Characterization of the VULCANO test products for fuel debris removal from the Fukushima Daiichi Nuclear Power Plant

The characteristics of fuel debris are required to develop tools to remove it from severely damaged nuclear power plants, but the knowledge on molten core concrete interaction (MCCI) product is limited.The VULCANO MCCI test campaign, VBS-U4, was selected for the analysis as the conditions are similar to MCCI at Fukushima daiichi nuclear power plant.Physicochemical phenomena during MCCI were estimated from the macrostructure of the samples.Moreover, heterogeneous microstructure of the oxide region and homogeneous microstructure of the metallic region was confirmed.Additionally, the obvious difference of Vickers hardness between oxide and metallic phase is evaluated.