"We are not in a scenario of an accident with a melting core," reassured EDF, a parent company of the Taishan Nuclear Power Plant.
Operators of a nuclear power plant in southern China are fixing a "performance issue" at the facility, its French part-owner said on Monday.
Gas emissions carried out to do so are within acceptable limits, Franamore stressed.
The company commented following a recent report by US broadcaster CNN that the US government has been investigating a reported leak at the Taishan Nuclear Power Plant in Guangdong province.
EDF, the parent company of Framatome, said the plant's number one reactor experienced a build-up of noble gases in its primary circuit, which is part of the cooling system.
Noble gases are elements which have low chemical reactivity. Those at the plant are the xenon and krypton gases.
The gas leaked after the coating on some fuel rods had deteriorated, a spokesman for EDF said.
It is currently unclear how extensive the issue is.
EDF said that while there has been as increased level of rare gases around the reactor, it pointed out that this was common. It added that the gases were not dangerous and that any build-up was within safety parameters.
"We are not in a scenario of an accident with a melting core," the EDF spokesman stressed. "We are not talking about contamination, we are talking about controlled emissions," he explained.
The International Atomic Energy Agency, the UN's nuclear watchdog, said in a statement that it had contacted its counterpart in China regarding the issue but currently "has no indication that a radiological incident occurred."
But CNN alleged that the Chinese safety authority was raising the acceptable limits for radiation outside the facility in order to avoid having to shut it down. It cites a letter from Framatome to the US energy department as proof of this.
EDF is calling an extraordinary meeting with the Chinese operator of the Taishan plant and make a decision on the situation.
The Taishan plant is located in the south of China, 40 kilometers (25 miles) from the city of Taishan. The plant's two reactors came online in 2018 and 2019.
kmm/aw (AFP, dpa)