Irradiation Embrittlement Behavior and Prediction of Domestic Reactor Pressure Vessel

Reactor pressure vessel (RPV) is the core component that related to operation safety and economy of nuclear power plants (NPPs). Irradiation embrittlement is the most important factor in RPV structural integrity evaluation. China is now developing the 3rd generation RPV with 60 years’ designed life time. However the irradiation embrittlement behavior and prediction model for the neutron fluence equal to 60 effective full power year (EFPY) are unknown, which may lead to difficulty in predicting irradiation embrittlement of domestic RPV. In this work, mechanical test specimens of A508-3 steel were irradiated at temperature of (288±8) ℃ and the fluence is 1×10²⁰ cm^-2 (E>1 MeV) which is equivalent to 60 EFPY. Then tensile, impact and fracture toughness tests were carried out, and the irradiation embrittlement behavior was analyzed. On the basis of EONY, a modified irradiation embrittlement prediction model for domestic RPV steel was established. Then the model was verified by the test data. The result shows that the prediction model can predict the irradiation embrittlement of domestic A508-3 steel accurately and reliably.