[en] The results of experimental determination of rewetting rate of the preliminary heated bundle of seven fuel rods arranged in a vertical channel, when upflow cooling, are given. The experiments are carried out at 0.3-1.6 kg/(mxs) spray density, 20-95 deg C inlet water temperature, 300-700 deg C initial temperature of rods, heat flux up to 60 kW/m², 0.1 MPa pressure. The conclusion is made that time of total cooling of the rod bundle with spacers is mainly determined by formation of additional regions of wetting on spacers