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Nara, Yoshitaka*; Kashiwaya, Koki*; Oketani, Kazuki*; Fujii, Hirokazu*; Zhao, Y.*; Kato, Masaji*; Aoyagi, Kazuhei; Ozaki, Yusuke; Matsui, Hiroya; Kono, Masanori*
Zairyo, 73(3), p.220 - 225, 2024/03
The fractures in the rock are the main pass of groundwater flow and solute transport. The filling of fine-grained particle, such as clay minerals, was confirmed to decrease the permeability of rock by laboratory experiment. This research aimed to verify the occurrence of the phenomena in the field. The water containing the clay minerals was injected into the rock at the 200m stage of the Mizunami Underground research laboratory. The hydraulic conductivity decreased two order before and after the injection. This result suggested that the decrease of hydraulic conductivity by the filling of fine-grained particle in the fractures occurred in the real field.
Lokotko, T.*; Leblond, S.*; Lee, J.*; Doornenbal, P.*; Obertelli, A.*; Poves, A.*; Nowacki, F.*; Ogata, Kazuyuki*; Yoshida, Kazuki; Authelet, G.*; et al.
Physical Review C, 101(3), p.034314_1 - 034314_7, 2020/03
Times Cited Count:10 Percentile:69.78(Physics, Nuclear)The structures of the neutron-rich Co isotopes were investigated via () knockout reactions at the Radioactive Isotope Beam Factory, RIKEN. Level schemes were reconstructed using the coincidence technique, with tentative spin-parity assignments based on the measured inclusive and exclusive cross sections. Comparison with shell-model calculations suggests coexistence of spherical and deformed shapes at low excitation energies in the Co isotopes.
Elekes, Z.*; Kripk, *; Sohler, D.*; Sieja, K.*; Ogata, Kazuyuki*; Yoshida, Kazuki; Doornenbal, P.*; Obertelli, A.*; Authelet, G.*; Baba, Hidetada*; et al.
Physical Review C, 99(1), p.014312_1 - 014312_7, 2019/01
Times Cited Count:10 Percentile:64.15(Physics, Nuclear)The nuclear structure of the Ni nucleus was investigated by (,) reaction using a NaI(Tl) array to detect the deexciting prompt rays. A new transition with an energy of 2227 keV was identified by and coincidences. Our shell-model calculations using the Lenzi, Nowacki, Poves, and Sieja interaction produced good candidates for the experimental proton hole states in the observed energy region, and the theoretical cross sections showed good agreement with the experimental values. Although we could not assign all the experimental states to the theoretical ones unambiguously, the results are consistent with a reasonably large Z = 28 shell gap for nickel isotopes in accordance with previous studies.
Shand, C. M.*; Podolyk, Zs.*; Grska, M.*; Doornenbal, P.*; Obertelli, A.*; Nowacki, F.*; Otsuka, T.*; Sieja, K.*; Tostevin, J. A.*; Tsunoda, T.*; et al.
Physics Letters B, 773, p.492 - 497, 2017/10
Times Cited Count:25 Percentile:87.36(Astronomy & Astrophysics)Morales, A. I.*; Benzoni, G.*; Watanabe, H.*; Tsunoda, Yusuke*; Otsuka, T.*; Nishimura, Shunji*; Browne, F.*; Daido, R.*; Doornenbal, P.*; Fang, Y.*; et al.
Physics Letters B, 765, p.328 - 333, 2017/02
Times Cited Count:34 Percentile:91.97(Astronomy & Astrophysics)Morales, A. I.*; Benzoni, G.*; Watanabe, H.*; Nishimura, Shunji*; Browne, F.*; Daido, R.*; Doornenbal, P.*; Fang, Y.*; Lorusso, G.*; Patel, Z.*; et al.
Physical Review C, 93(3), p.034328_1 - 034328_14, 2016/03
Times Cited Count:25 Percentile:85.25(Physics, Nuclear)Benzoni, G.*; Morales, A. I.*; Watanabe, H.*; Nishimura, Shunji*; Coraggio, L.*; Itaco, N.*; Gargano, A.*; Browne, F.*; Daido, R.*; Doornenbal, P.*; et al.
Physics Letters B, 751, p.107 - 112, 2015/12
Times Cited Count:20 Percentile:78.02(Astronomy & Astrophysics)Sakurai, Takeru; Iguchi, Masahide; Nakahira, Masataka; Saito, Toru*; Morimoto, Masaaki*; Inagaki, Takashi*; Hong, Y.-S.*; Matsui, Kunihiro; Hemmi, Tsutomu; Kajitani, Hideki; et al.
Physics Procedia, 67, p.536 - 542, 2015/07
Times Cited Count:3 Percentile:73.28(Physics, Applied)Japan Atomic Energy Agency (JAEA) has developed the tensile strength prediction method at liquid helium temperature (4K) using the quadratic curve as a function of the content of carbon and nitrogen in order to establish the rationalized quality control of the austenitic stainless steel used in the ITER superconducting coil operating at 4K. ITER is under construction aiming to verify technical demonstration of a nuclear fusion generation. Toroidal Field Coil (TFC), one of superconducting system in ITER, have been started procurement of materials in 2012. JAEA is producing materials for actual product which are the forged materials with shape of rectangle, round bar, asymmetry and etc. JAEA has responsibility to procure all ITER TFC Structures. In this process, JAEA obtained many tensile strength of both room temperature and 4K about these structural materials, for example, JJ1: High manganese stainless steel for structure (0.03C-12Cr-12Ni-10Mn-5Mo- 0.24N) and 316LN: High nitrogen containing stainless steel (0.2Nitrogen). Based on these data, accuracy of 4K strength prediction method for actual TFC Structure materials was evaluated and reported in this study.
Nakajima, Hideo; Hemmi, Tsutomu; Iguchi, Masahide; Nabara, Yoshihiro; Matsui, Kunihiro; Chida, Yutaka; Kajitani, Hideki; Takano, Katsutoshi; Isono, Takaaki; Koizumi, Norikiyo; et al.
Proceedings of 24th IAEA Fusion Energy Conference (FEC 2012) (CD-ROM), 8 Pages, 2013/03
The ITER organization and 6 Domestic Agencies (DA) have been implementing the construction of ITER superconducting magnet systems. Four DAs have already started full scale construction of Toroidal Field (TF) coil conductors. The qualification of the radial plate manufacture has been completed, and JA and EU are ready for full scale construction. JA has qualified full manufacturing processes of the winding pack with a 1/3 prototype and made 2 full scale mock-ups of the basic segments of TF coil structure to optimize and industrialize the manufacturing process. Preparation and qualification of the full scale construction of the TF coil winding is underway by EU. Procurement of the manufacturing equipment is near completion and qualification of manufacturing processes has already started. The constructions of other components of the ITER magnet systems are also going well towards the main goal of the first plasma in 2020.
Saito, Shigeru; Kikuchi, Kenji*; Hamaguchi, Dai; Usami, Koji; Endo, Shinya; Ono, Katsuto; Matsui, Hiroki; Kawai, Masayoshi*; Dai, Y.*
Journal of Nuclear Materials, 431(1-3), p.44 - 51, 2012/12
Times Cited Count:2 Percentile:17.8(Materials Science, Multidisciplinary)To evaluate the lifetime of the beam window of an accelerator-driven transmutation system (ADS), post irradiation examination (PIE) of the STIP (SINQ target irradiation program, SINQ; Swiss spallation neutron source) specimens was carried out. The specimens tested in this study were made from the austenitic steel JPCA (Japan primary candidate alloy). The specimens were irradiated at SINQ Target 4 (STIP-II) with high-energy protons and spallation neutrons. The irradiation conditions were as follows: the proton energy was 580 MeV, irradiation temperatures ranged from 100 to 430C, and displacement damage levels ranged from 7.1 to 19.5 dpa. Tensile tests were performed in air at room temperature (R.T.), 250C and 350C. Fracture surface observation after the tests was done by SEM (Scanning electron microscope). Results of the tensile tests performed at R.T. showed the extra hardening of JPCA at higher dose compared to the fission neutron irradiated data. At the higher temperatures, 250C and 350C, the extra hardening was not observed. Degradation of ductility bottomed around 10 dpa, and specimens kept their ductility until 19.5 dpa. All specimens fractured in ductile manner. The result from a microstructure observation on a specimen irradiated to 19.3 dpa at 420C indicates that some agglomeration of bubbles on grain boundaries was observed in the specimen irradiated to 19.3 dpa at 420C. However the tensile specimen irradiated up to 18.4 dpa at 425C still exhibited little loss of ductility. Since He/dpa was very high on SINQ target irradiations, the formation of highly dense small bubbles in the matrix consequently avoided the accumulation of He on grain boundaries, which might have resulted in avoiding grain boundary embrittlement.
Belik, A. A.*; Iikubo, Satoshi; Kodama, Katsuaki; Igawa, Naoki; Shamoto, Shinichi; Maie, Makoto*; Nagai, Takuro*; Matsui, Yoshio*; Stefanovich, S. Y.*; Lazoryak, B. I.*; et al.
Journal of the American Chemical Society, 128(3), p.706 - 707, 2006/01
Times Cited Count:114 Percentile:89.99(Chemistry, Multidisciplinary)The crystal structure of BiScO have been determined by neutron diffraction and electron diffraction measurements. All experimental results shows space group of BiScO is C2/c, which has a center of symmetry.
Kitazawa, Shinichi; Ida, H.*; Matsui, Y.*; Takayanagi, Toshinobu*; Wakiya, K.*; Iemura, K.*; Otani, Shunsuke*; Suzuki, H.*; Kanai, Yasuyuki*; Safronova, U. I.*
Journal of Physics B; Atomic, Molecular and Optical Physics, 34(16), p.3205 - 3220, 2001/08
Times Cited Count:5 Percentile:31.39(Optics)no abstracts in English
Ando, Toshinari; Hiyama, Tadao; Takahashi, Yoshikazu; Nakajima, Hideo; Kato, Takashi; Sugimoto, Makoto; Isono, Takaaki; Kawano, Katsumi; Koizumi, Norikiyo; Hamada, Kazuya; et al.
IEEE Transactions on Applied Superconductivity, 9(2), p.628 - 631, 1999/06
Times Cited Count:8 Percentile:51.51(Engineering, Electrical & Electronic)no abstracts in English
Kitazawa, Shinichi; *; Machida, Shuichi*; Matsui, Y.*; Ida, H.*; *; Wakiya, K.*; *; F.Currell*; *; et al.
Journal of Physics B; Atomic, Molecular and Optical Physics, 31(14), p.3233 - 3243, 1998/00
Times Cited Count:9 Percentile:47.63(Optics)no abstracts in English
Kitazawa, Shinichi; *; *; Matsui, Y.*; Ida, H.*; *; Wakiya, K.*; Sekiguchi, M.*
Annual Report 1994,Institute for Nuclear Study,University of Tokyo, 0, p.118 - 119, 1995/00
no abstracts in English
Saito, Shigeru; Kikuchi, Kenji*; Hamaguchi, Dai; Endo, Shinya; Usami, Koji; Sakuraba, Naotoshi; Miyai, Hiromitsu; Ono, Katsuto; Matsui, Hiroki; Kawai, Masayoshi*; et al.
no journal, ,
no abstracts in English
Iguchi, Masahide; Sakurai, Takeru; Morimoto, Masaaki*; Hong, Y.-S.*; Inagaki, Takashi; Tanaka, Nobuhiko; Nakahira, Masataka; Hemmi, Tsutomu; Matsui, Kunihiro; Koizumi, Norikiyo
no journal, ,
no abstracts in English
Kamata, Kento*; Nara, Yoshitaka*; Fujii, Hirokazu*; Zhao, Y.*; Matsui, Hiroya; Ozaki, Yusuke
no journal, ,
The precipitation of carbonate minerals in rock is expected to close the fracture opening. In Horonobe URL, we perform the carbonated water injection test to heal the EDZ by the carbonate mineral precipitation. We compare the permeability before and after the injection to evaluate the closure of fractures in the EDZ. The significant change in permeability is not recognized at the present due to the short injection period and continuous injection would be required to change the permeability of EDZ by the precipitation.
Kamata, Kento*; Nara, Yoshitaka*; Matsui, Hiroya; Ozaki, Yusuke; Fujii, Hirokazu*; Zhao, Y.*
no journal, ,
In this study, we perform a carbonated water injection experiment into the fractured rock to investigate the reduction of permeability due to the sealing of fractures by the precipitation of carbonated minerals at the 350m stage in Horonobe URL. We drilled a 80cm borehole from the drift wall and injected the carbonated water into the fractures there in the excavated damaged zone. The hydraulic test that we performed regularly during the injection experiment indicates the reduction of hydraulic conductivity slightly. To understand the mechanism of the reduction of permeability, we plan to analyze the core sample collected by overcoring.
Kamata, Kento*; Nara, Yoshitaka*; Kashiwaya, Koki*; Tada, Yohei*; Fujii, Hirokazu*; Zhao, Y.*; Matsui, Hiroya; Ozaki, Yusuke
no journal, ,
We conducted a carbonated water injection experiment at 350m stage in Horonobe URL. Two boreholes with 1m were drilled from drift wall and carbonated water was injected. The cement material powder was added one of the boreholes. The hydraulic conductivity around the borehole where only carbonated water was injected slightly decreased. The hydraulic conductivity around the borehole where both cement material powder and carbonated water decreased and increased because of the clogging of fracture by the powder and dissipation of it.
Kuwabara, Shogo*; Nara, Yoshitaka*; Kashiwaya, Koki*; Fujii, Hirokazu*; Zhao, Y.*; Matsui, Hiroya; Ozaki, Yusuke; Hiroyoshi, Naoki*
no journal, ,
This study aims to develop a healing method of fractured rock by injection of cement powder and carbonated water to form carbonated minerals. The in-situ hydraulic tests were carried out to confirm the effect of their injection into rock. The decrease of hydraulic conductivity was recognized after the injection of both cement powder and carbonated water, whereas the injection of only carbonated water did not induce the decrease of hydraulic conductivity.