More delays and cost hikes have hit the U.K.’s project to build the 3,260-MW Hinkley Point C plant nuclear project in Sommerset, England. The French state-controlled project owner Electricité de France now says first electricity generation will start at least four years later than originally planned and cost around 70% more.

When the U.K. government approved the project in September 2016, EDF forecast completion in 2025 at a cost of $23 billion. In its latest update on Jan. 23, the company forecast completion between 2029 and 2031 with costs rising to $39 to 43 billion—up from a revised mid 2022 forecast that had already pushed completion back to June 2027 and revised the cost up to around $32 billion at 2015 prices.

“Restarting the British nuclear industry has been hard,” said project managing director Stuart Crooks, in a company update. “We’ve had to train a new workforce, teach suppliers how to build nuclear and … change our design to meet British regulation.” 

Around 7,000 design changes have led to 35% more steel and 25% more concrete being needed. Like other infrastructure projects, Hinkley Point C is taking longer than planned, Crooks added.

Site contractors last month placed a 270-ton steelwork dome on the first reactor building. The team used what was said to be the world’s largest crane to place the 154-ft-dia, 46-ft-tall dome on the 144-ft-tall building. 

The lift “allows us to get on with the fitting of equipment, pipes and cables, including the first reactor which is on site and ready to be installed [in 2024],” noted Simon Parsons, EDF nuclear island area director.