Construction of the second reactor at the Hinkley Point C plant in Somerset, England, passed a major milestone with the lifting of the first part of the massive steel containment liner, EDF Energy announced yesterday. Lifted by the world's largest crane, 'Big Carl', just nine months after the same lift for the first reactor, construction of the 170-tonne liner cup was 30% quicker than the identical part on the first reactor.
The liner cup is the base for the reactor's steel containment which is being prefabricated in five parts and lifted into place by 'Big Carl'. EDF Energy said this innovation means welding can take place in covered bunkers protected from weather, helping to improve quality and efficiency. This is a learning from the construction of other EPR projects around the world.
The liner cup for Hinkley Point C's second unit was built in 39 days compared with 57 days for the first. The construction and lift were completed on schedule, despite workers having to adapt to coronavirus working conditions.
The cup is one of more than 500 prefabricated steel and concrete elements that 'Big Carl' will lift, including whole sections of buildings, walls and pre-cast air ducts. The heaviest of these items weigh 1600 tonnes. Able to stand up to 250 metres high, 'Big Carl' - a Sarens SGC-250 crane - can carry 5000 tonnes in a single lift.
"This milestone shows how replication and innovation are driving efficiency at Hinkley Point C as we build our second identical reactor on site," said Nigel Cann, Hinkley Point C construction delivery director. "In turn that will benefit our planned third and fourth units at Sizewell C in Suffolk. Hitting the schedule during coronavirus is a tribute to the workforce that has had to adapt to new ways of working to ensure the safety of the site and the community around it."
Replication is the key to reducing the cost of nuclear new-build projects and attracting investment in firm, low-carbon power and heat, Julia Pyke, director of Sizewell C financing & economic regulation at EDF Energy, said in late-July. Speaking during an OECD-Nuclear Energy Agency webinar, she said Hinkley Point C is already showing the benefits of fleet build with unit 2. About 45% more steel has been installed in the same timeframe; it has taken 50% less time to install the cooling system components; and there has been an 85% efficiency saving from reducing the time between the arrival of the common raft's sumps to concrete pour.
As a copy of the Hinkley Point C plant, Sizewell C will effectively be units 3 and 4 of the UK EPR fleet and will cost up to GBP4 billion less to build. Half of this figure comes from not having to repeat the design approval process with UK regulators.