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Kobayashi, Takane*; Onishi, Tsuyoshi*; Osawa, Takahito; Pratt, A.*; Tear, S.*; Shimoda, Susumu*; Baba, Hidetada*; Laitinen, M.*; Sajavaara, T.*
Small, 18(46), p.2204455_1 - 2204455_9, 2022/11
Times Cited Count:0 Percentile:0(Chemistry, Multidisciplinary)An all-solid-state battery is a secondary battery that is charged and discharged by the transport of lithium ions between positive and negative electrodes. To fully realize the significant benefits of this battery technology, for example, higher energy densities, faster charging times, safer operation, it will be essential to understand how lithium ions are transported and distributed in the battery during operation. However, as the third lightest element, methods for quantitatively analyzing lithium during operation of an all-solid-state device are limited such that real time tracking of lithium transport has not yet been demonstrated. Here, we report that the transport of lithium ions in an all-solid-state half-cell was quantitatively tracked in near real time by utilizing a thermal neutron-induced nuclear reaction, utilizing lithium-6 as a tracer, and utilizing a high-intensity thermal neutron source. Furthermore, it is also mentioned that the migration mechanism and migration region of lithium ions in the solid electrolyte used could be determined by tracking the transport of lithium ions. From these results, it can be said that the development of all-solid-state batteries has entered a phase where further advances could be carried out while understanding the transport of lithium ions in the batteries. As a result, the research and development of all-solid-state batteries would be further accelerated.
Sato, Rika*; Nishi, Tsuyoshi*; Ota, Hiromichi*; Hayashi, Hirokazu; Sugawara, Takanori; Nishihara, Kenji
Dai-43-Kai Nihon Netsu Bussei Shimpojiumu Koen Rombunshu (CD-ROM), 3 Pages, 2022/10
no abstracts in English
Yamano, Hidemasa; Takai, Toshihide; Emura, Yuki; Fukuyama, Hiroyuki*; Higashi, Hideo*; Nishi, Tsuyoshi*; Ota, Hiromichi*; Morita, Koji*; Nakamura, Kinya*; Fukai, Hirofumi*; et al.
Proceedings of 13th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS-13) (Internet), 12 Pages, 2022/09
This paper describes the project overview and progress of experimental and analytical studies conducted until 2020. Specific results in this paper are the measurement of the eutectic reaction rates and the validation of physical model describing the eutectic reaction in the analysis code through the numerical analysis of the BC-SS eutectic reaction rate experiments in which a B
C pellet was placed in a SS crucible.
Sato, Rika*; Nishi, Tsuyoshi*; Ota, Hiromichi*; Yamano, Hidemasa
International Journal of Thermophysics, 43(6), p.85_1 - 85_15, 2022/06
Times Cited Count:0 Percentile:0.01(Thermodynamics)In this study, we developed a simple viscosity measurement method based on the principle of least squares to derive the period and logarithmic decrement of oscillation. To confirm the reproducibility of the proposed method, the viscosity of molten nickel was measured and found to be in good agreement with those reported in the literature. The measurement error was less than 3%. Further, the experimental data showed good reproducibility, and the measurements were obtained with high accuracies using the proposed method.
Nagata, Sho*; Miyake, Shugo*; Igarashi, Takahiro; Ota, Hiromichi*; Nishi, Tsuyoshi*
Jikken Rikigaku, 22(2), p.105 - 111, 2022/06
Thermal easy axis and thermal diffusivity of uniaxial carbon fiber-reinforced plastic sheets were determined by a offset periodic laser heating method, and investigated relationship between the thermal easy axis and fiber orientation with different thickness of CFRP sheet specimen, experimentally. It was clarified that the orientation of the thermal easy axis spreads in the in-plane direction with the sheet thickness deceases. Then, thermal diffusivity of CFRP specimens in the out-of-plane and in-plane direction were measured by two method: a variable-frequency method and a variable-displacement method, respectively. In the results of the out-of-plane directions, thermal diffusivity almost consistent with the carbon fiber direction were obtained. In contrast, the in-plane directions of those were exhibited unexpected value. Moreover, thermal diffusivity determination by offset periodic heating method was carried out. Finally, it is found that the thermal diffusivity considering the thermal easy axis with fiber angle was different characteristics from the in-plane direction measurement.
Takatsuka, Yuriko*; Matsumoto, Saori*; Nishi, Tsuyoshi*; Ota, Hiromichi*; Hori, Ayumi*; Hayashi, Kiichiro*; Yamano, Hidemasa
Jikken Rikigaku, 22(2), p.117 - 119, 2022/06
This study clarified the effect of the viscosities of molten casting steels for high temperature by measuring them using the oscillating crucible method. The casting steels for high temperature samples used for viscosity measurements contained 0, 10, 20, 30, 40, and 50 mass% Ni. Viscosities were evaluated using Roscoe's equation and measured in the temperature range of 1693-1803 K.
Matsumoto, Saori*; Nishi, Tsuyoshi*; Ota, Hiromichi*; Hori, Ayumi*; Hayashi, Kiichiro*; Yamano, Hidemasa
Jikken Rikigaku, 22(2), p.112 - 116, 2022/06
In this study, the viscosity of the molten Ni-based superalloys were measured by the oscillating crucible method. When the logarithm of the viscosity was plotted against the inverse temperature (Arrhenius-type plot), all alloys showed a good Arrhenius-type linearity over the temperature range investigated. It was also found that the viscosities of molten Ni-based superalloys decreased with increasing the Co contents.
Nishi, Tsuyoshi*; Sato, Rika*; Ota, Hiromichi*; Kokubo, Hiroki*; Yamano, Hidemasa
Journal of Nuclear Materials, 552, p.153002_1 - 153002_7, 2021/08
Times Cited Count:2 Percentile:53.86(Materials Science, Multidisciplinary)Determining high precision viscosities of molten BC-stainless steel (B
C-SS) alloys is essential for the core disruptive accident analyses of sodium-cooled fast reactors and for analysis of severe accidents in boiling water reactors (BWR) as appeared in Fukushima Daiichi. However, there are no data on the high precision viscosities of molten B
C-SS alloys due to experimental difficulties. In this study, the viscosities of molten SS (Type 316L), 2.5mass%B
C-SS, 5.0mass%B
C-SS, and 7.0mass%B
C-SS alloys were measured using the oscillating crucible method in temperature ranges of 1693-1793 K, 1613-1793 K, 1613-1793 K, and 1713-1793 K, respectively. The viscosity was observed to increase as the B
C concentration increased from 0 to 7.0 mass%. Using the experimental data of the molten 2.5mass%B
C-SS and 5.0mass%B
C-SS and 7.0mass%B
C-SS in the temperature range of 1713-1793 K, the equation for the viscosity of molten B
C-SS alloys was determined, and the measurement error of the viscosity of molten B
C-SS alloys is less than
8%.
Yamano, Hidemasa; Takai, Toshihide; Furukawa, Tomohiro; Kikuchi, Shin; Emura, Yuki; Kamiyama, Kenji; Fukuyama, Hiroyuki*; Higashi, Hideo*; Nishi, Tsuyoshi*; Ota, Hiromichi*; et al.
Proceedings of 28th International Conference on Nuclear Engineering (ICONE 28) (Internet), 11 Pages, 2021/08
One of the key issues in a core disruptive accident (CDA) evaluation in sodium-cooled fast reactors is eutectic reactions between boron carbide (BC) and stainless steel (SS) as well as its relocation. Such behaviors have never been simulated in CDA numerical analyses in the past, therefore it is necessary to develop a physical model and incorporate the model into the CDA analysis code. This study focuses on B
C-SS eutectic melting experiments, thermophysical property measurement of the eutectic melt, and physical model development for the eutectic melting reaction. The eutectic experiments involve the visualization experiments, eutectic reaction rate experiments and material analyses. The thermophysical properties are measured in a range from solid to liquid state. The physical model is developed for a CDA computer code based on the measured data of the eutectic reaction rate and the physical properties. This paper describes the project overview and progress of experimental and analytical studies conducted until 2019. Specific results in this paper are the validation of physical model describing B
C-SS eutectic reaction in the CDA analysis code, SIMMER-III, through the numerical analysis of the B
C-SS eutectic melting experiments in which a B
C block was placed in a SS pool.
Uno, Masayoshi*; Nishi, Tsuyoshi*; Takano, Masahide
Comprehensive Nuclear Materials, 2nd Edition, Vol.7, p.202 - 231, 2020/08
On the thermodynamic and thermophysical properties of the actinide nitrides in Comprehensive Nuclear Materials published by Elsevier as the first edition in 2012, we have revised them by adding some brand-new data. The main topics added are the solid solubility of the actinide nitrides into the zirconium nitride matrix for transmutation fuel, the lattice expansion of actinide nitrides induced by self-irradiation damage, the influence of defects accumulation on thermal conductivity, and the thermal expansion in curium nitride lattice.
Yamano, Hidemasa; Takai, Toshihide; Furukawa, Tomohiro; Kikuchi, Shin; Emura, Yuki; Kamiyama, Kenji; Fukuyama, Hiroyuki*; Higashi, Hideo*; Nishi, Tsuyoshi*; Ota, Hiromichi*; et al.
Proceedings of 2020 International Conference on Nuclear Engineering (ICONE 2020) (Internet), 10 Pages, 2020/08
One of the key issues in a core disruptive accident (CDA) evaluation in sodium-cooled fast reactors is eutectic reactions between boron carbide (BC) and stainless steel (SS) as well as its relocation. Such behaviors have never been simulated in CDA numerical analyses in the past, therefore it is necessary to develop a physical model and incorporate the model into the CDA analysis code. This study focuses on B
C-SS eutectic melting experiments, thermophysical property measurement of the eutectic melt, and physical model development for the eutectic melting reaction. The eutectic experiments involve the visualization experiments, eutectic reaction rate experiments and material analyses. The thermophysical properties are measured in a range from solid to liquid state. The physical model is developed for a severe accident computer code based on the measured data of the eutectic reaction rate and the physical properties. This paper describes the project overview and progress of experimental and analytical studies conducted until 2018. Specific results in this paper are boron concentration distributions of solidified B
C-SS eutectic sample in the eutectic melting experiments, which would be used for the validation of the eutectic physical model implemented into the computer code.
Yamano, Hidemasa; Takai, Toshihide; Furukawa, Tomohiro; Kikuchi, Shin; Emura, Yuki; Kamiyama, Kenji; Fukuyama, Hiroyuki*; Higashi, Hideo*; Nishi, Tsuyoshi*; Ota, Hiromichi*; et al.
Proceedings of International Nuclear Fuel Cycle Conference / Light Water Reactor Fuel Performance Conference (Global/Top Fuel 2019) (USB Flash Drive), p.418 - 427, 2019/09
Eutectic reactions between boron carbide (BC) and stainless steel (SS) as well as its relocation are one of the key issues in a core disruptive accident (CDA) evaluation in sodium-cooled fast reactors. Since such behaviors have never been simulated in CDA numerical analyses, it is necessary to develop a physical model and incorporate the model into the CDA analysis code. This study is focusing on B
C-SS eutectic melting experiments, thermophysical property measurement of the eutectic melt, and physical model development for the eutectic melting reaction. The eutectic experiments involve the visualization experiments, eutectic reaction rate experiments and material analyses. The thermophysical properties are measured in the range from solid to liquid state. The physical model is developed for a severe accident computer code based on the measured data of the eutectic reaction rate and the physical properties. This paper describes the project overview and progress of experimental and analytical studies by 2017. Specific results in this paper is boron concentration distributions of solidified B
C-SS eutectic sample in the eutectic melting experiments, which would be used for the validation of the eutectic physical model implemented into the computer code.
Ota, Hiromichi*; Kokubo, Hiroki*; Nishi, Tsuyoshi*; Yamano, Hidemasa
Proceedings of International Nuclear Fuel Cycle Conference / Light Water Reactor Fuel Performance Conference (Global/Top Fuel 2019) (USB Flash Drive), p.858 - 860, 2019/09
A viscosity measurement apparatus has been developed. It is known that the measurement of the viscosity of molten alloy at elevated temperatures is difficult due to the difficulty of handling for low viscosity fluids such as the stainless steel (SS)+BC alloy. In this study, the viscosities of the molten nickel (Ni) and stainless steel (SS) were measured by the oscillating crucible method to confirm the performance of the viscosity measurement apparatus as a first step. This method is suitable for high temperature molten alloys. A crucible containing molten metal is suspended, and a rotational oscillation is given to the crucible electromagnetically. The oscillation was damped by the friction of molten metal. The viscosity is determined from the period of oscillation and the logarithmic decrement. The crucible was connected to a mirror block and an inertia disk made of aluminum, and whole of them was suspended by a wire made of platinum-13% rhodium alloy. A laser light is irradiated to the mirror. The reflection light is detected by the photo-detectors, and then, the logarithmic decrement of molten metal is determined. The viscosities of molten nickel and SS melts were measured up to 1823 K. In these results, the measured viscosity values of molten Ni and SS were close to those of the literature values of molten Ni and SS. By the equipment, the viscosity of molten SS+B
C alloys are measured. The B
C concentration dependence of the viscosity of molten SS+B
C alloys is to be clarified.
Kokubo, Hiroki*; Nishi, Tsuyoshi*; Ota, Hiromichi*; Yamano, Hidemasa
Nihon Kinzoku Gakkai-Shi, 82(10), p.400 - 402, 2018/09
Times Cited Count:6 Percentile:38.28(Metallurgy & Metallurgical Engineering)It is important to obtain the viscosity of a mixed alloy consisting of molten stainless steel and boron-carbide (SUS316L + BC alloy) for the improvement of severe accident assessment methodology for sodium-cooled fast reactors. In this study, the viscosities of the molten nickel (Ni) and stainless steel (SUS316L) were measured by the oscillating crucible method to confirm the performance of the viscosity measurement apparatus as a first step. The viscosities of molten Ni and SUS316L melts were measured up to 1823 K. It was found that the measured viscosity values of molten Ni and SUS316L were estimated from the deviation of the experimental data, were
4% and
3%, respectively. It was also found that those of molten Ni and SUS316L were close to those of the literature values of molten Ni and similar composite stainless steels. Moreover, we tentatively measured the viscosity of molten SUS316L-5 mass%B
C alloy. The fitted results of the viscosity for molten Ni and SUS316L were obtained.
Tzeng, Y.-C.*; Onishi, Hiroaki; Okubo, Tsuyoshi*; Kao, Y.-J.*
Physical Review B, 96(6), p.060404_1 - 060404_7, 2017/08
Times Cited Count:17 Percentile:66.87(Materials Science, Multidisciplinary)Mukai, Hiroki*; Hirose, Atsushi*; Motai, Satoko*; Kikuchi, Ryosuke*; Tanoi, Keitaro*; Nakanishi, Tomoko*; Yaita, Tsuyoshi; Kogure, Toshihiro*
Scientific Reports (Internet), 6, p.21543_1 - 21543_7, 2016/02
Times Cited Count:118 Percentile:96.99(Multidisciplinary Sciences)Sudo, Ayako; Nishi, Tsuyoshi; Shirasu, Noriko; Takano, Masahide; Kurata, Masaki
Journal of Nuclear Science and Technology, 52(10), p.1308 - 1312, 2015/10
Times Cited Count:12 Percentile:71.06(Nuclear Science & Technology)For understanding the control blade degradation mechanism of BWR, the thermodynamic database for the fuel assembly materials is a useful tool. Although iron, boron, and carbon ternary system is a dominant phase diagram, phase relation data is not sufficient for the region in which the boron and carbon compositions are richer than the eutectic composition. The phase relations of three samples were analyzed by X-ray diffraction, scanning electron microscope and energy dispersed X-ray spectrometry. The results indicate that Fe(B,C) phase only exists in the intermediate region at 1273 K and that the solidus temperature widely maintains at about 1400 K for all three samples, which are different from the calculated data using previous thermodynamic database. The difference might be originated from the over-estimations of the interaction parameter between boron and carbon in Fe
(B,C).
Nishi, Tsuyoshi; Nakajima, Kunihisa; Takano, Masahide; Kurata, Masaki; Arita, Yuji*
Journal of Nuclear Materials, 464, p.270 - 274, 2015/09
Times Cited Count:3 Percentile:28.28(Materials Science, Multidisciplinary)no abstracts in English
Hayashi, Hirokazu; Nishi, Tsuyoshi*; Sato, Takumi; Kurata, Masaki
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1811 - 1817, 2015/09
Transmutation of long-lived radioactive nuclides including minor actinides (MA: Np, Am, Cm) has been studied in Japan Atomic Energy Agency (JAEA). Accelerator-driven system (ADS) is regarded as one of the powerful tools for transmutation of MA under the double strata fuel cycle concept. Uranium-free nitride fuel was chosen as the first candidate fuel for MA transmutation using ADS. To improve the transmutation ratio of MA, reprocessing of spent fuel and reusing MA recovered from the spent fuels is necessary. Our target is to transmute 99% of MA arisen from commercial power reactor fuel cycle, with which the period until the radiotoxicity drops below that of natural uranium can be shorten from about 5000 years to about 300 years. A pyrochemical process has been proposed as the first candidate for reprocessing of the spent nitride fuel. This paper overviews the current status of the nitride fuel cycle technology. Our recent study on fuel fabrication, fuel property measurements, reprocessing of spent fuel, development of the property database of MA nitride fuel, and fuel behavior simulation code are introduced. Our research and development (R&D) plan based on the roadmap of the development is also introduced.
Hasegawa, Noboru; Nishikino, Masaharu; Tomita, Takuro*; Onishi, Naofumi*; Ito, Atsushi*; Eyama, Tsuyoshi*; Kakimoto, Naoya*; Izutsu, Rui*; Minami, Yasuo*; Baba, Motoyoshi*; et al.
X-Ray Lasers and Coherent X-Ray Sources; Development and Applications XI (Proceedings of SPIE, Vol.9589), p.95890A_1 - 95890A_8, 2015/09
Times Cited Count:1 Percentile:57.2We have improved a soft X-ray laser (SXRL) interferometer synchronized with a Ti:Sapphire laser pulse to observe the single-shot imaging of the nano-scaled structure dynamics of the laser induced materials. By the precise imaging optics and double time fiducial system having been installed, the lateral resolution on the sample surface and the precision of the temporal synchronization between the SXRL and Ti:Sapphire laser pulses were improved to be 700 nm and 2 ps, respectively. By using this system, the initial stage (before 200 ps) of the ablation process of the Pt surface pumped by 80 fs Ti:Sapphire laser pulse was observed by the comparison between the soft X-ray reflective image and interferogram. We have succeeded in the direct observation of the unique ablation process around the ablation threshold such as the rapid increase of the surface roughness and surface vibration.