ASN authorizes postponement of Flamanville EPR vessel cover replacement

While the Flamanville EPR is scheduled to start in the first quarter of 2024, the French nuclear safety authority has authorized the replacement of the reactor vessel cover after a first operating cycle that will last 15 to 18 months. This operation should occur in 2025 instead of 2024 as initially planned.

With the startup of the Flamanville EPR fast approaching, the question of replacing the reactor vessel cover must be decided. As a reminder, in 2018, the French nuclear safety authority (Autorité de sûreté nucléaire) expressly requested the replacement of this part. It had found locally higher concentrations of carbon than specified, namely 0.3% instead of 0 22%. The authority, therefore, requested that the vessel cover be replaced during the first shutdown of the Flamanville EPR and no later than 31 December 2014.

At the time of the ASN’s decision in 2018, the startup of the EPR was planned for autumn 2019. But now, the reactor is scheduled to operate in the first quarter of 2024. Maintaining the initial ASN decision would require a concise first operating cycle. Thus, Framatome, in charge of manufacturing the new cover, has officially asked the ASN to postpone this replacement until the first reactor shutdown.

Avoiding a specific shutdown

In a press release, the ASN explains that “the first shutdown for reloading the reactor (is) planned between 15 and 18 months after its commissioning. The duration of use of the cover would be less than that envisaged in 2018 when the ASN authorized the commissioning of the vessel, and this postponement would avoid a specific shutdown of the reactor between early 2024 and late 2024 to replace the cover”.

Thus the nuclear watchdog, in its decision, writes: “The ASN considered Framatome’s request to be acceptable and authorized the use of the cover until the first shutdown to reload the reactor. The decision was rather expected. Indeed, when questioned on this subject at a January meeting, the ASN had already expressed the idea that this issue did not pose a major technical problem and that the schedule adjustment could be studied. ■

By Ludovic Dupin (Sfen)

Photo: The Flamanville EPR is scheduled to start up in the first quarter of 2024 – ©EDF/MorinAlexis