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Minato, Kazuo; Hayashi, Hirokazu; Mizuguchi, Koji*; Sato, Takeyuki*; Amano, Osamu*; Miyamoto, Satoshi*
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.778 - 781, 2003/11
The simulation technology for the pyrochemical reprocessing of oxide fuels was developed to analyze experimental data, to predict experimental results, and to propose adequate conditions and processes. The simulation method was based on calculations of chemical equilibrium and electrochemical reactions. Some model calculations to simulate the experimental results were made on the process of electro-codeposition of UO
and PuO. Although it was difficult to trace the experiments and compare the calculated results with the experimental results quantitatively due to the limitation of available data on the experimental conditions, the calculated results were consistent with the experimental results. The phenomena of the repeated oxidation-reduction reactions between Pu
and Pu
ions and those between Fe and Fe
ions were theoretically analyzed,which caused the low current efficiency in the electro-codeposition process.
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.
Inoue, Masaki*; Iwai, Takashi; Arai, Yasuo; Asaga, Takeo*
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.1694 - 1703, 2003/11
no abstracts in English
Mineo, Hideaki; Asakura, Toshihide; Hotoku, Shinobu; Ban, Yasutoshi; Morita, Yasuji
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.1250 - 1255, 2003/11
An advanced aqueous reprocessing process has been proposed for the next generation fuel cycle. Key technologies applied to the process are: removal of I-129, separation of Np and FP(Tc) separation by selective reduction of Np(VI) and high acid scrubbing of Tc within a single cycle process, MA separation by extraction chromatography and Cs/Sr separation. U separation just after dissolution was supposed to be effective to reduce the required capacity of the following extraction step. Among them Np reduction rate in TBP solution was measured, which was found to be lower than that in aqueous solution. Using an improved flow sheet spent fuel test, based on the Np reduction test, was carried out and about 90% of Np was separated before U and Pu partitioning step.
Degueldre, C.*; Akie, Hiroshi; Boczar, P.*; Chauvin, N.*; Meyer, M.*; Troyanov, V.*
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.1967 - 1973, 2003/11
no abstracts in English
Sakaba, Nariaki; Nakagawa, Shigeaki; Tachibana, Yukio
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.293 - 299, 2003/00
Safety demonstration tests using the HTTR are now underway in order to verify the inherent safety features and to improve the safety design and evaluation technologies for HTGRs, as well as to contribute to research and development for the VHTR, which is one of the Generation IV reactors. The first phase of the safety demonstration tests includes the reactivity insertion test by means of control-rod withdrawal and the coolant flow reduction test by tripping the gas circulators. The coolant flow reduction tests are simulation tests of anticipated transients without scram (ATWS). In the second phase of the safety demonstration tests, accident simulation tests will be conducted. This paper describes the plan of the overall safety demonstration tests and coolant flow reduction tests with test method, test conditions, and analytical and experimental results. From the results, it was found that the negative reactivity feedback of the core brings the reactor power safely to a stable level without a reactor scram in the case of a rapid decrease of the coolant flow rate after tripping of gas circulators.
Takano, Masahide; Ito, Akinori; Akabori, Mitsuo; Minato, Kazuo; Numata, Masami
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.2285 - 2291, 2003/00
Stability of AmN and (Am,Zr)N was studied comparatively from the viewpoints of the hydrolytic and evaporative behavior. AmN powder reacted with moisture to form hydroxide Am(OH)
, while the solid solution (Am
Zr
)N remained stable as long as 1000 hours. Stabilization effect of ZrN was found to depend significantly on its mole fraction from the experiments on (Dy,Zr)N. In the oxidation experiments on (Dy,Zr)N by TG-DTA technique, rapid weight gain by the oxidation occurred above 700 K. Effect of ZrN on the stability against oxygen was slight. Nitrogen release by the evaporation of AmN and (AmZr)N in He gas flow was measured by gas chromatography. Evaporation rate constants of AmN were obtained at 1623-1733 K. Although the evaporation rate constant of AmN in the solid solution were lower than those of the pure AmN, the selective evaporation of AmN from the solid slution were recognized, which resulted in a decrease in the Am mole fraction.
Minato, Kazuo; Ogawa, Toru
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.1068 - 1074, 2003/00
The research and development of the ZrC-Triso coated particle fuel was reviewed, especially on the fabrication, chemical reactions, high-temperature stability, and retention of fission products. The fabrication process of stoichiometric ZrC coating layer has been established based on the in-situ generation of zirconium halide vapor. The irradiation experiments, the postirradiation heating tests, and the out-of-reactor experiments demonstrated that the ZrC coating layer is less susceptible than the SiC coating layer to chemical attack by the fission product palladium, and that the ZrC-Triso coated UO particles perform better than the normal Triso-coated particles at high temperatures, especially above 1873 K. It was revealed that the ZrC-Triso coated particles retain the fission products better than the SiC-Triso coated particles, though the ZrC coating layer is a less effective barrier to ruthenium than the SiC coating layer.
Nishihara, Tetsuo; Inagaki, Yoshiyuki
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.320 - 324, 2003/00
HTGR hydrogen production system has potential possibility to provide hydrogen without CO emission. Key technology for developing this system is to establish the control technology for preventing propagation of thermal turbulence from the hydrogen production system to the HTGR. Japan Atomic Energy Research Institute (JAERI) has planed a demonstration test of hydrogen production using an HTGR named high temperature engineering test reactor (HTTR) to develop the control technology. Thermal load absorber concept using the steam generator located downstream of the chemical reactor is proposed to mitigate the variation of outlet helium temperature of the chemical reactor. This concept leads to the stable controllability and enables to operate the HTGR and the hydrogen production plant independently. Plant simulation analyses are carried out to verify the performance of this concept.
Arai, Yasuo; Iwai, Takashi; Nakajima, Kunihisa; Nagashima, Hisao; Nihei, Yasuo; Katsuyama, Kozo*; Inoue, Masaki*
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.1686 - 1693, 2003/00
no abstracts in English
Oigawa, Hiroyuki; Ouchi, Nobuo; Kikuchi, Kenji; Tsujimoto, Kazufumi; Kurata, Yuji; Sasa, Toshinobu; Takano, Hideki; Nishihara, Kenji; Saito, Shigeru; Futakawa, Masatoshi; et al.
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.1374 - 1379, 2003/00
JAERI is developing an Accelerator Driven System (ADS) for transmutation of nuclear waste such as minor actinide and long-lived fission product. To acquire the knowledge and the elemental technology that are necessary for the validation of engineering feasibility of ADS, JAERI has started a comprehensive research and development (R&D) program since 2002. The first stage of the program will be continued for three years. The program is conducted by JAERI with many institutes, universities and private companies. Items of R&D are concentrated on three technical areas peculiar to ADS: (1) a superconducting linear accelerator, (2) lead-bismuth eutectic as spallation target and core coolant, and (3) subcritical core design and physics. The outline and the preliminary results of the program are summarized in the present report.
Sasaki, Yuji; Suzuki, Shinichi; Tachimori, Shoichi*; Kimura, Takaumi
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), 4 Pages, 2003/00
no abstracts in English