Evaluation of Radiation Damage in Reactor Pressure Vessel Steel by Elastic-Plastic Fracture Mechanics

Elastic-plastic toughness characterization of SA533B nuclear pressure vessel steel is described in terms of the J integral approach. A simple test procedure has been proposed from which the J_IC value at crack extension can be estimated for both unirradiated and irradiated steels using a single compact tension specimen. The values of J_IC determined by the proposed method are compared with those determined by the single specimen compliance method. The J_IC fracture toughness of the pressure vessel steel irradiated at 200°C to a neutron flux density ranging from 6.2 × 10¹⁷ to 2.34 × 10¹⁹ n/cm² (E>1 MeV) has been explored for different test temperatures. It is shown that irradiation significantly reduces the J_IC fracture toughness of this material. These results are compared with the data available in the literature.