Energy developer Horizon Nuclear Power has bought a 232-hectare site from the Nuclear Decommissioning Authority to build on next to Wylfa A, near Cemaes on the island’s north coast.
The site was included in the final version of the Government’s Nuclear National Policy Statement.
Isle of Anglesey County Council and Horizon entered a planning performance agreement in October.
Council chief executive Richard Parry Jones said this would provide "the necessary capacity and resource to deal effectively with Horizon’s proposals without adversely impacting upon existing service provision".
The council has long sought a new power station to replace Wylfa A, which is an important local employer and is due to close in the next few years. The council is pursuing its ‘energy island’ project to make Anglesey a centre of both nuclear and renewable energy generation.
Wales' business minister Edwina Hart has also proposed an enterprise zone for the island, but has not confirmed its boundaries.