A small number of damaged fuel rods is causing a build-up of radioactive gases at the Taishan nuclear power plant, Chinese authorities said on Wednesday, who ruled out any danger.
The American television channel CNN on Monday reported a possible "leak" in this plant located in the south of China, which has the only EPR reactors to have entered service in the world.
This technology, designed to offer improved power and safety, is presented as the flagship of the French nuclear industry and a showcase for EDF.
Beijing had hitherto put the risks into perspective and explained that the levels of radioactivity around the plant were normal.
On Wednesday, the Chinese Ministry of the Environment and the Nuclear Safety Authority gave the first technical explanations.
In a joint statement, they admitted an increase in radioactivity inside one of the reactors caused "by about five damaged fuel rods".
A phenomenon described as "current" by the authorities, due to "uncontrollable factors" during the manufacturing process, transport or installation in the plant.
Fuel rods (or "rods") contain uranium pellets and provide energy in the core of a nuclear reactor.
The increase in radioactivity in the plant is "within the regulatory range" but "there is no radioactive leakage into the environment," the statement said.
EDF, which is a 30% shareholder in the Taishan plant alongside the Chinese group CGN, on Monday reported the presence of "rare gases" in the primary circuit of the first reactor.
The procedure provides for these gases to be collected and treated in order to remove the radioactivity, before being released into the air.
EPR technology has suffered many setbacks in recent years.
The setbacks and budgetary slippages accumulated on the first EPR project, launched in 2005 in Olkiluoto (Finland) on behalf of the electrician TVO.
And it is more than ten years late that electricity production should finally start in early 2022.
The second EPR, under construction since 2007 in Flamanville (Manche) in France, has also had many setbacks, due in particular to anomalies discovered in the composition of the steel of the tank cover and bottom.
The problem revealed to Taishan comes at a time when EDF is hoping for new projects abroad for its reactor.
© 2021 AFP