THE PROCESS OF FRAGMENTATION OF MODEL CORIUM DURING INTERACTION WITH THE COOLANT

This paper presents the results of a study of the granulometric parameters, elemental and phase compositions of a solidified model melt of a nuclear reactor core (corium) obtained in out-of-pile conditions. The out-of-pile experiments are conducted in the EAGLE test-bench of the IAE NNC RK, which allows obtaining a melt of the burden from the components of the core and implementing its interaction with the coolant. To obtain the model corium of a fast neutron reactor, aluminum oxide (Al₂O₃) was used, and sodium was used as a coolant.

The results of the studies revealed the presence of three modifications of aluminum oxide Al₂O₃ in the phase composition of the solidified simulator. The main one is the α-modification (corundum), which is also the basic component of the initial burden. The appearance and regular distribution of other crystalline modifications of aluminum oxide is definitely a sign associated with the features of the processes occurring during the interaction between model corium and the coolant. Such features may be characteristic and extend to the actual melt of the reactor core, but may also be specific to the simulator used.

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