In its annual report on nuclear safety and radiation protection, the French Nuclear Safety Authority (Autorité de Sûreté Nucléaire, or ASN) has highlighted a "serious anomaly" in the composition of the steel in certain parts of the reactor vessel of the nuclear plant under construction at Flamanville, in northern France.
Areva, the company supplying the "evolutionary power reactor" (EPR)," informed France's nuclear regulator of the flaws, which were first identified during chemical and mechanical tests in 2014.
Sebastien Balibar, a leading authority in physics and a research director at France's National Center for Scientific Research, told VICE News that EPRs are the "third generation" of nuclear reactors, and feature "a number of safety improvements" on the previous model.
But despite the Flamanville reactor being hailed as the cutting edge of nuclear safety, the ASN has detected "manufacturing anomalies" in the bottom of the pressure vessel of the EPR as well as its cover. The agency determined that the mechanical resilience of the steel — its ability to absorb shock — was inadequate.
"You have to make sure that in this very thick metal vessel, no cracks are forming that could then spread," said Balibar. "If the severity of the issue is confirmed,they will have to build another vessel, which will have political, technical and financial implications."
Japan's 2011 Fukushima nuclear disaster highlighted the need for more stringent standards in nuclear safety. There is considerable danger that corium — a lava-like mixture formed during a nuclear meltdown — would leak from the reactor in the event of an accident.
"If there is a small crack somewhere, there is the risk of a future leak," Balibar noted. "After Fukushima, the ASN asked EDF [an electricity company largely owned by the French government] to reinforce the concrete under the nuclear reactor vessels, so that even in the event of a very serious incident, the radioactive matter would not leak through the ground — 'radiate' it — and seep into the groundwater."
According to ASN president Pierre-Franck Chevet, the nuclear authority has "extremely high requirements regarding equipment standards," and will be undertaking further surveys to establish whether or not the facility at Flamanville is safe.
Speaking to VICE News on Thursday, Chevet explained that it would take several months to undertake the necessary research in collaboration with Areva, which is just one of various companies in charge of building the reactor. Chevet described the highlighted anomaly as "a serious flaw, which concerns a part [of the reactor] that is crucial in terms of security."
The launch of the EPR, which was initially scheduled for 2012, has been postponed until 2017. If the vessel fails the new tests and has to be removed, there could be further delays.
"It's complicated to remove it," said Chevet, "and we've only just installed it."
On Wednesday, the environmental organization Greenpeace, which opposes nuclear power, claimed that a vessel is practically impossible to replace once it is installed.Despite the material challenges involved, Chevet disagrees that it can't be done. In the case of the reactor at Flamanville, he said it was possible because it hasn't yet been "irradiated."
The project in Flamanville will be the first reactor of its kind, which explains the many headaches and delays that have hindered its completion. The initial budget, estimated at 3.3 billion euros, has already ballooned to 8.5 billion euros.
"A one-year delay could mean an extra 700 to 800 million Euros," a nuclear expert told French daily Le Monde last November.
The project is being overseen by a consortium of public and private companies, including Areva, EDF, and Bouygues, and is surveyed twice a month by the ASN. These visits have already flagged several security issues. In 2014, ASN ordered a suspension of concrete pouring on the site over safety concerns.
Further delay to the completion could soon become an issue, as France's aging nuclear plants continue to get older. Half of the country's nuclear plants have been slated for replacement by 2025, pending a decision by the ASN.
In March, the nuclear plant in Fessenheim, Alsace, was shut down after a leak was discovered on a pipe in Reactor 1 — one of two 900-megawatt nuclear reactors at the plant.