In the paper the large-scale irradiation experiment is described. It is aimed at the experimental assessment of the effect of reactor pressure vessel wall on neutron flux, neutron energy spectrum as well as irradiation embrittlement through the vessel wall. The experiment was realized within the IAEA Technical cooperation project. The irradiation was performed in the RIAR, Dimitrovgrad, Russian Federation, under the coordination by the Nuclear Research Institute Rez plc, Rez, Czech Republic. Mechanical testing and neutron dosimetry will be performed in both organizations with the larger part in the coordinating institute.