A fire started in the No. 2 reactor building of the Penly Nuclear Power Plant (NPP) northeast of Dieppe, France last Thursday, said plant operator Electricite de France SA (EDF).
EDF teams and local fire brigades entered the reactor building and extinguished the blaze, which included small quantities of burning oil. Firemen ensured the fire was totally out.
Around 7:30 p.m., EDF then informed the French nuclear agency, Autorité de Sûreté Nucléaire (ASN), a defect on a primary pump seal led to a water leak above the normal values. However, dedicated circuits were able to collect the leak, officials said.
By the next day, EDF confirmed with ASN the leak stopped.
There were no injuries and no radiological consequences from the fire or subsequent pump leak. ASN provisional classification of the incident is at level 1 on the INES scale.
The Penly reactor will remain shut down until authorized for restart by ASN, which will undertake a technical assessment of the incident by ASN and its technical support organization the Institute for Radiological Protection and Nuclear Safety.
The primary pumps ensure the water circulation in the reactor primary circuit. In normal situation, a water injection inside some mechanical parts of the pump enables the cooling activity. This system consists of circuits dedicated to the collection of this water. At the Penly NPP, internal damages in the pump led to the collection of abnormal quantities of leaks, bigger than expected. The primary pumps are in the reactor building.
EDF said a faulty joint on a pump used to cool the reactor had caused a leak inside the reactor building. The joint suffered damage in the fire, which occurred after lubricant from one of the reactor’s cooling pumps spilled on the floor, generating smoke and small flames. The reactor automatically shut down after the fire and continued to cool normally.