French utility giant EDF was an official sponsor of the Summer Olympic and Paralympic Games in Paris, and it’s management knows only too well how embarrassing a false start can be. For that was the case with its initial announcement last week about the starting up of the European Pressurized Reactor (EPR) at Flamanville, northern France – the most awaited event in the French nuclear energy industry in recent history.
On September 4th, EDF announced that the nuclear reaction process that had been launched the previous day at the Flamanville 3 reactor, 12 years after the date initially planned when work began at the site, had been halted by an “automatic” shutdown. A second attempt, on September 7th, proved successful when the nuclear reaction process was restarted at 8.21 a.m. local time, after which the reactor’s output was to be limited to 0.2% of its rated power.
At “each stage” of the starting process the “highest level of safety” was ensured, commented Maxence François, head of the nuclear energy sector branch of the CGT trades union. “It is the first EPR reactor in the French nuclear fleet, so naturally one discovers certain things,” he said. “On the EPR, we’re almost all first-timers. It’s new material and it’s the first time that we’re faced with certain factors, so the time taken for assessment is necessarily going to be a bit longer.”
François, a former technician who worked on the two Pressurized Water Reactors (PWRs) at the site, which came on stream in 1986 and 1987 respectively, minimised the latest delays in what has been a 17-year tale of missed deadlines and repeated budget-busting. “There we lost close to a month during the summer, but for us it’s no big deal.”
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None of that has any impact for the electricity network because the Flamanville EPR is not yet connected to it. “The EPR will only produce its first electrons when its turbine will be working,” explained Bruno Chareyron, scientific advisor for the Committee for independent research and information on radioactivity (CRIIRAD), an association dedicated to reporting on the dangers of radioactive activity in France. “For its turbine to operate, its [reactor] needs to be at 25% of its power, which won’t be for tomorrow.”
In explanation of why this reactor, which has become such a sensitive subject of embarrassment for the nuclear industry and such a painful symbol for EDF (overdue by 12 years and now costing 19.1 billion euros, according to the French national audit body, la Cour des comptes) could have run into problems in less than 24 hours of being started up, EDF issued a statement saying: “This shutdown could be linked to an inappropriate configuration of the installation.”
France’s official Nuclear Safety Authority described the reason in little less woolly terms. “The operational mode of the intervention was not respected,” said the watchdog, meaning that a human error was made during the start-up process of nuclear reaction, which “led to the appearance of a certain number of alarms and the automatic shutdown of the reactor”.
It was in an email sent out by the Benoît Fidelin, president of the Flamanville Local Information Commission (CLI), a body dedicated to informing the public on events at the nuclear site, and addressed to CLI members, that the reason behind the incident was made clearer: “An operator overlooked two IT stages” while connecting a computer to the “control-command” system, which is the brain of the reactor. The result was that “the protection system activated itself and gave the order for the automatic shutdown of the reactor”.
In his email, Fidelin added that for the management of the Flamanville 3 EPR, the shutdown showed that “the protection system functioned well”. But for Yannick Rousselet, a member of the CLI who acts as a consultant on nuclear matters, the incident highlights more problems to come. “It is a human error, but it is linked to the fact that the person in question was trying to avoid an industrial defect in the design of the EPR,” he commented. The flaw concerns the flow of neutrons within the reactor. “The manner in which water rises in the EPR reactor vessel can make the fuel rods move and therefore set off neutronic disruptions,” said Rousselet, who previously acted as a specialist on nuclear issues for Greenpeace France.
“This EPR reactor will never function properly, it’s not possible when you draw up the list of all its design and production flaws.
The problem of hydraulic vibration is well known. It led to the lengthy shutdown of EPR 1 at the Taishan nuclear power plant in China in 2021. “Hitting the bottom of the vessel, the water rises back up at 180°, crosses the fuel assemblages in the reactor and vibrates in an abnormal manner because of a design problem,” said Bruno Chareyron of the CRIIRAD. “In the end, these vibrations damage the nuclear fuel,” he continued, adding that “one way of solving the problem is to remove the cause and reconsider the design of the vessel”.
The French Institute for Radiation Protection and Nuclear Safety did not respond to questions submitted to it by Mediapart.
Another well documented flaw that was found in the Flamanville 3 reactor was an anomaly in the makeup of the metal of its dome-like vessel head, which will have to be replaced when the first refuelling comes about.
“This EPR reactor will never function properly, it’s not possible when you draw up the list of all its design and production flaws,” insisted Bruno Chareyron. “The complexity is too vast and the solutions put in place each time are done so too rapidly.”
In July, a number of French associations (la CRIIRAD, Crilan, Global Chance, Robin des Bois and Réseau Sortir du nucléaire) launched legal action to prevent what they see as a too “hasty” operational launch of the Flamanville EPR. Maxence François of the CGT trades union dismisses that claim, and said the initial shutdown last week showed that EDF “prefers to take the time to do things properly, rather than to be slapdash and do things anyhow”. For Fabrice Coudour, deputy secretary-general of the CGT’s nuclear energy branch, “the delay, the rise in costs, all of that is the consequence of 20 years of deregulation of the sector”.
EDF has said the first connection to the national electricity grid “is scheduled before the end of autumn 2024”, adding that “testing will continue throughout reactor ramp-up, which will be carried out in successive stages over several months”.
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- The original French version of this report can be found here.
English version by Graham Tearse