Semi-Mechanistic Analytical Model for Radiation Embrittlement and Re-Embrittlement Data Analysis

Abstract

A simple model based on the additive contribution of three independent radiation damage mechanisms has been developed in order to analyse and understand embrittlement and re-embrittlement data. The proposed model can also be used for fitting purposes if sufficient data points are available and in those cases where non-regular behaviour is observed. In particular, the model can explain the different behaviour of re-embrittlement when compared to primary embrittlement as has been observed for annealed VVER-440 RPV materials with high P contents. The model itself, its assumptions and its potential are explained in detail in this paper together with the predicted behaviour and comparison with available selected example data from JRQ steel, 15H2MFA VVER-440 RPV forgings and VVER-440 welds.