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Inagawa, Jun; Kitatsuji, Yoshihiro; Otobe, Haruyoshi; Nakada, Masami; Takano, Masahide; Akie, Hiroshi; Shimizu, Osamu; Komuro, Michiyasu; Oura, Hirofumi*; Nagai, Isao*; et al.
JAEA-Technology 2021-001, 144 Pages, 2021/08
JAEA-Technology-2021-001.pdf:12.98MB
Plutonium Research Building No.1 (Pu1) was qualified as a facility to decommission, and preparatory operations for decommission were worked by the research groups users and the facility managers of Pu1. The operation of transportation of whole nuclear materials in Pu1 to Back-end Cycle Key Element Research Facility (BECKY) completed at Dec. 2020. In the operation included evaluation of criticality safety for changing permission of the license for use nuclear fuel materials in BECKY, cask of the transportation, the registration request of the cask at the institute, the test transportation, formulation of plan for whole nuclear materials transportation, and the main transportation. This report circumstantially shows all of those process to help prospective decommission.
laser stripping at J-PARC 3-GeV RCSSaha, P. K.; Harada, Hiroyuki; Kinsho, Michikazu; Miura, Akihiko; Yoshimoto, Masahiro; Okabe, Kota; Suganuma, Kazuaki; Yamane, Isao*; Irie, Yoshiro*; Liu, Y.*; et al.
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.806 - 810, 2018/08
Harada, Hiroyuki; Saha, P. K.; Yoneda, Hitoki*; Michine, Yurina*; Inoue, Shunsuke*; Sato, Atsushi*; Suganuma, Kazuaki; Yamane, Isao*; Kinsho, Michikazu; Irie, Yoshiro*
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.811 - 815, 2018/08
The high-intensity proton accelerator adopts a charge exchange injection scheme, which injects with exchanging from negative Hydrogen ion to proton by using carbon foil. This scheme can realize high intensity proton beam but the uncontrolled beam losses occur by scattering at the foil. Additionally, the beam collision at the foil may cause the break itself. Therefore, a new injection scheme for higher intensity is needed as an alternative to the foil. We newly propose and develop a laser stripping injection scheme. At the first step, we propose a proof-of-principle (POP) experiment of the scheme in J-PARC and develop a laser system. In this presentation, we will introduce the laser stripping injection scheme and describe an overview of a POP experiment. We will report a current status of the laser system.
Saha, P. K.; Harada, Hiroyuki; Kinsho, Michikazu; Miura, Akihiko; Yoshimoto, Masahiro; Irie, Yoshiro*; Yamane, Isao*; Yoneda, Hitoki*; Michine, Yurina*
Proceedings of 61st ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams (HB 2018) (Internet), p.422 - 427, 2018/07
Harada, Hiroyuki; Yamane, Isao*; Saha, P. K.; Suganuma, Kazuaki; Kinsho, Michikazu; Irie, Yoshiro*; Kato, Shinichi
Proceedings of 14th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.684 - 688, 2017/12
The high-intensity proton accelerator adopts a charge exchange injection scheme, which injects with exchanging from negative Hydrogen ion to proton by using carbon foil. This scheme can realize high intensity proton beam but the uncontrolled beam losses are caused by scattering between beams and the foil. Additionally, the collision may occur the foil beak. Therefore, a new injection scheme for higher intensity is needed as an alternative to the foil. In the J-PARC 3GeV RCS, we newly propose and develop a laser stripping injection scheme. However, it is necessary that laser power is two order higher than latest laser one. To realize this big issue, we develop the laser storage ring, which can provide laser pulse of high repetition rate by recycling one. In this presentation, we will introduce the laser stripping injection scheme and describe the concept of the laser storage ring with high repetition rate and report the current status.
stripping to protons by using only lasers in the 3-GeV RCS of J-PARCSaha, P. K.; Harada, Hiroyuki; Yamane, Isao*; Kinsho, Michikazu; Miura, Akihiko; Okabe, Kota; Liu, Y.*; Yoshimoto, Masahiro; Kato, Shinichi; Irie, Yoshiro*
Proceedings of 14th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.866 - 870, 2017/12
Harada, Hiroyuki; Saha, P. K.; Yamane, Isao*; Kato, Shinichi; Kinsho, Michikazu; Irie, Yoshiro*
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.983 - 986, 2016/11
The high-intensity proton accelerator adopts a charge exchange injection scheme, which injects with exchanging from negative Hydrogen ion to proton by using carbon foil. This scheme can realize high intensity proton beam but the uncontrolled beam losses are caused by scattering between beams and the foil. Additionally, the collision may occur the foil beak. Therefore, a new injection scheme for higher intensity is needed as an alternative to the foil. In the J-PARC 3GeV RCS, we newly propose and develop a laser stripping injection scheme However, it is necessary that laser power is two order higher than latest laser one. To realize this big issue, we develop the laser storage ring, which can provide laser pulse of high repetition rate by recycling one. In this presentation, we will introduce the laser stripping injection scheme and describe the concept of the laser storage ring with high repetition rate.
stripping to proton by using only lasers in the J-PARC RCSSaha, P. K.; Harada, Hiroyuki; Kato, Shinichi; Kinsho, Michikazu; Irie, Yoshiro*; Yamane, Isao*
Proceedings of 57th ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams (HB 2016) (Internet), p.310 - 314, 2016/08
Takahashi, Naoki; Yoshinaka, Kazuyuki; Harada, Akio; Yamanaka, Atsushi; Ueno, Takashi; Kurihara, Ryoichi; Suzuki, Soju; Takamatsu, Misao; Maeda, Shigetaka; Iseki, Atsushi; et al.
Nihon Genshiryoku Gakkai Homu Peji (Internet), 64 Pages, 2016/00
no abstracts in English
Kiuchi, Hisao*; Niwa, Hideharu*; Kobayashi, Masaki*; Harada, Yoshihisa*; Oshima, Masaharu*; Chokai, Masayuki*; Nabae, Yuta*; Kuroki, Shigeki*; Kakimoto, Masaaki*; Ikeda, Takashi; et al.
Electrochimica Acta, 82(1), p.291 - 295, 2012/10
Times Cited Count：14 Percentile：34.42(Electrochemistry)We study the characteristics of oxygen adsorption on metal-free carbon-based cathode catalysts derived from nitrogen-containing polyamide (PA) and nitrogen-free phenolic resin (PhRs). Electrochemical analysis and Raman spectroscopy showed higher 2-electron oxygen reduction reaction (ORR) activity and more defect sites in PA than PhRs. The increase in the amount of adsorbed oxygen in PA was also identified by oxygen adsorption isotherms. 
X-ray photoelectron spectroscopy reveals that graphite-like nitrogen contributes to oxygen adsorption and C=O components are dominant in PA. These experimental results indicate that the adsorbed C=O components near the graphite-like nitrogen can be assigned as active sites for 2-electron ORR.
Saha, P. K.; Yoshimoto, Masahiro; Hatakeyama, Shuichiro; Hotchi, Hideaki; Harada, Hiroyuki; Yamazaki, Yoshio; Kinsho, Michikazu; Irie, Yoshiro*; Sugai, Isao*
Proceedings of 2nd International Particle Accelerator Conference (IPAC 2011) (Internet), p.3511 - 3513, 2011/09
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.
Nakanishi, Shigeyuki*; Hosoya, Takusaburo; Kubo, Shigenobu*; Kotake, Shoji; Takamatsu, Misao; Aoyama, Takafumi; Ikarimoto, Iwao*; Kato, Jungo*; Shimakawa, Yoshio*; Harada, Kiyoshi*
Nuclear Technology, 170(1), p.181 - 188, 2010/04
Times Cited Count：14 Percentile：67.77(Nuclear Science & Technology)A self-actuated shutdown system (SASS) for sodium cooled fast reactor (SFR) is a passive safety feature which inserts control rods by the gravity force, where the detachment of the rods would be achieved by the coolant temperature rise under anticipated transient without scram (ATWS) conditions. Various out-of-pile tests have already carried out to investigate the basic characteristics of SASS, and a demonstration test of holding stability under the reactor operation condition has been performed, where a function test of the driving system to re-connect and of pulling out the control rod have been done in the experimental reactor JOYO. The element irradiation tests have been also conducted to confirm that no impact will be foreseen by the irradiation. The effectiveness of SASS for a reference core design of JSFR has been evaluated through all types of ATWS. As a result, it is ensured that JSFR will have a reliable passive shutdown system.
Np for fast neutronsHarada, Hideo; Nakamura, Shoji; Hatsukawa, Yuichi; Toh, Yosuke; Kimura, Atsushi; Ishiwatari, Yuki*; Yasumi, Atsushi*; Mabuchi, Yukio*; Nakagawa, Tsutomu*; Okamura, Kazuo*; et al.
Journal of Nuclear Science and Technology, 46(5), p.460 - 468, 2009/05
Times Cited Count：4 Percentile：30.49(Nuclear Science & Technology)The neutron capture cross section of Np has been measured for fast neutrons supplied at the center of the core in the Yayoi reactor. The activation method was used for the measurement, in which the amount of the product 
Np was determined by 
-ray spectroscopy using a Ge detector. The representative neutron energy and the corresponding capture cross section of Np in the experiment were analytically deduced as 0.80 
0.04 b at 0.214 0.009 MeV from the measured reaction rate by combining the energy dependence of the cross section in the nuclear data library ENDF/VII.0. The deduced cross section of Np at the representative neutron energy agrees with the evaluated data of ENDF/B-VII.0, but shows 15% larger value than that of JENDL-3.3 and 13% larger value than that of JENDL/AC-2008.
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.
Nakanishi, Shigeyuki; Kubo, Shigenobu*; Takamatsu, Misao; Ikarimoto, Iwao*; Kato, Jungo*; Shimakawa, Yoshio*; Harada, Kiyoshi*
Proceedings of 2008 International Congress on Advances in Nuclear Power Plants (ICAPP '08) (CD-ROM), p.519 - 525, 2008/06
A self-actuated shutdown system (SASS) is a passive safety feature which inserts control rods by the gravity force, where the detachment of the rods would be achieved by the coolant temperature rise under anticipated transient without scram (ATWS) conditions. Various out-of-pile tests have already carried out to investigate the basic characteristics of SASS, and a demonstration test of holding stability under the reactor operation condition has been performed, where a function test of the driving system to re-connect and of pulling out the control rod have been done in the experimental reactor JOYO. The element irradiation tests have been also conducted to confirm that no impact will be foreseen by the irradiation. The effectiveness of SASS for a reference core design of JSFR has been evaluated through all types of ATWS. As a result, it is ensured that JSFR will have a reliable passive shutdown system.
(Si
Ge
)Matsuda, Yasuhiro*; Inami, Toshiya; Owada, Kenji; Murata, Yuto*; Nojiri, Hiroyuki*; Murakami, Yoichi*; Mitsuda, Akihiro*; Wada, Hirofumi*; Miyazaki, Hiroshi*; Harada, Isao*
Journal of the Physical Society of Japan, 77(5), p.054713_1 - 054713_7, 2008/05
Times Cited Count：25 Percentile：74.44(Physics, Multidisciplinary)The magnetic-field-induced valence transition in EuNi(SiGe) (x=0.82, 0.85) has been studied by X-ray absorption spectroscopy at low temperatures. The field dependence of the Eu valence is directly observed for the first time. We find a significant decrease in the valences at high magnetic fields above 40 T. The valence of Eu changes from v = 2.75 at a zero field to v = 2.33 at 40 T for x = 0.82. The results are analyzed using a theoretical model. The hybridization parameter V between the Eu
and Eu
states and the energy separation 
are determined, which are crucial for quantum mechanical mixing.
Takamatsu, Misao; Sekine, Takashi; Uchita, Masato*; Harada, Kiyoshi*
Proceedings of 13th International Conference on Nuclear Engineering (ICONE-13), 0 Pages, 2005/05
Self actuated shutdown system (SASS) with a Curie point electromagnet (CPEM) is being developed for use in a large scale fast breeder reactor (FBR) in order to establish the passive shutdown capability against anticipated transient without scram (ATWS) events. In order to confirm the stability of CPEM in holding the control rod and demonstrate the functions of the driving system to re-connect and pull out the control rod under the actual reactor-operational environment, the component function test using the reduced-scale model experimental equipment of SASS was conducted in the experimental fast reactor JOYO MK-III. As a result of this test conducted for 117 days during the 1st and 2nd operational cycles of JOYO MK-III from May to Oct. 2004, the rod-holding stability and the recovering functions of the driving system were fully confirmed. A neutron fluence of over 6
1018n/cm2 (E
0.1MeV) was obtained for CPEM. This corresponded to 60 years of use in a large-scale FBR and satisfied the required fluence for stability assurance. The results also will likely dispel the apprehensiveness about the operational trouble involving the unexpected drop of SASS.
