Nigel Cann, delivery director for the nuclear power station build, said planned works are now 49% complete as the massive project reached the halfway point this week.
Five years after getting the go-ahead, the number of people across Britain now working on the Hinkley Point C power station has reached 22,000.
The growing number includes 6,300 on site, compared to just 1,500 at the height of the pandemic last year.
And numbers on site are due to be ramped up to around 8,500 in the next 18 months as the project emerges from the worst of the pandemic and moves to full throttle.
Since starting in September 2016, 3,600 British companies have won contracts on the project.
This includes more than 400 businesses in the North of England where spending so far has already topped £1.2bn.
Cann said: “Looking forward we’ve still got challenges as we know, we move forward cautiously with the pandemic still around us and all the market issues that has caused as far as materials and services are concerned.
“We are very confident we will hit all our 2021/22 milestones and we really remain focused on dome lift in 2022.”
Unite National Officer for Construction, Jerry Swain said: “Hinkley Point is the most significant construction project in a generation, as it is fundamental to the UK’s future energy policy.
“It is essential that the lessons learnt and the skills developed at Hinkley are not allowed to be lost in the sands of time. To avoid this, the government must urgently make a decision to support the development of Sizewell C, so workers with their skills and experience can bridge across to this project, which is also essential to meet the UK’s future energy needs.”