Event Timeslots (1)

Day 1 – June 20
Insoluble dopants such as chromia, Cr₂O₃, and alumina, Al₂O₃, are often added to UO₂ fuel to enhance fuel properties. Such properties include larger grain sizes and increased fission gas retention. Dopants may segregate towards more favourable regions in the fuel, such as grain boundaries, creating amorphous or disordered regions. Diffusion along potentially disordered grain boundaries may differ to that observed in the crystalline bulk, which has been discussed in previous modelling work on ZrO₂. In this work, we use classical molecular dynamics to simulate amorphous undoped and Cr doped UO₂ systems. A range of temperatures and Cr concentrations have been analysed, and diffusion of all species have been computed. Comparisons have been made between crystalline and amorphous, undoped and doped, counterparts where appropriate. This will allow us to deduce whether diffusion is impacted based on the structure of the system, and how this may relate to potential amorphous grain boundary formation in doped UO₂ fuel pellets.