World Nuclear News reported earlier today:
Inspection work has revealed tiny cracks on a penetration at the bottom of Gravelines 1’s reactor pressure vessel. The power unit remains shut down until a repair has been made.
In France’s 900-MWe class pressurized water reactors, some 50 small tubes around 38 mm in diameter penetrate the bottoms of the reactor pressure vessels. They allow for instruments to be inserted through the vessel and into the reactor core, but their construction is important to nuclear safety because it represents part of the boundary of the pressurized cooling system.
Gravelines is owned by nuclear giant EDF, which may have a larger and very costly problem on its hands:
EDF has been requested by the ASN (Autorité De Sûreté Nucléaire, the French equivalent of the Nuclear Regulatory Commission) to check all its 900 MWe and 1300 MWe reactors for similar cracks – a total of 54 units.