Hinkley Point C: EDF tests a new acoustic fish deterrent system

Tuesday, March 4, 2025

The company that built the Hinkley Point C nuclear power plant in southwest England had originally been given planning permission in 2013 for a scheme with low -speed cooling water admission heads and a fish return system to minimize the number of fish that are absorbed by the plant cooling water system. He also involved having 280 submarine speakers to expel noise to keep fish away from admission areas.

However, EDF later said that “fast flow tides and poor visibility represented significant risks for divers. This was not considered acceptable to mitigate the remaining impact size on the population of local fish and, as a result, the project has recently been exploring the creation of new saline habitat areas around Severn as a compensation measure.”

The proposal to drop the plan of deterrence of acoustic fish and create more than 800 acres (324 hectares) of Saltmarsh, has faced the local opposition in community consultations and legal challenges have threatened to increase delays for the nuclear energy plant project.

The new deterrent element of acoustic fish

EDF says that the “innovative” new type of indoor fish deterrence “was not known by us when we launched meetings with communities last year.” It implies the use of ceramic transducers to make a very high frequency target sound and “we are working with experts to provide scientific data to underpin the case for use in the new energy station.” He says that it is a fairly new technology deployed in the fishing industry to reduce the capture of bias and that it had not been considered for use for a power plant before.

The company says that it would not require much power, so no high -voltage energy cables would be needed and that they can be lowered in place and stay from the surface without the need for divers. The tests with fish labeling have already begun, what EDF says shows that the salmon “tends to move in the main channel away from the admission heads.”

EDF says that the high frequency system will be adjusted to “maximize the effectiveness of fish deterrence while minimizing impacts on larger marine mammals such as seals and dolphins.”

He says that technology is “tested and deployed internationally. This new type of acoustic fish deterre is now the preferred project solution and we are working with experts to provide scientific data to prop up the case to use it in Hinkley Point C”.

_{The acoustic fish deterrent system aims to stop fish that enter the water intake (Image: EDF)}

In his statement, EDF adds: “While the work to demonstrate the effectiveness of the new deterrence of acoustic fish will continue for 2025, we are stopping all the design and development work in the creation of Saltmarsh.

“We are currently not planning any additional consultation on the creation of Saltmarsh and we hope that it is no longer necessary. However, until the scientific work on acoustic fish is complete, we still cannot rule out the need for the creation of Saltmarsh or other compensation measures such as improvements in the future.”

The Environment Agency estimates that even without a system of deterrence of acoustic fish, the impact on the fish on the Severn estuary from the new power plant would be 44 tons per year, “less than the real capture of a small fishing container”, with the fish deterrence system with the aim of reducing that figure.

What are the planning implications?

There have been plans to send an application of material change to the consent of original planning for Hinkley Point C, but, if the new deterrence works, it will not be necessary to obtain an updated permit for the elimination of a system of acoustic fish deterrence and replacement with alone compensatory salt.

However, EDF says that it will still submit its request to change material to the permit in 2026, due to the proposals to change the way the fuel is stored and also changes to some other “infrastructure on the site, such as the retention of a substation.”

While EDF says that until it is demonstrated that the new system works, it cannot “rule out the need for the marina or improve the landfills above in the Severn estuary. We are still obliged by the current environmental regulations that require compensation if an acoustic fish deterrence does not adjust.”

The Hinkley Point C project

Construction of Hinkley Point C – Composed of two EPR pressurized water reactors of 1630 MWE each – began in December 2018, with unit 1 of the plant originally scheduled to begin at the end of 2025, before it was reviewed by 2027 in May 2022. Last year, EDF announced that the “base of the base” was now operational of unit 1 in 2030 in 2030, with the revised cost of GBP26 66 6. Among GBP31-34 billion, in the prices of 2015.

When completed, the two EPR reactors will produce sufficient carbon free electricity for six million homes, and are expected to operate for 80 years.