Authors’ summary: This paper is devoted to the numerical simulation of liquid film flow on surfaces of revolution. The momentum integral method is applied in the frame of safety analysis of pressurized water reactors under hypothetical loss of flow accident conditions to simulate numerically film condensation, rewetting and vaporization on the inner surface of a water reactor containment. From the conservation of mass and momentum of a liquid film we derive an integro-differential equation for the mean velocity along a meridian of the surface of revolution. Assuming a laminar regime of the liquid film, we also derive from the above integro-differential equation an ordinary differential equation of the first-order for the film velocity, which can be integrated numerically. The film thickness distribution is obtained by using the known velocity distribution. Applications of the integral momentum method are shown for calculations of reactor containments.