French nuclear regulator ASN has ordered state-controlled utility EDF to reinforce and monitor parts of the dyke which protects the Tricastin nuclear power station from the waters of the Donzère-Mondragon canal in southern France.ASN said that in September 2017 it ordered EDF to temporarily shut down all four reactors at the four-unit Tricastin following the discovery of flaws in the canal dyke bordering the facility.