An Empirical correlation to predict the distance for fragmentation of simulated Molten-Core materials discharged into a sodium pool

Matsuba, Kenichi  ; Isozaki, Mikio; Kamiyama, Kenji  ; Suzuki, Toru; Tobita, Yoshiharu

In order to evaluate the distance for fragmentation of molten core material discharged into the lower sodium plenum during core disruptive accidents in sodium-cooled fast reactors, experiments with simulated molten materials and coolants (water, sodium) was carried out, where an empirical correlation of the distance for fragmentation was developed. The empirical correlation developed by this study showed a good agreement with the measurement results obtained by the present experiments. It was found that in order to well-predict the distance for fragmentation in sodium, thermal phenomena, such as sodium boiling and resultant vapor expansion, needed to be considered.