In the last few weeks, The Planning Inspectorate has been holding several Issue Specific Hearings regarding the pending decision on whether to move forward with building a new nuclear power station at Sizewell, Suffolk.

The plant, known as Sizewell C, is currently in the news regarding its potential ownership and funding, however many other fundamental questions still remain unanswered regarding the project – including how to prevent the cooling water system from adversely affecting the surrounding aquatic ecosystem.

As EDF and NNB, the proposed builders of Sizewell C, currently have no plans to install an Acoustic Fish Deterrent (AFD) at the plant, despite being an integral part of Environment Agency Best Practice, Fish Guidance Systems attended the hearings to put the case forward for the installation of an AFD. 

An AFD system uses sound to deter fish from entering the intakes of the plant and there is wide consensus from the environmental community that AFD’s should be installed, as demonstrated at the recent Hinkley Point C public inquiry. 

In addition, the AFD is part of a three pronged, co-dependent approach to deterring fish from entering the cooling water system, with the other two being a low velocity side entry intake head and a fish return system. As experts in the field, Fish Guidance Systems believe the other two aspects of the system become redundant if not supplemented with an AFD.

Fish Guidance System’s Response

As part of The Planning Inspectorate’s Issue Specific Hearing 7 (ISH7) on Biodiversity and Ecology (Part 2 – Marine Ecology), and specifically the Cooling Water System and the requirement for an Acoustic Fish Deterrent (AFD) system, Fish Guidance System’s Dr David Lambert provided evidence. A full written response can be requested by emailing [email protected], but an overview can be found below.

  • Environment Agency Best Practice for the development of cooling water systems using once-through-cooling, as proposed at Sizewell C, is based upon the assumption that all mitigation measures available will be used, these being an AFD, Low Velocity Side-Entry (LVSE) Intake Heads and a Fish Recovery and Return (FRR) system. Any deviation from this specification that omits one or more of the three mitigation techniques should be considered non-BAT-compliant and other methods of plant cooling should be sought.  
  • As a result, if an AFD is not installed then serious consideration should be given to Sizewell C using cooling towers, rather than once-through cooling.  We assume this will not be acceptable to any of the stakeholders in the project, so the project should continue and be based upon the inclusion of an AFD, or it should be abandoned completely. 
  • The environmental conditions, as well as the much higher potential for the impingement of significant numbers of clupeids at Sizewell C means that any decision at Hinkley Point C regarding the removal of the AFD is not relevant at Sizewell C, as under Best Practice, each site must be assessed individually.

The hearings will continue in the coming weeks and can be viewed on The Planning Inspectorate’s YouTube Channel.