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The brittle–ductile transition temperature (BDTT) and fracture toughness are useful indicators of the brittleness of reactor pressure vessel materials. However, current methods to analyze these parameters are expensive and time-consuming; moreover, the relevant mechanism is not very clear. Thus, in this study, a body-centered cubic crystal plasticity finite element model (CPFEM) based on the densities of dislocation and irradiation defects, which are full- and partial-absorption dislocation loops, was numerically implemented on A508-3 steel. Irradiation embrittlement was investigated in the CPFEM framework. The cleavage failure model for a representative volume element was proposed to calculate the BDTT, the results of which agreed well with experimental results in the literature for both unirradiated and irradiated samples. The risk for brittle failure is higher for irradiated samples at constant temperature. Furthermore, the proposed model combined with the Beremin cleavage fracture local approach, could estimate the fracture toughness of A508-3 steel at different temperatures before and after irradiation. The results obtained were consistent with reported experimental data, indicating that irradiation exacerbates the embrittlement. This work is beneficial to the calculation and evaluation of irradiation effect of RPV steel, providing reference for the research of reactor life extension. [ABSTRACT FROM AUTHOR]

The study of irradiation hardening and embrittlement is critically important for the development of next-generation structural materials tolerant to neutron irradiation, and could dramatically affect the approach to the design of components for advanced nuclear reactors. In addition, a growing interest is observed in the field of research and development of irradiation-resistant materials. This review aims to provide an overview of the theoretical development related to irradiation hardening and embrittlement at moderate irradiation conditions achieved in recent years, which can help extend our fundamental knowledge on nuclear structural materials. After a general introduction to the irradiation effects on metallic materials, recent research progress covering theoretical modelling is summarized for different types of structural materials. The fundamental mechanisms are elucidated within a wide range of temporal and spatial scales. This review closes with the current understanding of irradiation hardening and embrittlement, and puts some perspectives deserving further study. [ABSTRACT FROM AUTHOR]

Basing on the analysis of the radiation embrittlement of RPV materials, the paper proposes a model and dependencies for description of WWER-1000 vessel material embrittlement with copper content above 0.10%. Standard dose-time trend curves have been modernized. The dose-time trend curves have been modernized. [ABSTRACT FROM AUTHOR]

In fractographic study of steels of nuclear reactor vessels after tests for crack resistance, two major sources of brittle destruction are detected: nonmetallic impurities and intergranular or subgranular boundaries. X-ray spectral microanalysis reveals that these are manganese sulfides and silicon oxides. The probable size of nonmetallic impurities (∼1 μm) which can initiate brittle destruction is detected. The interrelation between critical stress intensity coefficient K and distance from 'leader' to fatigue crack point CID (cleavage initiation distance) is considered. The influence of irradiation conditions on crack resistance of steels is demonstrated. [ABSTRACT FROM AUTHOR]