Electricite de France has completed the biggest single pour of concrete in Britain at the site of a new nuclear power plant in Somerset.
The utility poured 9 000 cubic meters of the material at Hinkley Point, exceeding the amount of concrete that went into the Shard skyscraper in London. It was reinforced by 5 000 t of steel built into a nest 4 meters high that will serve as the base of the first new reactor in the UK since 1995.
The announcement marks completion of the first part of construction work at the Hinkley Point C project, allowing erection of the facilities above ground to begin in earnest. That leaves the £19.6-billion plant on track to start generating electricity within six years, producing enough energy to supply six million homes.
“This is a huge achievement for Hinkley Point C and a major milestone for the UK’s nuclear industry,” Andrew Stephenson, the UK government minister in charge of nuclear power at the Department for Business, Energy and Industrial Strategy, said in a statement released by EDF on Friday.
The scale of the new Hinkley plant makes it the biggest engineering project in the UK by some distance. It will cost more than the tunnel connecting England and France, use enough steel for a railway from between London to Rome and require enough concrete to build 75 sports stadiums.
The company built facilities to mix concrete at the site 1 1/2 years before they were needed to perfect the exact mix of cement, water and aggregate needed to ensure no cracking. Reinforcement bars were laid with precision, no more than 2 cm askew from the plan submitted to regulators.
Other concrete structures at the site include two tunnels to the sea more than 7 m in diameter, drilled by the machines that worked on London’s new Crossrail line. Those will bring water to cool the reactors, capable of filling an Olympic swimming pool in 20 seconds.
Bouygues SA and Laing O’Rourke Plc are the contractors working on the base. Framatome SA is forging the pressure vessel and steam generators that will form the heart of the reactor base just finished. Sarens NV is putting together the world’s biggest crane at the site to aid the construction at a later stage.
EDF said the project currently employs 4,000 people, including 430 apprentices. Another 8 500 have been trained to work at the site.
The project got underway after EDF and its partner, China General Nuclear Power Corp., signed final contracts with the UK government in September 2016. Those call for the plant to earn 92.50 pounds for every megawatt-hour of electricity it produces, almost double the average market rate of 56 pounds over the past year.
Britain currently gets about 8.9 GW from 15 nuclear reactors, and about half that capacity is due to close by 2025, according to the World Nuclear Association. That power represents about a fifth of UK power supply.
The last plant to be completed was the Sizewell B unit in 1995. It’s scheduled to keep working until 2035.