## 3 Research Results and Discussion  
When conducting the computer simulation of the induction heating of the burden at the set power level of the inductor, the temperature at the control points reached 2500 K in \(\sim\)75 min after the start of heating. Therefore, the average temperature of the resulting cerium was \(\sim\)2350 K. Figure 3 shows the results of computer simulation. Figure 4a shows  
After the computer simulation, an experiment was conducted to produce a prototype of corium in the MR's melt trap. Table 1 provides the main data obtained based on the experiment. Therefore, the main parameters of the physical experiment correlated with the results of the computer simulation. Figure 5 shows the diagram of the burden temperature in the trap. According to expectations, due to the features of induction heating, in particular the skin effect [15], more intense heating occurred at the side walls of the refractory blocks, as shown by thermocouples 1-04 and 1-05. Thermocouple 1-08 failed. As the presented diagram shows, at 50 min there were sharp changes in the thermocouple readings near the side walls of the refractory blocks. Thus, it is possible to make an assumption about the beginning of the melting process and the intense interaction of the burden components (probably, the melting of steel and zirconium). Thus, it could be concluded that the metal components became liquid and formed a corium pool in the melt trap within an hour after starting the experiment. Visual confirmation of the melting of the corium components were the smudges of the solidified melt revealed after the opening of the MR, which escaped through one of the horizontal cracks in the lower third of the concrete trap (Figure 6). At the same time, as it was supposed in the course of computer simulation, the inductive heating of the corium led to the formation of overheated regions and thermal stress centers in the concrete wall of the trap. Due to the thermal stresses that occurred in the wall of the concrete trap, cracks formed through which the melt flow  
Figure 5: Change in the burden temperature during the experiment. \begin{table}
\begin{tabular}{c c c} \hline
**No.** & **Parameter** & **Value** \\ \hline
1 & Test duration, min & 120 \\ \hline
2 & Active heating phase, min & 80 \\ \hline
2 & Inductor average power, kW & 120 \\ \hline
3 & Integral amount of heat supplied to the corium, MJ & 529.74 \\ \hline
4 & Maximum temperature, K & 2305 \\ \hline \end{tabular}
\end{table} 
Table 1: Experiment parameters. When studying the burden material resulting from the heating, its components were removed layer by layer in two stages. Figure 8 shows the removed material. At the first stage, fragments of steel and zirconium loading rods were removed (Figure 8, left), which were the remains of vertically located loading rods melted from  
Figure 8: Materials removed from the trap. Figure 6: Solidified melt escaped through a crack in the wall of the concrete trap. (**a**) Location of the solidified melt on the surface of the trolley; (**b**) Material collected from the surface of the trolley; (**c**) Solidified melt drops from the bottom of the MR vessel. Figure 7: Outer view of the trap after removing a part of the wall. below. Following these were the partially sintered fragments of the dispersed components of the mixture (uranium dioxide pellets, zirconium dioxide powder, zirconium plates) (Figure 8, right). In the second stage, the remains of the vertical loading rods were removed, melted at or slightly below the maximum protruding level of the compacted burden. The removal led to the separation of part of the burden fragments that had undergone melting, which formed a \"crust\" from uranium dioxide pellets bound by a metal melt (Figure 9). Based on the study of the produced cerium, as Figures 8 and 9 show, it can be concluded that the components of the burden in the concrete trap were not completely melted.