[en] The experimental and calculational investigations of radiation heating in fissionableless materials used in thermal heterogeneous reactor channels is out. The character of the heating radial distribution in the zone of an axial reflector is determined. The technique for determining energy release during ν radiation absorption in Be, Zr, Al and Fe based on the Gray theory is developed. The mesurements are performed at the critical assembly representing a strongly heterogeneous system the core of which consists of 108 channels in a water moderator and surrounded by a radial reflector. An ionization chamber of special construction was used for measurements. Calculation of heating is performed according to the QUANTA program which realizes the solution of stationary equation of ν radiation transport in heterogeneous medium by the Monte Carlo method. It is shown that ν radiation flux over the assembly radius in all cross sections by the fuel height and over the height of the assembly for all channels can be described by the same distribution within the limits of 10%. The comparison of experimental and calculational absolute values shows the presence of their systematic divergence within the limits of 30%. It is concluded that the data obtained permit to perform correction of the methods and programs for heating calculation and have a practical advantages when solving the problems of heat release profiling in the reactor core