What can nuclear do for us?
Urenco is an international supplier of enrichment services and fuel cycle products for the civil nuclear industry, serving utility customers worldwide who provide low carbon electricity through nuclear energy.
Climate change and a fast-growing demand for electricity calls for reliable, sustainable solutions. Nuclear power provides round-the-clock energy generation, complements renewables and helps to cuts carbon emissions by reducing our dependence on fossil fuels.
Beyond energy, isotopes produced with nuclear technology improve lives and support human progress through their use in medicine, semiconductor manufacturing and quantum computing.
How is nuclear energy produced?
Urenco's core business is uranium enrichment, a key step in producing nuclear energy, which plays an essential role in providing reliable low carbon energy.
Find out about the stages of the nuclear fuel cycle and where Urenco fits in below or by watching our video.
1. Mining
Uranium ore is extracted from the earth, then purified and milled—a process that grinds it into a yellow powder known as uranium oxide (U₃O₈), commonly referred to as yellowcake.
2. Conversion
U₃O₈ is chemically converted into uranium hexafluoride (UF₆) – also known as ‘feed’. The UF₆ is solid at room temperature, and is transported in sealed cylinders to our enrichment facilities.
5. Power generation
The fuel rods are placed inside nuclear reactors where they undergo nuclear fission, which generates heat to produce steam. This drives turbines that power electricity generators, providing a reliable source of low-carbon electricity.
4. Fuel fabrication
Customers’ enriched uranium is converted into ceramic uranium dioxide (UO2) pellets at fuel fabrication facilities. These pellets are compressed at high temperatures, then loaded into metal tubes to form fuel rods, ready for use in nuclear reactors.
3. Enrichment and feed materials
This is where Urenco comes in. We heat UF6 to turn it into a gas and then feed it into our gas centrifuges.
The centrifuge separates the two isotopes contained in uranium: 235uranium (235U) and 238uranium(238U). The lighter 235Uis typically enriched to up to 5%, which is sufficient to sustain a continuous fission reaction in a nuclear power plant.
The enriched UF6 is then cooled to a solid, ready for transportation.
Find out more about the enrichment process below.
1. Mining
Uranium ore is extracted from the earth, then purified and milled - a process that grinds it into a yellow powder known as uranium oxide (U₃O₈), commonly referred to as yellowcake.
2. Conversion
U₃O₈ is chemically converted into uranium hexafluoride (UF₆) – also known as ‘feed’. The UF₆ is solid at room temperature, and is transported in sealed cylinders to our enrichment facilities.
3. Enrichment and feed materials
This is where Urenco comes in. We heat UF6to turn it into a gas and then feed it into our gas centrifuges.
The centrifuge separates the two isotopes contained in uranium: 235uranium (235U) and 238uranium (238U). The lighter 235U is typically enriched to up to 5%, which is sufficient to sustain a continuous fission reaction in a nuclear power plant.
The enriched UF6is then cooled to a solid, ready for transportation.
Find out more about the enrichment process below.
4. Fuel fabrication
Customers’ enriched uranium is converted into ceramic uranium dioxide (UO2) pellets at fuel fabrication facilities. These pellets are compressed at high temperatures, then loaded into metal tubes to form fuel rods, ready for use in nuclear reactors.
5. Power generation
The fuel rods are placed inside nuclear reactors where they undergo nuclear fission, which generates heat to produce steam. This drives turbines that power electricity generators, providing a reliable source of low-carbon electricity.
How does Urenco enrich uranium?
Uranium atoms exist in two main forms, known as isotopes: 235Uranium (235U) and 238Uranium (238U). When it is mined, uranium ore contains about 0.7% of 235U isotopes compared to 99.3% of 238U.
To be able to work efficiently as fuel, the uranium must be 'enriched' to increase the levels of 235U up to 5%. This is enough to sustain a nuclear fission reaction, which generates the heat nuclear power plants need to produce energy.
At Urenco, we use centrifuges to separate these two isotopes, gradually increasing the levels of 235U until we reach the levels required by our customers.
Scroll through the slider below or take our virtual tour to learn how this process works.
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1. Heating uranium hexfluoride (UF6) to turn it into a gas
Approved suppliers deliver UF6 to our enrichment facilities in international, standardised transport containers.
UF6 is solid at ambient temperature. At our enrichment facilities, we connect the transport container holding UF6 to the plant feed system. We then heat the container to vaporise the UF6 and turn it into gas at sub atmospheric pressure.
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2. Spinning UF6 in high speed centrifuges to enrich it
We feed the UF6 gas into a centrifuge casing containing a cylindrical rotor which spins at high speed, separating uranium’s two isotopes. The heavier isotope 238Uranium (238U) is forced closer to the cylinder wall than the lighter 235Uranium (235U). As a result, the UF6 gas closer to the wall is depleted in 235U and the UF6 gas nearer the rotor axis is slightly enriched in 235U.
We repeat the process many times in a series of centrifuges, known as cascades, until we achieve the desired levels of 235U enrichment to meet our customers’ specifications, typically between 3% and 5%.
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3. Compressing and cooling the enriched uranium
We feed the enriched uranium from the centrifuge cascades into a compressor and then into a cooling box containing a cylinder. As it cools, the UF6 vapour solidifies within cylinders. We homogenise the UF6 in the cylinders and check the quality of a sample before delivering it to customers.
We weigh all cylinders to comply with the accounting and tracking requirements of the European Atomic Energy Community, United States Nuclear Regulatory Commission and the International Atomic Energy Agency.
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4. Storing and converting depleted uranium
The UF6 gas closer to the centrifuge wall is partially depleted in 235U. This by-product is known as tails. We collect and cool tails in a cooling box containing a cylinder, weighing it to ensure all material can be accounted for. Tails still contain a low concentration of 235U and can be re-enriched if economically viable.
We store tails at our enrichment facilities in internationally approved containers pending deconversion to a chemically stable form, uranium oxide (U3O8), for long term storage for future enrichment or final disposal. Our Tails Management Facility is responsible for deconversion and converts UF6 to U3O8. This process also creates hydrofluoric acid, a valuable chemical used globally by industry.
How do we manage our by-product?
Our role in the nuclear fuel cycle does not stop at enrichment - ensuring that our by-product is responsibly managed forms an essential part of our activities.
During the enrichment process, depleted uranium hexaflouride (UF6) is produced as a by-product. Commonly known as tails, it can be managed in one of two ways:
Re-enrichment
Tails still contains low levels of 235U and can therefore be passed through our centrifuges again to be re-enriched, which is a common industry practice. This promotes the conservation of resources and Urenco will take this approach whenever it is commercially viable to do so.
Storage
When it is not commercially viable to re-enrich tails, we store it, safely and securely ourselves or with our partners, for enrichment at a future date or deconversion.
Deconversion involves converting tails to uranium oxide (U3O8) for longer term storage pending reuse or final disposal. Urenco has invested in a multi-million pound Tails Management Facility (TMF) in the UK to handle the deconversion process and it currently serves our European sites.
