The handover marked far more than an industrial milestone. It signaled a deepening nuclear partnership between France and the United Kingdom, and a new chapter in Britain’s effort to secure low-carbon electricity at massive scale.
A 500-ton steel colossus heads for Somerset
On November 28, 2025, French nuclear specialist Framatome completed a key component for Hinkley Point C’s second EPR reactor: the reactor pressure vessel (RPV). This forged steel cylinder-13 meters long and weighing about 500 tons-will sit at the very core of the plant.
The vessel was manufactured at Framatome’s Saint-Marcel site near Chalon-sur-Saône, an industrial complex that combines heavy forging with ultra-precise machining. Here, raw steel ingots are pressed, heated, and shaped under massive hydraulic presses before undergoing years of machining and non-destructive testing.
The French-built reactor vessel will help supply low-carbon electricity to about six million U.K. homes once Hinkley Point C is fully operational.
The RPV is far more than a large metal tube. It must contain the reactor core, where uranium fuel splits and releases immense heat. Engineers designed the vessel to withstand about 300°C, internal pressures above 150 bar, and decades of neutron bombardment without losing integrity.
That combination of heat, pressure, and radiation makes the component a piece of high-end technology rather than simple steelwork. Fabrication involves months of welding, heat treatment, polishing, and microscopic inspection. Any defect-even a hairline crack-can end a vessel’s service life before it ever reaches the site.
Second of its kind for Hinkley Point C
This is not the first French-made RPV headed to Somerset. The vessel for Hinkley Point C Unit 1, forged at the Creusot site, reached the United Kingdom in early 2023 and was installed in the reactor building in December 2024.
The new cylinder for Unit 2 has now passed its final checks in France. Technicians carried out a final round of inspections in a subdued, almost ceremonial atmosphere before the component was secured to its heavy transport cradle for the trip to a suitable port and then across the English Channel.
On the U.K. side, the steel dome of Reactor Building 2 was lifted into place only days earlier, creating a window for the vessel’s arrival and installation. If schedules hold, the second RPV should follow a similar assembly sequence to that of Unit 1, with final integration and system testing later in the decade.
Hinkley Point C and the nuclear comeback
Hinkley Point C is the United Kingdom’s first new nuclear power station project in more than 30 years-and arguably its most controversial infrastructure effort in decades. The Somerset site will host two European Pressurized Reactors (EPRs) of about 1,630 MW each.
Once both units run at full power, they are expected to provide around 7% of Britain’s electricity needs. Critically, they will generate electricity around the clock, strengthening a grid that increasingly depends on weather-sensitive wind and solar power.
Criticized for cost overruns and delays, Hinkley Point C has also become a test bed for how nuclear and renewables can coexist in a net-zero energy system.
Civil works began in 2018. The first unit’s concrete base, inner structures, and dome are already in place. Current planning points to first power around 2030, followed by a multi-decade operating life. That timeline has slipped several times, but EDF, which leads the project, argues that lessons from early construction will shorten build times at future plants such as Sizewell C.
Steam generators the size of office buildings
Alongside the reactor vessel, Framatome has been fabricating several other massive components for Hinkley Point C. Among them are the steam generators for Unit 2, which act as the primary heat exchangers between the reactor’s primary circuit and the secondary water loop that drives the turbines.
Each steam generator stands about 25 meters tall and weighs roughly 520 tons, resembling an oversized industrial silo. Pressurized hot water from the reactor core flows through thousands of tubes inside these units. On the outside, feedwater boils into steam, which then spins the turbine-generator sets that produce electricity.
The first steam generator for Hinkley Point C was delivered in May 2024 and installed a couple of months later. Remaining units are scheduled to arrive by 2026, leaving enough margin for mechanical and safety tests ahead of fuel loading.
A hefty bill, a long-term bet
The price tag for Hinkley Point C has risen repeatedly since the project was first announced. Current estimates range from £31 billion to £34 billion in 2015 pounds, translating to significantly more in today’s prices.
EDF and the U.K. government frame the project as a long-term investment in reliable, low-carbon power. While offshore wind and solar have grown rapidly in Britain, they do not provide guaranteed output during calm or cloudy periods. Nuclear plants, by contrast, can run at high capacity factors for months at a time.
- Planned capacity: about 3.2 GW for both reactors combined
- Expected share of U.K. electricity: roughly 7%
- Design lifetime: around 60 years, with potential extensions
- Main partners: EDF (France), the U.K. government, and private investors
Experience gained at Hinkley will likely shape the design, schedule, and financing of Sizewell C in Suffolk, which plans to use the same EPR technology. Supporters argue that repeating the design should reduce risk and cost, much as standardization did for earlier nuclear series in France.
French engineering at the heart of the U.K. energy mix
For France, the project showcases national nuclear expertise on a high-profile international stage. Framatome supplies major nuclear components, from RPVs to steam generators. EDF serves as the lead developer, handling overall design, safety cases, and site coordination.
Brexit did not stop this cooperation. Regulatory processes have become more complex, and supply chains now cross customs boundaries, yet both governments maintain strong ties in nuclear technology, fuel services, and safety oversight.
Cross-Channel nuclear cooperation has survived political shocks and now stands as one of the most tangible industrial links between London and Paris.
The relationship extends beyond Hinkley Point C. France has exported technology and services to plants in the Middle East, China, and Finland, and continues to propose EPRs in countries seeking large-scale low-carbon capacity.
Where EPR reactors stand worldwide
The EPR is a Generation III reactor design intended to deliver higher safety margins and better efficiency than older plants. Its rollout has been bumpy, with high-profile delays at Flamanville in France and Olkiluoto in Finland. Still, several units now operate at full power, while others continue through construction.
| Country | Site | Unit | Status (late 2025) | Net capacity (MW) | Start-up / forecast |
|---|---|---|---|---|---|
| France | Flamanville | Flamanville 3 | Final commissioning | 1,630 | 2024–2026 |
| Finland | Olkiluoto | Olkiluoto 3 | In operation | 1,600 | 2023 |
| China | Taishan | Taishan 1 | In operation | 1,660 | 2018 |
| China | Taishan | Taishan 2 | In operation | 1,660 | 2019 |
| United Kingdom | Hinkley Point C | HPC 1 | Under construction | 1,630 | 2030 (planned) |
| United Kingdom | Hinkley Point C | HPC 2 | Under construction | 1,630 | 2031 (planned) |
| United Kingdom | Sizewell C | SWC 1 & 2 | Approved project | 2 × 1,630 | mid-2030s (planned) |
Key nuclear concepts behind the headlines
The story of this 500-ton vessel combines engineering jargon with major policy questions. A few terms help explain what is actually happening in Somerset and Saint-Marcel.
What is a reactor pressure vessel?
The reactor pressure vessel is the thick-walled steel container that holds the nuclear fuel assemblies and circulating coolant. In a pressurized water reactor such as the EPR, it forms the heart of the primary circuit, where water is kept under high pressure so it does not boil.
Because the vessel cannot realistically be replaced once the plant is operating, engineers design it for the full life of the station-typically 60 years or more. Its toughness helps determine how long the plant can run and under what conditions.
Why nuclear and renewables need each other
Models of future U.K. electricity demand suggest sharp increases from heat pumps, electric vehicles, and data centers. Wind and solar can meet a large share of that demand at low operating cost, but their output varies with weather patterns.
Nuclear reactors provide steady “baseload” generation. That stability can support a grid with more renewables by supplying a reliable floor of power during wind lulls or extended cold spells. Gas plants can also fill this role, but they emit CO₂ and expose customers to volatile fuel prices.
Risks, safeguards, and long timelines
Nuclear projects carry specific risks: construction delays, cost escalation, long-term waste management, and severe accident scenarios. Designs like the EPR include multiple safety systems, thick containment buildings, and passive cooling features intended to keep the core covered with water even in extreme events.
On site, regulators in both France and the United Kingdom enforce layers of inspections and licensing steps before any fuel enters the core. The journey of this 500-ton French vessel to Hinkley Point C is only one step in that long chain, but it highlights the scale, complexity, and shared interests now binding the two countries’ energy strategies.
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