Cattenom nuclear power station;
On Friday 17 February 2023, the EDF-CNPE de Cattenom confirmed a delayed detection of non-compliance with technical specifications of exploitation.
On 12 February 2023, as part of the activities following the restart of reactor no. 1 of the Cattenom power plant, the teams carried out the "digital implantation of the parameters for adjusting the protection system of the reactor". This system allows the automatic shutdown of the reactor and the triggering of the appropriate safety systems in an accidental situation. In accordance with the procedures, the activity is controlled by a national entity validating the physical tests of the restart of the reactor.
This control, carried out on 13 February, questioned the correctness of a value, which in the case of a transient requiring the activation of the protection would have slowed down its activation (additional delay of the order of 4%). The system was considered unavailable until a new value was implanted. The teams at the plant started reducing the power of the production unit n°1, in order to carry out a new installation which proved to be compliant.
The discrepancy was detected less than 24 hours after the event and did not have a real impact on safety. However, the conduct to be followed provided by the general rules of operation provides for an intervention under eight hours, which has not been respected.
Due to the late taking into account of this procedure, the management of the Cattenom nuclear power plant declared this event as a significant event of level 1 of the INES scale, graduated from 0 to 7, to the Nuclear Safety Authority on 16 February 2023.
