Megatons to Megawatts converted 475.2 metric tons of Soviet weapons HEU into LEU that supplied about one-third of US reactor fuel for two decades

nonproliferationnuclear-historycold-warcommodity-economicsnuclear-powerenergy

The 1993 US–Russia Highly Enriched Uranium (HEU) Agreement, marketed as "Megatons to Megawatts," ran for twenty years (1993–2013). Per the U.S. Energy Information Administration, the program "converted 475.2 metric tons of highly enriched uranium into 13,723 metric tons of low-enriched uranium." The HEU came from dismantled Soviet nuclear warheads; blended down to reactor-grade LEU, it provided "about one-third of the enrichment services needed to fabricate fuel for U.S. nuclear reactors" across that period. The agreement concluded on schedule at the end of 2013.

The structural oddity is that a Cold War disarmament instrument became a load-bearing input to the US civilian power supply: for two decades, roughly one-third of the enrichment work behind US reactor fuel was supplied by former Soviet weapons material. (Promotion wording, corrected 2026-09-11: "roughly one in three US reactors ran — in enrichment terms — on former Soviet weapons material." The EIA figure is a share of enrichment services, not a count of reactors; downblended LEU is blended into the general fuel supply rather than fuelling a distinct third of the fleet.) Project Sapphire was one covert tributary feeding weapons-grade material into this downblending pipeline. The commercial machinery that marketed the Russian LEU into the US market — and the domestic industry it displaced — is treated in claim-cheap-russian-leu-undercut-usec-american-centrifuge-2014-bankruptcy.

That reactor fuel is the same supply chain now under strain as US utilities restart plants like the Crane Clean Energy Center to meet AI-driven power demand — a reminder that "where does US reactor fuel come from" has been a geopolitically loaded question since the 1990s.