By lyndamyer
The final stages of offshore work on EDF’s Hinkley Point C nuclear power station project in Somerset are being started by Main contractor Balfour Beatty and marine construction specialist New Waves Solutions.
In order to helping install six vertical shafts into the seabed of the Bristol Channel, two large jack-up vessels have arrived off the coast of Somerset, while Deme Group’s 132m long Sea Challenger and 60m long Neptune vessels are equipped with cranes on their platforms and stand on four legs that elevate them above sea level.
Delivery of this phase of the project is up to Developer EDF and Balfour Beatty with collaboration of New Waves Solutions.
As the key components of the Hinkley Point C nuclear power station’s cooling water system, the shafts are due to be drilled to a depth of more than 20m and will link the project’s three cooling water tunnels with the seabed.
The date of completion of these tunnels, which are two 3.5km intake and one 1.8km outfall system, was August 2022 and they will supply the two reactors at Hinkley Point C with cooling water and then discharge it back into the Bristol Channel.
Following installation, the shafts, a horizontal connection between the bottom of the shaft and the tunnels is slated to be dug by the project team. While this forms the first part of linking the tunnels with the intake and outfall heads that were lowered onto the seabed last summer, the six 5,000t head structures will cap the tunnels and help with the supply of cooling water.
A complex dredging campaign prepared the seabed for the installation of the tunnel heads. Legal action brought by campaigners attempting to halt the dredging was dismissed by the High Court in March 2022.
Using two large marine cranes working in tandem, the heads were lowered into place in previous summer and the structures are also being piled to the seabed.
According to EDF area delivery director for Hinkley Point C Jonathan Smith: “This is one of the final stages of our offshore operations, which will see teams from EDF, Balfour Beatty and New Waves Solutions working together to deliver yet another incredible feat of engineering.”
“The arrival of Neptune and Sea Challenger marks another significant step forward in the successful delivery of the first new nuclear power station in the UK for over 20 years. We now look forward to utilizing our unique capability and unrivalled expertise to continue with the linking up of the six miles of tunnels which are buried below the Bristol Channel – this is another important chapter in the offshore works required for Hinkley Point C’s critical water cooling system,” added Balfour Beatty project director Roger Frost.
