France launches fabrication of Europe’s largest nuclear aircraft carrier with first K22 reactor units.

Naval Group in Cherbourg began welding the first steel plate for the PA-NG aircraft carrier’s nuclear confinement enclosures on 25 September 2025, initiating the construction of France’s next-generation nuclear-powered carrier.

On September 25, 2025, Naval Group’s Cherbourg shipyard began welding the first steel plate for the confinement enclosures of the PA-NG (Porte-Avions Nouvelle Génération), which will house two K22 nuclear reactors. The activity, supervised by the Direction générale de l’armement with TechnicAtome and the CEA responsible for nuclear systems, marks the start of physical construction work on France’s next aircraft carrier.
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If all goes to plan, by 2038, France will have in service a thoroughly modern carrier that can operate well into the 2060s. (Picture source: Naval Group)

The K22 reactors, each rated at approximately 225 megawatts thermal, are designed to support electromagnetic catapults and long-endurance carrier operations, with overall program schedules aiming for construction launch in late 2025 or early 2026 and entry into service around 2038. The enclosure work sits on the program’s critical path because it conditions the downstream assembly of the nuclear section and the broader hull. The K22 is a pressurized water reactor using light water as coolant and moderator, developed by TechnicAtome in the early 2020s under CEA oversight to power the PA-NG. Each unit delivers about 225 MW of thermal output, roughly 50 percent more than the K15 used on Charles de Gaulle, and adopts a new plate-type steam generator for greater compactness and efficiency.

Designed for rapid power variation required by carrier operations, the K22 enables sustained speeds of 27 knots and around ten years between refuelings. Its compact configuration combines the reactor and generator within a reinforced metallic enclosure resistant to shock and external aggression. Manufacturing of the main components is shared between Framatome at Le Creusot and Naval Group’s Nantes-Indret site, with validation using the Cadarache test reactor. This new generation of propulsion plant consolidates France’s naval nuclear expertise while providing the energy margins needed for electromagnetic catapults and future combat aircraft.

Each metallic enclosure for a K22 plant is designed at roughly 14 meters in height, 13 meters in diameter, and about 1,300 tons, making them among the largest dedicated assemblies ever produced for a French naval propulsion plant. Unlike submarines, whose pressure hulls provide comparable functions, the carrier requires stand-alone enclosures that will be integrated with the boiler rooms and then inserted in the hull in a nested sequence similar to Charles de Gaulle. Program leadership notes that the K22 generation will renew a wide span of French nuclear-propulsion design and manufacturing competencies, expanding experience built on K15 plants used in Charles de Gaulle and the submarine force. Manufacturing begins with the enclosure bottom, which concentrates the most demanding plate-forming and welding operations typical of advanced boiler-making.

This fabrication start follows a 600 million euro order notified on 26 April 2024 to secure long-lead propulsion items, including the K22 boiler rooms, their confinement enclosures, and the secondary loop that converts steam energy into electricity. Framatome subsequently confirmed it would forge boiler-room components over five years at Le Creusot and deliver them to Naval Group’s Nantes-Indret and Cherbourg sites for fabrication and assembly. These actions run in parallel with studies initiated in 2018, preliminary design work from 2021, and detailed design launched in April 2023, all intended to de-risk the timeline ahead of the realization decision and the start of block construction.

Industrial flow planning centers on assembling the nuclear section at Saint-Nazaire using components delivered from Nantes-Indret and Cherbourg, then joining the remainder of the hull around that section with large-vessel infrastructure. Current planning foresees a compressed block-erection period on the slip, launch, and alongside outfitting before transfer to Toulon around mid-2035. Prior to fueling, the program is assessing limited platform trials, including at sea, using temporary diesel generators to power the ship’s electrical network and propulsion motors, which could allow a self-propelled transit to the Mediterranean under escort. Nuclear-propulsion trials are planned in the Mediterranean with an objective of completing acceptance trials by late 2036 or early 2037 to support commissioning in 2038.

Design characteristics refined during detailed studies now cite an approximate displacement around 78,000 tons, an overall length near 310 meters, and a maximum flight-deck width close to 85 meters. The PA-NG is planned to employ EMALS catapults and AAG recovery gear, aligning its launch and recovery architecture with U.S. Gerald R. Ford-class practice rather than the ski-jump configuration used on the UK’s Queen Elizabeth class, while remaining a catapult carrier like Charles de Gaulle. The air wing plan accommodates Rafale M during transition, E-2D Hawkeye, future combat aircraft, and unmanned systems, supported by a Sea Fire fixed-panel radar, vertically launched Aster surface-to-air missiles, and close-in remotely operated artillery. These features aim to sustain higher sortie rates and flexible air operations in dense threat environments.

Flight-deck and island arrangements position the island aft with two aircraft elevators forward of it to improve deck flow during simultaneous launch and recovery. Provision exists for a third forward EMALS track in addition to two baseline catapults to increase launch capacity and add redundancy. Enlarged deck and hangar volumes are configured to support more numerous, shorter missions, integration of unmanned effectors, and concurrent air policing, strike, and fleet defense. Crew sizing is planned to remain close to Charles de Gaulle despite the size increase, with roughly 1,100 ship’s company and the total rising to about 2,000 when the air wing, staff, and specialists are embarked.

The organization mobilizes Naval Group, Chantiers de l’Atlantique, TechnicAtome, and the MO Porte-avions joint venture, with more than 200 trades engaged and an industrial ecosystem that includes forging and materials partners such as Framatome, Aubert et Duval, and Industeel. Two Naval Group sites are particularly engaged, Cherbourg for the confinement enclosures and Nantes-Indret for the main boiler-room capabilities, while TechnicAtome is receiving initial boiler-room prototypes at Cadarache. The plan underlines that timely orders for critical items are required to maintain schedule, which is why long-lead propulsion work began before the full realization decision, mirroring practices on major carrier programs abroad to protect the critical path.

The PA-NG continues France’s catapult carrier lineage established by Charles de Gaulle while moving closer to the electromagnetic launch and advanced recovery paradigm pioneered by the U.S. Navy’s Ford class. By selecting EMALS and AAG rather than a ski-jump and STOBAR operations as on some conventional carriers, France keeps fixed-wing airborne early warning and heavier strike options that remain central to blue-water carrier doctrine. At the same time, the program’s intent to support unmanned aviation and higher deck throughput reflects trends across multiple carrier fleets, while the nuclear propulsion choice maintains endurance and high-speed margins associated with France’s existing model and distinguishes PA-NG within Europe.

Written by Jérôme Brahy

Jérôme Brahy is a defense analyst and documentalist at Army Recognition. He specializes in naval modernization, aviation, drones, armored vehicles, and artillery, with a focus on strategic developments in the United States, China, Ukraine, Russia, Türkiye, and Belgium. His analyses go beyond the facts, providing context, identifying key actors, and explaining why defense news matters on a global scale.