You're going to have to be more specific as to what you call a failure... Closing the Fessenheim plant even though it was in perfect condition, safe, and very useful, just for base politician reasons... is this maybe what you mean? If you count the MWh/€, the excellent safety records, it's hard to see the failure. Maybe the slow production of an EPR reactor, the giving up on efforts towards 4th-gen reactors?