Sticky situation at Gravelines

11 August 2009

Refuelling of Gravelines 1 has been interrupted by a stuck fuel assembly. Owner-operator Electricité de France has evacuated the reactor building in line with regulations until a technical team has freed the assembly. The French Nuclear Safety Authority is monitoring the situation on site and has rated the event at Level 1 on the International Nuclear Event Scale - an 'anomaly'. The vessels of pressurized water reactors are opened periodically for some of the fuel assemblies to be replaced and for others to be rearranged, and it was during one of these many individual moves that one assembly became caught on another reactor structure. The assemblies are kept under water at all times to ensure cooling and radiation protection.