Inside the De Gaulle, the only European nuclear aircraft carrier

Under the flight deck of the aircraft carrier Charles de Gaulle (R91), the only nuclear-powered one in Europe, beats an unflagging heart: two K15 pressurized water reactors. This marvel of naval engineering allows a giant of 261 meters and 42,500 tons to sail the seas at a speed of 27 knots, boasting a theoretical range that enables it to operate for about a decade without the need for fossil fuel refueling.

The K15 reactors, born from research by the CEA and industrialized by TechnicAtome in collaboration with Naval Group, generate about 150 MW thermal each. They use low-enriched uranium (about 7.5% U-235) to balance high energy density with non-proliferation constraints. This true floating power plant not only provides propulsion but also powers the desalination plants, the onboard electrical grid, and produces the essential high-pressure steam for the two 75-meter catapults. Thanks to this power, the 24-30 operationally deployed aircraft (including Rafale M fighters and E-2C Hawkeye radar aircraft) can take off fully loaded even in adverse weather and sea conditions, ensuring France a formidable global strategic projection.

However, managing nuclear energy in open seas requires absolute safety standards. The design of the reactors is based on the principle of "defense in depth": redundant cooling circuits, physical compartmentalization, and advanced diagnostics. Civilian (ASN) and military (DEND and IRSN) authorities constantly oversee the facility, imposing stringent controls. Confirming this rigor, during a recent safety review, a preventive replacement of some steam pipes was scheduled, demonstrating careful and verifiable monitoring of the facility's aging.

The protection of safety continues even when the aircraft carrier is in port. During major maintenance periods at the Toulon base, strict radiation protection plans are activated with continuous environmental monitoring. In 2025, the local Prefecture of Var updated a detailed risk dossier that informs citizens about emergency procedures and safety perimeters, finding a virtuous balance between public transparency and necessary military confidentiality.