The Taishan nuclear power plant (Guangdong), made up of two EPR-type nuclear reactors and built with Electricité de France (EDF) in southern China, is under surveillance for a leakage problem at the core of a reactor, but the gas discharges into the air thus generated are within the authorized limits, assure EDF and the Chinese operator.
“EDF has been informed of the increase in the concentration of certain rare gases in the primary circuit of reactor number 1 of the Taishan nuclear power plant, owned and operated by TNPJVC, a joint venture of CGN (70%) and EDF (30 %) “, announced the French group, Monday June 14, in a press release, after US channel CNN reported a possible leak problem.
The primary circuit is a closed circuit containing pressurized water, which heats up in the reactor vessel in contact with the fuel elements, which are stacked in tanks. “Pencils” surrounded by metal sheaths.
Nuclear fission produces rare gases, in this case xenon and krypton, which leaked in this circuit through the cladding – a phenomenon minimized by EDF and experts. EDF has ruled out any dynamic of core melting, as in former nuclear disasters. “The presence of certain rare gases in the primary circuit is a known phenomenon, studied and foreseen by the operating procedures of the reactors”, said EDF.
“Controlled, controlled” discharges
The procedure provides for these gases to be collected and treated in order to remove the radioactivity, before being released into the air. They have been “In compliance with the regulatory limits defined by the Chinese safety authority”, then clarified EDF, saying that these limits were in the international average. “We are not dealing with contaminations, we are dealing with controlled, controlled discharges”, stressed the group during a press conference.
“There must be leaky metal sheaths, allowing rare gases to pass which contaminate the primary fluid”, explained Karine Herviou, Deputy Director General of the French Institute for Radiation Protection and Nuclear Safety (IRSN). She adds that, for the moment, nothing allows to speak of” accident “ :
“We don’t know the values, the concentration, we don’t know the extent of the phenomenon. But there is no more to worry about for the moment, considering what we know. “
Pencils “Leaky” are “A fairly normal and banal phenomenon, although undesirable, in any case not rare in the nuclear industry”, said David Fishman, of energy consultancy The Lantau Group in China. The International Atomic Energy Agency (IAEA), based in Vienna, said, for its part, that” at this stage ” she didn’t have “No indication that a radiological incident has occurred”.
“Radiological threat”
The two Taishan reactors, not far from Macao and Hong Kong, are to date the only EPRs to have entered service in the world, in 2018 and 2019. Other units of these third generation reactors are under construction in Finland , in France and in the United Kingdom, but numerous technical setbacks delayed their commissioning by several years.
Framatome, the EDF subsidiary which participated in the construction of the Taishan reactors, had declared Monday morning to monitor “The evolution of one of the operating parameters” reactor, but without giving details or mentioning any leaks.
CNN, based on a letter sent by Framatome to the US Department of Energy on June 8, reported a possible “Leak” in this central. Framatome reportedly approached the United States to request authorization for technical assistance to resolve “An imminent radiological threat”. It is not known why the American endorsement is necessary to intervene. Also 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.
For its part, the operator of the plant, China General Nuclear Power Group (CGN), reported in a press release on environmental indicators. “Normal”, without however directly referring to the information of CNN. The Chinese Foreign Ministry did not respond to requests either, as did the French Atomic Energy and Alternative Energies Commission. EDF nevertheless requested the holding of an extraordinary board of directors with the joint venture TPNJVC.
China has around fifty operating nuclear reactors, which ranks it third in the world behind the United States and France.