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Cheng, S.; 田上 浩孝; 山野 秀将; 鈴木 徹; 飛田 吉春; 竹田 祥平*; 西 津平*; 錦戸 達也*; Zhang, B.*; 松元 達也*; et al.
Journal of Nuclear Science and Technology, 51(9), p.1096 - 1106, 2014/09
被引用回数：25 パーセンタイル：87.38(Nuclear Science & Technology)Studies on debris bed self-leveling behavior with non-spherical particles are crucial in the assessment of actual leveling behavior that could occur in core disruptive accident of sodium-cooled fast reactors. Although in our previous publications, a simple empirical model (based model), with its wide applicability confirmed over various experimental conditions, has been successfully advanced to predict the transient leveling behavior, up until now this model is restricted to calculations of debris bed of spherical particles. Focusing on this aspect, in this study a series of experiments using non-spherical particles was performed within a recently-developed comparatively larger-scale experimental facility. Based on the knowledge and data obtained, an extension scheme is suggested with the intention to extend the base model to cover the particle-shape influence. Through detailed analyses, it is found that by coupling this scheme, good agreement between experimental and predicted results can be achieved for both spherical and non-spherical particles given current range of experimental conditions.
Cheng, S.; 田上 浩孝; 山野 秀将; 鈴木 徹; 飛田 吉春; 中村 裕也*; 竹田 祥平*; 西 津平*; Zhang, B.*; 松元 達也*; et al.
Mechanical Engineering Journal (Internet), 1(4), p.TEP0022_1 - TEP0022_16, 2014/08
To clarify the mechanisms underlying the debris-bed self-leveling behavior, several series of experiments were elaborately designed and conducted within a variety of conditions in recent years, under the collaboration between Japan Atomic Energy Agency (JAEA) and Kyushu University. The current contribution, including knowledge from both experimental analyses and empirical model development, is focused on a recently developed comparatively larger-scale experimental facility using gas-injection to simulate the coolant boiling. Based on the experimental observation and quantitative data obtained, influence of various experimental parameters, including gas flow rate (
300 L/min), water depth (180 mm and 400 mm), bed volume (3 7 L), particle size (1 6 mm), particle density (beads of alumina, zirconia and stainless steel) along with particle shape (spherical and irregularly-shaped) on the leveling is checked and compared. As for the empirical model development, aside from a base model which is restricted to calculations of spherical particles, the status of potential considerations on how to cover more realistic conditions (esp. debris beds formed with non-spherical particles), is also presented and discussed.
Cheng, S.; 山野 秀将; 鈴木 徹; 飛田 吉春; 中村 裕也*; 竹田 祥平*; 西 津平*; Zhang, B.*; 松元 達也*; 守田 幸路*
Proceedings of 21st International Conference on Nuclear Engineering (ICONE-21) (DVD-ROM), 8 Pages, 2013/07
To confirm the mechanisms of self-leveling behavior, several series of experiments were elaborately designed and performed in recent years under the constructive collaboration between Japan Atomic Energy Agency and Kyushu University. This paper summarizes the recent knowledge obtained from the newly developed large-scale experiments using gas-injection to simulate coolant boiling. Compared to previous investigations, it can cover a much wider range of gas velocities (presently up to a flow rate of around 300 L/min). The experiments were conducted in a cylindrical tank, in which water, nitrogen gas and different kinds of solid particles, simulate the coolant, vapor and fuel debris, respectively. Based on the quantitative data obtained, influence of various experimental parameters, including gas flow rate, water depth, particle size as well as particle density on the leveling was checked and compared. Moreover, with the help of dimensional analysis technique, a set of empirical correlations to predict the self-leveling development depending on particle size, particle density and gas injection velocity was proposed and validated over current conditions.
