Liquid Metal Fast Reactors (LMFRs) represent one of the most promising concepts within the Generation IV framework. Fission reactor core design is an inherently complex, multi-physics challenge, making the development of reliable and computationally efficient simulation tools essential. These tools support preliminary design phases and accurately predict core behavior during operational and off-normal transients. The unique characteristics of LMFRs, specifically their fast neutron spectrum and the high thermal inertia of liquid metal coolants, yield dynamic behaviors that differ fundamentally from traditional Light Water Reactors, necessitating dedicated computational codes. In this context, the Fast REactor Neutronics/Thermal-hydraulICs (FRENETIC) code was developed at Politecnico di Torino as an advanced multi-physics tool for the full-core simulation of liquid-metal-cooled fast reactors.