Energy giant EDF has leased offices to provide a base for a large part of the project team working on the Hinkley Point C nuclear power station.
Their work will support the construction of the proposed new nuclear power station in Somerset, which will create thousands of jobs.
The announcement came amid recent speculation of a delay in the so-called final investment decision for the £18 billion project.
The French company has said a decision will be made “soon”, with mid-February now a possible date.
Today’s announcement said the offices, in Bristol, will be fitted out in the next few months.
EDF Energy has already invested in facilities in Somerset, including a new national training centre, and is involved in Bridgwater College’s Construction Skills Centre.