A semiempirical correlation for an estimate of crust thickness in a molten pool is presented and validated against published experimental data. The proposed correlation between the dimensionless crust thickness and the Biot and the Prandtl numbers has been developed as [overbar]* = 14.49BiPr -0.074. A scaling methodology is discussed to analyze the thermal resistance of the crust. The results are of interest for the corium melt coolability in a postulated severe accident scenario in a light water reactor.