Reaction experiment on core melt concrete interface under temperature gradient

Sudo, Ayako ; Onozawa, Atsushi ; Takano, Masahide 

To characterize the layer structure and respective temperatures of MCCI products, MCCI experiments using a light-concentrating furnace were performed. As the core-melt constituents, a powder mixture of (UZr)O (No.1) and (UZr)O/Zr/SUS316L/BC (No.2) were compacted into tablets (10 mm in diameter) respectively. The tablet was placed on a cylindrical piece of basaltic concrete (25 mm in diameter). The light was concentrated on the tablet under argon gas flow and samples were heated. After heating, the vertical cross-section of the solidified sample piece was subjected to phase identification and elemental analysis by XRD and SEM/EDX. No.1 sample seemed to maintain original shape, but EDX analysis showed the inner region melted. This melt was identified as-melted (U,Zr)O particle and silicate glass containing U and Zr. Ca, Fe and Mg oxide were dissolved in the particle. UO and ZrO were dissolved in the silicate glass. No.2 sample had same phases, but Fe-Cr oxide deposits from SS was identified.