On the radiation embrittlement of materials of support structures for WWER RPV. Part 2. Analysis of the completed studies

The features of the radiation embrittlement of materials of support structures for WWER RPV are considered. These features are connected with low irradiation temperature no exceeding 90oC and also with a use of the steels which are usually applied for building of the metal structures and have not a high resistance to the radiation embrittlement. The model for prediction of material radiation embrittlement as function of the neutron fluence and impurity of Cu and P is proposed. An irradiation temperature effect on the different mechanisms resulting in the material radiation embrittlement is considered: materials hardening due to nucleation of point defects and formation of dislocation loops, copper precipitation and materials non-hardening due to phosphorus segregation.