Why Can't Advanced Nuclear Reactors Scale Without HALEU?

Scott Nolan says advanced reactors cannot scale without high-assay low-enriched uranium, HALEU, because that fuel is what makes a smaller core possible and almost nobody outside Russia sells it.

Today's grid reactors run on uranium enriched to about 3 to 5 percent. HALEU is enriched to just under 20 percent, about 19.75 percent. The higher level unlocks a much smaller core, so the reactor can be built in a factory and shipped in modules instead of constructed as a one-off on site. That smaller format is a large part of how the new designs try to bring cost down.

Supply is the other half. Only Russia makes HALEU commercially today. In mid-2024, Congress passed a ban on imports of Russian uranium that takes effect on January 1, 2028. Nolan's first mission is to produce HALEU before the end of the decade for those reactors, and the second is to bring the cost of that fuel down.