Insufficient seismic resistance of a part of the canal embankment along the Tricastin NPP

Print View Posted on: 28 September 2017

Event Date: 18 August 2017 Event Type: Power Reactor
Event Location: France, TRICASTIN-1 INES Rating: 2 (Final)

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.

INES Rating: 2 - Incident (Final) as per 28 September 2017
Release beyond authorized limits? No
Overexposure of a member of the public? No
Overexposure of a worker? No

Contamination spread within the facility? No
Damage to radiological barriers (incl. fuel damage) within the facility? No

Degradation of Defence In-Depth Yes

Person injured physically or casualty? No
Is there a continuing problem? No

Julien Husse
Autorité de Sûreté Nucléaire (ASN)
Site Sponsors
Site Sponsors: IAEA, NEA and WANO
This site is hosted by the International Atomic Energy Agency (IAEA) and co-sponsored by the Nuclear Energy Agency of the Organization of Economic Cooperation Development (OECD/NEA) and World Association of Nuclear Operators (WANO).
This site is hosted by the IAEA, however, event reports are filed and updated by authorities in participating countries, which remain responsible for all related content. Read more >