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田村 健太*; 出口 祥啓*; 村中 亮太*; 草野 剛嗣*; 高田 孝*; 菊地 晋; 栗原 成計
Proceedings of 24th International Symposium on Transport Phenomena (ISTP-24) (USB Flash Drive), 5 Pages, 2013/11
本研究の目的はナトリウム-水反応(気相反応)の反応経路および反応生成物を明らかにすることである。本研究ではアルゴンで希釈した水蒸気を反応容器上方より、液体ナトリウムプールに導入する対向流拡散火炎試験装置を用いている。反応場において、Na, Na
, HOや反応生成物をレーザー計測技術により測定した。また、計測性を向上させるため、反応場におけるNaの凝縮を抑制するために温調設備を改良した。試験結果から主要な反応生成物はNaOHであることが明らかになり、Na-HO系の素反応解析により反応経路を検討した。
永武 拓; 秋本 肇; 吉田 啓之; 高瀬 和之
no journal, ,
Huge earthquake attacked eastern area of Japan on March 11, 2011. At the Fukushima Daiichi Nuclear Power Station, huge tsunami caused station black out and loss of the final heat sink. Finally, core melt down was induced as the consequence of tsunami attack at Unit 1, 2 and 3 reactors. To identify the key thermal-hydraulic phenomena prior to the core meltdown in the unit-1 reactor, an analysis was performed using the TRAC-BF1 code. The TRAC-BF1 code showed that the water inventory inside the RPV was decreased with time. The decreasing rate of the water inventory was controlled by the mass discharge rate through the safety relief valve resulting from the steam generation due to the decay heat. In this analysis, the following two main natural circulations occurred: (1) Natural circulation among the upper plenum, downcomer, lower plenum, reactor core and reactor core bypass; and, (2) Natural circulation among the lower part of the upper plenum, reactor core and reactor core bypass.
永武 拓; 古谷 正裕*; 高瀬 和之; 吉田 啓之; 永瀬 文久
no journal, ,
At the Fukushima Daiichi Nuclear Power Plant, the Great East Japan Earthquake and tsunami attacked the power plant on March 11, 2011. The tsunami caused station black out. Finally, the core meltdown occurred at Unit-1, 2 and 3. To clarify the core meltdown process, it is necessary to understand the melting behavior of fuel elements which consist of fuel assemblies and control rods. To understand this melting behavior, the fundamental characteristics and mechanism of the melting fuel elements must be evaluated. Then, we have developed the numerical simulation method for fundamental melting behavior of fuel elements based on the Moving Particle Semi-implicit (MPS) method. In this paper, outline of the presently developed numerical simulation method is shown. Then, the experiment to obtain the validation data for the simulation method is explained. The preliminary analysis results by the presently developed simulation method are shown and compared with the experimental results.
Jiao, L.; 吉田 啓之; 高瀬 和之
no journal, ,
In this study, a numerical simulation of bubbly flow in a vertical circular pipe was performed using TPFIT code developed in JAEA. Moreover, the simulation results were compared with existing experimental data to check the applicability of the TPFIT to bubble dynamics regarding bubble deformation, coalescence and fragmentation. In this simulation, bubble developing process in a vertical circular pipe under the two-phase flow condition consisting of air and water were investigated numerically. And the bubbly flow with the wall peak bubble distribution was predicted. Furthermore, the difference between experimental results and numerical simulation was analyzed in detail from the development of bubble size in the flow direction and the generation of bubbles. It is pointed out that the details of bubble coalescence and fragmentation can be predicted by the TPFIT by refining the grid size near air injection nozzles in future.
吉田 啓之; 永武 拓; 高瀬 和之; 金子 暁子*; 文字 秀明*; 阿部 豊*
no journal, ,
In this study, two-phase flow simulation method under earthquake conditions has been developed based on a detailed two-phase flow simulation code with an advanced interface tracking method TPFIT. And developed simulation method is validated for two-phase flow under earthquake conditions by comparing predicted results with measured results. In this paper, rising bubble behavior under accelerating conditions was simulated by using the developed simulation method based on the TPFIT. Moreover, predicted time series of bubble shapes were compared with measured results. In the results, predicted bubble behavior including bubble shape and lean angle agreed with measured data observed by the high speed camera. Furthermore, a time lag of bubble lean angle to acceleration of vibration was almost the same as measured results.