DR Congo’s cobalt boom carries an unwanted cargo: uranium

On the southern border of the Democratic Republic of Congo, the lumbering trucks carrying cobalt into Zambia may soon have to pass through towering radiation detectors — a sign of mounting concerns about uranium contamination in the ores that are powering the electric revolution.

The DR Congo is the world’s largest producer of cobalt, an essential metal for batteries. But the frequent presence of radioactive materials at some of its biggest cobalt mines has led to health risks for workers, rejected shipments and concerns about safeguarding nuclear material, according to an investigation by the FT and Lighthouse Reports, a journalism non-profit.

With limited state oversight in mining regions, non-proliferation specialists and Congolese officials worry that uranium-laced cobalt ore and other radioactive material could fall into the wrong hands or enter a covert supply chain hidden from international regulators.

Uranium occurs naturally across the country’s vast “copper belt” region, which includes the mine that produced the uranium used in the atomic bombs in the second world war.

New research shows the amount of uranium mingled with the country’s cobalt exports is much greater than previously believed: between 2000 and 2024 it was enough to produce 600 nuclear weapons, or fuel a large 1GW nuclear reactor for a decade, if extracted and enriched.

The long and porous borders of the DR Congo, combined with the civil war on its eastern border, have for decades made the region a hotspot for uranium smuggling concerns. But in recent years, as demand for cobalt has soared because of the rise of electric vehicles, the battery metal has triggered a fresh uranium challenge — one that has flown under the radar until now.

“It is a proliferation concern,” said David Albright, a nuclear weapons expert who founded the Institute for Science and International Security in Washington. “It is low level, but over time these quantities can lead to larger quantities of uranium.”

The accumulation of unmonitored stocks of natural uranium was a risk, he added, “that can lead to some very dangerous situations”.

The issue is drawing fresh attention from Congolese officials, with the Central African country seeking overseas funding to install radiation detectors for trucks leaving the country.

Florimond Kabanda, head of the DR Congo’s nuclear safety agency, CNPRI, said radioactive smuggling was an increasing risk that presented a major international security threat.

“Because of this war going on [in eastern DR Congo], because of the vulnerability of our borders, we have to take more steps to protect Congo and to protect the world at the same time,” he told the FT, pointing out that radioactive material was found in the eastern provinces controlled by rebel groups, as well as in the southern copper belt.

“My worry is that [rebel groups could] use radioactive material to harm our population, and later on to say ‘you see, Congo is not protecting its border’.”

Most of the cobalt leaving the DR Congo is ultimately heading to China, the world’s largest cobalt processor as well as a nuclear power, raising questions about what happens to the uranium contained within it.

The scale of the issue is significant. According to the Nature Communications paper, the DR Congo’s cobalt hydroxide exports contained an estimated 2,000 tonnes or more of natural uranium between 2000 and 2024.

Checks on the ground also show the prevalence of uranium. Over the past 12 months, in routine testing of cobalt hydroxide by the country’s nuclear agency, the mean dose rate (the intensity of the radiation) exceeded the limit for public exposure, said Steve Muanza, head of the nuclear energy agency.

“There is a mix between copper, cobalt, and uranium at different concentrations, all over the place,” said Muanza, whose group sends agents into industrial sites to measure radioactivity levels.

“This is a big issue for public health in the DR Congo,” he added.

For mine workers, exposure to low doses of radiation over long periods, or breathing in the radon gas generated by radioactive material, can increase cancer rates and cause other health problems.

A 2020 study of newborns with visible birth defects in Lubumbashi, the capital of the copper belt region, found that having a father with a mining job increased the odds of such problems fivefold.

“It is very important, very critical to monitor the risk of naturally occurring radioactive substances” in mines, said Eric Kalala, chief executive of Entreprise Générale du Cobalt, the state-backed company responsible for managing artisanal cobalt production in the DR Congo.

Cobalt’s uranium trail

Over the past two decades, a pattern has emerged of uranium contamination reoccurring across the DR Congo’s largest cobalt copper mines. The metals are often found together.

One complex in particular, the Tenke Fungurume project owned by China’s Cmoc, has a history of previously unreported uranium contamination in its cobalt ores, according to corporate documents spanning 2015-21.

At Tenke, which is one of the DR Congo’s biggest cobalt exporters according to trade data, a problem with uranium persisted under the mine’s former American owner Freeport-McMoRan and continued after Cmoc bought Freeport’s stake in November 2016. 

Corporate documents show the uranium levels in Tenke’s cobalt hydroxide were repeatedly above legal limits, exceeding both the DR Congo legal threshold of 75 parts per million, as well as the international shipping limit, equivalent to about 81ppm.

Testing records covering June 2016 to December 2020 show that uranium levels in the dry ore produced at Tenke were above the Congolese threshold on more than 70 per cent of days for which data was recorded. Uranium levels rose as high as 15 times that limit in December 2016, shortly after Cmoc’s purchase had closed. The records do not show if the cargoes were exported at those high levels.

The mine still does not have a dedicated process to remove uranium from its ores, according to three sources familiar with its operations.

Cmoc said it was “not familiar with” the historical data. “There are no instances of uranium levels exceeding applicable limits,” the company added.

Cmoc said all the Tenke cobalt hydroxide “complies with local regulatory requirements and the procurement standards of global downstream customers with respect to uranium content”. It was “unnecessary” to have a “dedicated uranium-removal process” either in the DR Congo or once the ore had been shipped to China as it was “below the relevant threshold”, Cmoc said in a statement.

Freeport declined to comment.

Other miners have faced similar problems.

In November 2018, Glencore, the biggest western producer of cobalt, discovered a uranium issue in ores from its Kamoto Copper Company in the southern DR Congo. The mine had to halt cobalt hydroxide exports for five months and redesigned its processing systems to use phosphoric acid to remove uranium from the ore.

Around the same time, a similar issue occurred at the Metalkol project owned by Eurasian Resources Group. 

“When ERG started ramping up the Metalkol plant, the issue of uranium was brought to the fore,” said Doug Alexander, who was head of metallurgy for ERG in Africa until 2020. 

The company added new processing systems and used phosphoric acid to strip out the metal, understanding that “taking uranium out of the ore would serve as a competitive advantage”, said Alexander. “None of the operations outside of Glencore and Metalkol has actually adopted uranium removal as being necessary,” he added.

Issues have persisted: in March, illegal mining at a historical waste facility known as T17, which belongs to Glencore’s KCC, led to a breach of radiation control measures and prompted the government to issue a safety alert.

Glencore said at the time that “the prolonged presence at T17 by illegal miners has compromised our ability to conduct essential monitoring and controls” at the site. The company declined to comment further.

ERG Africa said the Congolese nuclear safety agency had certified that Metalkol “remains fully compliant with all applicable regulatory requirements and its environmental and social impact assessment commitments”.

Congolese cobalt exports have recently dropped significantly because of government efforts to shore up prices and tackle a market glut. The country banned cobalt exports in February 2025, then imposed a new export quota system in October.

A radioactive blind spot

The production of uranium is banned in the DR Congo today, in part because of its sensitive history, and the government has repeatedly tried to crack down on illicit uranium mining. In 2010, a UN report revealed that gangs operating in the east of the country had attempted to sell uranium that had been mined during the Belgian colonial era.

In theory, each truck leaving the country today is checked by hand for radioactivity, but officials said the system did not necessarily capture every shipment.

Muanza, the head of the DR Congo nuclear agency, said shipments of cobalt that exceeded the legal limit were buried if the radioactivity level was very high, or returned to the producer to be reprocessed.

It was “extremely rare” for material to be buried, but returns to producers happened “from time to time”, he said.

There may still be a proliferation risk. The Nature Communications paper said that given the vast amount of cobalt ore exported, even if all shipments were under the legal limit, 40 tonnes of uranium would leave the country annually.

“Limited adoption” of uranium-removal processes such as the use of acid “suggests that consistent compliance with this threshold is unlikely”, wrote the authors, Ryan Manzuk of Princeton University and Sébastien Philippe of the University of Wisconsin–Madison.

While the Vienna-based International Atomic Energy Agency, which was set up in 1957 as part of the UN’s non-proliferation programme, monitors uranium production globally, the DR Congo’s low-grade uranium-bearing ore exports do not require reporting if they are for non-nuclear purposes.

That raises questions over whether other countries, including China, may be extracting uranium from cobalt ore.

One facility in Finland has shown that it is possible. The Kokkola cobalt refinery on Finland’s west coast, the largest outside China, receives hydroxide from the DR Congo and has a licence to produce and store nuclear material.

It is the only facility known to have recently extracted uranium from cobalt hydroxide. Records reviewed by the FT show enough was extracted to supply Comurhex, a subsidiary of French nuclear fuel producer Orano.

Kokkola’s owner Umicore said the uranium was “treated as an incidental impurity, not as a co-product or value stream”, adding that the process was a burden, not a business, for the refinery. “Concentrations are extremely small, and materials are subject to strict regulatory and contractual acceptance criteria.”

An IAEA expert said the agency had no indications that the DR Congo was not meeting its safeguarding obligations regarding the uranium-bearing cobalt hydroxide ore leaving the country.

“When cobalt is exported, it is normally exported for the mineral, not for the uranium, and for non-nuclear purposes,” the expert said. “Most of the time, [the uranium] ends up in the tailings,” they added, referring to mining waste.

But documents seen by the FT show the IAEA has kept tabs on the issue.

A 2009 internal memo, attributed to a consultant, identified the copper belt region as “an area where illegal exports of uranium-bearing ores take place” and pointed to cobalt ore as a particular risk.

Non-proliferation specialists say China could, in principle, extract uranium from this ore during the refining process.

Olli Heinonen, a fellow at the Stimson Center in Washington DC and a former deputy director-general at the IAEA, told the FT it was “plausible” that uranium was extracted from Congolese cobalt once it reached China. The country’s demand for uranium is rising as it builds out its nuclear power plant fleet.

Albright, the nuclear weapons expert, said China was “known to extract uranium from their cobalt”, which “raised questions about whether others were doing it”.

Muanza, the Congolese official, also said it was likely. “I would be astonished to learn that they don’t really exploit all of the ore that arrives in China.” But he said he had no proof that was happening.

As a nuclear power, China can purchase uranium on the open market; however, most uranium-producing countries require that buyers use the material only for civilian purposes.

China runs a large fleet of nuclear power stations, and possesses a stockpile of more than 600 nuclear warheads, which is expanding and expected to reach more than 1,000 warheads by 2030, according to the US defence department. Its domestic uranium resources are limited, and the country does not disclose how it procures uranium for weapons use.

Any uranium would need to be enriched to a very high level to be used in warheads, which also require significant plutonium.

China’s defence ministry has previously objected to American reports on the size of its nuclear arsenal, and recently accused the US of “making groundless speculation and sensationalising the issue”. China’s Ministry of Industry and Information Technology did not respond to a request for comment.

Whether or not uranium is being recovered abroad, officials said the immediate challenges were monitoring shipments before they left the DR Congo and mitigating the health risks to workers.

Congolese nuclear authorities have requested government funding to install automatic radiation monitors for trucks driving from the copper belt region into Zambia along National Road One, which is estimated to cost $12mn-$15mn.

But a full rollout across the vast country is expected to cost 20 times that, and authorities are in discussions with the US government about potential funding.

The US National Nuclear Security Administration said it “works with partner nations around the world to counter nuclear smuggling”, but did not confirm if the funding would be provided.

Muanza said the system would “limit” the chances of “uranium trafficking”.