Study finds thousands of metric tons of undeclared uranium exported from Congo via cobalt shipments

A study published in Nature Communications in August 2026 reveals that the Democratic Republic of the Congo has exported thousands of metric tons of uranium—undeclared and with no accounting for its destination. The uranium wasn’t shipped on its own: it traveled embedded in cobalt exports, effectively invisible to international oversight.

The findings come from researchers at the University of Wisconsin–Madison and Princeton University, led by nuclear security expert Sébastien Philippe and geologist Ryan Manzuk.

Study identifies large volumes of untracked uranium in DRC cobalt exports

The research was conducted in partnership with Lighthouse Reports and the Financial Times—a collaboration that gave the findings both scientific credibility and investigative reach. Philippe, a nuclear engineering professor at UW–Madison, led the team alongside Ryan Manzuk, a geologist and research fellow working across both institutions.

This isn’t a theoretical risk flagged in advance—it’s a gap that has already allowed substantial quantities of uranium to cross borders untracked.

Their core finding is hard to brush off. The DRC has exported thousands of metric tons of uranium with no systematic record of where it ended up—not a rounding error or a minor data gap, but a structural hole in how the global community tracks one of the most sensitive materials on Earth.

Publication in Nature Communications gives the findings peer-reviewed weight. Combined with investigative reporting from Lighthouse Reports and the Financial Times, the research is positioned to land with both the scientific community and policymakers who might actually do something about it.

How uranium enters cobalt supply chains undetected

The mechanism isn’t complicated, though it’s easy to miss if you’re not looking for it. Uranium naturally co-occurs with cobalt deposits in the DRC’s Copperbelt region—the two minerals share geological space, which means when cobalt ore gets extracted and processed, uranium often comes along for the ride. Philippe and Manzuk used countrywide mineralization and geochemical data to map how widespread this co-occurrence actually is, and their analysis shows it’s a consistent feature of the region’s geology, not an isolated anomaly.

Cobalt ore processing and export procedures don’t systematically screen for uranium content. They don’t require it to be declared either. Shipments leave the country carrying uranium that nobody officially acknowledges is there.

Crucially, the study frames this as a structural gap rather than deliberate smuggling. The uranium isn’t being hidden on purpose—it’s simply not being looked for. That distinction matters for how the international community responds, but it doesn’t make the oversight failure any less serious.

Implications for nuclear nonproliferation oversight

The study puts it plainly: this is a blind spot in nuclear nonproliferation frameworks. No international body currently holds a clear record of where the exported uranium has gone. Tracking uranium movement—even low-grade material—is a cornerstone of global nuclear security, which makes that absence genuinely alarming.

The volume involved is large enough to concern specialists in the field. Philippe’s background in nuclear security underscores why the findings carry weight beyond academic interest. This isn’t a theoretical risk flagged in advance—it’s a gap that has already allowed substantial quantities of uranium to cross borders untracked.

International nuclear safeguards are built around declared nuclear activities and facilities. When uranium moves embedded in a commodity export tracked primarily for its industrial value, it falls outside the standard monitoring architecture entirely. The study suggests that architecture has a meaningful hole in it—one that existing institutions weren’t designed to catch.

Without destination records, retroactively determining where thousands of metric tons of uranium ended up becomes extraordinarily difficult. That ambiguity is precisely what makes the finding so concerning to those working in nonproliferation.

Background: The DRC’s role in global cobalt and uranium supply

To understand why this matters at scale, the DRC’s position in global supply chains needs some context. The country produces roughly 70% of the world’s cobalt, making it the dominant supplier of a mineral critical for electric vehicle batteries and consumer electronics. Its cobalt supply chain is already among the most scrutinized in the world, largely because of concerns about labor conditions and conflict minerals.

What gets far less attention is the DRC’s uranium history. The country holds significant uranium deposits, and its ore played a direct role in the Manhattan Project—a reminder that the DRC’s uranium isn’t a minor footnote. It carries real strategic significance.

Cobalt’s importance to the clean energy transition has pushed its supply chain into the spotlight, but the focus has been almost entirely on labor rights and sourcing transparency. What else might be traveling alongside the cobalt has barely registered as a question. The uranium finding adds a new dimension to an already complicated conversation—one the industry wasn’t having.

Existing international nuclear safeguards simply weren’t designed with this scenario in mind, having been built to monitor declared nuclear programs and facilities rather than uranium moving quietly inside non-nuclear commodity exports. Closing that gap would likely require new monitoring requirements at the point of extraction and export, according to the American Nuclear Society—a significant logistical and diplomatic undertaking by any measure.

Implications extend beyond one country’s records

The study’s central finding is that thousands of metric tons of uranium have left the DRC inside cobalt shipments, undeclared and untracked. Led by Philippe and Manzuk and published in Nature Communications, the research identifies this as a structural gap in nonproliferation oversight—not deliberate smuggling, but a systemic failure to look. Given the DRC’s dominant role in global cobalt supply and its historically significant uranium deposits, the implications extend well beyond one country’s export records. The findings point to a need for updated international frameworks that account for uranium embedded in non-nuclear commodity trade.

Kelly Lippke

Kelly is an experienced writer with 15 years of experience exploring the big stories that shape our world, from tech breakthroughs and space exploration to climate, energy, and the fascinating quirks of science. She has a talent for turning complex ideas into sharp, memorable insights that stay with readers long after they’ve finished reading.