Radiation embrittlement of support structure materials for WWER RPVs.

Radiation embrittlement of materials of support structures (SS) for reactor pressure vessel (RPV) of WWER types is considered. The features of radiation embrittlement of SS materials are connected with low irradiation temperature no exceeding 90 °C and also with a use of the steels which are usually applied for different building structures and have not a high resistance to the radiation embrittlement. The experimental date on standard mechanical properties and fracture toughness have been obtained for various steels and weld metals in the initial and irradiation conditions. SEM investigation of fracture surface of fractures toughness specimens and investigation with atomic-tomography method have been performed. The model for prediction of material radiation embrittlement as a function of the neutron fluence and the impurity (Cu and P) content is developed. The irradiation temperature effect is considered on various mechanisms of radiation embrittlement of a material. [ABSTRACT FROM AUTHOR]