The Experts below are selected from a list of 1809 Experts worldwide ranked by ideXlab platform

Hideki Takano - One of the best experts on this subject based on the ideXlab platform.

  • neutronics design for lead bismuth cooled accelerator driven system for transmutation of Minor Actinide
    Journal of Nuclear Science and Technology, 2004
    Co-Authors: Kazufumi Tsujimoto, Kenji Nishihara, Toshinobu Sasa, Hiroyuki Oigawa, Hideki Takano
    Abstract:

    Neutronics design study was performed for lead-bismuth cooled accelerator-driven system (ADS) to transmute Minor Actinides. Early study for ADS indicated two problems: a large burnup reactivity swing and a significant peaking factor. To solve these problems, effect of design parameters on neutronics characteristics were searched. The design parameters were initial plutonium loading, buffer region between spallation target and core, and zone fuel loading. Parametric survey calculations were performed considering fuel cycle consisting of burnup and recycle. The results showed that burnup reactivity swing depends on the plutonium fraction in the initial fuel loading, and the lead-bismuth buffer region and the two-zone loading were effective for solving the problems. Moreover, an optimum value for the effective multiplication factor was also evaluated using reactivity coefficients. From the result, the maximum allowable value of the effective multiplication factor for a practical ADS can be set at 0.97. Conse...

  • design study of lead bismuth cooled ads dedicated to nuclear waste transmutation
    Progress in Nuclear Energy, 2002
    Co-Authors: Takakazu Takizuka, Kenji Nishihara, Kazufumi Tsujimoto, Toshinobu Sasa, Hideki Takano
    Abstract:

    Research and development on nuclear waste transmutation are being carried out with a special emphasis placed on dedicated accelerator-driven systems at the Japan Atomic Energy Research Institute under the Japanese OMEGA Program. The reference accelerator-driven system design employs eutectic lead-bismuth as spallation target material and coolant. The fuel for the subcritical core is Minor-Actinide mononitride. The system consists of a 1.5GeV, 14mA proton accelerator and an 800MWt subcritical core with an effective neutron multiplication factor of 0.95. The transmutation rate of Minor Actinides is approximately 250 kg/y at 80% load factor. The design has salient features that the coolant inventory is large due to the tank-type configuration, the temperature rise through the core is relatively low, and the power conversion is operated on a saturated steam turbine cycle. These features make the plant response to a beam trip slow and much less demanding.

Kazufumi Tsujimoto - One of the best experts on this subject based on the ideXlab platform.

  • Integral Validation of Minor Actinide Nuclear Data by using Samples Irradiated at Dounreay Prototype Fast Reactor
    2015
    Co-Authors: Kazufumi Tsujimoto, Hiroyuki Oigawa, Nobuo Shinohara
    Abstract:

    Abstract. The reliability of nuclear data for Minor Actinides was evaluated by using the results of the post-irradiation experiment for Actinide samples irradiated at the Dounreay Prototype Fast Reactor. The burnup calculations with JENDL-3.3, ENDF/B-VI.8, and JEFF-3.0 were performed. From the comparison between the experimental data and the calculational results, in general, the reliability of nuclear data for the Minor Actinides are at an adequate level for the conceptual design study of transmutation systems. It is, however, found that improvement of the accuracy is necessary for some nuclides, such as 238Pu, 242Pu, and 241Am

  • analytical validation of uncertainty in reactor physics parameters for nuclear transmutation systems
    Journal of Nuclear Science and Technology, 2010
    Co-Authors: Takanori Sugawara, Kenji Nishihara, Kazufumi Tsujimoto, Toshinobu Sasa, Hiroyuki Oigawa
    Abstract:

    To confirm the reliability of calculated reactor physics parameters for the nuclear transmutation systems, the uncertainty deduced from the covariance data prepared in JENDL-3.3 is compared with the differences in the reactor physics parameters in the Monte-Carlo calculation using different nuclear data libraries, ENDF/B-VII.0 and JEFF-3.1.1. The Accelerator-Driven System (ADS) and the Minor Actinide (MA)-loaded Fast Reactor (FR) are selected as the representative transmutation systems. The criticality and void reactivity of these systems are discussed. The results show that the uncertainties deduced from the JENDL-3.3 covariance data are smaller than the differences in the reactor physics parameters among the nuclear data libraries. The cause of this discrepancy is that the covariance data of main nuclides and reactions in JENDL-3.3 are smaller than the relative differences in the cross sections among the nuclear data libraries. It is required to verify the uncertainty of the reactor physics parameters by integral experiments and to discuss the uncertainty utilization for the nuclear design accuracy.

  • neutronics design for lead bismuth cooled accelerator driven system for transmutation of Minor Actinide
    Journal of Nuclear Science and Technology, 2004
    Co-Authors: Kazufumi Tsujimoto, Kenji Nishihara, Toshinobu Sasa, Hiroyuki Oigawa, Hideki Takano
    Abstract:

    Neutronics design study was performed for lead-bismuth cooled accelerator-driven system (ADS) to transmute Minor Actinides. Early study for ADS indicated two problems: a large burnup reactivity swing and a significant peaking factor. To solve these problems, effect of design parameters on neutronics characteristics were searched. The design parameters were initial plutonium loading, buffer region between spallation target and core, and zone fuel loading. Parametric survey calculations were performed considering fuel cycle consisting of burnup and recycle. The results showed that burnup reactivity swing depends on the plutonium fraction in the initial fuel loading, and the lead-bismuth buffer region and the two-zone loading were effective for solving the problems. Moreover, an optimum value for the effective multiplication factor was also evaluated using reactivity coefficients. From the result, the maximum allowable value of the effective multiplication factor for a practical ADS can be set at 0.97. Conse...

  • design study of lead bismuth cooled ads dedicated to nuclear waste transmutation
    Progress in Nuclear Energy, 2002
    Co-Authors: Takakazu Takizuka, Kenji Nishihara, Kazufumi Tsujimoto, Toshinobu Sasa, Hideki Takano
    Abstract:

    Research and development on nuclear waste transmutation are being carried out with a special emphasis placed on dedicated accelerator-driven systems at the Japan Atomic Energy Research Institute under the Japanese OMEGA Program. The reference accelerator-driven system design employs eutectic lead-bismuth as spallation target material and coolant. The fuel for the subcritical core is Minor-Actinide mononitride. The system consists of a 1.5GeV, 14mA proton accelerator and an 800MWt subcritical core with an effective neutron multiplication factor of 0.95. The transmutation rate of Minor Actinides is approximately 250 kg/y at 80% load factor. The design has salient features that the coolant inventory is large due to the tank-type configuration, the temperature rise through the core is relatively low, and the power conversion is operated on a saturated steam turbine cycle. These features make the plant response to a beam trip slow and much less demanding.

Toshinobu Sasa - One of the best experts on this subject based on the ideXlab platform.

  • analytical validation of uncertainty in reactor physics parameters for nuclear transmutation systems
    Journal of Nuclear Science and Technology, 2010
    Co-Authors: Takanori Sugawara, Kenji Nishihara, Kazufumi Tsujimoto, Toshinobu Sasa, Hiroyuki Oigawa
    Abstract:

    To confirm the reliability of calculated reactor physics parameters for the nuclear transmutation systems, the uncertainty deduced from the covariance data prepared in JENDL-3.3 is compared with the differences in the reactor physics parameters in the Monte-Carlo calculation using different nuclear data libraries, ENDF/B-VII.0 and JEFF-3.1.1. The Accelerator-Driven System (ADS) and the Minor Actinide (MA)-loaded Fast Reactor (FR) are selected as the representative transmutation systems. The criticality and void reactivity of these systems are discussed. The results show that the uncertainties deduced from the JENDL-3.3 covariance data are smaller than the differences in the reactor physics parameters among the nuclear data libraries. The cause of this discrepancy is that the covariance data of main nuclides and reactions in JENDL-3.3 are smaller than the relative differences in the cross sections among the nuclear data libraries. It is required to verify the uncertainty of the reactor physics parameters by integral experiments and to discuss the uncertainty utilization for the nuclear design accuracy.

  • neutronics design for lead bismuth cooled accelerator driven system for transmutation of Minor Actinide
    Journal of Nuclear Science and Technology, 2004
    Co-Authors: Kazufumi Tsujimoto, Kenji Nishihara, Toshinobu Sasa, Hiroyuki Oigawa, Hideki Takano
    Abstract:

    Neutronics design study was performed for lead-bismuth cooled accelerator-driven system (ADS) to transmute Minor Actinides. Early study for ADS indicated two problems: a large burnup reactivity swing and a significant peaking factor. To solve these problems, effect of design parameters on neutronics characteristics were searched. The design parameters were initial plutonium loading, buffer region between spallation target and core, and zone fuel loading. Parametric survey calculations were performed considering fuel cycle consisting of burnup and recycle. The results showed that burnup reactivity swing depends on the plutonium fraction in the initial fuel loading, and the lead-bismuth buffer region and the two-zone loading were effective for solving the problems. Moreover, an optimum value for the effective multiplication factor was also evaluated using reactivity coefficients. From the result, the maximum allowable value of the effective multiplication factor for a practical ADS can be set at 0.97. Conse...

  • design study of lead bismuth cooled ads dedicated to nuclear waste transmutation
    Progress in Nuclear Energy, 2002
    Co-Authors: Takakazu Takizuka, Kenji Nishihara, Kazufumi Tsujimoto, Toshinobu Sasa, Hideki Takano
    Abstract:

    Research and development on nuclear waste transmutation are being carried out with a special emphasis placed on dedicated accelerator-driven systems at the Japan Atomic Energy Research Institute under the Japanese OMEGA Program. The reference accelerator-driven system design employs eutectic lead-bismuth as spallation target material and coolant. The fuel for the subcritical core is Minor-Actinide mononitride. The system consists of a 1.5GeV, 14mA proton accelerator and an 800MWt subcritical core with an effective neutron multiplication factor of 0.95. The transmutation rate of Minor Actinides is approximately 250 kg/y at 80% load factor. The design has salient features that the coolant inventory is large due to the tank-type configuration, the temperature rise through the core is relatively low, and the power conversion is operated on a saturated steam turbine cycle. These features make the plant response to a beam trip slow and much less demanding.

Kenji Nishihara - One of the best experts on this subject based on the ideXlab platform.

  • analytical validation of uncertainty in reactor physics parameters for nuclear transmutation systems
    Journal of Nuclear Science and Technology, 2010
    Co-Authors: Takanori Sugawara, Kenji Nishihara, Kazufumi Tsujimoto, Toshinobu Sasa, Hiroyuki Oigawa
    Abstract:

    To confirm the reliability of calculated reactor physics parameters for the nuclear transmutation systems, the uncertainty deduced from the covariance data prepared in JENDL-3.3 is compared with the differences in the reactor physics parameters in the Monte-Carlo calculation using different nuclear data libraries, ENDF/B-VII.0 and JEFF-3.1.1. The Accelerator-Driven System (ADS) and the Minor Actinide (MA)-loaded Fast Reactor (FR) are selected as the representative transmutation systems. The criticality and void reactivity of these systems are discussed. The results show that the uncertainties deduced from the JENDL-3.3 covariance data are smaller than the differences in the reactor physics parameters among the nuclear data libraries. The cause of this discrepancy is that the covariance data of main nuclides and reactions in JENDL-3.3 are smaller than the relative differences in the cross sections among the nuclear data libraries. It is required to verify the uncertainty of the reactor physics parameters by integral experiments and to discuss the uncertainty utilization for the nuclear design accuracy.

  • neutronics design for lead bismuth cooled accelerator driven system for transmutation of Minor Actinide
    Journal of Nuclear Science and Technology, 2004
    Co-Authors: Kazufumi Tsujimoto, Kenji Nishihara, Toshinobu Sasa, Hiroyuki Oigawa, Hideki Takano
    Abstract:

    Neutronics design study was performed for lead-bismuth cooled accelerator-driven system (ADS) to transmute Minor Actinides. Early study for ADS indicated two problems: a large burnup reactivity swing and a significant peaking factor. To solve these problems, effect of design parameters on neutronics characteristics were searched. The design parameters were initial plutonium loading, buffer region between spallation target and core, and zone fuel loading. Parametric survey calculations were performed considering fuel cycle consisting of burnup and recycle. The results showed that burnup reactivity swing depends on the plutonium fraction in the initial fuel loading, and the lead-bismuth buffer region and the two-zone loading were effective for solving the problems. Moreover, an optimum value for the effective multiplication factor was also evaluated using reactivity coefficients. From the result, the maximum allowable value of the effective multiplication factor for a practical ADS can be set at 0.97. Conse...

  • design study of lead bismuth cooled ads dedicated to nuclear waste transmutation
    Progress in Nuclear Energy, 2002
    Co-Authors: Takakazu Takizuka, Kenji Nishihara, Kazufumi Tsujimoto, Toshinobu Sasa, Hideki Takano
    Abstract:

    Research and development on nuclear waste transmutation are being carried out with a special emphasis placed on dedicated accelerator-driven systems at the Japan Atomic Energy Research Institute under the Japanese OMEGA Program. The reference accelerator-driven system design employs eutectic lead-bismuth as spallation target material and coolant. The fuel for the subcritical core is Minor-Actinide mononitride. The system consists of a 1.5GeV, 14mA proton accelerator and an 800MWt subcritical core with an effective neutron multiplication factor of 0.95. The transmutation rate of Minor Actinides is approximately 250 kg/y at 80% load factor. The design has salient features that the coolant inventory is large due to the tank-type configuration, the temperature rise through the core is relatively low, and the power conversion is operated on a saturated steam turbine cycle. These features make the plant response to a beam trip slow and much less demanding.

Kaimin Shih - One of the best experts on this subject based on the ideXlab platform.

  • quantification of the partitioning ratio of Minor Actinide surrogates between zirconolite and glass in glass ceramic for nuclear waste disposal
    Inorganic Chemistry, 2017
    Co-Authors: Chang-zhong Liao, Chengshuai Liu, S U Minhua, Kaimin Shih
    Abstract:

    Zirconolite-based glass-ceramic is considered a promising wasteform for conditioning Minor Actinide-rich nuclear wastes. Recent studies on this wasteform have sought to enhance the partitioning ratio (PR) of Minor Actinides in zirconolite crystal. To optimize the PR in the SiO2–Al2O3–CaO–TiO2–ZrO2 system, a novel conceptual approach, which can be derived from the chemical composition and quantity of zirconolite crystal in glass-ceramic, was introduced based on the results of Rietveld quantitative X-ray diffraction analysis and transmission electron microscopy energy dispersive X-ray spectroscopy. To verify this new conceptual approach, the influences of the crystallization temperature, the concentration of additives, and ionic radii on the PR of various surrogates (Ce, Nd, Gd, and Yb) in zirconolite were examined. The results reveal that the PR of Nd3+ in zirconolite can be as high as 41%, but it decreases as the crystallization temperature increases. The quantities of all phases (including crystalline an...

  • Quantification of the Partitioning Ratio of Minor Actinide Surrogates between Zirconolite and Glass in Glass-Ceramic for Nuclear Waste Disposal
    2017
    Co-Authors: Chang-zhong Liao, Chengshuai Liu, Kaimin Shih
    Abstract:

    Zirconolite-based glass-ceramic is considered a promising wasteform for conditioning Minor Actinide-rich nuclear wastes. Recent studies on this wasteform have sought to enhance the partitioning ratio (PR) of Minor Actinides in zirconolite crystal. To optimize the PR in the SiO2–Al2O3–CaO–­TiO2–ZrO2 system, a novel conceptual approach, which can be derived from the chemical composition and quantity of zirconolite crystal in glass-ceramic, was introduced based on the results of Rietveld quantitative X-ray diffraction analysis and transmission electron microscopy energy dispersive X-ray spectroscopy. To verify this new conceptual approach, the influences of the crystallization temperature, the concentration of additives, and ionic radii on the PR of various surrogates (Ce, Nd, Gd, and Yb) in zirconolite were examined. The results reveal that the PR of Nd3+ in zirconolite can be as high as 41%, but it decreases as the crystallization temperature increases. The quantities of all phases (including crystalline and amorphous) remained nearly constant when increasing the loading of Nd2O3 in glass-ceramic products crystallized at 1050 °C for 2 h. Correspondingly, the PR of Nd3+ decreases in a linear fashion with the loading contents of Nd2O3. The radius of ions also has a great influence on the PR, and an increase in the ionic radius leads to a decrease in the PR. This new approach will be an important tool to facilitate the exploration of a glass-ceramic matrix for the disposal of Minor Actinide-rich nuclear wastes