France's most powerful nuclear reactor finally comes on stream

France connected its most powerful nuclear reactor to the national electricity grid on Saturday, marking a significant milestone in its nuclear energy program after years of delays and mounting costs.

The Flamanville 3 European Pressurized Reactor (EPR), located in Normandy, began supplying electricity to homes at 11:48 a.m. local time (1048 GMT), according to EDF power company CEO Luc Rémont.

“This is a great moment for the country,” President Emmanuel Macron said in a statement on X, formerly Twitter. He described the reactor as “one of the world’s most powerful” and called the move a testament to France’s approach to low-carbon energy production.

The reactor, which can generate 1,600 megawatts of power, is expected to provide electricity to more than two million homes.

The project started construction in 2007 and was originally slated for completion in 2012 but faced significant technical setbacks and budget overruns.

The final cost of the reactor is estimated at €13.2 billion ($13.76 billion), nearly four times the initial projection of €3.3 billion.

EDF described the reactor's start-up as "historic," with Rémont noting it was the first new nuclear reactor in France to go online in 25 years, following the Civaux 2 reactor.

Flamanville 3's launch began on Sept. 3, but operations were briefly interrupted by an automatic shutdown the following day. It resumed testing shortly afterward, gradually increasing output until Saturday's grid connection.

Nuclear Energy Strategy

Nuclear energy accounts for about 60% of France’s energy output, making the country a global leader in nuclear power production. The government has committed to expanding its nuclear energy program to bolster energy security and reduce carbon emissions.

Macron has pledged to build six next-generation EPR2 reactors and set plans for eight additional reactors, potentially requiring billions of euros in investment.

The launch of Flamanville 3 comes as France diverges sharply from its neighbor Germany, which shut down its last nuclear reactors last year.

Despite years of setbacks, French officials emphasized the reactor’s importance to the country’s energy sustainability. "Reindustrializing to produce low-carbon energy is ecology French style," Macron said.

The EPR technology, considered a new generation of pressurized water reactors, has been completed in only three other locations globally. Flamanville 3 is now fully operational, cementing its role in France’s ambitious energy goals.