Minor actinides represent the long-term radiotoxicity of nuclear wastes. As one of their potential incineration options, partitioning and transmutation in fission reactors are seriously considered worldwide. If implemented, these technologies could also be a source of nuclear fuel materials required for sustainability of nuclear energy. The objective of the U.S. DOE NERI Project is to assess the possibility, advantages and limitations of achieving ultra-long life VHTR (Very High Temperature Reactor) configurations by utilizing minor actinides as a fuel component. The analysis takes into consideration and compares capabilities of pebble-bed and prismatic core designs with advanced actinide fuels to approach the reactor lifetime long operation without intermediate refueling. This paper discusses the up-to-date research efforts. Whole-core/system 3D models with multi-heterogeneity treatments and property databases of actinide compounds are developed together with relevant benchmark problems to compare computational results with experiments. Obtained results are in agreement with the available HTTR and HTR-10 data. Studies of actinide-fueled VHTR configurations indicate promising performance characteristics. Utilization of minor actinides as a fuel component would facilitate development of new fuel cycles and support sustainability of a fuel source for nuclear energy assuring future operation of Generation IV nuclear energy systems.