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Villagers packed a public meeting to protest against EDF's plans to flood land to compensate for fish kills at Hinkley Point
How many fish does a nuclear power plant kill?
It sounds appalling, but for engineers on the Somerset coast who are building Britain's first nuclear power station in a generation, it's an urgent question.
And for conservationists and villagers on the banks of the River Severn in Gloucestershire, it has become such an urgent issue that they have packed a village hall to debate it.
Proposals for the seawater cooling system at Hinkley Point C will result in 44 tonnes of fish being swallowed and killed each year, according to EDF, the company building it.
EDF
Five miles of tunnels were dug under the Bristol Channel to bring in seawater to cool steam at Hinkley Point C
“This project will decimate fish stocks,” said wildlife conservationist Dave Seal.
“We have already lost 80% of our salmon, and half of those entering the Hinkley cooling system will be destroyed. »
But Andrew Cockroft, of Hinkley Point C, insisted there would be a “very, very small impact on fish populations”.
Why so much water?
At the heart of this dispute is a simple truth of physics: nuclear power plants, by design, get hot.
The steam drives huge turbines that spin and produce electricity.
At Hinkley Point in Somerset, they are about to install the nuclear reactor that will create all the heat in the first place. It will be at least another seven years before it is put into service.
But first, they have to think about fish.
EDF
EDF produced this diagram to show how water from the Bristol Channel will cool the steam which drives the Hinkley Point C turbines.
To keep the entire reactor cool, huge tunnels – eight kilometers long – were dug under the Bristol Channel.
When the plant is operational, 132,000 liters of seawater per second will be sucked into a system that will function like a huge car radiator.
The superheated steam that drives the turbines will pass through pipes surrounded by cold seawater, to cool it.
Seawater will never come near the nuclear reactor and can therefore be safely released into the sea.
The River Severn at Arlingham, Gloucestershire, where EDF plans to create a new 'salt marsh' to farm fish.
But with this enormous amount of water, millions of fish will produce.
The Bristol Channel is home to salmon, eels, herring, sprats and dozens of protected marine species.
And no one wants them to die just so we can turn on our lights and make dinner.
Can they stop the fish?
Engineers have done many things to save the fish, including installing a complex concrete “head” on the pipes on the sea floor where the water enters.
Narrow side openings allow water to enter, with screens to keep larger creatures out. Unlike previous power plants, this is not simply an open pipe sucking in seawater.
But they accept that some fish pass through the grids.
In fact, they estimate that around 44 tons of fish will be ingested each year.
Is that a lot?
For comparison, fishing boats from Newlyn in Cornwall landed 1,700 tonnes in July alone.
So, in a year, the nuclear power plant will “eat” about a day of fishing.
Andrew Cockroft of Hinkley Point C says the plant will have a “very, very low impact” on fish populations.
“Proportionally, that’s a very, very small number of fish,” Andrew Cockroft, of Hinkley Point C, said.
However, the Environment Agency wants EDF, which is building the plant, to do something to help marine life.
How to compensate?
EDF planners are now trying to find 340 hectares (840 acres) of land on the banks of the River Severn that they could flood to create new salt marsh habitats.
There, salmon, eels and countless marine species will be able to reproduce.
Mr Cockroft, who leads the public engagement program at Hinkley Point, said the salt pans provide a “natural” offset to the impact of the nuclear power station.
He said: “Salt pans reduce flooding. It provides shelter and breeding grounds for fish, is an amazing place for birds and can be great for humans too.
The question now is which fields should be flooded?
More than 100 people queued to enter the village hall for a public meeting on EDF's plans for a new salt marsh near Arlingham
The village of Arlingham lies on a bend of the River Severn, surrounded by fertile low-lying agricultural land.
Proposals to cross the banks to create new marshes have been very poorly received.
A public meeting organized on Monday in the village hall to hear the projects of the EDF teams was sold out.
“We have fertile agricultural land and rare wildlife,” one woman said. “Hares, bats, hedgehogs. Why would you choose Arlingham?
Another man told EDF officials, “Arlingham is a unique part of the country, and I don't see any reason why you should waste that just to solve your dead fish problem.”
The EDF team declared during the meeting that they were heard “to listen, to collaborate”.
They needed to find a place to create the new 340 acres of salt marsh, and Arlingham was one of four sites that met that criteria, they said.
But residents insist there is another, better solution.
Why have plans changed?
The initial plan for Hinkley Point approved by the government included a so-called “acoustic fish deterrent” device.
As the name suggests, a speaker system near the inlet pipes would simply scare the fish away.
EDF says it no longer thinks it will work. Some fish can't hear. Others, like dolphins and whales that use sonar for navigation, will be deafened.
Furthermore, EDF specifies that the enclosures should be maintained by divers working in the dark, at depth, in a risky location.
Activists are not convinced and believe the acoustic deterrent is much better than flooding 850 acres of land.
“You agreed to the acoustic fish deterrent,” Godfrey Bragg said.
“And now you want to go out and bother all these people.” It just frees you from your problem of killing fish.
Killing so many fish is “unacceptable,” said Dave Seal, a local wildlife activist.
Dave Seal, a local wildlife advocate, said at the meeting that it is far better to deter the fish than to let them ingest and kill.
“Imagine if a wind farm killed 184 million birds per year, that would be a completely unacceptable situation. So why is it okay to kill all these fish? » he said.
But in 2023, the Environment Agency ruled in favor of EDF and removed the requirement to install a noise deterrent from Hinkley's planning permission.
So they now need to find someone who will be happy to see their land flooded, without disturbing the neighbors.
Average BP
Crews worked through the night in December 2023 to raise a huge domed roof on the Hinkley Point C reactor building.
Since 2016, I have watched engineers and builders work on Europe's largest construction site, creating an extraordinarily complex power plant.
They owned the largest land crane in the world, nicknamed Big Carl.
It was installed in a 245-ton dome to cap the reactor building, itself the size of the roof of St. Paul's Cathedral.
But creating a new breeding ground for the River Severn's salmon and eel populations could be one of the thorniest problems they have faced so far.
And until they solve the problem, they won't be able to turn on the nuclear power plant.
