French Nuclear Plant Halted After Fish Clog Water Filters

(Bloomberg) -- Electricite de France SA had to disconnect all four reactors at its Paluel nuclear plant on France’s north coast Wednesday after a “significant and unforeseeable” number of fish got stuck in the filter drums of the pumping station.

Two of the plant’s generating units have been reconnected to the grid while one requires further checks, EDF said in a statement. The fourth will remain offline for a planned refueling that was due to start on Jan. 23.

The pumping station draws in sea water for cooling, exposing it to a range of environmental hazards. EDF’s Torness station in Britain has been halted several times due to excessive amounts of seaweed. In Sweden, the Oskarshamn plant shut in 2013 to clear jellyfish clogged in its water pipes, while rising sea temperatures the following year forced some plants to limit power output.

The Paluel plant outage comes after freezing weather earlier this month and worker strikes stretched European utilities’ generation capabilities to the limit. France’s 56 nuclear reactors produce more than 70% of the country’s electricity. Wind turbines were able to pick up some of the slack as generation rose to a record Wednesday evening, grid data show.

Hinkley Point C, a new nuclear plant that EDF is building in southwest England, will incorporate a fish return system, an underwater wheel that filters out the fish and sends them back to the Bristol Channel. The company is appealing a requirement to have an “acoustic fish deterrent” to keep the animals away.

Nuclear power plants need a constant flow of water to cool their reactors and turbine systems, which is why many plants are built near the sea or by rivers.