EDF hopes the deployment of new techniques will help put four nuclear reactors back online later this year, after technical glitches forced closures.

Two reactors were taken offline following the discovery of manufacturing problems and document falsification at the foundry of its supplier Areva, while the others were shut down by a sealing problem and an accident.
Fessenheim nuclear power plant
The outages have led to higher power prices, are undermining France’s security of supply and are costing EDF an average of EUR1m in lost revenue per reactor per day.

Philippe Sasseigne, the head of EDF’s 58 French nuclear power stations, told Reuters it had found several new technical fixes and that all four plants would restart this year if its proposals get the go-ahead from French nuclear regulator the Autorite de Surete Nucleaire (ASN).

Arguably EDF’s most significant problem is the closure of Areva’s Creusot Forge, which is under investigation by the ASN and is not expected to restart production before the summer.

Creusot Forge is EDF’s main supplier of steam generators, which turn a reactor’s heat into the steam that drives its power turbines. Each EDF reactors is cooled by three to four steam generators and every year EDF needs to replace one or two. The huge steel vessels – which have life spans of 30 years or more – have thousands of individual tubes inside them which gradually develop leaks and need to be blocked.

In October, an Areva-made steam generator set to be installed in EDF’s Gravelines 5 reactor in northern France was found to contain serious anomalies.

Sasseigne said the ASN last month allowed EDF to fix any leaks in the tubes by inserting new, smaller tubes in a process called “sleeving”. This is already practiced in the U.S., Sweden and Belgium and can extend the life of the part by two years.