Study on water jet penetration behavior in molten LBE during SGTR accident with simulant experiments

•The water jet penetration behavior is studied with simulant experiments.•The cavity effect caused by the bubbles produced by the boiling effect of the jet will periodically increase the maximum penetration depth of the jet.•Visualized images of ethanol jets under boiling and non-boiling conditions in FC-40 at different temperatures are obtained by experiments.•When the maximum penetration depth of the jet at a temperature higher than the boiling point under the pool pressure rises due to the isolation effect of the fragmented bubbles produced by the intense flashing phenomenon.