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

Abstract

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.

A Link between Neutron and Ion Irradiation Hardening for Stainless Austenitic and Ferritic-Martensitic Steels

“…The non-hardening mechanism is taken into account by changing the value of the coefficient k σ depending on the phosphorus content. FMS with an impurity content below the threshold (required for the formation of segregation) are embrittled only by the hardening mechanism [27]. For such materials, the coefficient k σ does not depend on the content of impurities.…”