Paris (AFP) - A new-generation nuclear power plant in northern France that has been hit by huge cost over-runs and manufacturing problems will not be ready before the end of 2022, French power group EDF said Friday, pushing back the date by three years.

Construction of the new plant at Flamanville on France's Channel coast began in 2007 and was initially due for completion in 2012.

The latest problem concerns welds inside the reactor.

"The time that we will need to prepare the repairs, carry out the repairs, test the repairs and get everything checked by (regulator) the ASN and then have the whole plant tested again and prepared to be launched ... that will lead to delays of more than three years," EDF chief executive Jean-Bernard Levy said.

"So we don't think it's possible to commission it before the end of 2022," he added.

The Taishan 1 reactor in China became the first next-generation nuclear plant based on EDF technology, known as the European Pressurised Reactor or EPR, to reach the operational stage last year.

In May, a second reactor, Taishan 2, carried out its first chain reaction.