Visualization of low-speed upflow in a cylindrical vesse

Kamiji, Yu; Terada, Atsuhiko  ; Hino, Ryutaro

Low-speed up-flow is generated due to the water radiolysis in the spent vessel used by contaminated water treatment facility of Fukushima Dai-ichi Nuclear Power Plant. Though it is important to understand the inside flow of the vessel for storage, it is not clear. Thus flow test was performed with a simulated acrylic cylindrical vessel. This paper reports results of visualization of low-speed upflow in a cylindrical vessel by using LASER light sheet and high speed camera. It was confirmed that stagnant flow was generated around the stepped section, and the stagnant flow repeated appearance and dissipation. It was also found that the behavior of the stagnation depended on gas flow rate.