Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
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
Konomura, Mamoru; SAIGUSA, Toshiie; Mizuno, Tomoyasu; OHKUBO, Yoshiyuki*
Fast Spectrum Reactors, 0 Pages, 2003/00
In Feasibility Studies on Commercialized Fast Reactor (FR) Systems, examining about the subject of three gas cooled FR concepts, (1) carbon dioxide cooled FR using pin type fuel, (2) helium cooled FR using pin type fuel, (3) helium cooled FR using coated particle fuel, a promising concept has been selected from three concepts. From a viewpoint of economic competitiveness and ensuring safety, etc, "helium cooled FR using coated particle fuel" has been selected as a promising concept of gas cooled FR. About fuel assembly concept of helium cooled FR using coated particle fuel, block type vertical flow cooling concept with 2nd boundaries was also examined, other than horizontal flow cooling concept with directly cooling system. About selected helium cooled FR using coated particle fuel, it drew up R&D plan about the most important R&D items influencing on the feasibility of the design concept.
Sagayama, Yutaka
Global 2003; International Conference on Atoms for Prosperity: Upda, 0 Pages, 2003/00
None
; Iwai, Takashi*; Arai, Yasuo*; Asaka, Takeo
Global 2003; International Conference on Atoms for Prosperity: Upda, 1694 Pages, 2003/00
Under the collaboration between JNC and JAERI, two uranium-plutonium mixed nitride fuel pins, whose smear densities were varied by fuel-to-cladding gap sizes, were irradiated in the experimental fast reactor JOYO. Linear heat rate, cladding mid-wall temperature, and burnup in peak were 75 kW/m, 906K, and 4.3 %FIMA, respectively. In order to evaluate nitride fuels for high burnup capability, the effect of fuel swelling behavior on irradiation performance was investigated. The larger smear density induced the greater cladding diameter increments. The wider gap size resulted in the more anisotropic deformations. Threshold temperature of fuel swelling was studied by thermal analysis using radial porosity and xenon retention profiles. To attain higher burnup, experimental results indicate that maximum fuel temperatures should be preferably lower than threshold temperatures of fuel swelling and that the detrimental effects of fuel pellet relocations need to be suppressed and accommodated.
Ichimiya, Masakazu; Mizuno, Tomoyasu; Konomura, Mamoru
Global 2003; International Conference on Atoms for Prosperity: Upda, 0 Pages, 2003/00
An innovative concept of sodium-cooled fast reactor, named JNC Sodium Cooled FR (JSFR) has been created through the Feasibility Study on Commercialized FR Cycle System, aiming at full satisfaction of the development targets. It is evaluated that JSFR possesses the highest potential in terms of technological feasibility to respond the diverse needs of society. JSFR supported by an appropriate fuel cycle is recognized as a promising candidate for the next generation nuclear energy system, such as GenerationIV system.
Osaka, Masahiko; Osaka, Masahiko; Koyama, Shinichi; Mitsugashira, Toshiaki
Global 2003; International Conference on Atoms for Prosperity: Upda, 0 Pages, 2003/00
Cm isotopes formed in irradiated MOX fuel in the experimental fast reactor JOYO were analyzed by applying a sophisticated radiochemical technique. Cm was isolated from the irradiated fuel by anion ion-exchange chromatography using a mixed medium of nitric acid and methanol. The isotopic ratio of Cm and its content were determined by thermal ionization mass spectroscopy and alpha-spectrometry, respectively. U, Pu, Am and Nd were also isolated and analyzed for the determination of the Cm content and burnup. The Cm content was less than 0.004 at.%, which is much smaller than that of PWR-MOX at 60 GWd/t. On the basis of the present analytical results, the transmutation behavior of Cm isotopes in a fast reactor was discussed from various viewpoints. Transmutation speeds of Cm isotopes were estimated; the speed for 246Cm, which is known to be a key nuclide in the transmutation of Cm, was smaller than the previously reported value. Transmutation behavior of each Cm isotope was also eval
; Fujii, Keiji; Inoue, Akira; Namba, Takashi; Sato, Koji
Global 2003; International Conference on Atoms for Prosperity: Upda, 0 Pages, 2003/00
The oxide electrowinning method is one of the non-aqueous reprocessing methods, and the construction of a compact, economical plant is expected in the combination with this reprocessing method and the fuel fabrication method utilizing the vibro-compaction process. For this reprocessing method, the rational process flow has been constructed on the basis of the existing technical information, from the viewpoint of the improvement of the economical efficiency. The conceptual design study of the main equipment concept and the equipment layout in main process cells on the basis of this process flow has been carried out from the viewpoint of the safety and operability. Then the number of equipments in this system and floor space of the process cells concerned with the economical efficiency have also been evaluated. In result, it has been seen that the capital cost by the future plant conceptual design study would be improved compared with the previous design, accordingly with the diminution
Sato, Koji; Fujioka, Tsunaaki; Nakabayashi, Hiroki; Kitajima, Shoichi; Yokoo, Takeshi*; Inoue, Tadashi*
Global 2003; International Conference on Atoms for Prosperity: Upda, 0 Pages, 2003/00
We have been performing the feasibility study on conceptual design for an integrated metallic fuel recycle plant of 38 tHM/y throughput. As a result of this study, the process concept was constructed, and the main equipment and devices were designed considering rationalixation,operationability, reduction of environmental impact and safety for the future commercialization. Furthermore, the image of the whole building included in cells was examined. In particular, the electrorefiner was enlarged from its current size and the cathode processor was improved from the current batch type to the continuation type to increase throughput. The plant was evaluated comprehensively. We confirmed that the major specifications for plant design would be satisfied. The economical cometitiveness of the plant has been evaluated.
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
Takeda, Toshikazu*; Hamada, Yuzuru*; Kitada, Takanori*; Nishi, Hiroshi; Ishibashi, Junichi; Kitano, Akihiro
Proceedings of International Conference on Advanced Nuclear Energy and Fuel Cycle Systems (GLOBAL 2003) (CD-ROM), p.1005 - 1010, 2003/00
A new 3-D transport calculation method taking into account the heterogeneity of fuel assemblies has been developed by combining the characteristics method and the nodal transport method. In the axial direction the nodal transport method is applied, and the characteristics method is applied to take into account the radial heterogeneity of fuel assemblies. The numerical calculations have been performed to verify 2-D radial calculations of FBR assemblies and partial core calculations. Results are compared with the reference Monte-Carlo calculations. A good agreement has been achieved. It is shown that the present method has an advantage in calculating reaction rates in a small region.