Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Miyahara, Shinya*; Arita, Yuji*; Nakano, Keita; Maekawa, Fujio; Sasa, Toshinobu; Obayashi, Hironari; Takei, Hayanori
Nuclear Engineering and Design, 403, p.112147_1 - 112147_17, 2023/03
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)It is important to evaluate the inventories and the release and transport behavior of the spallation products (SPs) in the Lead-Bismuth Eutectic (LBE) coolant system of Accelerator Driven System (ADS) for the safety studies of the radiological hazard both in the cases of normal operation and accident. University of Fukui and JAEA have been developing the computer analysis code TRAIL (Transport of RAdionuclides In Liquid metal systems) which predicts the time dependent behavior of SPs within the LBE coolant system of ADS for the wide range of operational events. The source term of both radioactive and stable SPs in the LBE coolant is given as input and the radioactive decay chain model for the radioactive SPs is implemented in the code to evaluate the effect of precursors on the SPs mobility. This paper presents the recent advancement status of the code development and the validation results comparing with the distribution data of volatile SPs in MEGAPIE spallation target.
Ueta, Shohei; Sasaki, Koei; Arita, Yuji*
Nihon Genshiryoku Gakkai-Shi ATOMO, 63(8), p.615 - 620, 2021/08
no abstracts in English
Miyahara, Shinya*; Ohdaira, Naoya*; Arita, Yuji*; Maekawa, Fujio; Matsuda, Hiroki; Sasa, Toshinobu; Meigo, Shinichiro
Nuclear Engineering and Design, 352, p.110192_1 - 110192_8, 2019/10
Times Cited Count:5 Percentile:48.99(Nuclear Science & Technology)Lead-Bismuth Eutectic (LBE) is used as a spallation neutron target and coolant materials of Accelerator Driven System (ADS), and many kinds of elements are produced as spallation products. It is important to evaluate the release and transport behavior of the spallation products in the LBE. The inventories and the physicochemical composition of the spallation products produced in LBE have been investigated for an LBE loop in the ADS Target Test Facility (TEF-T) in J-PARC. The inventories of the spallation products in the LBE were estimated using the PHITS code. The physicochemical composition of the spallation products in the LBE was calculated using the Thermo-Calc code under the conditions of the operation temperatures of LBE from 350C to 500C and the oxygen concentrations in LBE from 10 ppb to 1 ppm. The calculation showed that the 5 elements of Rb, Tl, Tc, Os, Ir, Pt, Au and Hg were soluble in LBE under the all given conditions and any kinds of compound were not formed in LBE. It was suggested that the oxides of Ce, Sr, Zr and Y were stable as CeO, SrO, ZrO and YO in the LBE.
Ishizawa, Akihiro*; Idomura, Yasuhiro; Imadera, Kenji*; Kasuya, Naohiro*; Kanno, Ryutaro*; Satake, Shinsuke*; Tatsuno, Tomoya*; Nakata, Motoki*; Nunami, Masanori*; Maeyama, Shinya*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 92(3), p.157 - 210, 2016/03
The high-performance computer system Helios which is located at The Computational Simulation Centre (CSC) in The International Fusion Energy Research Centre (IFERC) started its operation in January 2012 under the Broader Approach (BA) agreement between Japan and the EU. The Helios system has been used for magnetised fusion related simulation studies in the EU and Japan and has kept high average usage rate. As a result, the Helios system has contributed to many research products in a wide range of research areas from core plasma physics to reactor material and reactor engineering. This project review gives a short catalogue of domestic simulation research projects. First, we outline the IFERC-CSC project. After that, shown are objectives of the research projects, numerical schemes used in simulation codes, obtained results and necessary computations in future.
Nishi, Tsuyoshi; Nakajima, Kunihisa; Takano, Masahide; Kurata, Masaki; Arita, Yuji*
Journal of Nuclear Materials, 464, p.270 - 274, 2015/09
Times Cited Count:3 Percentile:25.85(Materials Science, Multidisciplinary)no abstracts in English
Ozu, Akira; Tachi, Yoshiaki; Arita, Yuji*
Reza Kenkyu, 42(12), p.913 - 917, 2014/12
Laser-induced breakdown spectroscopy (LIBS) analysis has been applied to the molten alloy production process, in which simulated metals (Zr, Cu, Sm, Ce) are used instead of nuclear metallic fuels contained minor actinide (MA), with the aim of in-situ monitoring the elementary composition of the surface of the molten alloy in a chamber and vapor particles generated from the surface of the molten alloy. The variation in the ratio of elementary composition of the surface of the molten alloy in the crucible was successfully observed depending on temperature of the crucible. The elementary composition of the vapor particles appeared in the molten alloy chamber was also measured. The practical experimental results show that LIBS technique is very useful for investigating the elementary composition in the process and understanding the behavior of molten alloy in the crucible.
Shibahara, Yuji; Ishigami, Tsutomu; Morishita, Yoshitsugu; Yanagihara, Satoshi*; Arita, Yuji*
JAEA-Technology 2012-038, 72 Pages, 2013/01
To implement a decommissioning project reasonably, it is necessary and important to beforehand evaluate project management data as well as to select an optimum dismantling scenario among various scenarios postulated. Little study on the subject of selecting an optimum scenario has been carried out, and it is one of the most important subjects in terms of decision making. In FY 2009, Japan Atomic Energy Agency and University of Fukui launched the joint research of a decision making method which is important to determine a decommissioning plan. The purpose of this research is to construct a methodology for selecting an optimum dismantling scenario among various scenarios postulated based on calculated results of project management data for FUGEN. Project management data for several dismantling scenarios postulated at FUGEN were evaluated based on actual dismantling work for feedwater heater at FUGEN, and an optimum scenario was discussed using the AHP, one of Multi-Criteria Decision Analysis Method. This report describes the results of the joint research in FY 2010.
Minato, Kazuo; Konashi, Kenji*; Yamana, Hajimu*; Yamanaka, Shinsuke*; Nagasaki, Shinya*; Ikeda, Yasuhisa*; Sato, Seichi*; Arita, Yuji*; Idemitsu, Kazuya*; Koyama, Tadafumi*
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 5 Pages, 2011/12
Actinide science research is indispensable to maintain sustainable development of innovative nuclear technology. For actinide science research, special facilities with containment and radiation shields are needed to handle actinide materials. The number of facilities for actinide science research has been decreased, especially in universities, due to the high maintenance cost. J-ACTINET was established in 2008 to promote and facilitate actinide science research and to foster many of young scientists and engineers in actinide science. The research program was carried out, through which young researchers were expected to learn how to make experiments with advanced experimental tools and to broaden their horizons. The summer schools and computational science school were held to provide students and young researchers with the opportunities to come into contact with actinide science research. The overseas dispatch program was also carried out.
Shibahara, Yuji; Ishigami, Tsutomu; Morishita, Yoshitsugu; Yanagihara, Satoshi; Arita, Yuji*
JAEA-Technology 2011-021, 35 Pages, 2011/07
To implement reasonable decommissioning of nuclear facilities, it is necessary and important to beforehand evaluate project management data as well as to select optimum dismantling scenario among various scenarios postulated. Little study on the subject of selecting an optimum scenario has been carried out, and it is one of the most important subjects in terms of decision making. In FY2009, Japan Atomic Energy Agency and University of Fukui launched the joint research of a decision making method which is important to determine a decommissioning plan. The purpose of the research is to construct a methodology for selecting optimum dismantling scenario among various scenarios postulated based on calculated results of project management data for Fugen. Project management data for several dismantling scenarios postulated at Fugen were evaluated based on actual dismantling work for feed water heater at Fugen, and an optimum scenario was discussed using the multi-criteria decision analysis. This report describes the results of the joint research in FY2009.
Nakajima, Kunihisa; Iwai, Takashi; Arai, Yasuo; Kurata, Masaki*; Nakamura, Kinya*; Arita, Yuji*
Proceedings of 10th OECD/NEA Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation (CD-ROM), 9 Pages, 2010/00
Information on phase diagram and thermodynamic data of transuranium (TRU) alloys are required for the development of metallic fuel fabrication technology and fuel design for TRU transmutation. In the present study, TRU alloys were prepared from their mixed oxides to establish these informations. A few grams of mother alloys containing TRU elements were prepared from their mixed oxides in the electrochemical reduction method. However, it was found in the electrochemical reduction of PuO that only the sample surfaces were reduced to metal. It is anticipated that the electrochemical conversion of mixed oxides with high Np and Pu contents into metals are difficult owing to production of low-melting metals. Thus, the Li reduction method was applied to the reduction of mixed oxides with high TRU contents and the alloys with high Np and Pu contents were prepared.
Matsui, Tsuneo*; *; *; Imai, Hisashi
Journal of Nuclear Materials, 186, p.7 - 12, 1991/00
Times Cited Count:13 Percentile:78.38(Materials Science, Multidisciplinary)no abstracts in English
Tachi, Yoshiaki; Asaka, Takeo; Arita, Yuji*
no journal, ,
no abstracts in English
Nakajima, Kunihisa; Iwai, Takashi; Arai, Yasuo; Kurata, Masaki*; Nakamura, Kinya*; Arita, Yuji*
no journal, ,
no abstracts in English
Kurata, Masaki*; Nakamura, Kinya*; Yahagi, Noboru*; Nakajima, Kunihisa; Arai, Yasuo; Arita, Yuji*
no journal, ,
no abstracts in English
Tachi, Yoshiaki; Asaka, Takeo; Arita, Yuji*
no journal, ,
no abstracts in English
Tachi, Yoshiaki; Asaka, Takeo; Arita, Yuji*
no journal, ,
no abstracts in English
Nakajima, Kunihisa; Iwai, Takashi; Arai, Yasuo; Kurata, Masaki*; Nakamura, Kinya*; Arita, Yuji*
no journal, ,
no abstracts in English
Kurata, Masaki*; Nakamura, Kinya*; Yahagi, Noboru*; Nakajima, Kunihisa; Arita, Yuji*
no journal, ,
no abstracts in English
Shibahara, Yuji; Morishita, Yoshitsugu; Ishigami, Tsutomu; Yanagihara, Satoshi; Arita, Yuji*
no journal, ,
no abstracts in English
Minato, Kazuo; Konashi, Kenji*; Yamana, Hajimu*; Yamanaka, Shinsuke*; Nagasaki, Shinya*; Fujii, Toshiyuki*; Ikeda, Yasuhisa*; Sato, Seichi*; Arita, Yuji*; Idemitsu, Kazuya*; et al.
no journal, ,
To promote and facilitate the actinide research, close cooperation with the facilities and sharing of technical and scientific information must be very important and effective. The Japan Actinide Network, J-ACTINET, has been established since March 2008. One of the main activities of the J-ACTINET is the training and education of young scientists and graduate students. The J-ACTINET summer school 2009 and 2010 were held in Ibaraki and Kansai, respectively, where graduate students and young scientists had an experience in actinide handling and experiments. In the framework of "The training and education of nuclear energy under the Japan actinide network", which started in December, 2010 and will end in March, 2013, J-ACTINET winter school for simulation and modeling and summer school for actinide experiments will be held for graduate students and young scientists, and J-ACTINET will give them chances to attend the summer school in Europe and international scientific conferences.