EDF has detected deviations from the study guidelines for welds and piping at the Flamanville EPR, according to the Nuclear Safety Authority (ASN), which asks the electrician to find solutions to correct them.
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EDF reported to ASN "
a design deviation concerning three taps of the main primary circuit of the EPR reactor under construction on the Flamanville site
" (Manche), indicates a note from the authority.
The tapping corresponds to the part of a pipe which connects it to another or to a vessel.
The connections in question are located on the main primary circuit, which contains the water used to cool the reactor core and to transfer the energy resulting from the nuclear reaction to the steam generators.
They do not correspond to the initial reference because EDF and Framatome decided in 2006 to increase the diameter of the weld of the nozzles in order to facilitate control.
In the event of failure, the breach to be taken into account would be greater than that of the safety studies.
ASN asked EDF “
to indicate its strategy for dealing with this
design
deviation
”.
The authority also asked the electrician "
to identify
" its "
root causes
", the "
reasons for its late detection
" and to implement "
corrective actions
" to "
ensure the absence of other deviations on the main primary circuit
”.
Launched in 2006, the construction in Flamanville of the first French third-generation reactor has multiplied the setbacks.
It should start at the end of 2022, that is to say at least ten years behind the initial schedule.
