The project is tightly integrated into the long-term scientific collaboration between the LRS at EPFL and the Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA, France) in the field of Light Water Reactor (LWR) safety. It benefits from the ongoing OECD/NEA Framework for Irradiation Experiments (FIDES), as well as from the NEA’s NEST (“Nuclear Education, Skills and Technology”) Initiative. The focus is on the modelling and simulation of LWR nuclear fuel, in particular on the be-haviour of irradiated fuel during a postulated Loss of Coolant Accident (LOCA). In the project, LOCA tests carried out at the MIR reactor in Russia with VVER-type fuel will be simulated by making use of two cutting-edge and internationally recognized computational tools, namely: the CEA’s software platform PLEIADES/ALCYONE, and EPFL’s OpenFOAM-based software OFFBEAT. The main goal of the work is the validation, calibration and further development of the two codes based on newly available experimental data. In addition, a first-of-a-kind code-to-code benchmark of two modern multi-dimensional codes for fuel behaviour will be performed.