Administrative Tribunal Halts Bugey Nuclear Expansion Over Ecological Concerns

The administrative tribunal of Lyon has annulled modifications to urban planning documents that permitted the expansion of the Bugey nuclear power plant with two new EPR2 reactors, each generating 1670 MW. The court ruled on December 10, 2025, that ecological impacts had not been sufficiently considered in the environmental impact assessments related to the site's expansion plans.

The 150-hectare site, situated in Loyette near the Rhône River in the Ain region, currently operates four 900 MW reactors. The expansion plan, initiated by EDF and RTE, aimed to have the new reactors operational by 2040.

The tribunal particularly criticized the territorial coherence scheme (SCOT) revision made by the mixed syndicate Bugey-Côtière-Plaine de l'Ain in February 2023 and the local urban planning revision (PLU) by Loyette in September 2024. The court found the SCOT modification "tainted by illegality" and requiring a stricter process, as well as significant shortcomings in the PLU's environmental analysis.

Key environmental concerns included the presence of 104 protected bird species and four protected reptiles, such as the green and yellow snake, on lands adjacent to the Rhône River and less than 100 meters from the Natura 2000 Isle Crémieux, a site of high ecological value and vulnerability.

Representing the activist group Sortir du nucléaire Bugey, Me Jean-Baptiste Ollier hailed the ruling as a victory for environmental protection but acknowledged the ongoing nature of the dispute. Meanwhile, Alexandre Nanchi, president of the mixed syndicate, described the decision as "regrettable" but stated plans to appeal and pursue a stay of execution. The municipality of Loyette is also considering an appeal.