Production of prototypic corium in the VULCANO facility using uranothermite and induction heating

• Uranothermite to produced corium with fifty weight percent of silica oxide. • Uranothermite to produced corium with twenty-four weight percent of iron. • Used of uranothermite with induction heating to produced fuel debris prototypes. • Production of corium simulant of the Fukushima Daiichi Unit 2 lower head debris. VULCANO is a facility of the PLINIUS severe accident platform at CEA, designed to melt up to 90 kg of UO 2 -containing prototypic corium. It is equipped with standard cameras, a thermal camera, pyrometers, weighing scales and up to 150 type-K thermocouples and 10 type-C thermocouples. In VULCANO, two melting techniques can be used separately or combined: uranothermite and induction heating. Since 2014, a 400 kW induction generator has been installed on the PLINIUS platform, with a frequency range of 80 to 300 kHz. This device has been used in various tests to directly melt corium. In 2016, a thermite workshop was added, enabling the fabrication of up to 100 kg of uranothermite in controlled conditions. A large variety of composition has been fabricated and used inside VULCANO and others PLINIUS facilities. Both melting techniques have their advantages and limitations. However, it is possible to optimize the process by combining the rapid increase in uranothermite temperature with induction heating (to simulate the decay heat or continue to increase the temperature for example). Once the corium is molten, several kinds of experiments can be done in VULCANO facility. For example: let it cool to fabricate a fuel debris block, maintain the induction heating to simulate a molten core concrete interaction or spread the molten corium on a surface. In this paper, the temperature measurement results, dismantling observation of the solidified ingot for experiments with uranothermitic heating and uranothermitic and induction heating that have been done in the VULCANO facility are highlighted.