Enrichment and Fuel Fabrication: Decommissioning Issues in Europe

Reference article · Updated 2026-11-06

Why enrichment and fabrication plants need decommissioning

Enrichment and fuel fabrication plants are chemical and mechanical facilities. They handle uranium in many forms, mostly hexafluoride, oxide and metal. After operation they contain contaminated equipment, process residues and large volumes of metal.

In radiological terms the hazards are generally lower than for a power reactor, because there are no fission products and no activation of structural materials. Two things still matter: the chemical hazards from fluorides, and the sheer quantity of material. Equipment may carry deposits of uranium compounds, so waste classification and measurement are the main cost drivers. The fuel cycle context is covered on the enrichment page and the fuel facilities overview.

Europe's enrichment capacity moved from gaseous diffusion to gas centrifuges. Diffusion uses huge amounts of electricity and thousands of compressors and diffusers. The transition left France with a large legacy plant to dismantle. Centrifuge operators in the United Kingdom, Germany and the Netherlands run operating plants. Their decommissioning issues therefore concern older or replaced cascades (banks of linked centrifuges) and legacy buildings, not whole sites.

Georges Besse I at Tricastin

The Eurodif plant at Tricastin in southern France, also called Georges Besse I, enriched uranium by gaseous diffusion. It stopped production in 2012 after about 33 years of service. The centrifuge-based Georges Besse II plant took over its role and started production in April 2011. What is now Orano operates both plants.

The regulatory path was as follows:

• The operator submitted its application for final shutdown and decommissioning in March 2015.
• The French nuclear safety authority (ASN, now part of the combined authority ASNR) reviewed it. A decree ordering Orano to decommission Georges Besse I was published on 5 February 2020.
• In 2024 the authority approved the dismantling of the two cooling towers.

Orano's own account says that deconstruction of the towers started in April 2025 and was expected to take about 18 months. It also says the whole dismantling project is estimated at 1.2 billion euros and extends to 2051.

What the work involves

Dismantling a diffusion plant covers several stages:

• removing residual uranium from the process equipment, a step known as rinsing or treatment;
• cutting and removing thousands of large metal components;
• measuring and sorting waste into categories according to its contamination;
• demolishing buildings.

The material is mainly steel and aluminium alloys with low-level uranium contamination. Operators have therefore considered recycling in controlled circumstances where regulations allow, as well as disposal as low-level waste. The French authority's decommissioning reports discuss these waste management routes. They also discuss the need for dedicated storage while materials are characterised.

Characterisation

Characterisation, meaning the measurement and description of the waste, is a major effort in its own right. Before operators can cut and ship large components, they measure residual uranium by gamma spectrometry and other methods. They estimate the inventory in inaccessible parts and decide the category of each package. The accuracy of these measurements affects cost directly, because disposal costs differ between very low-level and low-level waste.

The French authority has also underlined the importance of managing the radiological and chemical risks to workers during cutting and handling. This includes controlling dust and fluorinated compounds.

Non-nuclear infrastructure

The plant used large volumes of electricity and cooling water, so it also has substantial non-nuclear infrastructure, such as the cooling towers and electrical installations. Operators can demolish these after clearing the nuclear parts. The towers' deconstruction in 2025 is therefore a visible milestone, but only one stage of a decades-long programme.

Regulation and funding arrangements

In France the nuclear safety authority's authorisation system governs decommissioning. Operators must submit a decommissioning file, public consultation takes place, and a decree sets the framework. The law requires operators to set aside dedicated assets to cover the long-term costs of decommissioning and waste management. The state supervises whether these provisions are adequate. The authority's annual reports and its publication on decommissioning challenges describe the regime. They stress the need to plan from the design stage and to keep records of past operations.

Across Europe, responsibility for decommissioning generally rests with the operator under the polluter-pays principle, though national arrangements differ. In the United Kingdom, for example, public arrangements under the Nuclear Decommissioning Authority have handled legacy facilities at sites such as Capenhurst and Springfields in part. The commercial operators have handled the rest. This page does not cite cost figures for those sites because none was verified.

For a comparison with the United States, see the US decommissioning page and the US enrichment page. There the regulator sets financial assurance rules and the Department of Energy manages legacy plants.

Open issues and practical constraints

Several issues recur in European decommissioning of fuel cycle plants:

• Cost estimates run over decades and are uncertain, so operators regularly revise provisions.
• Waste routes depend on the availability of disposal facilities for very low-level and low-level waste.
• Treating large volumes of lightly contaminated metal is a particular challenge.
• Depleted uranium hexafluoride from enrichment must be stored or converted. Its management ties decommissioning to the stockpile questions on the DU inventories page.
• Historical records of how plants were used are sometimes incomplete. This complicates characterisation of buried or embedded contamination.

Readers interested in the wider regulatory frame may consult the regulation overview.

Frequently asked questions

Sources and further reading

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