Experimental study on surface reaction during water injection on molten Zr/Fe pool

•Neither vapor explosion nor melt ejection is found for the investigated experimental conditions.•When the content of Zr is 60%, H2 produced by Zirconium-water reaction accounted for a small proportion of total gas generation but led to some cavities on the metal production.•There were three kinds of oxides on the surface of metal production all of which composed of oxides of iron and zirconium in different proportions.