Video report by ITV News Correspondent Juliet Bremner
The Hinkley Point nuclear deal means that China and France are one step closer to controlling a stake in Britain's nuclear power industry.
China's General Nuclear Power Corporation (CGN) will join France's EDF to provide energy for the UK from 2025 but while the technology is regarded as cleaner, there are still concerns over safety.
At the Flamanville reactor in France, where the Chinese and French companies are building the first of these new generation reactors, the nuclear watchdog is warning there are problems with the vessel that holds the reactor.
Deputy Director General of the French nuclear regulator ASN, Julien Collet, told ITV News that there were concerns over the main pressure vessel, the main component of the nuclear reactor.
Areva (the manufacturers) has detected a defect in the reactor and we are wondering if this defect could increase the risk of failure of the main pressure vessel.
The flawed pressure vessel is now being tested by its manufacturers Areva and ASN but it is not clear what will happen next.
Collet said it is not certain whether parts of the reactor can be replaced easily. An alternative is to limit the reactor's operation.
But the chief executive of EDF Energy, Vincent de Rivaz said EDF and CGN are confident that the technology is going to work and will be safe.
He said that the problem in Flamanville is "totally under control" and that there are "no worries at all" about what is happening in France.
It is the safest nuclear technology under construction at the moment in the world.