Introduction — Found in the Earth's crust, uranium is a radioactive metal mainly used to produce fuel for nuclear power plants. However, mined ore cannot be loaded directly into most reactors: it must be concentrated, converted, sometimes enriched and then made into pellets. This industrial chain, concentrated in a few countries, makes uranium an energy, mining and geopolitical issue. In Africa, Namibia and Niger are among the continent's longstanding producers.
Key facts
- Nature: a naturally radioactive heavy metal found in rocks and soils.
- Isotopes: natural uranium contains around 99.3% uranium-238 and 0.7% uranium-235.
- Global production: around 60,200 tonnes of uranium were mined in 2024.
- Leading African producers in 2024: Namibia, with around 7,300 tonnes, and Niger, with nearly 1,000 tonnes.
What is natural uranium?
Uranium is a chemical element naturally present in most rocks, but generally at low concentrations. Its symbol is U and its atomic number is 92. Its main isotopes are uranium-238 (U-238) and uranium-235 (U-235). The former accounts for the vast majority of natural uranium. The latter, much rarer isotope can sustain a fission reaction under the conditions present in a nuclear reactor.
Uranium ore is not a ready-to-use raw material. After extraction, it is crushed and processed to isolate and concentrate the uranium. The resulting product is often called ‘yellowcake’ because of its usual colour, although its appearance can vary. It is a chemical concentrate, mainly in the form of uranium oxide, rather than finished nuclear fuel.
How is uranium extracted?
The chosen method depends on deposit geology, ore grade, depth, water availability and environmental rules. Open-pit mines remove rock layers covering a deposit close to the surface. Underground mines target deeper deposits and require specific safety measures, particularly to control exposure to radon and dust.
A third method, in-situ recovery, circulates a solution through a porous geological formation to dissolve uranium, then pumps the solution to a processing facility. It limits excavation of large quantities of rock but requires thorough subsurface characterisation and groundwater monitoring. More than half of recent global mine production comes from this technique, which is particularly widely used in Kazakhstan.
In conventional mines, ore is ground and then leached using suitable solutions. Uranium is recovered and concentrated, while mine tailings are stored in engineered facilities. These tailings still contain naturally radioactive elements and chemicals. Containment, water management, dam stability and monitoring after site closure are responsibilities of the operator and authorities.
From ore to nuclear fuel
After milling and processing, uranium concentrate must pass through several stages before supplying most light-water reactors. It is first converted into uranium hexafluoride, a compound that can be used in gaseous form in enrichment facilities. Enrichment increases the proportion of U-235, generally to a few percent for light-water reactor fuel.
Enriched uranium is then converted into uranium dioxide powder. This powder is pressed and fired to form small ceramic pellets. Stacked inside metal tubes, they become fuel rods, which are themselves grouped into fuel assemblies. These assemblies are designed for a particular reactor type and loaded into the plant's core.
Not every reactor follows exactly the same route. Some use natural uranium or low-enriched fuel depending on their design. However, for the light-water reactors that dominate the global nuclear fleet, enrichment is a central stage. After use, assemblies become spent fuel: they must be cooled, stored and, depending on national policies, reprocessed or destined for permanent disposal.
Resources, production and security of supply
Identified resources are not immediately available reserves. Extraction depends on uranium prices, deposit quality, infrastructure, permits and investment. The 2024 edition of the joint assessment by the Nuclear Energy Agency and the International Atomic Energy Agency estimates identified recoverable resources at nearly 7.9 million tonnes across several cost categories, using data available at the beginning of 2023. However, it emphasises that new investment in exploration, mines and processing facilities will be needed to support strong nuclear growth.
Production remains geographically concentrated. In 2024, Kazakhstan supplied around 39% of uranium mined worldwide, ahead of Canada and Namibia. Supply chains extend beyond mines: conversion and enrichment are also specialised stages spread across a limited number of countries. Secure supply therefore requires long-term contracts, inventories, diversified sources and industrial capacity throughout the cycle.
Africa's role
Namibia was Africa's leading producer and the world's third-largest in 2024, with around 7,300 tonnes of uranium. Niger produced nearly 1,000 tonnes that year amid changes in its national industry and evolving relations with operators. South Africa also has resources, but its mine production remains limited compared with major global producers. Other countries, such as Tanzania and Botswana, are associated with projects or resources yet to be developed.
For producing countries, benefits are not measured solely by exported volumes. Public revenues, employment, training, local procurement and control of health and environmental impacts are decisive. Further processing of ore can create value, but conversion and enrichment facilities require capital, skills, reliable energy, high safety standards and a sufficiently predictable market.
The central issue is therefore resource governance. Contract transparency, revenue distribution, worker protection, radiological monitoring and site rehabilitation must accompany extraction. Rising nuclear demand may strengthen interest in African deposits; by itself, it does not guarantee that economic and industrial benefits will reach people in the producing country.
Frequently asked questions
Is natural uranium radioactive?
Yes. It emits ionising radiation, but the level of risk depends on the material's form, its concentration and exposure duration. Extraction and processing require radiation protection, dust control and environmental monitoring measures.
Can yellowcake directly fuel a power plant?
No. It is an intermediate concentrate. It must be converted, then enriched for most light-water reactors, before being made into fuel in the form of pellets and assemblies.
Is uranium a renewable energy resource?
No. It is a finite mineral resource extracted from underground. Nuclear energy is generally classified as low-carbon during electricity generation, but its cycle includes extraction, fuel manufacturing, waste management and decommissioning.