ConverDyn studies second US uranium conversion plant amid supply concerns

ConverDyn’s look at a second uranium conversion plant put one of the nuclear fuel cycle’s most exposed chokepoints back in focus: the only domestic U.S. source of uranium hexafluoride for enrichment. At the World Nuclear Fuel Cycle 2026 conference in Monaco, Hyder Ramatala said stronger market certainty helped justify the company’s February plan to raise output at Metropolis Works in Illinois, and that ConverDyn had begun studying a possible second facility, which he described as Metropolis 2.0.

The practical problem is straightforward. Uranium oxide concentrate has to be converted into UF6 before enrichment can happen, and Metropolis Works is still the only commercial U.S. plant doing that work. A second facility would give utilities and reactor developers a hedge against supply disruption, reduce reliance on a sole-source bottleneck, and improve the odds that new reactor projects can secure fuel on the schedule they need. For a sector trying to support both existing reactors and advanced designs, that is not a theoretical issue.

Solstice Advanced Materials said on February 10 that Metropolis Works was projected to produce more than 10 kilotonnes of UF6 in 2026, about 20% above planned 2024 output. The company said its backlog was more than $2 billion, driven by long-term customers, many of them domestic utilities, and said it had retained a leading engineering, procurement and construction firm to complete an initial engineering analysis for new capacity expansion investments. It also said it was actively exploring additional projects to increase production at the plant.

That makes the conversation more than conference-stage signaling. ConverDyn, the partnership between Solstice Advanced Materials and General Atomics that markets all UF6 from the site, has moved into early engineering work, the first real step toward any future permitting and capital decision. Ramatala said the study would examine how long a new plant could take, what it would cost and whether modularity is possible in conversion infrastructure.

Metropolis Works has deep roots in the industry. Built in the 1950s, it began supplying civilian UF6 in the late 1960s and later reached a nameplate capacity of 15,000 tonnes a year after upgrades and expansions. The plant was idled from 2017 to 2023 because of weak market conditions, then restarted in July 2023 after ConverDyn secured enough long-term contracts. A U.S. Nuclear Regulatory Commission inspection covering July 1 to September 30, 2023 found no violations of more than minor significance during restart-related work.

The timing matters because the market is changing fast. A 2016 Department of Energy document described Metropolis Works as the only domestic commercial conversion facility authorized to turn U3O8 into UF6, while FluxPoint Energy says it is developing what it expects to be the first new U.S. conversion plant in 70 years. With U.S. policy aiming to quadruple nuclear capacity by 2050, conversion has moved from a background utility function to one of the decisive links in the next buildout.