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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.
/Np couple at liquid Cd and Bi electrodes in LiCl-KCl eutectic meltsShirai, Osamu; Uozumi, Koichi*; Iwai, Takashi; Arai, Yasuo
Journal of Applied Electrochemistry, 34(3), p.323 - 330, 2004/03
Times Cited Count：28 Percentile：52.41(Electrochemistry)The electrode reactions of the Np/Np couple at liquid Cd and Bi electrodes were investigated by cyclic voltammetry at 723, 773 and 823 K in LiCl-KCl eutectic melt. It was found that the diffusion of Np in the salt phase was a rate-determining step in the cathodic reaction when the concentration of NpCl
was less than about 1 wt.% and the liquid Cd or Bi phase was not saturated with Np. The redox potentials of the Np/Np couple at liquid Cd electrode at 723, 773 and 823 K were observed more positively than those at Mo electrode by 0.158, 0.140 and 0.126 V, respectively. The potential shift would result from a lowering of activity of Np in Cd phase according to the alloy formation of NpCd
at 723 K and NpCd
at 773 and 823 K. The redox potentials of the Np/Np couple at liquid Bi electrode at 723, 773 and 823 K were more positive than those at Mo electrode by 0.427, 0.419 and 0.410 V, respectively, which would be attributable to a lowering of activity of Np in Bi phase according to the formation of NpBi
.
Uozumi, Koichi*; Iizuka, Masatoshi*; Kato, Tetsuya*; Inoue, Tadashi*; Shirai, Osamu*; Iwai, Takashi; Arai, Yasuo
Journal of Nuclear Materials, 325(1), p.34 - 43, 2004/02
Times Cited Count：109 Percentile：98.55(Materials Science, Multidisciplinary)Experiments were conducted on simultaneous recovering of uranium and plutonium electrochemically into laboratory scale liquid cadomium cathodes(LCCs) at different U/Pu ratios in the salt phase. The influence of the salt composition on the recovered amount of uranium and plutonium, the morphology of uranium and plutonium in the LCCs, and the behavior of americium were examined. It was shouwn that there is a threshold in the U/Pu ratio in the salt phase for the successful simultaneous recovery of uranium and plutonium up to 10wt% in high current efficiencies.
Kato, Tetsuya*; Uozumi, Koichi*; Inoue, Tadashi*; Shirai, Osamu*; Iwai, Takashi; Arai, Yasuo
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.1591 - 1595, 2003/11
Electrolysis experiments were carried to recover plutonium and uranium into liquid cadmium cathodes from molten salt at high cathode current densities. In the electrolysis at 101mA/cm
, 10.4wt.% of heavy metals in the cathode was recovered at almost 100% of current efficiency. In the electrolysis at 156mA/cm, the cathode potential ascended after approximately 8wt.% of heavy metals was recovered and some deposit was observed outside of the crucible.
Shirai, Osamu; Uozumi, Koichi*; Iwai, Takashi; Arai, Yasuo
Journal of Nuclear Science and Technology, 39(Suppl.3), p.745 - 748, 2002/11
no abstracts in English
/U couple at liquid Cd and Bi electrodes in LiCl-KCl eutectic meltsShirai, Osamu; Uozumi, Koichi*; Iwai, Takashi; Arai, Yasuo
Analytical Sciences (CD-ROM), 17(Suppl.), p.959 - 962, 2002/03
no abstracts in English
Iizuka, Masatoshi*; Uozumi, Koichi*; Inoue, Tadashi*; Iwai, Takashi; Shirai, Osamu; Arai, Yasuo
Journal of Nuclear Materials, 299(1), p.32 - 42, 2001/10
Times Cited Count：76 Percentile：97.56(Materials Science, Multidisciplinary)no abstracts in English
Iizuka, Masatoshi*; Uozumi, Koichi*; Inoue, Tadashi*; Iwai, Takashi; Shirai, Osamu; Arai, Yasuo
Proceedings of 6th International Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation (CD-ROM), p.327 - 341, 2000/00
no abstracts in English
Nakamura, Kinya*; Kikuchi, Hironobu; Ogata, Takanari*; Iwai, Takashi; Arai, Yasuo; Uozumi, Koichi*; Hijikata, Takatoshi*; Koyama, Tadafumi*; Itagaki, Wataru; Soga, Tomonori
no journal, ,
Irradiation test of metallic fuel at fast test reactor JOYO is planned. By using techniques of casting, fabrication, analysis and inspection, metallic fuel elements were made for the first time in Japan. In this paper, fabrication technique of metallic fuel elements is reported. After filling up thermal bond (Na), a reflector element, a thermal shelter element and a fuel slug, the upper plug was welded. Sodium bonding treatment was carried out by vibrating the fuel element under heating. By inspection, it was confirmed that the specifications were satisfied.
Nakamura, Kinya*; Kikuchi, Hironobu; Ogata, Takanari*; Iwai, Takashi; Arai, Yasuo; Uozumi, Koichi*; Hijikata, Takatoshi*; Koyama, Tadafumi*; Itagaki, Wataru; Soga, Tomonori
no journal, ,
Irradiation test of metallic fuel elements at fast test reactor JOYO is planned. By the development of fabrication technique of casting, structure, analysis and inspection, metallic fuel elements were fabricated. In this paper, the structure technique is reported. Thermal bond (Na), element insulator and fuel slug were filled in PNC-FMS cladding, and upper plug was welded. Sodium bonding treatment was performed by shaking the fuel element under heating. By inspection, it was confirmed that the specification were satisfied.
Sekiguchi, Yuma*; Terai, Takayuki*; Uozumi, Koichi*; Koyama, Tadafumi*; Amamoto, Ippei
no journal, ,
no abstracts in English
