By Agence France-Presse
The European Pressurised Reactor (EPR) in Taishan, southern China "carried out its first chain and therefore it has started," tweeted Xavier Ursat, head of new nuclear projects for EDF, which has a 30 percent holding in two reactors under construction in the city.
"This is excellent news for the entire nuclear industry," he added.
With EPRs in Finland and France facing setbacks, the Taishan 1 reactor is the first of its kind.
Taishan 1 will undergo further testing and commercial operations are still many weeks away. Taishan 2 is expected to enter service next year.
The dates for both reactors to start working have been pushed back several times.
"Local defects" were found last year in Taishan 1's deaerator, a device used to remove oxygen from water circuits, according to China General Nuclear Power Corporation (CGN), -- which manages the project alongside French state utility EDF.
The two reactors under construction in Taishan, in Guangdong province, are 51 percent owned by CGN, 30 percent owned by EDF and 19 percent owned by the region's electrical utility firm.
Last September Britain gave the green light, with conditions, to EDF and CGN to build another such reactor at Hinkley Point in southwest England, after a heated debate which included worries over China's involvement.
That reactor is not expected to be completed until the mid 2020s.