Nuclear reactor incident in China’s Taishan EPR: cause identified

The incident that led to the shutdown of the reactor at the EPR nuclear power plant in Taishan (China) in July is believed to be due to a malfunction in the ship’s design, CRIIRAD said on Saturday, warning of a risk. Similar problem in other EPRs.

The association formed in the aftermath of the Chernobyl disaster wrote a letter to the administration of the Atomic Energy Commission (ASN) on Saturday to share this information with the Independent Research and Information Commission for Radiology (CRIIRAD). He claims to be a “whistleblower”.

“This is a Frenchman working in the nuclear field who has access to the most accurate technical information on the status of the Tyshan 1 nuclear reactor,” said Bruno Charoron, director of the laboratory. Told CRIIRAD.

Chinese operator CGN, the plant’s main operator (70% stake) EDF (30%), announced on July 1 that reactor 1 of the Taishan EPR nuclear power plant near Hong Kong would be “shut down for maintenance”. The only EPR installation currently in service in the world.

The incident was reported on June 14: a small number of damaged uranium fuel rods (“rods”) accumulated rare radioactive gases in the sealed primary circuits of the power plant. Authorities described the incident as “current” and ruled out any danger.

In its letter to AFP, CRIIRAD, based on the information sent by this whistleblower, stated that “these degenerations observed at the nuclear fuel assemblies (…) are mainly caused by abnormal vibrations of these assemblies and are” linked to a defect in the tank design of the EPR sector “.

According to CRIIRAD, from 2007-2008, “the results of tests on the 0.2 mock-up” at Framatome in Le Creusot revealed these defects in the hydraulics of the tank.

Therefore, the association asks ASN, among other things, whether it was reported “about the detection of abnormally large vibrations of rod assemblies in Tyshan”.

It also calls on the Flymanville EPR under construction: “Shouldn’t EDF be required to replace the tank lid before something goes wrong?” “;” In terms of safety and radiation protection, is it acceptable to load new fuel (…) at the reactor as it is? “.

ASN contacted by AFP, did not want to speak.

“Fuel and ship exploration work on the Taishan reactor 1, which began after it was unloaded, is still ongoing. The origin of the fuel line leaks will only be determined at the end of this expertise,” the EDF said.