Comparison Of Radiation Embrittlement Prediction Models for Reactor Pressure Vessel

In order to promote the establishment of the material prediction model of domestic reactor pressure vessel (RPV) under high neutron flux irradiation, the prediction model of reference toughness and brittle-transition temperature variation (ΔT_R,NDT) in foreign relevant guidelines and standards were compared and analyzed from the aspects of data basis, scope of applicable neutron flux and reliability of results. The results show that all prediction models are based on a large number of experimental data, and their reliability varies greatly. RG1.99 (Rev.2) has the worst reliability, while FIS has the highest reliability. When the neutron flux is less than or equal to 7.2 × 10¹⁹ cm⁻² (E ≥ 1.0 MeV), the results of JEAC 4201 model are more conservative than NUREG/CR-6551, but when the neutron flux is larger than 7.2 × 10¹⁹ cm⁻² (E ≥ 1.0 MeV), the results are opposite. The range of neutron flux applicable to each model is different, among which RG1.99 (Rev.2) and JEAC-4201 prediction models are the highest, reaching 10.0 × 10¹⁹cm⁻² (neutron energy E ≥ 1.0 MeV). The establishment of the prediction model of domestic RPV materials under the condition of high neutron flux irradiation requires a large number of irradiation tests and in-depth research on the irradiation embrittlement mechanism, which lays the data and theoretical foundation for the establishment of the prediction model of domestic RPV materials under the condition of high neutron flux irradiation.