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Cheng, S.; 松場 賢一; 磯崎 三喜男; 神山 健司; 鈴木 徹; 飛田 吉春
Annals of Nuclear Energy, 85, p.740 - 752, 2015/11
被引用回数：28 パーセンタイル：89.61(Nuclear Science & Technology)Studies on local fuel-coolant interactions (FCI) in a molten pool are crucial to the analyses of severe accidents that could occur for sodium-cooled fast reactors (SFRs). To clarify the characteristics of this interaction, in recent years a series of simulated experiments, which covers a variety of conditions including much difference in water volume, melt temperature, water subcooling and water release site (pool surface or bottom), was conducted at the Japan Atomic Energy Agency by delivering a given quantity of water into a molten pool formed with a low-melting-point alloy. In this study, motivated by acquiring further evidence for understanding its mechanisms, interaction characteristics including the pressure-buildup as well as mechanical energy release and its conversion efficiency, are investigated using the SIMMER-III, an advanced fast reactor safety analysis code. It is confirmed that, similar to experiments, the water volume, melt temperature and water release site are observable to have remarkable impact on the interaction, while the role of water subcooling seems to be less prominent. The performed analyses also suggest that the most probable reason leading to the limited pressurization and resultant mechanical energy release for a given melt and water temperature within the non-film boiling range, even under a condition of much larger volume of water entrapped within the pool, should be primarily due to an isolation effect of vapor bubbles generated at the water-melt interface.
Cheng, S.; 松場 賢一; 磯崎 三喜男; 神山 健司; 鈴木 徹; 飛田 吉春
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 9 Pages, 2015/05
To clarify the mechanisms underlying local fuel-coolant interactions (FCI) in a molten pool, in this study, several latest calculations with reactor materials were performed using SIMMER-III, an advanced fast reactor safety analysis code. The performed SIMMER-III analyses suggest that despite of a comparatively larger temperature range of molten-fuel and sodium possibly varied during reactor accidents, the isolation effect of vapor bubbles generated at the melt-sodium interface seems to be the unique dominant mechanism that leads to the limited pressurization. Knowledge and fundamental data from this work might be utilized for future empirical-approach studies (e.g. those investigating the characteristics of critical coolant volume required for achieving the saturated pressurization at varied melt and coolant temperatures).
Cheng, S.; 松場 賢一; 磯崎 三喜男; 神山 健司; 鈴木 徹; 飛田 吉春
Science and Technology of Nuclear Installations, 2015, p.964327_1 - 964327_14, 2015/00
被引用回数：7 パーセンタイル：48.66(Nuclear Science & Technology)To clarify the mechanisms underlying local fuel-coolant interactions (FCI) in a molten pool, in recent years several experimental tests, with comparatively larger difference in coolant volumes, were conducted at the Japan Atomic Energy Agency by delivering a given quantity of water into a molten pool formed with a low-melting-point alloy. In this study, to further understand this interaction, interaction characteristics including the pressure-buildup as well as mechanical energy release and its conversion efficiency are investigated using the SIMMER-III, an advanced fast reactor safety analysis code. It is found that the SIMMER-III code not only reasonably simulates the transient pressure and temperature variations during local FCIs, but also supports the limited tendency of pressurization and resultant mechanical energy release as observed from experiments when the volume of water delivered into the pool increases. The performed analyses also suggest that the most probable reason leading to such limited tendency should be primarily due to an isolation effect of vapor bubbles generated at the water-melt interface.
