France-based utility EDF is providing maintenance work for pumping station pipes at 20 nuclear reactors to increase safety in preparation for future potential earthquakes.

The work was requested following an in-depth investigation that revealed that metal is thinning in certain sections of the piping, which makes the system vulnerable.

The pipe system is part of a fire safety system, designed to supply and filter water.

EDF said in a statement: “Investigations have revealed that in the event of a design-base-type earthquake, this could potentially cause flooding in the pumping station of 20 reactor units, thereby resulting in the functional loss of both reactor cooling water systems.”

“The pipe system is part of a fire safety system, designed to supply and filter water.”

So far, EDF has worked on Belleville 1-2, Cattenom 3-4, Dampierre 1-2, Golfech 1-2, and et Saint-Laurent-des-Eaux B1 reactor units.

Pipes are also being reinforced on five reactor units currently in outage. The work is expected to be completed before restarting these units, which include Chinon B3, Cruas 1, Dampierre 3, Nogent 1, and Saint-Laurent-des-Eaux B2.

EDF has also completed reinforcement work on one of the two reactor cooling water systems. Repairs on the second cooling water system are currently underway at the Cattenom 1-2, Chinon B4, Cruas 4, Dampierre 4, and Nogent 2 units.

In addition, EDF reported the piping system problem to the French nuclear regulatory authority (ASN) as a level 2 incident out of seven based on the International Nuclear Event Scale (INES) scale.