This report shows that the installation of the Acoustic Fish Deterrent (AFD) is feasible on a technical level and presents the simplest solution for the installation of the AFD without the need for a disruptive saltmarsh or a second public inquiry.

In 2016, EDF unilaterally halted development on the AFD at Hinkley Point C. Despite a subsequent Welsh Government report, a public inquiry, and a final decision letter from the Secretary of State for Business Energy and Industrial Strategy all stating that the AFD must be installed, no further action has been taken to develop the AFD. 

This report bridges the gap between 2016 and 2024, highlighting the innovations in technical ability, technology, logistics, and science. It shows that Remotely Operated Vehicles (ROVs), new AFD technologies such as Active Pressure Compensation Systems, and logistical innovations can reduce maintenance times from 72 days per year down to just 19, proving the AFD can be installed safely in the Severn Estuary.

Our conclusions are:

1. Innovations over the last eight years have led to improvements in ROV design, extending the operating capabilities and water velocities that ROVs can operate in.
2. Developments in AFD systems, including Active Pressure Compensation Units, have increased the service interval of AFD systems from 18 months to a minimum of 24 months.
3. These improvements mean divers will not be required to carry out the routine maintenance work on the AFD system, and won’t be required for any of the installation work, although divers are already working on the AFD ready Intake Heads, so some diving activities will be acceptable, if required.
4. The AFD cannot be heard from shore, and does not affect marine mammals. This information is provided in the Appendix.
5. The new developments outlined here result in the original 72 days estimated by EDF that would be required each year to maintain the AFD system will now be reduced to less than 19 days per year.
6. The overall conclusion is that the AFD can be maintained without the need for divers to carry out the work. In relation to installation, no more diving time would be required than other Hinkley Point C installations. 

The Group urges EDF to embrace the new technology and work with the industry experts to finalise the design of an AFD system, compliant with mandatory requirements as noted above, ensuring it is installed, tested and operational before the station starts to abstract cooling water.  There is no evidence-based defence for failing to comply with this obligation.

The Acoustic Fish Deterrent Delivery Group.