https://www.spglobal.com/platts/en/market-insights/latest-news/electric-power/061621-chinas-taishan-1-reactor-has-five-damaged-fuel-rods-ministry

There are likely five damaged fuel rods in the 1,750 MW Taishan-1 EPR in China, which have led to an increase in radiation levels within the reactor coolant, the Chinese Ministry of Ecology and Environment said in a statement June 16, providing the first official explanation for the nuclear reactor's recent technical problems.

It also said the increase in radioactivity in Taishan-1's primary circuit is related to fuel-rod damage.

"Due to the influence of uncontrollable factors in fuel manufacturing, transportation, loading and so on, it is a common phenomenon that a small number of fuel rods are damaged in the operation of nuclear power units," it said.

Taishan-1, which started commercial operation in December 2018, was the first EPR anywhere in the world to produce power. China has relied on a mix of foreign-designed and domestically developed reactors to deploy a fast-growing fleet of nuclear units.

Martial Chateau, a technical spokesman for French anti-nuclear non-governmental organization Sortir du Nucleaire, said June 16 that Taishan-1 should be shut because of the issues at the plant, noting that a reactor in France in similar circumstances would have stopped operating.

"We know there is a small crack in the tubes containing the fuel elements in the primary circuit. We don't know what caused it. It could have been a foreign object like a screw or a bolt circulating in the water under pressure. Or it could be a design fault," Chateau said. "There have been incidents like this in France."

Chateau said technical problems at Taishan "are huge," and could affect the ability of EDF, which owns the reactor's supplier Framatome, to market the EPR design to countries such as India.

"If It emerges that there is a problem with the fuel ducts in the Taishan reactor and they have to be replaced it could mean closing the reactor for six months, if all goes well, and a year if it doesn't," he said.