A step into nickel thermal diffusion: from self-diffusion to stainless steel substrate

Internal parts of the RPV are exposed to a high flux of energetic neutrons that can lead to irradiation damage, such as irradiation induced embrittlement, void swelling and irradiation creep. This study focuses on the thermal diffusion coefficients of nickel into nickel and into iron to understand better the mechanism of irradiation creep. The thin film method has been used to analyse the diffusion properties of nickel and iron. In order to predict the concentration profile of nickel in two different substrates a computer simulation has been performed using the computer algebra system Maxima. The concentration profiles, obtained with the simulation, show that nickel self-diffusion is faster than the thermal diffusion of nickel into iron. Moreover, between 500 °C and 600 °C temperature affects diffusion more than the diffusion time. Further studies will be conducted by Anna Nastruzzi