Test Site is known to be heavily contaminated by the first USSR atomic bomb test in August 1949. Soil samples around Dolon were taken in October 2005 in an attempt to evaluate internal thyroid dose arising from incorporation of radioiodine isotopes (mainly I). Iodine-129 in soil was measured by using the technique of Accelerator Mass Spectrometry. From the relationship between I and Cs (corrected for background and decay from 1949 to 2005) accumulated levels, the background level of I and the I/Cs ratio around Dolon were estimated to be (6.4 0.4) 10 atoms m and 0.25 0.16, respectively. This I/Cs ratio is almost similar to the fission yield ratio for Pu fast fission (0.24).
Sakanaka, Shogo*; Ago, Tomonori*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; Harada, Kentaro*; Hiramatsu, Shigenori*; Honda, Toru*; et al.
Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.205 - 207, 2008/06
Future synchrotron light sources based on the energy-recovery linacs (ERLs) are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. Our Japanese collaboration team is making efforts for realizing an ERL-based hard X-ray source. We report recent progress in our R&D efforts.
Shima, Shigeki*; Gasa, Shinichi*; Amano, Hikaru; Nagao, Seiya*; Yamamoto, Masayoshi*; Momoshima, Noriyuki*; Furukawa, Masahide*; Kimura, Hideki*; Kawamura, Hisao*
JAEA-Conf 2008-003, p.28 - 31, 2008/04
Concentrations of I in surface seawater around Japan were approximately 210atoms/L in literatures. However, the atomic ratio of iodine to cesium was ten times as high as that of the global fallout. The origin of I in the water columns seems to be difficult to be explained by only the global fallout. Discharge from European plants was one of the possible origins of iodine from the standpoint of air mass trajectory analysis. Concentration of I in rain water was 10 times higher than that in surface seawater. Anthropogenic inorganic iodine in surface seawater predominantly dissolves as an iodide ion (I).
Muroga, Masataka*; Suzuki, Hirokazu*; Udono, Haruhiko*; Kikuma, Isao*; Zhuravlev, A. V.; Yamaguchi, Kenji; Yamamoto, Hiroyuki; Terai, Takayuki*
Thin Solid Films, 515(22), p.8197 - 8200, 2007/08
Times Cited Count:6 Percentile:31.38(Materials Science, Multidisciplinary)Semiconducting -FeSi has received much attention as a material for Si-based optoelectronic devices. There are a number of studies on heteroepitaxy of -FeSi film on Si. However, growth experiments of -FeSi film on single crystalline -FeSi substrate have not been investigated yet. Recently, single crystalline -FeSi with large growth facets by solution growth method using Ga solvent. By obtaining a smooth surface on the substrate, we have succeeded in growing -FeSi film on -FeSi(110) substrate using molecular-beam epitaxy.