During preventive maintenance checks on the reactor No . 1 of the Civaux nuclear power plant (in the Vienne department of France), scheduled as part of its ten-yearly in-service inspection, some defaults were detected close to the welds on the pipes of the safety injection system (SIS) circuit... As part of the ten-yearly in-service inspection of reactor No . 1 of the Penly nuclear power plant, preventive maintenance checks revealed similar defects on the SIS circuit.