Areva reports that on 31 July the water gate between the Gulf of Bothnia, in the Baltic Sea, and the seawater intake structures of Olkiluoto 3 nuclear power plant unit was opened successfully to start the filling operation of the cooling water pumping station, in accordance with the action plan approved by the plant operator, TVO.

This operation is an important pre-requisite for the upcoming commissioning tests to be performed on the service water and cooling water systems of both the nuclear and conventional islands of the plant unit.

Once the leak tightness of the structures was checked and confirmed, the filling operation was successfully completed on August 1 by reaching equilibrium with sea level after a total filling duration of 7.5 hours.

The pumping station now contains 30.000 cubic metre of seawater safely isolated from the rest of the plant unit by concrete walls and physical blockings. The water will later supply the plant unit’s cooling systems.