There were, according to reports obtained by Bellona Web, no releases of radiation into the atmosphere or irradiation of plant employees. The reactor unit was also shut down.

The Nuclear Safety Authority (ASN) classed the incident as level 1 on its 0-7 scale of danger and plant bosses said there was “no risk” to the environment from the incident. The ASN scale corresponds to the International Atomic Energy Agency’s  International Radiological Event Scale (INES), with the exception that the INES does not include a “0” in its scale.

The incident is nonetheless cause for alarm as there have been five level “1” incidents at Gravelines over the past three years and an incident of similar severity happened in July 2008 at the EDF nuclear power station at Tricastin in the Drôme in the south of France, the Connexion reported.

The most recent incident occurred when plant operators were clearing out spent nuclear fuel rods from the No. 1 reactor overnight on Saturday-Sunday when one became jammed on a support frame in the upper part of the reactors active zone, said the ASN.

The operation was halted immediately, and all personnel, as per the plant’s protocol were evacuated from the reactor building.