How is a nuclear power plant in Somerset affecting Welsh wildlife?

It’s old news that the world needs to get its act together and move away from fossil fuels and move to renewable and low-carbon ways to produce the energy we need. Hence, the UK Government have commissioned the French company EDF to build a new nuclear power plant just across the Seven Estuary at Hinckley known as Hinkley Point C (HPC). Nuclear energy is promoted as a green, renewable, low-carbon source of energy. Whichever camp you sit in on the nuclear debate, we need to consider if nuclear energy is truly green as there are significant impacts on nature in the Seven Estuary.

So, let’s start with some background basics; whilst nuclear power stations and their reactor design and technology have changed over the years, one thing hasn’t - the reactors get sizzling hot and need to be kept cool. As well as water being used in the energy creation process itself (the nuclear ‘fission’ process heats water to produce high-pressure steam which produces the electricity), unsurprisingly it is also needed to cool the reactors down. And quite a lot of it in HPC’s case in fact 132,000 cubic liters of seawater per second, through 8-metre high cooling intake tunnels placed in the Severn Estuary. But of course it's not just water that will get sucked in. The UK’s Governments Environment Agency (EA) concluded that 178 tonnes of fish will be sucked in per year, that is 182 million fish per year killed.

That’s the same Severn Estuary that is so internationally significant it has every European site designation (Special Area of Conservation, Special Protection Area and Ramsar Site). So an Olympic-sized swimming pool of water every 12 seconds will be needed for the next 70 years from the Severn Estuary. Many of those fish species are already vulnerable including Atlantic salmon, Twaite shad and the European eel, as well as many being a critical food source for overwintering bird species and the tens of thousands of waterfowl that call the place home. This is how an English power plant will impact wildlife in Wales as half the estuary is in Wales and the migratory fish are trying to enter Welsh rivers.

You won’t be surprised to hear that the initial application was put under huge amounts of scrutiny before being approved. Unsurprisingly the need to limit fish deaths was a condition of the planning permission which required EDF to mitigate for the devastating impact that this would have on fish populations with several measures. The three main fish protection measures were:

1. An Acoustic Fish Deterrent (AFD) - a clever device that creates a low-frequency underwater sound field that deters fish from being drawn into the water intake tunnels.
2. Low Velocity Side Entry intakes (LVSE) - the heads of these water intakes work in combination with the AFD, to deflect fish away from the intake.
3. A Fish Recovery and Return System (FRR) - fine mesh screens to prevent fish from entering the system but allow smaller organisms such as eggs and larvae to pass through.

In 2019 EDF proposed to remove the AFD requirement on the grounds that they were difficult to install and maintain and a risk to divers given the harsh conditions in the estuary. This went to public inquiry, with a wide group of environmental organisations including the Wildlife Trusts, collectively giving evidence to support the Environment Agency (EA) in challenging EDF’s proposal. In August 2022 the UK Secretary of State for the Environment officially ruled in favor of the EA that the AFD should remain.

In 2024 Welsh Government formed the Hinckley Point C Reference Group an expert panel to review the implications for Wales of HPC and Rachel Sharp Director of Wildlife Trusts Wales was a member.  This resulted in a report advising the Welsh Government on all aspects of the development. One piece of advice was that any future mitigation measures must include input from Welsh bodies to ensure the requirements of Welsh legislation are fulfilled. Wales has a commitment to maintain and restore resilient ecosystems, such as the Severn Estuary, in the Well-Being of Future Generations (Wales) Act. Wales also has international commitments to effectively protect and manage at least 30% of Welsh seas by 2030 plus a plethora of other marine legislation requirements. Therefore the first step has to be to stop any loss or damage to our marine environment. However, it is clear that HPC, although key to the UK Government’s energy strategy, is not green as it will have a significant impact on the Severn Estuary ecosystem.

After the Secretary of State decision was made, EDF essentially had two options - to either install the AFD or find an alternative legal process to get the conditions removed. So that’s what they did. Article 6 (4) of something called the Habitats Directive exists to enhance Europe’s biodiversity by protecting its most important habitats and species. It does this by ensuring that the decision-making authorities (in HPC's case Natural England, Environment Agency and Natural Resources Wales) assess the impact of any proposed plans or projects that may have a significant effect on these “European sites” - in this case, the marine environments of the Severn Estuary. Those authorities cannot consent to plans or projects they determine may have an “adverse effect on the integrity of a European site.

EDF have decided not to fit the AFD through a get-out clause in the Habitats Directive that offers a derogation under article 6(4) which allows plans or projects that have a negative impact on a site (that’s the killing of maybe 182 million fish) to be approved provided three tests are met:

1. There are no feasible alternative solutions to the plan or project which are less damaging.
2. There are “imperative reasons of overriding public interest” (IROPI) for the plan or project to proceed.
3. Compensatory measures are secured to ensure that the overall coherence of the network of European sites is maintained.

Using the argument that the alternative solution of an AFD EDF has headed straight for points 2 and 3 on that list. They have applied for changes to the initial 2013 DCO (Development Consent Order) – that’s big planning permission to you and me - through an IROPI, with the argument that installation of the AFD would further delay the completion of HPC and hold up the UK’s net zero plans. 

EDF then also proposed a package of measures claimed to be adequate compensation for the loss of fish in the estuary – initially this has been the proposed creation of nearly 800 acres of salt marsh in Somerset. According to a recent EDF announcement, the new natural habitat creation is a better solution than an AFD. But whilst creating saltmarsh is great for biodiversity it doesn’t address the long-term decimation of fish populations. EDF are looking at other compensatory measures but in no structured way. It is also lacking proper public consultation to the point that many landowners don’t want to talk to EDF. The Wildlife Trusts believe that small piecemeal compensation is not sufficient for the huge impact the plant will have. Also, a lot is promised by companies but never has compensation been implemented in full, monitored or maintained, making a mockery of the whole process.

The Wildlife Trusts are working as part of a wider eNGO group to challenge EDF’s current plans. Whilst the group accept that habitat restoration of saltmarsh, oysterbeds, kelp forest and river work could make an important and positive impact on the estuary there is not enough evidence that it will address the huge losses of fish life that the cooling intakes will cause.

The group are calling for:

• More evidence of the potential impact of the AFD removal to determine the amount of compensation needed, including more consultation with independent groups of experts.
• Agreement on comprehensive and long-term monitoring of the impact of the water intakes and the compensatory habitat as it develops throughout the lifetime of the power station.
• A commitment to an adaptive response to the results of the evidence gathering and monitoring with additional compensatory habitat, the fitting of fish deterrents on the intakes and/or reduction in intake water volumes as alternative cooling techniques are more affordable or legislated.

Imagine if instead of fish the impact was on birds would the public stand for millions of birds being killed over the next 70 years? Just because our precious fish stocks are out of sight in the rich, murky silt-laden waters of the Severn Estuary doesn’t mean we don’t owe it to future generations to protect them as best we can.

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