Experimental Simulation of Decay Heat of Corium at the Lava-B Test-Bench

During the development of a severe accident at a nuclear power plant (NPP), corium is formed—a melt of core materials. A distinctive feature of corium, due to the content of fuel elements in its composition, is the presence of decay heat, which makes a significant contribution to the nature of the interaction of the corium melt with the structural materials of the reactor plant. In this regard, the decay heat should be taken into account when conducting computational studies and physical experiments. For this reason, certain requirements are imposed on the methods of simulating decay heat in the corium prototype, which relate to both the uniformity of the volume distribution and its intensity.

This paper presents the results of calibration experiments to substantiate the operability of the induction heating system of the Lava-B test bench, which is used to simulate decay heat in the study of processes occurring during an accident with the NPP core meltdown. So, in order to obtain optimal characteristics of the heating system, a series of experiments was conducted on heating the graphite block in the experimental section of the Lava-B test bench. In the experiments, the capacitance of the used oscillating circuit capacitor banks and the electrical power on the inductor varied. As a result of the analysis of the data obtained, the most optimal parameters of the inductor-load simulator system were determined. In general, the performed experiments confirmed the operability of the induction heater and the possibility of its use in experimental studies of the interaction of corium with the various structural elements of the NPP reactor core at the Lava-B test bench.