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Deguchi, Yoshihiro*; Muranaka, Ryota*; Kamimoto, Takahiro*; Takagi, Taku*; Kikuchi, Shin; Kurihara, Akikazu
Applied Thermal Engineering, 114, p.1319 - 1324, 2017/03
Times Cited Count：4 Percentile：18.83(Thermodynamics)The purpose of this study aims to clarify the gas phase sodium-water reaction path and reaction products quantitatively. The counter-flow diffusion experiment device was employed to analyze the reaction path and reaction products using laser diagnostics. The main product of sodium-water reaction was determined to be NaOH and the sodium oxide was not notably measured compared with NaOH.
Deguchi, Yoshihiro*; Muranaka, Ryota*; Kamimoto, Takahiro*; Takagi, Taku*; Kikuchi, Shin; Kurihara, Akikazu
Proceedings of 3rd International Workshop on Heat Transfer Advances for Energy Conservation and Pollution Control (IWHT 2015) (CD-ROM), 6 Pages, 2015/10
The purpose of this study aims to clarify the gas phase sodium-water reaction path and reaction products quantitatively. The counter-flow diffusion experiment device was employed to analyze the reaction path and reaction products using laser diagnostics. The main product of sodium-water reaction was determined to be NaOH and the sodium oxide was not notably measured compared with NaOH.
Deguchi, Yoshihiro*; Takata, Takashi*; Yamaguchi, Akira*; Kikuchi, Shin; Ohshima, Hiroyuki
Mechanical Engineering Journal (Internet), 2(1), p.14-00029_1 - 14-00029_11, 2015/02
In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. This process ends up damages on the heat transport equipment in the SFR. Therefore, the study on sodium-water chemical reactions is of paramount importance for security reasons. This study aims to clarify the sodium-water reaction mechanisms using an elementary reaction analysis. From analytical results, the main reaction was Na + H
O = NaOH + H at gas-phase reaction.
Tamura, Kenta*; Deguchi, Yoshihiro*; Muranaka, Ryota*; Kusano, Koji*; Takata, Takashi*; Kikuchi, Shin; Kurihara, Akikazu
Proceedings of 24th International Symposium on Transport Phenomena (ISTP-24) (USB Flash Drive), 5 Pages, 2013/11
The purpose of this study aims to clarify the gas phase sodium-water reaction path and reaction products. The counter-flow diffusion experiment device is in the form of introducing the argon-based water vapor from the top of depressurized reaction chamber to the liquid sodium pool. Na, Na, HO, and reaction products in the counter-flow sodium-water reaction field were measured using laser diagnostics. The temperature controlled device was also improved to reduce the condensation of Na in the reaction zone for the better measurement performance. The main product in the sodium-water reaction was determined to be NaOH from the experimental results and its reaction path was discussed using Na-HO elementary reaction analysis.
Deguchi, Yoshihiro*; Tamura, Kenta*; Muranaka, Ryota*; Kusano, Koji*; Kikuchi, Shin; Kurihara, Akikazu
Reza Kenkyu, 41(11), p.927 - 931, 2013/11
In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. Therefore the study on sodium-water chemical reactions is of paramount importance for security reasons. This study aims to clarify the sodium-water reaction mechanisms using laser diagnostics. The measurement results show that the sodium-water reaction proceeds mainly by the reaction Na + HO = NaOH + H and the main product is NaOH from this reaction.
Deguchi, Yoshihiro*; Imanaka, Koichi*; Takata, Takashi*; Yamaguchi, Akira*; Kikuchi, Shin; Ohshima, Hiroyuki
Proceedings of 3rd Asian Symposium on Computational Heat Transfer and Fluid Flow (ASCHT 2011) (CD-ROM), 6 Pages, 2011/09
In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. This process ends up damages on the heat transport equipment in the SFR. Therefore, the study on sodium-water chemical reactions is of paramount importance for security reasons. This study aims to clarify the sodium-water reaction mechanisms using an elementary reaction analysis. As a result of the analysis, It was demonstrated that the main reaction is Na+HO 
NaOH+H as gas-phase reaction.
Ohshima, Hiroyuki; Yamaguchi, Akira*; Narabayashi, Tadashi*; Deguchi, Yoshihiro*
Dai-16-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu, p.1 - 2, 2011/06
When a heat transfer tube is failed in a steam generator (SG) of a sodium-cooled fast reactor (SFR), pressurized water and/or water vapor leaks into liquid sodium surrounding the tube and forms a reacting jet with high temperature. This reacting jet might cause the secondary failure of adjacent heat transfer tubes due to wastage or over-heating tube rapture resulting in undesirable development of the accident. Therefore, the sodium-water reaction phenomenon (SWR) is one of most important issues for the design and safety assessment of SFRs. This paper describes the research and development plan of a new multi-physics numerical simulation system which is based on mechanistic and theoretical modeling of the SWR rather than empirical modeling and can contribute to detailed and quantitative evaluations of the SWR in any types of SGs including commercial SFRs.
Yamaguchi, Akira*; Takata, Takashi*; Ohshima, Hiroyuki; Sogabe, Joji*; Deguchi, Yoshihiro*; Kikuchi, Shin
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM), 8 Pages, 2010/05
Sodium-water reaction (SWR) is a design basis accident of a sodium fast reactor (SFR). A breach of the heat transfer tube in a steam generator (SG) results in contact of liquid sodium with water. The purpose of the present paper is to delineate the mechanism and process of the SWR by a counter-flow diffusion flame experiment and a numerical simulation.
Deguchi, Yoshihiro*; Tamura, Kenta*; Muranaka, Ryota*; Kitani, Taiyo*; Kusano, Koji*; Kikuchi, Shin; Kurihara, Akikazu
no journal, ,
It is a photograph of the sodium-water counter-flow diffusion flame formed by water vapor introduced to a liquid sodium pool. The orange part is the sodium emission (D line: 589 nm) emerged by sodium-water reactions, and the green part is the reaction products (NaOH etc.) and sodium fine particles visualized by a laser scattering method. By controlling the water vapor temperature, reaction products and sodium fine particles can be shaped like arms which boost up the sodium emission.
Ohshima, Hiroyuki; Kurihara, Akikazu; Narabayashi, Tadashi*; Yamaguchi, Akira*; Takata, Takashi*; Deguchi, Yoshihiro*
no journal, ,
When a heat transfer tube is failed in a steam generator (SG) of a sodium-cooled fast reactor (SFR), pressurized water and/or water vapor leaks into liquid sodium surrounding the tube and forms a reacting jet with high temperature. This reacting jet might cause the secondary failure of adjacent heat transfer tubes due to wastage or over-heating tube rapture resulting in undesirable development of the accident. Therefore, the sodium-water reaction phenomenon (SWR) is one of most important issues for the design and safety assessment of SFRs. We have been developing a new multi-physics numerical simulation system which is based on mechanistic and theoretical modeling of the SWR rather than empirical modeling and can contribute to detailed and quantitative evaluations of the SWR in any types of SGs including commercial SFRs. In this presentation, the whole R&D plan, three-year study results and future works will be introduced.
Suzuki, Akimasa*; Deguchi, Yoshihiro*; Safil Alam, T.*; Mori, Yuma*; Kikuchi, Shin; Kurihara, Akikazu
no journal, ,
In this study, NaOH reagent as reaction product of sodium-water surface reaction was measured by using Raman spectroscopy for evaluation of cited reaction. From reagent based measurement, analysis on the reaction products at the reaction surface was performed.
Deguchi, Yoshihiro*; Kikuchi, Shin; Kurihara, Akikazu; Takata, Takashi; Ohshima, Hiroyuki
no journal, ,
Multi-level, multi-scenario simulation systems as safety fundamental technology for sodium cooled fast reactors (SFRs) has been developed. In this report, the physical property of reaction products measured by laser diagnostics as critical data of SFR for V&V is presented.
Wakaida, Ikuo*; Oba, Hironori*; Deguchi, Yoshihiro*
no journal, ,
We have developed a fiber-delivered laser-induced breakdown spectroscopy (fiber-LIBS) system for the remote analysis of nuclear fuel materials inside and outside the reactor in the decommissioning of Fukushima Daiichi nuclear power station. We proposed and demonstrated a method to simultaneously irradiate samples with long and short pulses of laser light to analyze samples in submerged, wet, and surface water flow environments.
Tamura, Kenta*; Deguchi, Yoshihiro*; Suzuki, Koichi*; Takata, Takashi*; Yamaguchi, Akira*; Kikuchi, Shin; Ohshima, Hiroyuki
no journal, ,
In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. This process ends up damages on the heat transport equipment in the SFR. Therefore, the study on sodium-water chemical reactions is of paramount importance for security reasons. This study aims to clarify the sodium-water reaction mechanisms using laser diagnostics. Temperature, H, HO, OH, Na and Particulate matter were measured using laser induced fluorescence and CARS in the counter-flow reaction field. From the measured results, major gas-phase reaction of sodium-water reaction was identified.
Muranaka, Ryota*; Deguchi, Yoshihiro*; Tamura, Kenta*; Takata, Takashi*; Kikuchi, Shin; Kurihara, Akikazu
no journal, ,
In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. Therefore, the study on sodium-water chemical reactions is of importance for security reasons. This study aims to clarify the gas phase sodium-water reaction path and reaction products. Na, Na, HO, and reaction products in the counter-flow sodium-water reaction field were measured using laser diagnostics such as Raman scattering and photo-fragmentation. The main product in the sodium-water reaction was determined to be NaOH and its reaction path was discussed using Na-HO elementally reaction analysis.
Deguchi, Yoshihiro*; Tamura, Kenta*; Muranaka, Ryota*; Kusano, Koji*; Takata, Takashi*; Kikuchi, Shin; Kurihara, Akikazu
no journal, ,
In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes in a steam generator. Therefore the study on sodium-water chemical reactions is of paramount importance for safety reasons. This study aims to clarify the sodium-water reaction mechanisms using laser diagnostics. The sodium-water, sodium-oxygen and sodium-hydrogen counter-flow reactions were measured using laser diagnostics such as Raman, absorption and photo-fragmentation spectroscopies. The measurement results show that the main product of the sodium-water reaction is NaOH. The sodium-water reaction rate is slower than that of the sodium-oxygen reaction and hydrogen does not react noticeably with sodium.
Ohshima, Hiroyuki; Kurihara, Akikazu; Yamaguchi, Akira*; Takata, Takashi*; Narabayashi, Tadashi*; Deguchi, Yoshihiro*
no journal, ,
When a heat transfer tube is failed in a steam generator (SG) of a sodium-cooled fast reactor (SFR), pressurized water and/or water vapor leaks into liquid sodium surrounding the tube and forms a reacting jet with high temperature and high alkali. This reacting jet might cause the secondary failure of adjacent heat transfer tubes due to wastage or over-heating tube rapture resulting in undesirable failure propagation. Therefore, the sodium-water reaction phenomenon (SWR) is one of the most important issues for the design and safety assessment of SFRs. The authors have carried out systematic experiments for the elucidation of SWR and developed a new multi-physics numerical simulation system which is based on mechanistic and theoretical modeling of SWR rather than empirical modeling and can contribute to detailed and quantitative evaluations of SWR in any types of SGs. This paper summarizes the results of four years' R&D activities.
Ohshima, Hiroyuki; Kurihara, Akikazu; Yamaguchi, Akira*; Takata, Takashi*; Narabayashi, Tadashi*; Deguchi, Yoshihiro*
no journal, ,
When a heat transfer tube is failed in a steam generator (SG) of a sodium-cooled fast reactor (SFR), pressurized water and/or water vapor leaks into liquid sodium surrounding the tube and forms a reacting jet with high temperature and high alkali. This reacting jet might cause the secondary failure of adjacent heat transfer tubes due to wastage or over-heating tube rapture resulting in undesirable failure propagation. Therefore, the sodium-water reaction phenomenon (SWR) is one of the most important issues for the design and safety assessment of SFRs. The authors have carried out systematic experiments for the elucidation of SWR and developed a new multi-physics numerical simulation system which is based on mechanistic and theoretical modeling of SWR rather than empirical modeling and can contribute to detailed and quantitative evaluations of SWR in any types of SGs. This paper summarizes the results of four-year R&D activities.
Suzuki, Akimasa*; Deguchi, Yoshihiro*; Safil Alam, T.*; Mori, Yuma*; Kikuchi, Shin; Kurihara, Akikazu
no journal, ,
In this study, reaction products, including NaOH, NaO, NaO in the sodium-water reaction field, were investigated by using Raman spectroscopy for evaluation of sodium-water surface reaction.
Ohshima, Hiroyuki; Takata, Takashi; Doda, Norihiro; Kikuchi, Shin; Koga, Nobuyoshi*; Deguchi, Yoshihiro*
no journal, ,
Development of multi-level, multi-scenario plant simulation systems has started as a fundamental technology to support mechanism elucidation of phenomena, design optimization, and innovative technology development toward the commercialization of sodium cooled fast reactors. In this presentation, the overall plan of this development project is introduced.
