The results of computational and experimental studies of the thermohydraulic characteristics of lead coolant-working body contact heat exchange are presented. Water, a steam-water mixture, and 100–350°C, 1–25 MPa steam were bubbled through 0.6–2 mm in diameter openings, under a layer of lead ranging in thickness from 100 to 3000 mm, at temperatures 350–600°C into a free space in a steam generator and into space of a steam generator crowded with piping-system simulaters in the case of bubble and plume efflux and with fragmentation of the working body stream against a tubular barrier.The following were determined in the experiments: the bubble size distribution, the rise velocity of the bubbles, the structure of the two-component flow (bubble distribution inside the lead), the change of the temperature of the bubbles as they rise, the characteristics of the vaporization of a water drop in a bubble, and the temperature pulsations in the two-component lead-working body flow.