Measurement of corium surface tension using the maximum bubble pressure

Highlights: • The maximum bubble pressure technique has been used to measure the density and the surface tension of molten materials up 2550 °C. • Original results have been obtained considering the corium C32 at the melting point 2470 °C. • These results have been compared to former RASPLAV test results showing good agreement. The paper proposes a description of the maximum bubble pressure (MBP) technique that has been used to measure the density and the surface tension of high temperature molten materials (up to 2550 °C). The technique has been implemented in the VITI facility in order to characterize corium thermophysical properties. The facility is presented together with its instrumentation and uncertainty assessment. In a first step, the VITI-MBP device has been qualified by measuring reference material surface tension at room temperature (ultrapure water) and at high temperatures (Pure Alumina, 99.99%). Then, original results of corium density and surface tension have been obtained considering the corium C32 (32% oxidized corium) at the melting point 2470 °C. These results have been compared to former RASPLAV test results showing good agreement.