Experimental study on debris bed characteristics for the sedimentation behavior of solid particles used as simulant debris

Shamsuzzaman, M.*; Horie, Tatsuro*; Fuke, Fusata*; Kamiyama, Motoki*; Morioka, Toru*; Matsumoto, Tatsuya*; Morita, Koji*; Tagami, Hirotaka ; Suzuki, Toru*; Tobita, Yoshiharu

Particle bed characteristics are experimentally investigated for the sedimentation and subsequent bed formation of solid particles, related to the coolability aspects in core-disruptive accidents. Presently a series of experiments with gravity driven discharge of solid particles into a quiescent water pool was performed to evaluate bed formation characteristic in the course of particle sedimentation. We evaluated the effects of the crucial factors: nozzle diameter, particle density, particle diameter and nozzle height on four key quantitative parameters of bed shape: mound dimple area, mound dimple volume, repose angle and mound height to illustrate the role of the crucial factors on forming the particle bed shape. The investigated crucial factors exhibit a significant role that diversifies the particle bed formation process. Based on the data obtained in the experimental observations, we developed an empirical correlation to compare the predicted results with the experimental bed heights. The proposed empirical correlation can reasonably demonstrate the general trend of the experimental bed height. This correlation could be useful to assess the particle bed elevation, and to identify the governing parameters.