Prospect deputy general secretary Garry Graham said: "This brings the Wylfa Newydd project one step closer to fruition which, when many of our large coal-fired power stations are due to come off-line, means it could be a major contributor to achieving a secure low-carbon energy supply for the future.

"Its importance to local and national economies cannot be overstated, given that up to 6,000 jobs are expected to be created during construction, with around 1,000 highly skilled jobs remaining when the plant is operating."

Graham said that while Hitachi's choice of reactor design has yet to undergo the UK's generic design assessment approval process, "it is a proven technology, so any construction in the UK will benefit from lessons learned in other countries.

"It also means, given the selection of Areva EPR reactor design for new plant planned for the Hinkley Point C site, that the UK's new nuclear fleet will benefit from a diversity of technology."