During the ten-yearly in-service inspection of reactor No. 1 of the Civaux nuclear power plant, which began on August 21, 2021, EDF performed ultrasonic testing of several welds in the emergency core cooling system, in accordance with the applicable preventive maintenance program.
The emergency core cooling system (ECCS) is a safety system that injects borated water into the reactor main coolant circuit (also called main primary circuit) to cool the core in the event of a breach affecting the main coolant circuit. The objective is thus to maintain a sufficient water level in the core to cool the fuel assemblies.