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Okazaki, Yasuyuki*; Hayashi, Hisashi*; Aoyagi, Kazuhei; Morimoto, Shingo*; Shinji, Masato*
Proceedings of 5th ISRM Young Scholars' Symposium on Rock Mechanics and International Symposium on Rock Engineering for Innovative Future (YSRM 2019 and REIF 2019) (USB Flash Drive), 6 Pages, 2019/12
In the design of tunnel support, the behavior of the rock mass around a tunnel and the stress acting on the tunnel support may be predicted using a numerical analysis. However, in such a numerical analysis, it is common to assume that each stratum comprises a homogeneous material, ignoring the heterogeneity of the geomechanical properties inherent to the rock mass. For this reason, it is not unusual for the results of the numerical analysis to differ from the actual behavior. We performed a tunnel excavation analysis considering the heterogeneity of the geomechanical properties in the rock mass to investigate the local increase in the tunnel support stress obtained in the 350 m gallery at the Horonobe Underground Research Laboratory. The results revealed that, in order to predict the locally increased support stress in advance, it is necessary to carry out a tunneling excavation analysis considering the heterogeneity of the geomechanical properties. It was also revealed that the scale at which the geomechanical properties fluctuate is an important factor.
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)Nakayama, Takuya; Yagi, Naoto; Sato, Kazuhiko; Hinoda, Shingo; Nakagiri, Toshio; Morimoto, Yasuyuki; Umezawa, Katsuhiro; Sugitsue, Noritake
JAEA-Review 2018-005, 163 Pages, 2018/03
JAEA-Review-2018-005.pdf:72.95MB
The Ningyo-toge Environmental Engineering Center of JAEA has been working together with local communities for more than 60 years. Through our R&D projects on from uranium exploration to uranium enrichment as a part of the nuclear fuel cycle (i.e., front-end), we have accumulated experiences in the fields of management of uranium related technology. Taking advantage of such our potential, we will start new R&D program on "Research on Uranium and the Environment". In December 2016 we announced our new concept of the "Uranium and Environmental Research Platform" as a framework aimed at contributing to regional and international society through R&D programs (environmental research and uranium waste engineering research) that are needed to steadily carry out decommissioning of uranium handling facilities.
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)Terunuma, Akihiro; Mimura, Ryuji; Nagashima, Hisao; Aoyagi, Yoshitaka; Hirokawa, Katsunori*; Uta, Masato; Ishimori, Yuu; Kuwabara, Jun; Okamoto, Hisato; Kimura, Yasuhisa; et al.
JAEA-Review 2016-008, 98 Pages, 2016/07
JAEA-Review-2016-008.pdf:11.73MB
Japan Atomic Energy Agency formulated the plan to achieve the medium-term target in the period of April 2010 to March 2015(hereinafter referred to as "the second medium-term plan"). JAEA determined the plan for the business operations of each year (hereinafter referred to as "the year plan"). This report is that the Sector of Decommissioning and Radioactive Waste Management has summarized the results of the decommissioning technology development and decommissioning of nuclear facilities which were carried out in the second medium-term plan.
Okazaki, Yasuyuki*; Aoyagi, Kazuhei; Kumasaka, Hiroo*; Shinji, Masato*
Doboku Gakkai Rombunshu, F1 (Tonneru Kogaku) (Internet), 72(3), p.I_1 - I_15, 2016/00
In the rational tunnel support design, numerical analysis is powerful tool to know the estimation of the behavior before tunnel construction in the case of the special ground condition and limited similar construction. In order to evaluate the support structure quantitatively, it is necessary to understand the effect of the inhomogeneity of rock mass to the tunnel support stress in advance. In this study, tunnel excavation analysis considering the inhomogeneity of rock mass was carried out. The analysis results were compared with the stress measured in the tunnel support in the Horonobe underground research laboratory. As a result, it was revealed that the local stress measured in the tunnel support can be simulated by considering the inhomogeneity of rock mass stochastically. In addition, this study evaluated the effect of the inhomogeneity of rock mass to the tunnel support stress quantitatively by processing analysis results statistically.
-ray irradiation facilitiesAgematsu, Takashi; Haruyama, Yasuyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Kaneko, Hirohisa; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; Takagi, Masahide*; et al.
JAEA-Review 2013-059, JAEA Takasaki Annual Report 2012, P. 181, 2014/03
The electron accelerator and the three -ray irradiation facilities were operated for various research subjects according to the operation plan in FY 2012. The number of research subjects at the electron accelerator kept constant compared with FY 2011. The number of research subjects at the -ray irradiation facilities slightly decreased year after year. Of all these research subjects, 14 ones at the electron accelerator and 93 ones at the -ray irradiation facilities were relevant to the Fukushima Daiichi nuclear disaster.
-ray irradiation facilitiesAgematsu, Takashi; Haruyama, Yasuyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Kaneko, Hirohisa; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; Takagi, Masahide*; et al.
JAEA-Review 2013-059, JAEA Takasaki Annual Report 2012, P. 180, 2014/03
The electron accelerator and the -ray irradiation facility have been operated without serious trouble. The annual operation time in FY 2012 for the electron accelerator, the first, the second cobalt irradiation facility and food irradiation facility are 910 h, 15,738 h, 10,537 h and 7,871 h, respectively. Typicaly repairs were next ones. The SF6 gas withdrawal system broke of the accelerator, and there was trouble of mixing in of air. The maintenance check of the first irradiation facility was done. The 
Co ources were purchased and loaded to the first irradiation facility. Fifteen pencil sources of Co with length of 30 cm each, twelve ball sources of Co and five 
Cs source were disposed of, and they were transferred to Japan Radioisotope Association (JRIA).
-ray irradiation facilitiesAgematsu, Takashi; Haruyama, Yasuyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Kaneko, Hirohisa; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; Takagi, Masahide*; et al.
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 174, 2013/01
The electron accelerator and the -ray irradiation facility have been operated without serious trouble. The annual operation time in FY 2011 for the electron accelerator, the first, the second cobalt irradiation facility and food irradiation facility are 1,059 h, 18,722 h, 9,976 h and 7,427 h, respectively. Typically repairs were next ones. The beam control circuit trouble and the isolation trouble by mixing in of air into SF
gas at electron accelerator were repaired. The maintenance check of the second irradiation facility was done. The Co sources were purchased and loaded to the second irradiation facility. Forty five pencil sources of Co with length of 30 cm each, eight coin sources of Co and the -ray radiographic apparatus with a Co source were disposed to Japan Radioisotope Association (JRIA).
-ray irradiation facilitiesHaruyama, Yasuyuki; Agematsu, Takashi; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Kaneko, Hirohisa; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; Takagi, Masahide*; et al.
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 175, 2013/01
The electron accelerator and the three -ray irradiation facilities were operated for various research subjects according to the operation plan in FY 2011 without serious trouble. The number of research subjects at the electron accelerator increased in the research fields of nuclear facilities and resources & biotechnology, and decreased in the fields of material processing and material for space. The number of research subjects at the -ray irradiation facilities increased in the fields of material for space and material processing, and decreased in the fields of nuclear facilities and resources & biotechnology. Of all these research subjects, 15 ones at the electron accelerator and 94 ones at the -ray irradiation facilities were relevant to the Fukushima Daiichi nuclear disaster.
-ray irradiation facilitiesHaruyama, Yasuyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Kaneko, Hirohisa; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; Takagi, Masahide*; Kawashima, Ikuo*; et al.
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 174, 2012/01
The electron accelerator and -ray irradiation facilities have been operated without serious troubles before the earthquake happened in March 11 2011. The electron accelerator and -ray irradiation facilities were stopped with concern about the earthquake damage, for 13 and 20 days, respectively.
-ray irradiation facilities and electron acceleratorKaneko, Hirohisa; Haruyama, Yasuyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Nagao, Yuto; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; Takagi, Masahide*; Kawashima, Ikuo*; et al.
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 175, 2012/01
Irradiation facilities and an electron accelerator were operated for various research subjects according to the operation plan in FY 2010 without serious trouble. Utilization was stopped until the end of the fiscal year due to inspection etc., after the earthquake occurred on March 11. The number at -ray irradiation facilities increased in the field of environment and basic technology, and decreased in the field of material processing and resource & bio-technology. The number of research subjects at the electron accelerator increased in the research fields of material for space, and decreased in the field of material processing and joint use.
-ray irradiation facilitiesKaneko, Hirohisa; Haruyama, Yasuyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; Takagi, Masahide*; Kawashima, Ikuo*; Matsuzaki, Shinya*
JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 183, 2011/01
An electron accelerator and three -ray irradiation facilities were operated for various research subjects according to the operation plan in FY 2009 without serious trouble. The number of experiment subjects at the electron accelerator increased in the research fields of materials for space and heat-resist material, and decreased in the field of basic technology and nuclear facilities. The number at -ray irradiation facilities increased in the field of nuclear facilities, and decreased in the field of materials processing and resource & bio-technology.
-ray irradiation facilitiesHaruyama, Yasuyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Kaneko, Hirohisa; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; Takagi, Masahide*; Kawashima, Ikuo*; Matsuzaki, Shinya*
JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 182, 2011/01
The accelerator served mainly for graft-polymerization for new material development, radiation effect study on semiconductors and various experiments of visiting users. The annual operation time of the electron accelerator was 947.9 h. The Co-60 -ray irradiation facilities consist of three buildings and cover a wide dose-rate range from 0.04 Gy/h to 20 kGy/h with eight irradiation rooms. The first irradiation facility served mainly for radiation-resistance testing of cables used in nuclear power plants. The second irradiation facility (No.6 irradiation room) operated as hourly scheduled. The food irradiation facility served radiation at lower dose rates. The annual operation time for the first, second cobalt irradiation facilities and food irradiation facility was 15,971 h, 12,389 h and 7,681 h respectively.
-ray irradiation facilitisHaruyama, Yasuyuki; Kaneko, Hirohisa; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Kanazawa, Takao; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; Takagi, Masahide*; Hirai, Toshiyuki*; et al.
JAEA-Review 2009-041, JAEA Takasaki Annual Report 2008, P. 176, 2009/12
no abstracts in English
-ray irradiation facilitiesKaneko, Hirohisa; Haruyama, Yasuyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Kanazawa, Takao; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; Takagi, Masahide*; Hirai, Toshiyuki*; et al.
JAEA-Review 2009-041, JAEA Takasaki Annual Report 2008, P. 177, 2009/12
no abstracts in English
-ray irradiation facilitiesKaneko, Hirohisa; Haruyama, Yasuyuki; Haneda, Noriyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Kanazawa, Takao; Kojima, Takuji; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; et al.
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 192, 2008/11
The accelerator served mainly for graft-polymerization for new material development, radiation effect study on semiconductors and various experiments of visiting users. The annual operation time of the electron accelerator is 706.3h. The Co-60 -ray irradiation facilities consist of three buildings (8 rooms) and cover a wide dose-rate range from 0.04 Gy/h to 20 kGy/h with eight irradiation cells. The annual operation time for the first, second cobalt irradiation facilities and food irradiation facility is 23,433h, 9,010h and 10,631h.
-ray irradiation facilitiesKaneko, Hirohisa; Haruyama, Yasuyuki; Haneda, Noriyuki; Hanaya, Hiroaki; Yamagata, Ryohei; Seito, Hajime; Kanazawa, Takao; Kojima, Takuji; Yamaguchi, Toshiyuki*; Yagi, Norihiko*; et al.
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 193, 2008/11
An electron accelerator and three -ray irradiation facilities were operated for various research subjects as operation plan in FY 2007 without serious trouble. The number of research subjects for the electron accelerator and -ray irradiation facilities is 505 and 1174, respectively. The number of experiment subject at the electron accelerator increased in the research fields of environment and nuclear facilities, and decreased in the field of heat resist. Also, the number at -ray irradiation facilities increased in the field of resource & bio-technology, and decreased in the field of nuclear facilities.
Tamai, Hiroshi; Matsukawa, Makoto; Kurita, Genichi; Hayashi, Nobuhiko; Urata, Kazuhiro*; Miura, Yushi; Kizu, Kaname; Tsuchiya, Katsuhiko; Morioka, Atsuhiko; Kudo, Yusuke; et al.
Plasma Science and Technology, 6(1), p.2141 - 2150, 2004/02
Times Cited Count：2 Percentile：6.49(Physics, Fluids & Plasmas)The dominant issue for the the modification program of JT-60 (JT-60SC) is to demonstrate the steady state reactor relevant plasma operation. Physics design on plasma parameters, operation scenarios, and the plasma control method are investigated for the achievement of high-
. Engineering design and the R&D on the superconducting magnet coils, radiation shield, and vacuum vessel are performed. Recent progress in such physics and technology developments is presented.
Ishida, Shinichi; Abe, Katsunori*; Ando, Akira*; Chujo, T.*; Fujii, Tsuneyuki; Fujita, Takaaki; Goto, Seiichi*; Hanada, Kazuaki*; Hatayama, Akiyoshi*; Hino, Tomoaki*; et al.
Nuclear Fusion, 43(7), p.606 - 613, 2003/07
no abstracts in English
