Techique for calculating flow and heat transfer in reactor inlet section in two-dimensional approximation is described. The reactor inlet section is presented in the form of a curved two-dimensional rotation surface, for which numerical solution of the system of hydrodynamic and heat transfer equations is performed. Results of numerical study of azimuthal nonuniformity of the field of coolant rate in the inlet slot of nuclear reactor and in intake header are presented. 6 refs.; 6 figs.