US Uranium Enrichment Plants: History and Status

Reference article · Updated 2026-11-06

Key facts

Enrichment at Portsmouth, Ohio ended in 2001; the Paducah, Kentucky plant stopped enriching on 31 May 2013.
Urenco USA (Louisiana Energy Services) near Eunice, New Mexico received its NRC licence in June 2006 and began operations in June 2010.
Its operating licence SNM-2010 is listed by the NRC as expiring on 9 June 2040.
Centrus has operated a 16-centrifuge HALEU demonstration cascade at Piketon, Ohio under a DOE contract since 2019.
Cleanup of the former diffusion plants is a DOE responsibility.

The gaseous diffusion era

The first US enrichment capacity was built during the Manhattan Project at Oak Ridge, Tennessee, where the K-25 diffusion plant and its successors operated. Postwar expansion added two large plants: Portsmouth in Piketon, Ohio and Paducah, Kentucky. Gaseous diffusion pumps uranium hexafluoride through porous barriers, a process that needs a very large number of stages and consumes enormous amounts of electricity, which was a main reason it was later displaced by gas centrifuges (see the enrichment page).

The diffusion plants also supplied the weapons programme in earlier decades, and later their output went to civilian reactor fuel. The government-owned plants were eventually superseded by technology with much lower energy use per unit of separative work. The units are explained on the enrichment mass-balance page, where the energy and tails trade-offs can be explored.

Portsmouth ended enrichment in May 2001 and went to cold standby; DOE accepted ownership of all nuclear material at the site in 2011. Paducah, the last operating diffusion plant in the country, ended enrichment on 31 May 2013. Before downsizing it had consumed about 3,000 megawatts of electricity at peak operation. Operation of the plants was for a period leased by DOE to the United States Enrichment Corporation (USEC), which was privatised in the 1990s and later became Centrus Energy.

Urenco USA at Eunice, New Mexico

The only commercial enrichment plant currently operating in the United States is the National Enrichment Facility near Eunice, New Mexico, run by Urenco USA. The licensee is Louisiana Energy Services, named for the site originally proposed for it. The NRC issued the licence in June 2006, construction began in August 2006 and initial operation was authorised in June 2010. The NRC lists the operating licence, SNM-2010, as expiring on 9 June 2040.

The plant was the first new commercial enrichment facility to be licensed in the United States in decades and the first to use centrifuges. Its licensing record, which includes the environmental review, the safety evaluation and hearings, is available through the NRC and illustrates how the agency handles enrichment applications: an environmental impact statement, a safety evaluation of the process and its criticality controls, and financial assurance for eventual decommissioning.

The plant uses gas centrifuge technology, like the other Urenco plants in Europe. An expansion of the facility has been reported by the International Panel on Fissile Materials as having started in 2024, with the aim of adding capacity. This page does not give capacity figures because they were not confirmed in a primary source; operators report them in their annual statements. NRC licensing for centrifuge plants is described on its gas centrifuge facility licensing page, and the licensee must have funded plans for disposing of its depleted uranium tails, which links to the stockpiles page.

USEC, Centrus and the American Centrifuge

USEC developed an American Centrifuge technology intended to replace diffusion and built a lead cascade and later a demonstration plant at Piketon. The company reorganised and emerged as Centrus Energy, and the commercial plant was not completed. Centrus continues to lease part of the Piketon site from DOE. Its annual reports describe a contract that started in 2019 under which it would build and operate a cascade of 16 centrifuges to demonstrate production of high-assay low-enriched uranium (HALEU), a fuel containing between 5 and 20 percent U-235 needed for many advanced reactor designs. A newer DOE task order is meant to move the Piketon facility from a small demonstration to commercial-scale HALEU production.

The lease has been extended to 30 June 2027, with DOE holding options to extend further. In an amendment dated 30 November 2022 the parties agreed that decommissioning and decontamination liabilities created under the HALEU contract would reside with DOE. HALEU relates to the same arithmetic as other enrichment: a higher product assay needs more separative work per kilogram, which the enrichment calculator shows.

Cleanup of the diffusion plants

Cleanup falls under DOE's Office of Environmental Management. At Paducah, waste treatment and disposal from operations was completed in 2016, according to published summaries. The vast buildings, process equipment and contaminated soil and groundwater at all three former diffusion sites require long programmes. DOE's depleted UF6 conversion plants at Paducah and Portsmouth are part of that effort, and their work is discussed on the inventories page. Decommissioning rules for commercial facilities, in contrast, are handled by the NRC; see the US decommissioning page.

One practical consequence is that the same sites combine three quite different roles: legacy cleanup, tails conversion and, at Piketon, new enrichment activity in a leased area. Responsibility is divided accordingly. DOE contractors handle cleanup and conversion, while Centrus holds the lease and is responsible for its own operations, with the liabilities arrangement noted above. Keeping these roles separate matters when reading budget figures or news items, which may refer to any one of them.

The scope and cost of the work differ by site and are reported in DOE budget documents and in reviews by the Government Accountability Office; figures change from year to year and are not reproduced here.

Current issues

Supply security. The United States relies on foreign enrichment services for a significant part of reactor fuel demand, a concern that shaped DOE's HALEU programme and discussion of new domestic capacity.
HALEU availability. Advanced reactors need fuel of higher enrichment than present reactors. The Piketon cascade is a demonstration and its scale relative to demand is a policy question.
Tails management. Commercial centrifuge plants produce depleted tails which must be deconverted and disposed of under NRC rules.
Legacy liabilities. The diffusion plants remain a DOE cleanup responsibility, with long timelines.

For the global picture of facility operators and locations see the fuel facilities page.

Frequently asked questions

Which US enrichment plant is operating today?

The Urenco USA plant near Eunice, New Mexico, licensed by the NRC in 2006 and operating since 2010. The Centrus facility at Piketon, Ohio is a small HALEU demonstration cascade.

When did US gaseous diffusion end?

Portsmouth ended enrichment in 2001 and Paducah on 31 May 2013.

What is HALEU?

High-assay low-enriched uranium, enriched to between 5 and 20 percent U-235, needed for many advanced reactor designs. Centrus is demonstrating production at Piketon under a DOE contract.

Who is responsible for cleaning up the diffusion plants?

The US Department of Energy, through its Office of Environmental Management.

When does the Urenco USA licence expire?

The NRC lists licence SNM-2010 as expiring on 9 June 2040.