Chinese EPR nuclear reactor under surveillance after "rare gas" surge

One of the EPR reactors at the Taishan nuclear power plant in southern China suffered an "increase in the concentration of certain rare gases" in a circuit, French group EDF said on Monday, after CNN reported a possible leak, and while the control unit ensures that the situation is normal. "EDF has been informed of the increase in the concentration of certain rare gases in the primary circuit of reactor n ° 1 of the Taishan nuclear power plant owned and operated by TNPJVC, a joint venture of CGN (70%) and EDF (30 %) ", indicates the French group in a press release.

The primary circuit is a closed circuit containing pressurized water, which heats up in the reactor vessel in contact with the fuel elements.

So-called "rare" gases include argon, helium, krypton, neon or even xenon.

"The presence of certain rare gases in the primary circuit is a known phenomenon, studied and foreseen by the operating procedures of the reactors", adds the company.

CNN reports possible "leak"

The two Taishan reactors are to date the only EPRs to have entered service in the world, in 2018 and 2019. Other examples of these third generation reactors are under construction in Finland, France and the United Kingdom, but multiple technical setbacks delayed their commissioning by several years.

Framatome, the EDF subsidiary which participated in the construction of the Taishan reactors, had earlier indicated to monitor "the evolution of one of the operating parameters" on the site, but without giving details or talking about leaks . The plant "is in its field of operation and authorized safety", assured Framatome in a statement to AFP.

CNN, on the basis of a letter sent by Framatome to the US Department of Energy on June 8, reported a possible "leak" at this plant.

Framatome reportedly approached the United States to request authorization for technical assistance to resolve "an imminent radiological threat".

Still according to the American channel, the Chinese safety authorities have also raised the acceptable limits of radiation outside the site to avoid having to shut down the plant.

EDF "brings its expertise"

For its part, the operator of the plant, China General Nuclear Power Group (CGN), reported in a press release of "normal" environmental indicators, without however making direct reference to CNN information.

"At present, continuous monitoring of environmental data shows that the environmental indicators of the Taishan nuclear power plant and its surroundings are normal," said the Chinese group, which did not respond to requests for information from AFP.

The Chinese Foreign Ministry also did not respond to the requests.

In France, the government, the Atomic Energy and Alternative Energies Commission (CEA) and the Nuclear Safety Authority (ASN) had not immediately commented.

EDF says it has contacted the TNPJVC joint venture and "brings its expertise". The French group also says it has "requested the holding of an extraordinary board of directors of TPNJVC so that the management presents all the data and the necessary decisions". China has about fifty reactors in operation, which ranks it third in the world behind the United States and France.