The government considered nuclear power unattractive as recently as 2003 but now says it will help Britain meet its climate change goals and avoid overdependence on imported energy as North Sea oil and gas supplies dwindle.
Nuclear power stations provide about 18 percent of Britain's electricity now, but many are nearing the end of their lives.
"We want Britain to be more secure in its energy supply," Prime Minister Gordon Brown told reporters. "We are inviting companies to express an interest in building a new generation of power stations to replace the existing ones."
Energy Secretary John Hutton said he would set no limit on the construction of new plants.
Nuclear operators welcomed the move and announced plans for at least four new reactors with the first running by late 2017.
Environmental group Greenpeace, which succeeded in blocking an earlier pro-nuclear decision, said the public had been misled during recent consultations and its lawyers were already considering a fresh challenge.
"This is bad news for Britain's energy security and bad news for our efforts to beat climate change," Greenpeace Executive Director John Sauven said, adding that government plans to store highly radioactive waste underground were not safe.
RENAISSANCE
Nuclear power is on the verge of a renaissance, having remained unchanged at 16 percent of the global mix for the last 20 years, when the Chernobyl disaster curbed its growth.
It is now becoming more competitive amid surging prices for oil and gas and buoyed by the need to cut carbon emissions to fight climate change.
