Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Koyama, Shinichi; Nakagiri, Toshio; Osaka, Masahiko; Yoshida, Hiroyuki; Kurata, Masaki; Ikeuchi, Hirotomo; Maeda, Koji; Sasaki, Shinji; Onishi, Takashi; Takano, Masahide; et al.
Hairo, Osensui Taisaku jigyo jimukyoku Homu Peji (Internet), 144 Pages, 2021/08
JAEA performed the subsidy program for the "Project of Decommissioning and Contaminated Water Management (Development of Analysis and Estimation Technology for Characterization of Fuel Debris (Development of Technologies for Enhanced Analysis Accuracy and Thermal Behavior Estimation of Fuel Debris))" in 2020JFY. This presentation summarized briefly the results of the project, which will be available shortly on the website of Management Office for the Project of Decommissioning and Contaminated Water Management.
-ray Spectrometry of Environmental Samples Collected in FukushimaSaegusa, Jun; Yoda, Tomoyuki; Maeda, Satoshi; Okazaki, Tsutomu; Otani, Shuichi; Yamaguchi, Toshio; Kurita, Yoshiyuki; Hasumi, Atsushi; Yonezawa, Chushiro*; Takeishi, Minoru
Proceedings of 14th International Congress of the International Radiation Protection Association (IRPA-14), Vol.3 (Internet), p.1078 - 1085, 2017/11
After the nuclear accident at the Fukushima Daiichi Nuclear Power Plant in March 2011, the Japan Atomic Energy Agency has newly set up a laboratory for radioactivity analysis in Fukushima. At the laboratory, radioactivity concentrations of environmental samples such as soil, water, dust filter, plant, etc., approximately 1,000 samples in a month, are measured with high-resolution -ray spectrometry systems. The systems employ n-type HPGe detectors from Ortec. Since September 2012, characterization and upgrade of the systems have been performed aimed at enhancing reliability of analysis and convenience of customers. Resolving both systematic and technical issues, the laboratory has been accredited the ISO/IEC 17025 standard as a testing laboratory for radioactivity analysis.
Usuki, Toshiyuki; Sato, Isamu; Suto, Mitsuo; Maeda, Koji; Osaka, Masahiko; Koyama, Shinichi; Tokoro, Daishiro*; Sekioka, Ken*; Ishigamori, Toshio*
JAEA-Testing 2014-001, 29 Pages, 2014/05
JAEA-Testing-2014-001.pdf:5.33MB
The penetration tests with solution containing radioactive nuclides were experimented to understand basic data for floor and wall materials of Fukushima Daiichi reactor buildings. The solution prepared from irradiated fuels was used as solution containing radioactive nuclides. The solution was applied to surface of epoxy paint, dried concrete and mortar used as specimens. Dose-rate profiles of direction of depth were given by radiation measurement and grinding of the specimens. The penetrations of radioactive nuclides for epoxy paint specimens were not clearly observed and the penetration depths would be within 0.4 mm. The penetrations of radioactive nuclides for dried concrete specimens proceeded. The penetration rates were substantially decreased when 16 days have elapsed from start. The dose rates of penetrated dried concrete specimens were reduced to background by grinding-2.0 mm. -ray spectrometry measurement showed that penetration behavior of near surface concrete are different among nuclides and the penetration behavior of radioactive nuclides into dried concrete and mortar materials through solution is similar to migration behavior of ions into those water-saturated materials.
Ura, Tamaki*; Takamasa, Tomoji*; Nishimura, Hajime*; Aoki, Taro*; Ueno, Michio*; Maeda, Toshio*; Nakamura, Masato*; Shimazu, Shunsuke*; Tokunaga, Sango*; Shibata, Yozo*; et al.
JAERI-Tech 2001-049, 154 Pages, 2001/07
JAERI-Tech-2001-049.pdf:11.24MB
JAERI has studied on design and operation of a nuclear powered submersible research vessel, which will navigate under sea in the Arctic Ocean, as a part of the design study of advanced marine reactors. This report describes operation conditions and an operating system of the vessel those were discussed by the specialists of hull design, sound positioning, ship motions and oceanography, etc. The design conditions on ship motions for submersible vessels were surveyed considering regulations in our country, and ship motions were evaluated assuming the observation activities in the Arctic Ocean. A submarine transponder system and an on ice communication buoy system were examined as a positioning and communication system supposing the activity under ice. Procedures to secure safety of nuclear powered submersible research vessel were discussed based on the investigation of accidents. These results were reflected to the concept of the nuclear powered submersible research vessel, and subjects fto be settled in the next step were clarified.
Usuki, Toshiyuki; Sato, Isamu; Kanayama, Fumihiko; Suto, Mitsuo; Maeda, Koji; Koyama, Shinichi; Kawatsuma, Shinji; Fukushima, Mineo; Tokoro, Daishiro*; Sekioka, Ken*; et al.
no journal, ,
no abstracts in English
Usuki, Toshiyuki; Sato, Isamu; Kanayama, Fumihiko; Suto, Mitsuo; Maeda, Koji; Koyama, Shinichi; Kawatsuma, Shinji; Fukushima, Mineo; Tokoro, Daishiro*; Sekioka, Ken*; et al.
no journal, ,
no abstracts in English
Saegusa, Jun; Yanagisawa, Kayo; Yamaguchi, Toshio; Manabe, Sachi; Yoda, Tomoyuki; Maeda, Satoshi; Utsumi, Azusa; Shibamichi, Masaru; Ejiri, Akira; Kurita, Yoshiyuki; et al.
no journal, ,
no abstracts in English
Shobu, Takahisa; Tominaga, Aki; Kisohara, Naoyuki; Maeda, Toshio*; Yamagishi, Ryuichiro*; Okihara, Shinichiro*; Tsuboi, Akihiko
no journal, ,
In this study, the internal defects and strain distribution in metal additive manufacturing and their changes by laser peening were evaluated. These studies using X-ray computed tomography and diffraction technique were carried out at BL22XU in synchrotron radiation facility SPring-8. As a result, it was confirmed that a large number of voids existed inside the additive manufacturing. However, almost no difference due to laser peening was confirmed. On the other hand, it was confirmed that the strain inside the additive manufacturing was almost
