France connected the Flamanville 3 nuclear reactor to its grid on Saturday morning, state-owned operator EDF said, marking the first addition to the country's nuclear power network in 25 years, Reuters reported.

The reactor, which began operating in September before being connected to the grid, is starting up 12 years later than originally planned and will cost about 13 billion euros, four times the original budget.

Europe's Flamanville 3 pressurized reactor is France's largest (1.6 gigawatts) and one of the largest in the world, along with China's 1.75 gigawatt Taishan reactor, built on a similar scheme, and Finland's Olkiluoto.

EDF plans to build six more new reactors to fulfill a promise made by President Emmanuel Macron in 2022 as part of the country's energy transition plans.