[en] The WWER-1000 RPV material embrittlement has been evaluated using the surveillance test data for the nuclear power plant which is under operation in Ukraine. The RPV materials after the neutron (E > 0,5 MeV) irradiation up to fluence of 22,9.10²² m^-2 have been studied. Fracture toughness tests were performed using pre-cracked Charpy specimens for the beltline materials (base and weld metal). The maximum shift of T₀ reference temperature is equal to 44^oC. A radiation embrittlement rate, A_F, for the RPV materials was estimated using the standard and reconstituted specimens. A comparison of the A_F values has shown a good agreement between the specimen sets before and after reconstitution both for base and weld metal. Furthermore it has been revealed there is no nickel effect for the studied materials. In spite of the high nickel content the radiation embrittlement rate for weld metal is not higher than for base metal with low nickel content. Fracture toughness analysis has shown the Master curve shape describes well a temperature dependence of K_Jc values. However a higher scatter of K_Jc values is observed in comparison to 95 % tolerance bounds. (author)