Tricastin NPP is located at the immediate border of the Donzère-Mondragon canal. The NPP base level is situated 6 meters under the normal operation level of the canal.
After the Fukushima Daiichi accident, ASN has requested EDF to conduct supplementary assessment of the canal embankment and any structure involved in the site protection against flooding to verify their resistance to a beyond design basis earthquake.
The most recent complementary investigations, aimed at improving the knowledge of a portion of the embankment structure, show that a 400-meter long part would not stand to the design basis earthquake (historical level of earthquake raised by a margin).
In case of such an earthquake, because of the induced flooding, the 4 reactors would loose power sources and cooling systems.
ASN has taken a resolution requesting EDF to temporarily shutdown all 4 reactors until the demonstration that the embankment can withstand the safety considered earthquake is given.
Event date: Fri, 18-08-2017