Washington’s gamble on metallic fast reactors could turn bomb metal into centuries of power.

In October 2025, the US Department of Energy launched an unprecedented offer: 19.7 tons of surplus weapons-grade plutonium, material that once sat at the heart of thousands of nuclear warheads, was now up for grabs by private reactor developers. 

Of this total, 4.4 tons remain in pure metallic form and 15.3 tons as oxide powder. The fraction in metallic form is the prize. It is the only form that can be directly alloyed with uranium and zirconium to make the high-performance fuel pins favored by the new generation of sodium-cooled fast reactors (SFRs). 

Contenders like Oklo (partnered with Lightbridge and Newcleo for Oak Ridge facilities), Curio (NuCycle demos), and TerraPower all have their eye on the prize, with selections due by year’s end. Applicants must foot all costs, potentially paying DOE fees, amid safeguards tying sites to IAEA lists.

The allure is not merely technical convenience but is also its breeding performance. A breeding ratio of 1.5 means that for every 100 kg of plutonium fissioned, the reactor produces 150 kg of new plutonium from the depleted-uranium blanket.

The breeding........

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