Hinkley Point C has finished digging a 620 metre tunnel for the power station's fish return system, which runs under the Bristol Channel.

The nuclear power station features a dedicated tunnel beneath the seabed to safely transport fish back into the Bristol Channel if they are sucked into the plant's massive cooling water intake system

The tunnel boring machine has dug its way through the seabed five months after setting off from dry land and has now been retrieved by a floating crane, so that it can be taken away to be cleaned and used on another site.

The fish return system is just one of three fish protection systems which will give the power station more fish protection than any other power station in the world. The other measures are an acoustic fish deterrent and four low speed water intakes, designed so that fish can swim away from as close as 2 metres in the 20km wide channel.

The tunnel boring machine was named Sarah Guppy by local school children after the pioneering 19th century engineer from Bristol.