Nuclear Boiler Aboard French Navy's 2nd Barracuda Type SSN Started For The 1st Time

Duguay-Trouin is the second Barracuda type SSN for the French Navy

Designed under the responsibility of the French Atomic Energy Commission (CEA), the nuclear boiler was produced under the supervision of TechnicAtome, designer of the boiler, Naval Group, being responsible for the production of the pressure vessels and for the integration of the nuclear reactors on board all Barracuda type SSNs.

About 700 employees from both companies are working full time on the reactors of the five five SSNs in the Barracuda program currently under construction. The first submarine in the series, the Suffren, was delivered in November 2020 and entered active service in June 2022. The first sea trial of Duguay-Trouin is set for the end of 2022.

“The first divergence of a nuclear reactor is a particularly emotional moment for our teams. I salute the quality of their work and the intensity of their commitment that made this event possible. After the RES [Ed. Note: land based demonstrator] in 2018, and Suffren in 2019, this third commissioning in four years marks an exciting time for nuclear propulsion professionals. Working with our partners to strengthen France’s place on the seas is a source of great pride for TechnicAtome.” - Loïc Rocard, TechnicAtome CEO

“The divergence of the nuclear attack submarine Duguay-Trouin, a particularly symbolic milestone, is the result of a collective effort demonstrating the expertise of the French nuclear industry, led by TechnicAtome and Naval Group. This step guarantees the French Navy
a technologically advanced tool, to benefit France’s sovereignty.” - Pierre Éric Pommellet, Naval Group CEO

To start the divergence, a controlled nuclear reaction in the core was initiated for the first time. This short operation marks the beginning of permanent monitoring of the nuclear boiler room by the operating teams. This monitoring will be uninterrupted until the final shutdown of the submarines, scheduled for the 2060s.

About Suffren-class SSN

The Suffren-class is designed to replace the Rubis-class in the French Navy (Marine Nationale). Naval Group is in charge of the construction of this submarines series, including the design and construction of the ship and information systems as well as the manufacturing of the main components of nuclear boiler rooms.

Suffren-class submarines specifications

• Surface displacement: 4,700 tonnes
• Diving displacement: 5,300 tonnes
• Length: 99 metres
• Diameter: 8.8 metres
• Maximum depth: > 350 meters
• Armament: naval cruise missiles, F21 heavy-weight wire-guided torpedoes, modernised Exocet SM39 anti-ship missiles
• Hybrid propulsion: pressurised water reactor derived from the reactors on board the Triomphant-type SSBN and Charles-de-Gaulle aircraft carrier, two propulsion turbines, two turbo generators and two electric motors
• Crew: 65 crew members + approx. 15 commandos
• Availability: > 270 days per year