In order to study radiation stability of the neutron supermirror coatings, the effect of large irradiation doses on polarizing (FeCoV/TiZr) and non-polarizing (NiMo/Ti and Ni/Ti) supermirrors has been studied. The samples were irradiated at the WWR-M reactor (Gatchina) inside a vertical channel behind the Be reflector, where the flux of thermal neutrons and neutrons with energies exceeding 1 MeV was, respectively, (0.6-1) × 10¹³ and 2 × 10¹¹ cm^-2 s^-1. During irradiation the temperature of the samples did not exceed 70°C. The data obtained at the reflectometer RPN-2M (PNPI) for FeCoV/TiZr and NiMo/Ti supermirrors (produced in PNPI) and for Ni/Ti supermirrors (produced in PSI), irradiated with different doses, are presented. The polarizing efficiency and the reflectivity of the supermirrors sputtered onto float-glass substrates have not revealed significant changes for the fluences up to 10¹⁹ cm^-2.