New cracks have been detected on several reactors in the nuclear fleet

Margaux Fodere

EDF is under pressure following the discovery of cracks on several reactors in France. These are caused by what is known as the phenomenon of thermal fatigue. Not insignificant, they could lead to prolonged stoppages in the production of electricity from the nuclear fleet.

Will dozens of nuclear reactors have to be inspected? With this case, EDF is under pressure and this could potentially cause prolonged shutdowns of reactors. Two days after the discovery of a crack of an unprecedented size on a reactor at the Penly nuclear power station, new cracks have been discovered. This time they are located on the second reactor of the Normandy plant. Another was also perceived on one of the four reactors of the Cattenom power plant, in Moselle.

Significant and detected cracks, like the first, on an emergency circuit which is used to cool the reactor in the event of an incident. On the second Penly reactor, the crack reached up to twelve millimeters deep. In Cattenom, it reaches four millimeters.

Thermal fatigue to be monitored

These cracks are caused by what is called the phenomenon of thermal fatigue. Concretely, the piping is subjected to significant temperature variations which can crack the steel. EDF is well aware of this problem, but the company had never spotted it on this part of the reactor.

EDF will therefore have to extend its thermal fatigue control program to new areas. This involves some 200 additional welds to be checked. The Nuclear Safety Authority has also asked it to review its strategy as soon as possible. We should therefore know in the coming days if this first leads to an extension of reactor outages and especially if this has an impact on electricity production in 2023.