In an open NNB Generation Company (HPC) Limited letter that explores changes to
Maisemore Weir as an alternative to the already approved Acoustic Fish Deterrent (AFD) at Hinkley
Point C, the company flagrantly disregards and negates the proven science and technology which would
prevent catastrophic environmental implications such as the death of 182 million fish in the Severn
Estuary.
For the last eight years, NNB Generation Company (HPC) Limited, majority owned by French energy
giant EDF Energy with a minority stake held by China General Nuclear Power Group (CGN), has been
contesting the application of the Acoustic Fish Deterrent and offering inadequate compensation
measures at Hinkley Point C for various reasons without any scientific backing.
Now, in an open letter dated 9 th September 2024, the company loosely claims that “Easing barriers for
migrating fish is considered a better solution than a largely un-tested acoustic fish deterrent, which
would have a limited benefit and use 280 speakers to make noise louder than a jumbo jet 24 hours a day
for 60 years. The system’s impact on whales, porpoises and other species is also unknown.”
Acoustic fish deterrents (AFDs) have in fact become the most effective way to guide and deter fish from
estuarine cooling water intakes and have recently been scrutinised by the UK Government in a public
inquiry, and an advisory group for the Welsh Government.
Backed by real world trials and acoustics, engineering, and environmental science, it has been concluded
that:
The AFD would not be heard from the shore or pose any disruption to human activities.
Standing on the nearest beach (2 miles away) the sound of the projectors would be just 36.5db,
which is quieter than a whisper in a library (55db), and much less than the noise of lapping
waves (70db).
Marine mammals such as seals, dolphins, porpoises and whales are not affected by the Acoustic
Fish Deterrent as the system emits low frequency sound, and mammals use high frequency
sound to communicate and hear. An AFD was tested in Hartlepool, where local seal populations
were monitored with no effect on their behaviour (AFD sounds at 1,000hz, peak range of sea
mammal hearing is 20,000hz).
In the letter, NNB Generation Company states that alternative weir improvements will “help to
implement current best practice and make the operational power station more efficient.” In fact, the
Environment Agency’s Best Practice Guide recommends installing AFD systems on estuarine intakes to
provide a cue for fish, enabling them to orientate themselves and swim away from an intake. In terms of
efficiency, the project is already hugely delayed and over budget and the continued lobbying against the
AFD will augment this situation.
Dr David Lambert, Managing Director of Fish Guidance Systems says “We have spent years innovating –
through sophisticated electronic systems, providing real time diagnostic and monitoring systems, active pressure compensation, advanced mapping, ROVs and longer maintenance schedules – to ensure that
acoustics are a necessary part of the nuclear future. This negation of scientifically backed research for
the purpose of marine conservation is unproductive in so many ways. We ask that this be rectified
immediately.”
