Japanese electronics giant Hitachi is to buy the nuclear power project Horizon, which includes a plan to build a new plant on Anglesey.
Hitachi says between five and six thousand jobs could be created during construction and a thousand permanent posts when it's up and running. It says that'll be in the first half of the 2020.
The Wylfa power station was due to close in 2014. The Anglesey site's Reactor 2 shut down in April.
Today, the announcement has been hailed as a boost to the area.
On Twitter, the Welsh Secretary, David Jones, has said the news is "terrific" for Anglesey.