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Tsuji, Tomoyuki; Sugitsue, Noritake; Sato, Fuminori; Matsushima, Ryotatsu; Kataoka, Shoji; Okada, Shota; Sasaki, Toshiki; Inoue, Junya
Nihon Genshiryoku Gakkai-Shi ATOMO, 62(11), p.658 - 663, 2020/11
no abstracts in English
Hayashi, Hirokazu; Okada, Shota; Izumo, Sari; Hoshino, Yuzuru; Tsuji, Tomoyuki; Nakata, Hisakazu; Sakai, Akihiro; Amazawa, Hiroya; Sakamoto, Yoshiaki
Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 7 Pages, 2017/04
A near surface disposal for low-level radioactive waste (LLW) generated from commercial nuclear power plants (NPP) is operating in Japan. However, the disposal of LLW from other nuclear facilities and radioisotope utilization facilities has not yet been implemented. Japan Atomic Energy Agency (JAEA) plans to implement the near surface disposal. In order to be disposed of these wastes, it must be confirmed by the regulator that each waste package (radioactive waste solidified with filling materials, such as cement, in a container by a regulated method is termed a waste package) conforms to technical standards that aim for safe disposal. JAEA has studied reasonable confirmation methods to demonstrate the conformity of the waste package to the technical standard as NPP operators have studied it. This report describes the outline of our activities focused on development of the confirmation method applicable to radioactive wastes from research facilities.
Okada, Shota; Izumo, Sari; Nakata, Hisakazu; Tsuji, Tomoyuki; Sakai, Akihiro; Amazawa, Hiroya
JAEA-Technology 2016-023, 129 Pages, 2016/11
Waste packages must meet the technical requirements. This is because JAEA has been preparing an operating procedure manual for quality control of radioactive waste disposal to be applied to the processing of the waste packages. Raw wastes generated by JAEA are segregated and stored by a method specified in the manual. The composition of raw wastes was characterized on the basis of records of the segregation process. Simulated waste packages were produced by placing the waste materials in a 200 liter drum, which was then filled with mortar, followed by curing in a controlled manner. The static load test was conducted to measure deformation and strain performance of the simulated waste package. Compression apparatuses which can imitate loading conditions in pit-type and trench-type facility that are planned by JAEA were used. Based on the test result, waste packages produced in accordance with the manual met the technical requirement under the condition.
Nakata, Hisakazu; Sakai, Akihiro; Okada, Shota; Izumo, Sari; Tsuji, Tomoyuki; Kurosawa, Ryohei; Amazawa, Hiroya
JAEA-Technology 2016-001, 112 Pages, 2016/03
The waste packages must meet the technical requirements that radioactive waste shall be solidified in a container by a method determined by the Nuclear Regulation Authority to prevent from radiation hazards. JAEA has been preparing operating procedure manual on quality control for radioactive waste disposal in order to promote the manufacturing the waste package. This report presents that simulant waste packages were produced by placing wastes in a 200 liter drum, which was then filled with mortar of a novel mix proportion, followed by curing in a controlled manner. Determination of the presence of harmful voidage and raw waste immobility were performed by direct measurement and visual inspection of a vertical cross section of the waste packages respectively.
Abderrahmane, A.*; Koide, Shota*; Tahara, Tomoyuki*; Sato, Shinichiro; Oshima, Takeshi; Okada, Hiroshi*; Sandhu, A.*
Journal of Physics; Conference Series, 433, p.012011_1 - 012011_8, 2013/04
Times Cited Count:6 Percentile:84.01(Physics, Multidisciplinary)We investigated the effect of high energy and high fluence proton irradiation on magnetoelectric properties of AlGaN/GaN micro-Hall sensors from 5.4 K to room temperature. The sensors show good resistance versus the irradiation translated by the stability of the sheet density therefore the stability of the absolute sensitivity of the sensor. However, the proton irradiation damaged the electrical properties of the sensor indicated by the dramatically decrease of the mobility at low temperature by rate of about 81% at 5.4 K. The existing of the 2DEG system either after irradiation with high energy was confirmed by investigation the magnetotransport measurements at low temperature and which show Shubnikov de Haas oscillations at high magnetic field. Damping of the Shubnikov de Haas oscillations and disappearance of Landau plateaus after irradiation were related to the degradation in the mobility causing by increasing the scattering at the interface.
Hase, Yoshihiro; Nozawa, Shigeki; Okada, Tomoyuki*; Asami, Itsuo*; Nagatani, Takeshi*; Matsuo, Yoichi*; Kanazawa, Akira*; Honda, Kazushige*; Narumi, Issei
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 95, 2013/01
Hase, Yoshihiro; Nozawa, Shigeki; Okada, Tomoyuki*; Asami, Itsuo*; Nagatani, Takeshi*; Matsuo, Yoichi*; Kanazawa, Akira*; Honda, Kazushige*; Narumi, Issei
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 100, 2012/01
Okada, Tomoyuki*; Ikeda, Hiroshi*; Ono, Yutaka; Yoshihara, Ryohei; Hase, Yoshihiro; Narumi, Issei
JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 63, 2011/01
no abstracts in English
Okada, Tomoyuki*; Iizuka, Masahide*; Yoshihara, Ryohei; Hase, Yoshihiro; Narumi, Issei
JAEA-Review 2009-041, JAEA Takasaki Annual Report 2008, P. 73, 2009/12
no abstracts in English
Takemura, Tomoyuki*; Shingu, Kazuki*; Sakogaichi, Kaoru*; Nishikawa, Yuji*; Okada, Yoichi*; Nakajima, Toshihide*; Yamashita, Mitsugu*
JNC TJ7420 2005-035, 152 Pages, 1998/03
The active fault survey tunnel that crossed the Mozumi-Sukenobu fault (MSF) is located at the Kamioka mine, northern Gifu prefecture, Central Japan. The comprehensive study of the active fault, such as the study of the earthquake mechanism and the development of the new initial stress measurement method is done by using this tunnel. One of the purposes of this investigation is to define the three-dimensional distribution of the MSF by geological survey, on the basis of the seismic and geophysical studies on this fault. The other purpose is to develop the new initial stress measurement method.
Takemura, Tomoyuki*; Shingu, Kazuki*; Takahashi, Eiichiro*; Okada, Yoichi*; Takebe, Akimitsu*; Nakajima, Toshihide*; Inoue, Toshio*
JNC TJ7420 2005-033, 128 Pages, 1998/03
The active fault survey tunnel that crossed the Mozumi-Sukenobu fault (a member of the Atotsugawa fault system) is located at the Kamioka mine, northern Gifu prefecture, Central Japan. The comprehensive study of the active fault is done by using this tunnel. The purpose of this investigation is to define the hydrological characteristics of the Mozumi-Sukenobu fault crush zones. The permeability of the crush zones is measured by the Lugeon test and the simple injection test.
Okada, Tomoyuki*; Iizuka, Masahide*; Yoshihara, Ryohei; Hase, Yoshihiro; Narumi, Issei
no journal, ,
no abstracts in English
Tajiri, Nobuhiro*; Hiroyasu, Tomoyuki*; Wada, Motoi*; Kenmotsu, Takahiro*; Kiriyama, Hiromitsu; Daito, Izuru; Sasao, Hajime*; Suzuki, Masayuki; Okada, Hajime
no journal, ,
no abstracts in English
Okada, Tomoyuki*; Iizuka, Masahide*; Ikeda, Hiroshi*; Nozawa, Shigeki; Yoshihara, Ryohei; Hase, Yoshihiro; Narumi, Issei
no journal, ,
no abstracts in English
Okada, Tomoyuki*; Iizuka, Masahide*; Hase, Yoshihiro; Nozawa, Shigeki; Narumi, Issei
no journal, ,
no abstracts in English
Okada, Tomoyuki*; Iizuka, Masahide*; Hase, Yoshihiro; Nozawa, Shigeki; Narumi, Issei; Sekiguchi, Masayuki*
no journal, ,
no abstracts in English