In 2022, the cost of the plant in Somerset was estimated at 拢26 billion in 2015 prices. But French firm EDF, which is developing the plant, has now raised its estimate to 拢31-35 billion in 2015 prices, which could be as much as 拢46 billion in today鈥檚 prices.

Its target completion date had been June 2027 but Stuart Crooks, managing director of Hinkley Point C, said he now expected the plants first unit to be operational 鈥渁round the end of the decade鈥�.

In a project update, Crooks said, 鈥淩estarting the British nuclear industry has been hard. We鈥檝e had to train a new workforce, teach suppliers how to build nuclear, and like any other developer, change our design to meet British regulations. That means 7,000 design changes and 35% more steel and 25% more concrete.

鈥淟ike other big infrastructure projects, we have found civil construction slower than we hoped, faced inflation, labour and material shortages, on top of Covid and Brexit disruption.鈥�

Towards the end of last year, contractors at the nuclear plant site lifted a dome into place on the first reactor building, two years later than originally planned. The closure of the building means that work on installing the first reactor can start.

Crooks put 15 months of that delay down to the pandemic. Crooks said, 鈥淏eyond Covid, we鈥檝e lost nine months since we began. That鈥檚 not perfect, but for the first nuclear plant to be build in Britain for a generation, it鈥檚 not too bad either.

鈥淭he good news is that our pioneering work has rebuilt an industry which will serve the country and its nuclear programme for decades to come. It鈥檚 very clear that once we learn something, there is a big improvement in performance when we do it again.

鈥淎t Hinkley Point, we鈥檙e building an identical second unit and it鈥檚 typically 20-30% faster. As someone who has been in the industry for almost 40 years, I can tell you that repeating a design is always easier than building a one-off.鈥�

Finding suppliers and manufacturers for the fit-out of the plant has also taken longer than expected, he said.

But he stressed that cost overruns on the project will not cost UK taxpayers more, after EDF agreed to take on the project risk and pay the full cost of construction, including any increases.