When the Department of Energy’s Advanced Research Projects Agency–Energy launched the Optimizing Nuclear Waste and Advanced Reactor Disposal Systems (ONWARDS) program in 2022, it posed a challenge that the nuclear industry had never seriously confronted before: how to design waste management solutions that anticipate the coming shift to advanced reactors and not merely retrofit existing systems built for an older generation of technology. The program’s objectives were ambitious—reduce disposal footprint, enable scalable pathways for unfamiliar waste streams, and build the technical foundations for future disposal—yet also tightly grounded in the realities of emerging nuclear fuel cycles. For the nuclear community, this was a timely call. Advanced reactors were accelerating toward deployment, but the waste management systems needed to support them had not kept pace.