France is starting up the long-delayed Flamanville-3 EPR nuclear power plant in France with teams starting work on activities needed for the first nuclear reaction.

EDF, the French state-owned operator of Europe’s biggest fleet of nuclear power stations, said on Monday (2 September) that the first chain reactions at the plant on France’s Normandy coast were due to get underway overnight.

It said the next key step in the startup process is achieving a stable nuclear reaction at very low power. The reactor will initially be brought to 0.2% of its nominal power.

This will be followed by a test programme as the reactor is brought to a power level of 25%. It is at this level that the Flamanville-3 EPR will be connected to the national electricity grid for the first time and will then produce electricity.

EDF said this first connection for the plant is planned for the end of autumn 2024.