United Kingdom, Oct. 6 -- A 620m tunnel has been completed beneath the seabed of the Bristol Channel at Hinkley Point C, in a complex feat of engineering delivered as part of the power station's Fish Return System.The Fish Return System is one of three measures designed to protect fish around Hinkley Point C's cooling water intakes, alongside an acoustic fish deterrent and four low-speed water intakes.The Tunnel Boring Machine (TBM), Sarah Guppy, broke through the offshore headwall five months after setting off from the launch shaft and was then recovered from the Bristol Channel using a floating crane. KierBAM, the joint venture delivering the works for client EDF Nuclear New Build, used the TBM to excavate the tunnel beneath the seabed. A...