[en] One-dimensional analysis of rewetting a vertical hot surface is carried out without neglecting heat transfer in the unwetted region. The physical model consists of an infinitely extended vertical thin slab whose initial surface temperature is higher than the Leidenfrost point. During rewetting, three different regions of constant heat transfer coefficients are assumed: (1) the surface of the wetted region as characterized by a higher constant heat transfer coefficient (h/sub c/), (2) the two regions of unwetted surface which is precooled via a lower constant heat transfer coefficient (h/sub df/) for the fog-film region, and (3) the negligible heat transfer coefficient for the superheated vapor-film region (h/sub ds/). An explicit formula which computes the wet front velocity is obtained for the more general case when the value of h/sub df/ is a finite value. A quantitative analyses of phi and fog length (l), which denotes the fraction of unevaporated water droplets (and vapor) constituting fog-film flow and the distance between the wet and fog front, respectively, are carried out using the most typical bottom-flooding experimental results as reported by Case et al., and PWR-FLECHT report. The results show that phi values fall within the upper and lower bounds derived from theory