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Yano, Yasuhide; Otsuka, Satoshi; Yamashita, Shinichiro; Ogawa, Ryuichiro; Sekine, Manabu; Endo, Toshiaki; Yamagata, Ichiro; Sekio, Yoshihiro; Tanno, Takashi; Uwaba, Tomoyuki; et al.
JAEA-Research 2013-030, 57 Pages, 2013/11
JAEA-Research-2013-030.pdf:48.2MB
It is necessary to develop the fast reactor core materials, which can achieve high-burnup operation improving safety and economical performance. Ferritic steels are expected to be good candidate core materials to achieve this objective because of their excellent void swelling resistance. Therefore, oxide dispersion strengthened (ODS) ferritic steel and 11Cr-ferritic/martensitic steel (PNC-FMS) have been respectively developed for cladding and wrapper tube materials in Japan Atomic Energy Agency. In this study, the effects of fast neutron irradiation on mechanical properties and microstructure of 9Cr-and 12Cr-ODS steel claddings for fast reactor were investigated. Specimens were irradiated in the experimental fast reactor Joyo using the CMIR-6 at temperatures between 420 and 835
C to fast neutron doses ranging from 16 to 33 dpa. The post-irradiation ring tensile tests were carried out at irradiation temperatures.
Otsuka, Satoshi; Kaito, Takeji; Yano, Yasuhide; Yamashita, Shinichiro; Ogawa, Ryuichiro; Uwaba, Tomoyuki; Koyama, Shinichi; Tanaka, Kenya
Journal of Nuclear Science and Technology, 50(5), p.470 - 480, 2013/05
Times Cited Count：5 Percentile：38.62(Nuclear Science & Technology)Four experimental fuel assemblies (EFAs) containing 9Cr-ODS steel cladding fuel pins were previously irradiated in the BOR-60. One of the EFAs achieved the best data, a peak burn-up of 11.9at% and a neutron dose of 51 dpa, without any microstructure instability or any fuel pin rupture. On the other hand, in another EFA (peak burn-up, 10.5at%; peak neutron dose, 44 dpa), peculiar irradiation behaviors such as microstructure instability and fuel pin rupture occurred. The combined effects of matrix Cr heterogeneity (presence of metallic Cr inclusions) and high-temperature irradiation were concluded to be the main cause of the peculiar microstructure change of 9Cr-ODS steel cladding tubes in the BOR-60 irradiation tests. They contributed to the fuel pin rupture.
Otsuka, Satoshi; Kaito, Takeji; Yano, Yasuhide; Yamashita, Shinichiro; Ogawa, Ryuichiro; Uwaba, Tomoyuki; Koyama, Shinichi; Tanaka, Kenya
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 6 Pages, 2011/12
This paper describes evaluation results of in-reactor integrity of 9Cr and 12Cr-ODS steel cladding tubes and the plan for reliability improvement in homogeneous tube production. A fuel assembly in the BOR-60 irradiation test including 9Cr and 12Cr-ODS fuel pins has achieved the highest burn-up, i.e. peak burn-up of 11.9at% and peak neutron dose of 51dpa, without any fuel pin rupture and microstructure instability. In another fuel assembly containing 9Cr and 12Cr-ODS steel fuel pins whose peak burn-up was 10.5at%, one 9Cr-ODS steel fuel pin failed near the upper end of the fuel column. A peculiar microstructure change occurred in the vicinity of the ruptured area. The primary cause of this fuel pin rupture and microstructure change was shown to be the presence of metallic Cr inclusions in the 9Cr-ODS steel tube, which had passed an ultrasonic inspection test for defects. In the next stage from 2011 to 2013, the fabrication technology of full pre-alloy 9Cr-ODS steel cladding tube will be developed.
Sone, Tomoyuki; Nakagawa, Akinori; Koyama, Hayato; Gunji, Kiyoshi; Nonaka, Kazuharu; Sasaki, Toshiki; Tashiro, Kiyoshi; Yamashita, Toshiyuki
JAEA-Technology 2009-023, 33 Pages, 2009/06
JAEA-Technology-2009-023.pdf:8.11MB
Steam reforming (SR) method consists of the gasification process in which organics are vaporized and decomposed with superheated steam and the oxidation process in which vaporized organics are decomposed by oxidizing reaction with heated air. 2,500L of waste TBP/n-dodecane contaminated with uranium was treated using the demonstration scale steam reforming system to examine the performance of the system. Results obtained in this study show that the temperature in the SR system was controlled under the self-regulation temperature, the concentration of CO and NOx in the off-gas were controlled less than 100ppm and 250ppm respectively, the distribution ratio of uranium to off-gas treatment system was under 0.12% and the gasification ratio of waste TBP was more than 99%. This long-term waste treatment test has demonstrated that the SR system can safely and effectively reduce the volume of the waste.
Takemura, Tomoyuki*; Sakogaichi, Kaoru*; Takahashi, Eiichiro*; Takebe, Akimitsu*; Nakajima, Toshihide*; Yamashita, Mitsugu*; Yamanouchi, Hirofumi*
JNC TJ7420 2005-041, 129 Pages, 1999/03
JNC-TJ7420-2005-041.pdf:65.88MB
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 such as the earthquake mechanism is done by using this tunnel. The purpose of this investigation is to define the hydrological characteristics inside and around the Mozumi - Sukenobu fault crush zones. The investigation is mainly Lugeon test and simple permeability test inside and around the crush zones.
Takemura, Tomoyuki*; Shingu, Kazuki*; Sakogaichi, Kaoru*; Nishikawa, Yuji*; Okada, Yoichi*; Nakajima, Toshihide*; Yamashita, Mitsugu*
JNC TJ7420 2005-035, 152 Pages, 1998/03
JNC-TJ7420-2005-035.pdf:27.16MB
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.
Maruyama, So; Yamashita, Kiyonobu; Fujimoto, Nozomu; Murata, Isao; Sudo, Yukio; Murakami, Tomoyuki*; Fujii, Sadao*
Journal of Nuclear Science and Technology, 30(11), p.1186 - 1194, 1993/11
Times Cited Count：7 Percentile：68.63(Nuclear Science & Technology)no abstracts in English
Momose, Takumaro; Endo, Kuniaki; Ito, Yasuhisa; Yamashita, Tomoyuki; Namiki, Atsushi; Sanada, Yukihisa; Akiyama, Kiyomitsu; Takeishi, Minoru; Tago, Itaru; Furuta, Sadaaki
no journal, ,
The first reprocessing pilot plant in Japan (Tokai Reprocessing Plant; TRP) has been operated since 1977 at Nuclear Fuel Cycle Engineering Laboratories, JAEA. General radiation protection in TRP is performed with continuous monitoring and sampling methods. The continuous monitors measuring 
-ray, neutron, particulate alpha and beta nuclides in the air are installed in the radiation controlled area as a central monitoring system to prevent from unnecessary exposure. Air and water effluents from the TRP are also monitored by continuous monitors or sampling methods to comply with regulations. In addition to this, environmental monitoring has been carried out to assess influences on public and environment by the plant operation. A feature of radiation protection and its recent relevant researches at TRP will be introduced in this presentation.
Takahata, Eiji; Iijima, Nobuo; Yamashita, Tomoyuki; Akiyama, Kiyomitsu
no journal, ,
A training program of the body surface contamination at the Tokai Reprocessing Plant is introduced. This program takes consideration with low-level measurement of alpha and beta () contamination in workplace. The training effect of this program is evaluated by actual survey tests.
Koyama, Hayato; Sone, Tomoyuki; Sasaki, Toshiki; Yamashita, Toshiyuki
no journal, ,
no abstracts in English
Iijima, Nobuo; Sanada, Yukihisa; Yamashita, Tomoyuki; Momose, Takumaro
no journal, ,
no abstracts in English
Hokama, Tomonori; Iijima, Nobuo; Sanada, Yukihisa; Yamashita, Tomoyuki; Momose, Takumaro
no journal, ,
no abstracts in English
Nakamura, Keisuke; Iijima, Nobuo; Yamashita, Tomoyuki; Shiba, Kozo; Momose, Takumaro
no journal, ,
no abstracts in English
Hokama, Tomonori; Sanada, Yukihisa; Yamashita, Tomoyuki; Shiba, Kozo; Momose, Takumaro
no journal, ,
Fukushima Daiichi Nuclear Power Plant released radioactive isotope accompany the Great Eastern Japan Earthquake. The radioactive isotope came at Tokai Reprocessing Plant, and their influence cannot be disregarded. Radiological control in reprocessing plant divided degree of influence into 3 situation, so we carried out radiological control depends on each situation.
Otani, Tomoyuki*; Yamashita, Mitsumasa*; Kojima, Satoru*; Wakai, Shoji; Kakamu, Kazuhiko
no journal, ,
no abstracts in English
Otani, Tomoyuki*; Yamashita, Mitsumasa*; Kojima, Satoru*; Wakai, Shoji*; Kakamu, Kazuhiko
no journal, ,
no abstracts in English
