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Baron, P.*; Cornet, S. M.*; Collins, E. D.*; DeAngelis, G.*; Del Cul, G.*; Fedorov, Y.*; Glatz, J. P.*; Ignatiev, V.*; Inoue, Tadashi*; Khaperskaya, A.*; et al.
Progress in Nuclear Energy, 117, p.103091_1 - 103091_24, 2019/11
Times Cited Count：107 Percentile：94.22(Nuclear Science & Technology)The results of an international review of separation processes for spent nuclear fuel (SNF) recycling in future closed fuel cycles with the evaluation of Technology Readiness Level are reported. This study was made by the Expert Group on Fuel Recycling Chemistry (EGFRC) organised by the Nuclear Energy Agency (NEA) of the Organisation for Economic Co-operation and Development (OECD). A unique feature of this study was that processes were classified according to a hierarchy of separations aimed at different elements within spent fuel (uranium; uranium-plutonium co-recovery; minor actinides; high heat generating radionuclides) and also the Head-end processes, used to prepare the SNF for chemical separation, were included. Separation processes covered both wet (hydrometallurgical) and dry (pyro-chemical) processes.
Shibata, Hiroki; Hayashi, Hirokazu; Koyama, Tadafumi*
Denki Kagaku Oyobi Kogyo Butsuri Kagaku, 83(7), p.532 - 536, 2015/07
Times Cited Count：4 Percentile：7.21(Electrochemistry)The electrochemical properties of curium in a LiCl-KCl eutectic melt were studied in the temperature range of 718-823 K. A small electrochemical cell used in this study was designed for the electrochemical measurement with a small amount (1-20 mg) of the highly radioactive minor actinides contained in molten salts achieved in a hot cell. Our data of apparent standard potentials of a Cm
/Cm couple are reasonably in agreement with Osipenko's data (2011) and are lower than Martinot's data (1975). The validity of our data and the reported apparent standard potentials were discussed.
Hayashi, Hirokazu; Takano, Masahide; Otobe, Haruyoshi; Koyama, Tadafumi*
Journal of Radioanalytical and Nuclear Chemistry, 297(1), p.139 - 144, 2013/07
Times Cited Count：2 Percentile：17.55(Chemistry, Analytical)Curium trichloride was synthesized by the solid state reaction of curium nitride with cadmium chloride heated from room temperature to 748K in a dynamic vacuum. The product was hexagonal 
CmCl
, of which lattice parameters were determined to be a= 0.7385
0.0005 and c= 0.42010.0005 nm. The melting temperature of the CmCl sample was determined to be 9703 K by differential thermal analyses using a gold crucible. These values are close to those reported in literatures. The results show that mg-scale CmCl samples for thermochemical measurements were prepared from the purified oxide sample without the use of corrosive reagents.
Shibata, Hiroki; Hayashi, Hirokazu; Koyama, Tadafumi*
Proceedings of 4th Asian Conference on Molten Salt Chemistry and Technology & 44th Symposium on Molten Salt Chemistry, Japan, p.257 - 263, 2012/09
The electrochemical properties of curium ions in LiCl-KCl eutectic melts were studied in the temperature range from 718 to 823 K. A small electrochemical cell used in the present study was designed for the electrochemical measurement of a small amount (1-20 mg) of the highly radioactive minor actinides contained in molten salts in a hot cell. Our data of apparent standard potentials of Cm/Cm couple are reasonably agreement with Osipenko's data (2011) and are lower than Martinot's data (1975). The validity of the reported apparent standard potentials was discussed.
Nakamura, Kinya*; Ogata, Takanari*; Kikuchi, Hironobu; Iwai, Takashi; Nakajima, Kunihisa; Kato, Tetsuya*; Arai, Yasuo; Uozumi, Koichi*; Hijikata, Takatoshi*; Koyama, Tadafumi*; et al.
Nihon Genshiryoku Gakkai Wabun Rombunshi, 10(4), p.245 - 256, 2011/12
Sodium-bonded metallic fuel elements were fabricated for the first time in Japan for the irradiation test in the experimental fast test reactor JOYO. U-20Pu-10Zr fuel slugs of 200 mm in length and approximately 5 mm in diameter were fabricated in a small-scale injection casting furnace. Each fuel slug was loaded into the ferritic martenstic stainless steel (PNC-FMS) cladding tube with the sodium thermal bond, thermal insulator and reflector in a helium gas atmosphere glove box. After top-end plug welding to the cladding tube and heat treatment of the welding area, each fuel element was subjected to the sodium bonding process. After the inspection such as element length, gas plenum length and helium-leak tightness, six metallic fuel elements are transported to the JOYO site for the coming irradiation test.
Nakamura, Kinya*; Ogata, Takanari*; Kikuchi, Hironobu; Iwai, Takashi; Nakajima, Kunihisa; Kato, Tetsuya*; Arai, Yasuo; Koyama, Tadafumi*; Itagaki, Wataru; Soga, Tomonori; et al.
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 8 Pages, 2011/12
CRIEPI and JAEA have fabricated sodium-bonded metallic fuel elements for the first time in Japan as a collaborative research, for use in the irradiation test at the experimental fast test reactor Joyo. The irradiation test aims to assess the irradiation behavior of the fuel and the internal wastage of the stainless-steel cladding by rare-earth fission products at a maximum cladding temperature above 873 K. U-20 wt% Pu-10 wt% Zr alloy fuel slugs of 200 mm length were fabricated in an injection-casting furnace using U metal, U-Pu alloy and Zr metal. Two types of fuel slug were fabricated, i.e., 5.05 mm and 4.95 mm in diameter, and loaded into a ferritic-martensitic stainless-steel cladding tubes, respectively. After top-end-plug welding to the cladding tube, each fuel element was subjected to sodium bonding to fill the annular gap between the fuel slug and the cladding with melted sodium. The fabrication results indicated that the characteristics of the fuel elements were within the required specifications.
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.
Koyama, Tadafumi*; Ogata, Takanari*; Myochin, Munetaka; Arai, Yasuo
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 8 Pages, 2011/12
no abstracts in English
Inoue, Tadashi*; Koyama, Tadafumi*; Arai, Yasuo
Proceedings of 2nd International Conference on Asian Nuclear Prospects 2010 (ANUP 2010) (CD-ROM), 7 Pages, 2010/10
no abstracts in English
Inoue, Tadashi*; Koyama, Tadafumi*; Myochin, Munetaka; Arai, Yasuo
Proceedings of 2008 Joint Symposium on Molten Salts (USB Flash Drive), p.851 - 856, 2008/10
Recent progress of pyrochemical reprocessing technology based on metal electrorefining process and nitride electrorefining process is introduced. This technology can be applied to oxide fuel as well as metal fuel by adding the oxide reduction process. In addition to the development of process technology for electrorefining, thermodynamic database of actinides and lanthanides in molten salt or liquid metal has been prepared. The progress of pyrochemical reprocessing technology, which has the advantage of proliferation resistance and whole recovery of minor actinides, has been demonstrated.
Inoue, Tadashi*; Koyama, Tadafumi*; Myochin, Munetaka; Arai, Yasuo
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM), p.728 - 737, 2007/09
no abstracts in English
Koyama, Tadafumi*; Hijikata, Takatoshi*; Usami, Tsuyoshi*; Inoue, Tadashi*; Kitawaki, Shinichi; Shinozaki, Tadahiro; Fukushima, Mineo; Myochin, Munetaka
Journal of Nuclear Science and Technology, 44(3), p.382 - 392, 2007/03
Times Cited Count：24 Percentile：81.85(Nuclear Science & Technology)Electrometallurgical pyroprocessing is a promising technology to realize actinide fuel cycle. Integrated experiments to demonstrate electrometallurgical pyroprocessing of plutonium oxide in continuous operation were carried out. In each test, 10 to 20 g of PuO
was reacted with Li reductant to form metal product. The reduction products were charged in the anode basket of the electrorefiner with LiCl-KCl-UCl
electrolyte. With using the anodes, deposition of uranium on the solid cathode was carried out, when PuCl concentration was low. After Pu/U ratio in salt electrolyte was increased enough, plutonium and uranium were recovered simultaneously on the liquid cadmium cathode. By heating up the deposits for distillation of the salt and the cadmium, U metal or Pu-U alloyed metal were obtained as residues in the crucible. It was first result to demonstrate the recovery of metal actinides in the continuous operation of pyroprocessing of oxide fuels.
Kitawaki, Shininchi; Shinozaki, Tadahiro; Fukushima, Mineo; Hijikata, Takatoshi*; Usami, Tsuyoshi*; Koyama, Tadafumi*
Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 5 Pages, 2005/10
Electrometallurgical pyroprocess is a key innovative technology to realize closed actinides cycle with keeping high proliferation-resistance and economy. JNC and CRIEPI have been carrying out the integrated tests of electrometallurgical reprocessing of metal and oxide Pu-containing fuel to demonstrate whole process in continuous operation. After intensive cold test to confirm the functions of experimental apparatus and the test conditions, recovery test of actinide metal product from actinide oxide fuels has started as a first series of the integrated tests. In this report, result of the recovery test is described to elucidate the material flow in the process.
O meltSakamura, Yoshiharu*; Iizuka, Masatoshi*; Koyama, Tadafumi*; Kitawaki, Shinichi; Nakayoshi, Akira; Kofuji, Hirohide
no journal, ,
An electrolytic reduction process of oxide fuels has recently been developed, however it was found that the behaviors of rare earth elements and zirconium are expected to be complicate because their oxides are stable and complex oxide compounds may form. After Fukushima- Daiichi reactor accident, studies on applicability of pyrometallurgical process to damaged fuel debris consisting of ZrO-UO have been started. In this study, reduction behaviors of ZrO, ZrO-LiO and ZrO-UO were investigated. It was proved that ZrO can be reduced to metallic form in LiCl melt and that ZrO easily reacts with dissolved LiO to give LiZrO. After ZrO is converted to LiZrO, zirconium metal is hardly obtained even in a LiCl melt with low LiO concentration.
Sekiguchi, Yuma*; Terai, Takayuki*; Uozumi, Koichi*; Koyama, Tadafumi*; Amamoto, Ippei
no journal, ,
no abstracts in English
Gu
var, C.*; Faure, J.*; Testud, V.*; Roger, J.*; Domenger, R.*; Valette, R.*; Brackx, E.*; Bouyer, V.*; Journeau, C.*; Berlemont, R.*; et al.
no journal, ,
The URASOL and the DA projects, respectively led by JAEA and CRIEPI in collaboration with ONET/CEA/IRSN, were proposed to obtain basic data on aerosols generation and characteristics from prototypic FD-simulants containing depleted uranium oxide cut by thermal or mechanical processing tools. The whole process developed by ONET/CEA/IRSN allows the manufacturing of specific compositions and supplying corium samples for cutting, the realization of cutting tests and the on-line dedicated aerosols measurements as well as sampling aerosols, to conduct initial FD simulants and aerosols post-trial analyses. This paper focuses on the initial FD simulant and aerosols chemical and microstructural analyses. Results on an ex-vessel composition of FD, named VF-U3, are given.
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.
Furukawa, Shizue*; Koyama, Tadafumi*; Kikuchi, Michio*; Otsuka, Taku*; Yamamoto, Takeshi*; Imaizumi, Ken*; Osugi, Takeshi; Nakazawa, Osamu; Kuroki, Ryoichiro
no journal, ,
In order to evaluate the application to the solidification of the water treatment secondary waste generated from Fukushima Daiichi Nuclear Power Station, research concerning the approach of applicability evaluation was conducted for solidification technology of practical scale.
Koyama, Tadafumi*; Uruga, Kazuyoshi*; Furukawa, Shizue*; Vienna, J.*; Parruzot, B.*; Xiaonan, L.*; Osugi, Takeshi; Sone, Tomoyuki; Kuroki, Ryoichiro
no journal, ,
no abstracts in English
Furukawa, Shizue*; Koyama, Tadafumi*; Uruga, Kazuyoshi*; Kikuchi, Michio*; Otsuka, Taku*; Yamamoto, Takeshi*; Imaizumi, Ken*; Osugi, Takeshi; Sone, Tomoyuki; Kuroki, Ryoichiro
no journal, ,
no abstracts in English
