The French Nuclear Safety Authority (Asn) identified on 7 April some "anomalies" in the vessel of the new-generation Epr reactor under construction at Flamanville, in Normandy. A week later, the head of the regulatory body, Pierre-Franck Chevet, explained to the Paris Senate that "the problem identified is serious. Very serious. It involves one of the main components of the structure. We will now assess the potential safety impacts, but that will take months."

The vessel is, in fact, a component designed to contain the reactor core: it is therefore a fundamental barrier protecting the surrounding environment from radioactivity. The Asn's warning does not, however, appear to have shaken the confidence of the Paris government: the Minister of Ecology, Ségolène Royal, has assured that the reactor, designed by nuclear giant Areva, "is not condemned — the opening will simply be delayed by one year. These are complex works: it is normal for adjustments to be made along the way. We will carry out the necessary tests, publish the results, and then work will resume as normal."

But the controversy surrounding the reactor does not stop at manufacturing anomalies. The plant, whose construction began in 2007, was supposed to be operational by 2012: the latest forecasts now point to 2018. And costs, like the timelines, have ballooned: an initial estimate of 3.3 billion euros has now grown to over 9 billion. The situation is not unlike that of Olkiluoto, in Finland, where since 2005 Areva has been building another Epr, with works expected to be completed in 2016 — seven years behind the original schedule. For the French company it has been a true economic catastrophe: the firm has already projected losses of 3.9 billion euros, exceeding the reactor's selling price of 3 billion.

Two further Epr reactors are also raising concerns in China, at Taishan: Beijing has indicated that it wishes to await the results of the Flamanville tests before loading fuel into the reactors (also supplied by Areva). And in the United Kingdom too, where the construction of two Epr reactors at Hinkley Point is being planned — at a stratospheric cost estimated at between 19 and 31 billion euros — very serious doubts could arise.