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Sun, Y.*; Takatani, Tomoya*; Muta, Hiroaki*; Fujieda, Shun*; Kondo, Toshiki; Kikuchi, Shin; Kargl, F.*; Oishi, Yuji*
International Journal of Thermophysics, 45(1), p.11_1 - 11_19, 2024/01
Times Cited Count:0 Percentile:0.07(Thermodynamics)no abstracts in English
Yamano, Hidemasa; Kurisaka, Kenichi; Takano, Kazuya; Kikuchi, Shin; Kondo, Toshiki; Umeda, Ryota; Shirakura, Shota*
Dai-27-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu (Internet), 5 Pages, 2023/09
This project studies investigation on safety design guideline and risk assessment technology for sodium-cooled fast reactor with the molten-salt heat storage system, development of evaluation method for heat transferring performance between sodium and molten-salt and improvement of the performance, and evaluation of chemical reaction characteristic between sodium and molten-salt and improvement of its safety. The project overview is presented in this report.
Kondo, Toshiki; Toda, Taro*; Takeuchi, Junichi*; Kikuchi, Shin; Kargl, F.*; Muta, Hiroaki*; Oishi, Yuji*
High Temperatures-High Pressures, 52(3-4), p.307 - 321, 2023/06
Times Cited Count:0 Percentile:0.02(Thermodynamics)In order to establish an evaluation method/numerical simulation for nuclear reactor safety under severe accidental conditions, it is necessary to obtain the physical properties, especially fluidity of the relevant molten materials at very high temperatures. In this study, thermophysical properties such as density and viscosity were obtained for (FeO)-(SiO), which is a representative composition in the early stage of severe accident. (FeO)-(SiO) is produced by the contact between the molten oxide of steel, which is the main component of the reactor, and SiO, which is the main component of concrete. As a result, the physical properties of the (FeO)-(SiO) mixture were almost the same as those of FeO obtained in previous studies, and it could be concluded that a small amount of SiO (about 5 mol.%) did not significantly affect the fluidity of FeO.
Emura, Yuki; Takai, Toshihide; Kikuchi, Shin; Kamiyama, Kenji; Yamano, Hidemasa; Yokoyama, Hiroki*; Sakamoto, Kan*
Journal of Nuclear Science and Technology, 10 Pages, 2023/00
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)Yamano, Hidemasa; Kurisaka, Kenichi; Takano, Kazuya; Kikuchi, Shin; Kondo, Toshiki; Umeda, Ryota; Shirakura, Shota*; Hayashi, Masaaki*
Proceedings of 8th International Conference on New Energy and Future Energy Systems (NEFES 2023) (Internet), p.27 - 34, 2023/00
Times Cited Count:0This project studies investigation on safety design guideline and risk assessment technology for sodium-cooled fast reactor with the molten-salt heat storage system, development of evaluation method for heat transferring performance between sodium and molten-salt and improvement of the performance, and evaluation of chemical reaction characteristic between sodium and molten-salt and improvement of its safety. The project overview is presented in this report.
Kondo, Toshiki; Toda, Taro*; Takeuchi, Junichi*; Kargl, F.*; Kikuchi, Shin; Muta, Hiroaki*; Oishi, Yuji*
Journal of Nuclear Science and Technology, 59(9), p.1139 - 1148, 2022/09
Times Cited Count:1 Percentile:31.61(Nuclear Science & Technology)no abstracts in English
Iwasaki, Shun*; Sakai, Yasuhiro*; Kikuchi, Shin; Koga, Nobuyoshi*
Journal of Thermal Analysis and Calorimetry, 147(11), p.6309 - 6322, 2022/06
Times Cited Count:5 Percentile:41.15(Thermodynamics)The influence of atmospheric water vapor on the multistep thermal decomposition of perlite concrete was investigated in detail by separating the component reaction steps using kinetic deconvolution analysis (KDA). The retardation of thermal decomposition of Ca(OH) and the acceleration of thermal decomposition of CaCO were identified as specific effect of atmospheric water vapor.
Sakai, Yasuhiro*; Iwasaki, Shun*; Kikuchi, Shin; Koga, Nobuyoshi*
Journal of Thermal Analysis and Calorimetry, 147(10), p.5801 - 5813, 2022/05
Times Cited Count:8 Percentile:59.41(Thermodynamics)The influence of atmospheric CO on the multistep thermal decomposition of perlite concrete was investigated in detail by separating the component reaction steps using kinetic deconvolution analysis (KDA). The carbonation of Ca(OH) and the retardation of the thermal decomposition of CaCO were identified as specific effect of atmospheric CO.
Kikuchi, Shin; Koga, Nobuyoshi*
Journal of Thermal Analysis and Calorimetry, 147(7), p.4635 - 4643, 2022/04
Times Cited Count:1 Percentile:7.32(Thermodynamics)In a sodium-cooled fast reactor (SFR), sodium-concrete reaction (SCR) may probably occur when liquid sodium from cooling system spilled into the floor may lead to fail the steel liner as protector of the structural concretes. The structural concretes of SFR comprises siliceous concreate as main body of reactor structure and perlite concrete placed between the steel liner and the siliceous concrete serving as a protector and an insulator, respectively. Therefore, the reaction behaviour between the perlite concrete and liquid sodium in the early stage of SCR should be focused. In this study, for the first step of elucidation on SCR, thermal behaviour of sodium-calcium hydroxide reaction was investigated using a differential scanning calorimetry (DSC). It was revealed that the reaction between Na(l) and Ca(OH)(s) initiates at approximately 550 K, producing the product layer composed of CaO(s) and NaOH(s), which is evident from XRD pattern of solid product after DSC measurement. The kinetic consideration of the cited reaction was carried out to obtain the activation energy.
Quaini, A.*; Goss, S.*; Payot, F.*; Suteau, C.*; Delacroix, J.*; Saas, L.*; Gubernatis, P.*; Martin-Lopez, E.*; Yamano, Hidemasa; Takai, Toshihide; et al.
Proceedings of International Conference on Fast Reactors and Related Fuel Cycles; Sustainable Clean Energy for the Future (FR22) (Internet), 10 Pages, 2022/04
CEA and JAEA defined new sub-tasks under the current implementing arrangement: Kinetics of interaction in core material mixtures- Physical properties of core material mixtures, High temperature thermodynamic data for the UO-Fe-BC system, Experimental studies on BC-SS kinetics and BC-SS eutectic material relocation (freezing), BC/SS eutectic and kinetics models for SIMMER code systems, Methodology for the modelling of mixtures liquefaction kinetics. The paper describes major R&D results obtained in the France-Japan collaboration under the previous implementing arrangement as well as experimental and analytical roadmaps under the current arrangement.
Koga, Nobuyoshi*; Kikuchi, Shin
Industrial & Engineering Chemistry Research, 61(7), p.2759 - 2770, 2022/02
Times Cited Count:0 Percentile:0(Engineering, Chemical)Kikuchi, Shin; Nakamura, Kinya*; Yamano, Hidemasa
Mechanical Engineering Journal (Internet), 8(4), p.20-00542_1 - 20-00542_13, 2021/08
In a postulated severe accidental condition of sodium-cooled fast reactor (SFR), eutectic melting between boron carbide (BC) and stainless steel (SS) may take place. Thus, kinetic behavior of BC-SS eutectic melting is one of the important phenomena to be considered when evaluating the core disruptive accidents in SFR. In this study, for the first step to obtain the fundamental information on kinetic feature of BC-SS eutectic melting, the thermal analysis using the pellet type samples of BC and Type 316L SS as different experimental technique was performed. The differential thermal analysis endothermic peaks for the BC-SS eutectic melting appeared from 1483K to 1534K and systematically shifted to higher temperatures when increasing heating rate. Based on this kinetic feature, apparent activation energy and pre-exponential factor for the BC-SS eutectic melting were determined by Kissinger method. It was found that the kinetic parameters obtained by thermal analysis were comparable to the literature values.
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 BC-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 BC-SS eutectic reaction in the CDA analysis code, SIMMER-III, through the numerical analysis of the BC-SS eutectic melting experiments in which a BC block was placed in a SS pool.
Kikuchi, Shin; Takai, Toshihide; Yamano, Hidemasa; Sakamoto, Kan*
Proceedings of 28th International Conference on Nuclear Engineering (ICONE 28) (Internet), 9 Pages, 2021/08
In a postulated severe accidental condition of sodium-cooled fast reactor (SFR), eutectic melting between boron carbide (BC) and stainless steel (SS) may occur. Thus, behavior of BC-SS eutectic melting is one of the phenomena to evaluate the core disruptive accidents in SFR. In this study, the reaction experiments using SS crucibles and the pellets of SS with low BC concentration as samples were performed to simulate the state of the reaction interface in which the eutectic reaction and interdiffusion of BC-SS have progressed to a certain extent. It was revealed that the rate constants of eutectic reaction between SS and SS with low BC concentration are smaller than that of BC-SS eutectic reaction at high temperatures.
Umeda, Ryota; Kondo, Toshiki; Kikuchi, Shin; Kurihara, Akikazu
Proceedings of 28th International Conference on Nuclear Engineering (ICONE 28) (Internet), 9 Pages, 2021/08
In this study, in order to obtain the fundamental information on aerosol transport behavior between cells, the Multiple cells with Expandable connecting pipe Test facility (MET) was manufactured and preliminary experiments were performed. In the preliminary experiments, simulated particles were used in a test system with two cells connected horizontally or vertically, and their transport behavior was measured. As a result, it was possible to confirm the behavior of the simulated particles transporting to the horizontal or vertical cells from the results such as images and sedimentation data.
Kikuchi, Shin; Sakamoto, Kan*; Takai, Toshihide; Yamano, Hidemasa
Nihon Kikai Gakkai 2020-Nendo Nenji Taikai Koen Rombunshu (Internet), 4 Pages, 2020/09
In a postulated severe accidental condition of sodium-cooled fast reactor (SFR), eutectic melting between boron carbide (BC) as control rod element and stainless steel (SS) as control rod cladding or related structure may occur. Thus, behavior of BC-SS eutectic melting is one of the phenomena to evaluate the core disruptive accidents in SFR. In order to clarify the kinetic feature of BC-SS eutectic melting process in the interface, the thinning test for SS crucibles using the pellets of BC or SS with low BC concentration were performed to obtain the rate constant with dependence of BC concentration against SS. It was found that the rate constants of eutectic melting between SS and SS low BC concentration were smaller than that of BC-SS in the high temperature range. Besides, the rate constant of eutectic melting between SS and BC containing SS became small when decreasing the BC concentration against SS.
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 BC-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 BC-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.
Kikuchi, Shin; Yamano, Hidemasa; Nakamura, Kinya*
Proceedings of 2020 International Conference on Nuclear Engineering (ICONE 2020) (Internet), 9 Pages, 2020/08
In a postulated severe accidental condition of sodium-cooled fast reactor (SFR), eutectic melting between boron carbide (BC) and stainless steel (SS) may take place. Thus, kinetic behavior of BC-SS eutectic melting is one of the important phenomena to be considered when evaluating the core disruptive accidents in SFR. In this study, for the first step to obtain the fundamental information on kinetic feature of BC-SS eutectic melting, the thermal analysis using the pellet type samples of BC and Type 316L SS as different experimental technique was performed. The differential thermal analysis endothermic peaks for the BC-SS eutectic melting appeared from 1483K to 1534K and systematically shifted to higher temperatures when increasing heating rate. Based on this kinetic feature, apparent activation energy and pre-exponential factor for the BC-SS eutectic melting were determined by Kissinger method. It was found that the kinetic parameters obtained by thermal analysis were comparable to the literature values.
Aoyagi, Mitsuhiro; Uchibori, Akihiro; Kikuchi, Shin; Takata, Takashi; Ohno, Shuji; Ohshima, Hiroyuki
Nihon Kikai Gakkai Rombunshu (Internet), 86(883), p.19-00366_1 - 19-00366_8, 2020/03
Sodium fire is one of key issues in sodium-cooled fast reactor plant. JAEA has developed sodium fire analysis codes, such as AQUA-SF and SPHINCS, to evaluate the consequence of sodium fire events. This paper describes the PIRT (Phenomena Identification and Ranking Table) process for sodium fire events. Ranking table for important phenomena and an assessment matrix are completed. As a part of comprehensive validation based on the assessment matrix, experimental analyses using the AQUA-SF and SPHINCS codes for a sodium spray fire experiment Run-E1 show good agreement with the experimental result.
Aoyagi, Mitsuhiro; Uchibori, Akihiro; Kikuchi, Shin; Takata, Takashi; Ohno, Shuji; Ohshima, Hiroyuki
Nuclear Engineering and Design, 353, p.110240_1 - 110240_10, 2019/11
Times Cited Count:5 Percentile:48.99(Nuclear Science & Technology)JAEA has developed sodium fire analysis codes to evaluate the consequences of sodium fire events. This paper describes a PIRT (Phenomena Identification and Ranking Table) process for such events. Because a sodium fire event involves complex phenomena, the FOMs are specified through a factor analysis. Associated phenomena in a sodium fire event are identified through both element- and sequence-based phenomena analyses. The importance of each phenomenon is evaluated by considering the sequence-based analysis of associated phenomena related to the FOMs. Then, a ranking table is established. An assessment matrix of important phenomena and experiments is completed to confirm the sufficiency of experimental data for the validation of the models in the sodium fire analysis codes. Additional assessments are discussed specifically for the aerosol module and the CFD module in three-dimensional codes from a perspective of careful validation.