Cost of Cigéo radioactive waste disposal project in Bure revised upwards: up to 37.5 billion euros

Launched in 1991, the Cigéo project, contested by environmentalists and local associations , is to house nuclear power plant waste 500 meters underground, which is expected to remain highly radioactive for several hundred thousand years. A total of 83,000 m³ is expected, half of which has already been produced.

The updated assessment represents, depending on the assumptions, an increase of 4.4% to 50% compared to the cost set in 2016 by the then Minister of Ecology and Energy, Ségolène Royal, or 25 billion euros at the economic conditions of the end of 2011. "This is a generally controlled cost, very close" to Andra's previous estimate in 2014, or 33.8 billion, assured Gaëlle Saquet, interim director general of the public institution leading the project.

Adding inflation, the bill would rise to between 32.8 and 45.3 billion euros (+21% for the maximum estimate and +26% for the minimum estimate).

The final word will rest with the Minister of Energy, who will have to set by decree "by the end of 2025" the new reference cost until reassessment, after having gathered the opinion of the Nuclear Safety and Radiation Protection Authority (ASNR) and the observations of the main waste producers. In this case, EDF, Orano and the CEA, which are financing the project through provisions according to the "polluter pays" principle.

Andra is aiming for an authorization decision around the end of 2027-beginning of 2028 to launch the project.

Several unknowns

The gradual descent of the "packages" of radioactive materials, into nearly a thousand cells, is announced from 2050, instead of the 2035-2040 deadline initially planned.

This new estimate covers all costs over "a period of more than 150 years," from construction (7.9 to 9.6 billion euros) to the closure of the repository "by 2170," including maintenance, security, insurance, and taxes.

But given the complexity of the project, "we didn't stop at a single figure," explains Gaëlle Saquet. "Unprecedented and unparalleled," the Cigéo project involves storage in a layer of clay, unlike Sweden and Finland, which have opted for granite terrain.

The figures thus present a configuration at the authorization application stage (29.8 to 37.5 billion) and three other configurations reflecting different scenarios. This notably includes uncertainties regarding the level of taxation, for a difference of approximately €7.4 billion on the bill. In addition, Andra has identified potential savings of up to €3.6 billion through technical optimizations. For example, the integration of more efficient materials or the lengthening of cells, which reduces the number of tunnels to be built.

On the other hand, new costs had to be factored in due to longer-than-expected design studies and feedback from major underground projects such as the Grand Paris Express metro. Added to this were site security costs of around €10 million per year and archaeological excavations.

The cost of the project covers the storage of waste already produced or future from existing or previously authorized nuclear facilities at the end of 2016, which constitute the "reference inventory." But not that of the six future EPR2 reactors announced in 2022 by Emmanuel Macron, which have not yet been authorized, Andra indicates.

However, "as part of adaptability," Andra has studied this hypothesis, which would represent a 5% increase in the volume of so-called "long-lived" waste and a 20% increase in so-called "high-level" waste compared to the total planned for Cigéo. These "will be integrated into the reserve inventory" and "the feasibility of their management [...] will be examined during the investigation."