MISTEE: Micro -Interactions in STeam Explosion Experiments

MISTEE facility (Figs. 1a & 1b) is dedicated to pursue a basic understanding of micro-interactions in melt coolant interactions, with the ultimate goal to identify the mechanisms which may limit the explosivity of molten corium in a prototypic severe accident scenario with fuel-coolant interactions (FCI). The facility can also be applied to investigate quench of high-temperature particle, oxidation of metallic droplet, and bubble dynamics.

As a feature, the measurement system aka SHARP (Simultaneous High-speed Visual Acquisition of X-ray Radiography and Photography) was developed to realize visualization and quantitative characterization of the complexity of multi-phase flow, through a fast synchronous imaging system which includes a high speed (up to 100,000 fps) digital photography and a high-speed (up to 8000 fps) X-ray radiography, with advanced image processing for post-test analysis.

Figure 1. MISTEE facility 

 

Figure 2. Time sequence photography (above) and X-ray radiography (below) of a single droplet binary oxide mixture of WO₃-CaO melt at eutectic composition (75:25 mol%, M_melt ≈1g, T_melt ≈ 1235 K and ∆T_sub ≈ 80K)