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Usui, Aya; Chiba, Atsuya; Yamada, Keisuke; Yokoyama, Akihito; Kitano, Toshihiko*; Takayama, Terumitsu*; Orimo, Takao*; Kanai, Shinji*; Aoki, Yuki*; Hashizume, Masashi*; et al.
Dai-28-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.117 - 119, 2015/12
no abstracts in English
Yuyama, Takahiro; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Ishizaka, Tomohisa; Chiba, Atsuya; Yamada, Keisuke; Yokoyama, Akihito; Usui, Aya; Miyawaki, Nobumasa; et al.
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.302 - 304, 2015/09
no abstracts in English
Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Kitamura, Akira; Yoshikawa, Hideki; Oda, Chie; Ishidera, Takamitsu; et al.
JAEA-Research 2014-030, 457 Pages, 2015/03
JAEA-Research-2014-030.pdf:199.23MB
JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and post-closure performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, based on some examples of developing method of hydro-geological structure model, acquired knowledge are arranged using the tree diagram, and model uncertainty and its influence on the evaluation items were discussed. With regard to (2) study on scenario development, the developed approach for "defining conditions" has been reevaluated and improved from practical viewpoints. In addition, the uncertainty evaluation for the effect of use of cementitious material, as well as glass dissolution model, was conducted with analytical evaluation. With regard to (3) study on setting radionuclide migration parameters, based on survey of precedent procedures, multiple-approach for distribution coefficient of rocks was established, and the adequacy of the approach was confirmed though its application to sedimentary rock and granitic rock. Besides, an approach for solubility setting was developed including the procedure of selection of solubility limiting solid phase. The adequacy of the approach was confirmed though its application to key radionuclides.
Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Hayano, Akira; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Oda, Chie; Kitamura, Akira; Osawa, Hideaki; et al.
JAEA-Research 2013-037, 455 Pages, 2013/12
JAEA-Research-2013-037.pdf:42.0MB
Following FY2011, JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, the tree diagram of methodology of groundwater travel time has been extended for crystalline rock, in addition, tree diagram for sedimentary rock newly has been organized. With regard to (2) study on scenario development, the existing approach has been improved in terms of a practical task, and applied and tested for near field focusing on the buffer. In addition, the uncertainty of some important processes and its impact on safety functions are discussed though analysis. With regard to (3) study on setting radionuclide migration parameters, the approaches for parameter setting have been developed for sorption for rocks and solubility, and applied and tested through parameter setting exercises for key radionuclides.
Yamaguchi, Masaaki; Maekawa, Keisuke; Takeuchi, Shinji*; Kitamura, Akihiro; Onishi, Yasuo*
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 20(2), p.53 - 69, 2013/12
We developed a simple novel and fast simulation model to predict a long-term distribution of 
Cs deposited on the land surface of Fukushima due to the Fukushima Dai-ichi Nuclear Power Plant accident triggered by a magnitude 9.0 earthquake and resulting tsunami on 11 March 2011. The model utilizes the Geographical Information System (GIS) to integrate online open data provided by individual institutes, and simulate mechanisms of soil erosion, transport and sedimentation. A preliminary calculation shows the significant deposition of sediments in lakes and reservoirs and eroded silt and clay tend to be transported downstream to river mouths than eroded sand. These results were found to be qualitatively consistent with existing data.
Seki, Hajime*; Fujita, Satoshi*; Minagawa, Keisuke*; Kitamura, Seiji; Watakabe, Tomoyoshi
Dynamics and Design Conference 2013 (D&D 2013) Koen Rombunshu (USB Flash Drive), 8 Pages, 2013/08
When we study the behavior of the pipes during an earthquake, the most important damage doesn't come from the maximal load by itself, but from the accumulation of the fatigue damage caused by the repetition of the cyclic load. Therefore, from the point of view of seismic design evaluation methods, techniques that can quantitatively assess the probability of fatigue failure of mechanical structures are needed. The relationship between failure and energy is evaluated, and examined by focusing on the Energy Balance Method said to be effective as an earthquake response analysis technique in the present. This study carries out failure experiments using 2-mass system model based on Energy Balance Method. Furthermore, we focus on the strain from the vicinity of broken point as local response.
Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Hayano, Akira; Mitsui, Seiichiro; Taniguchi, Naoki; Oda, Chie; Kitamura, Akira; Osawa, Hideaki; et al.
JAEA-Research 2012-032, 298 Pages, 2012/09
JAEA-Research-2012-032.pdf:33.68MB
JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and performance assessment in preliminary investigation phase. The topics and the conducted research are follows; (1) Study on selection of host rock: in terms of hydraulic properties, items for assessing rock property, and assessment methodology of groundwater travel time has been organized with interaction from site investigation. (2) Study on development of scenario: the existing approach has been embodied, in addition, the phenomenological understanding regarding dissolution of and nuclide release from vitrified waste, corrosion of the overpack, long-term performance of the buffer are summarized. (3) Study on setting nuclide migration parameters: the approach for parameter setting has been improved for sorption and diffusion coefficient of buffer/rock, and applied and tested for parameter setting of key radionuclides. (4) Study on ensuring quality of knowledge: framework for ensuring quality of knowledge has been studied and examined aimed at the likely disposal facility condition.
Watahiki, Masatoshi; Akai, Masanori; Nakai, Koji; Iemura, Keisuke; Yoshino, Masanori*; Hirano, Hiroshi*; Kitamura, Akihiro; Suzuki, Kazunori
Nihon Genshiryoku Gakkai Wabun Rombunshi, 11(1), p.101 - 109, 2012/02
Gloveboxes used for plutonium fuel development and fabrication are eventually dismantled for replacement or decommissioning. Since equipment interior and the inner surface of gloveboxes are contaminated in radioactive materials, glovebox dismantling work is performed by workers wearing an air fed suit with mechanical tools in a plastic enclosure system to control the spread of contamination. Various improvements of enclosure system are implemented including modification of the rooms to decontaminate and undress the air fed suit and introduction of inflammable filter and safety film near the size reduction workspace against fire. We describe the countermeasures deployed in the enclosure system against potential hazards and how these devices work in the real dismantling activities.
Arase, Sachiko*; Hase, Yoshihiro; Abe, Jun*; Kasai, Megumi*; Yamada, Tetsuya*; Kitamura, Keisuke*; Narumi, Issei; Tanaka, Atsushi; Kanazawa, Akira*
Plant Biotechnology, 28(3), p.323 - 329, 2011/06
Times Cited Count：20 Percentile：54.28(Biotechnology & Applied Microbiology)Iemura, Keisuke; Nakai, Koji; Watahiki, Masatoshi; Kitamura, Akihiro; Suzuki, Kazunori; Aoki, Yoshikazu
Dekomisshoningu Giho, (43), p.2 - 9, 2011/03
Plutonium fuel fabrication facility is constructed in 1972 and it is almost 40 years of age and equipment and components comprises the facility start degrading. Therefore we need to start dismantling gloveboxes from old ones first and at the same time to maintain the facility components and structures and gloveboxes as necessary. Also, since waste storage space is limited in the site, we effectively use open spaces generated after removing gloveboxes and equipment as temporal waste storage space. After shipping these wastes from the facility, final characterization of the facility will be conducted and demolition of the facility will be take place.
Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki
Proceedings of 2009 ASME Pressure Vessels and Piping Division Conference (PVP 2009) (CD-ROM), 7 Pages, 2009/07
Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki
Proceedings of 2008 ASME Pressure Vessels and Piping Division Conference (PVP 2008) (CD-ROM), 6 Pages, 2008/08
Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki
Transactions of the 19th International Conference on Structural Mechanics in Reactor Technology (SMiRT-19) (CD-ROM), 7 Pages, 2007/08
Although mechanical structures have sufficient seismic safety margin, comprehending the ultimate strength is very important in order to improve the seismic safety reliability in unexpected severe earthquake. The energy balance is adequate to investigate the influence of cumulative load because it includes cumulative information. The vibration experiments using simple single-degree-of-freedom experimental model are carried out in order to confirm a calculation technique of energy and to investigate behavior of energy in elasto-plastic region. The vibration failure experiments that lead experimental model to fatigue failure are carried out in order to investigate the relationship between input energy and fatigue failure.
Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki
Proceedings of 2007 ASME Pressure Vessels and Piping Division Conference/8th International Conference on Creep and Fatigue at Elevated Temperatures (PVP 2007/CREEP-8) (CD-ROM), 6 Pages, 2007/07
This paper describes the dynamic strength evaluation of piping installed in nuclear power plants from a viewpoint of energy balance. In this study, ultimate strength of a simple single degree of freedom model is investigated from a viewpoint of energy balance equation that is one of valid methods for structural calculation. The investigation is implemented by forced vibration experiment. In the experiment, colored random wave having predominant frequency similar to natural frequency of the experimental model is input. Stainless steel and carbon steel are selected as material of experimental model. As a result of the experiment, it is confirmed that input energy for fracture increase with an increase of time for fracture. In other words, more input energy for fracture is needed in case of small input level. Additionally it is confirmed that input energy for fracture depend on the material.
I in environmental samples by AMS and NAA using an anion exchange resin diskSuzuki, Takashi; Bamba, Shigeru*; Kitamura, Toshikatsu; Kabuto, Shoji*; Isogai, Keisuke*; Amano, Hikaru
Nuclear Instruments and Methods in Physics Research B, 259(1), p.370 - 373, 2007/06
Times Cited Count：14 Percentile：68.37(Instruments & Instrumentation)no abstracts in English
I using AMS at JAEA-MutsuSuzuki, Takashi; Kitamura, Toshikatsu; Kabuto, Shoji; Isogai, Keisuke*; Bamba, Shigeru*; Katayama, Atsushi; Kameo, Yutaka; Kuwabara, Jun; Sakamoto, Shinya*; Togawa, Orihiko; et al.
no journal, ,
no abstracts in English
Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki
no journal, ,
In this research, The strength evaluation technique for paying attention into energy is examined for the equipments and the piping in the nuclear power plant during the earthquakes. In this report, the shaking table tests for the one mass model were conducted, and the behavior of energy was examined.
Kitamura, Seiji; Okamura, Shigeki; Minagawa, Keisuke*; Fujita, Satoshi*
no journal, ,
The dynamic strength evaluation method that pays attention into energy is examined so that the equipment and piping in the nuclear power plant may clarify the condition to plasticity/destruction. It reports on the result of applying the idea of the energy evaluation to the dynamic excitation examination result of the Elbo element.
Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki
no journal, ,
It proposes a dynamic strength evaluation method of the piping systems, and the effectiveness of this method is examined. In this report, the behavior of the energy at the vibration fatigue failure by the one mass model was examined.
Minagawa, Keisuke*; Fujita, Satoshi*; Kitamura, Seiji; Okamura, Shigeki
no journal, ,
Mechanical structures installed in nuclear power plants such as piping are usually designed staically in elastic region. Although these mechanical structures have sufficient seismic safety margin, comprehending the ultimate strength is very important in order to improve of the seismic safety reliability in unexpected severe earthquake. The ultimate strength of piping is investigated from the viewpoint of energy balance method in this research. Vibration fracture experiments that lead one mass model to fatigue fracture are carried out in order to investigate the relationship between input energy and fracture.
