The program goal of ONWARDS is to support the development of technologies that address significant challenges to closing the back-end of advanced reactor (AR) nuclear fuel cycles. Specifically, projects funded under the ONWARDS Program will develop and demonstrate sustainable technologies that will significantly improve the disposal impact of used nuclear fuel (UNF) and other waste streams stemming from the implementation of AR fuel cycles by developing innovative and cost-effective approaches in reprocessing, material accountancy, and waste forms. ONWARDS metrics include an order-of-magnitude reduction in AR waste volume generation or repository footprint compared to light-water nuclear reactors (LWR), better than 1% fissile-mass accountancy in reprocessing streams, development of high-performance AR waste forms for a variety of potential deep-geological repositories (DGR) and disposal concepts, and costs in the range of $1/megawatt-hour (MWh).