**The enriched uranium recently returned to the United States(announced by the U.S. Department of Energy’s National Nuclear Security Administration on May 8–9, 2026, with the shipment arriving in early May)originated from the United Kingdom and was fuel for Venezuela’s now-decommissioned RV-1 research reactor.
It consisted of 13.5 kg (about 30 pounds) of highly enriched uranium (HEU, enriched to just above 20% U-235) in the form of spent/low-burnup nuclear fuel assemblies stored at the reactor site at the Venezuelan Institute for Scientific Research (IVIC), about 15 km southwest of Caracas. The RV-1 was a U.S.-designed (General Electric) pool-type materials testing reactor that went critical in 1960 under the U.S. Atoms for Peace program and operated for physics and nuclear research until it shut down in 1991; the fuel then became surplus.
### Key details on origin and history:
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UK origin of this specific material: The RV-1 used nuclear fuel containing uranium from both the United States and the United Kingdom during its lifetime. Earlier repatriations (1998–1999) removed 56 spent fuel assemblies of U.S.-origin HEU back to the United States under the U.S. Research Reactor Spent Nuclear Fuel Acceptance Program. The remaining ~20 fuel assemblies (the ones just removed in 2026) were of U.K. uranium origin—low-burnup HEU supplied by the United Kingdom. This is confirmed in official IAEA statements and historical records from the reactor’s fuel inventory.
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The uranium was not Venezuelan-mined or enriched domestically; Venezuela has no domestic enrichment capability. It was foreign-supplied reactor fuel under international safeguards.
### What happened to it:
The material was securely packaged into a spent-fuel cask at IVIC, transported overland (~100–160 miles) to the port of Puerto Cabello under Venezuelan military escort, then shipped by sea aboard a specialized U.K. Nuclear Transport Solutions vessel to the U.S. Savannah River Site in South Carolina. There, it will be processed (down-blended) into high-assay low-enriched uranium (HALEU) for future U.S. nuclear energy programs. The operation was a joint U.S.–Venezuela–U.K.–IAEA effort coordinated by the NNSA’s Office of Defense Nuclear Nonproliferation.
This completes the removal of all enriched uranium from Venezuela, eliminating a potential proliferation/security risk from the legacy reactor site. No other sources or origins (e.g., Russian, Iranian, or Venezuelan domestic production) are indicated in official U.S., IAEA, or related reporting.
Source: GROK A.I.