During its treatment of the stress corrosion (SC) phenomenon affecting several of its reactors, and in accordance with the strategy it had proposed, EDF carried out inspections on the piping of the Cattenom NPP reactor 1 safety injection system. These inspections, which were carried out close to the welds liable to be the most severely affected, revealed indications that could be attributed to SC cracking. Two of them were of significant dimensions, with maximum depths of 4.7 and 6.1 mm.