Modelling the system Cr-Fe-Ni-Te via the CALPHAD method, DFT and experiments : for fast nuclear reactor applications

Abstract: In the pursuit of safer, more environmentally friendly and sustainable forms of energy production for our ever growing demands, a type of nuclear reactor cooled by liquid metal instead of water is under development. Specific to this type of reactor are special forms of corrosion of the material that encapsulates the fuel pins in the reactor core, called Fuel-Clad Chemical Interaction (FCCI) or Fission Product-induced Liquid Metal Embrittlement (FPLME). This is a complicated chemical process which has been observed in the fuel pins of Sodium-cooled Fast neutron Reactors (SFR). In order to predict the consequences and impact of this corrosion, it must be simulated, which requires a description of the thermodynamics of the elements involved, i.e. Cr--Cs--Fe--Ni--Te--O. This thesis covers the development of a thermodynamic description of the Cr--Fe--Ni--Te system by model parameter optimizations supported by first-principles calculations and experimental investigations.