The FAST fuel performance code, the SCALE neutronics code, and the MELCOR severe accident code have been used to support NRC research, licensing, and oversight activities for more than 4 decades. NRC continues to update and improve its computer codes and analysis methodologies due to the recent interest in advanced nuclear technologies such as accident tolerant fuel (ATF) and advanced (non-light water) reactors. This exhibit will describe new features and capabilities that have been added to MELCOR, FAST, and SCALE to accommodate these new technologies.Examples will also be provided on how these updated computational tools are applied for these advanced nuclear technologies. These include SCALE/MELCOR modeling of the Hermes non-power test reactor (i.e., fluoride salt cooled high temperature reactor); development of regulatory source term for HALEU/HBU/ATF fuels; and demonstration workshops of the advanced reactor fuel cycle. MELCOR, SCALE, and FAST will continue to support the NRC in conducting timely reviews of advanced nuclear technologies to ensure public health and safety.