Meuse. Nuclear waste storage in Bure: the project could cost 12 billion euros more

The Cigéo project to bury the most radioactive nuclear waste in Bure (Meuse) could cost a total of between 26.1 and 37.5 billion instead of the 25 billion previously envisaged, according to the new assessment by the National Agency for Radioactive Waste Management (Andra), which must now be decided by the government.

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 cubic meters are 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 at the economic conditions of the end of 2011. At the time, environmental organizations denounced "a largely underestimated amount."

"This is a generally controlled cost, very close" to Andra's previous estimate in 2014, which was 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 "packages" of radioactive materials will be gradually stored in nearly a thousand cells starting in 2050, a process that will take around 95 years, before the closure of the site is planned "by 2170".

This new estimate therefore covers all costs over "a period of more than 150 years," from construction (€7.9 billion to €9.6 billion) to closure of the repository, including maintenance, security, insurance, and taxes. It is based on the "updated provisional schedule," which takes into account, in particular, "the additional time needed to carry out detailed preliminary design studies" and feedback "on underground work."

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 includes in particular uncertainties on the level of taxation of nuclear installations, for a gap of 7.4 billion euros between the high and low estimates; and the realization of savings made possible by optimizations of various maturities. For example, the integration of more efficient materials or the lengthening of cells, which reduces the number of galleries to be built.

The new estimate predicts site security costs of around 10 million euros per year, which were not anticipated in 2014.

The project's cost is intended to cover 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 those from 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."

If the nuclear revival goes further, with the eight additional EPR2s mentioned by Emmanuel Macron or small reactors (SMR), other studies will be necessary, and "if we add waste, the cost will inevitably increase," indicates Andra .

The final word on the project's cost will rest with the Energy Minister, 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.

In January 2023, Andra submitted its application for authorization to create the project, which is currently being examined by the ASNR, with a decision expected in late 2027/early 2028.