Trade Secretary Alan Johnson has said he has not yet decided if the UK should be building a new generation of nuclear power stations.
The UK's nuclear industry has a complicated structure
The minister said the government would bring forward proposals next year to allow a public debate on the issue.
He also said he was not ruling out privatising the firm charged with dismantling the oldest nuclear plants.
Tony Blair told his annual conference that all options for energy supply must be assessed, including nuclear power.
British Nuclear Fuels Limited wants to sell off its subsidiary, British Nuclear Group.
Mr Johnson said he had yet to decide but "was not saying no" to the idea.
Mr Johnson told the BBC Sunday AM programme: "You look at countries like Finland where environmentalists are to a large degree now supportive of nuclear energy, but the major question, and the point you make, it's still very controversial.
"What do we do with the waste? How do we afford it? And that's why I am certainly still agnostic on this."
The government would publish proposals next year and there would then be a public debate, he said.
State sector led
BNFL said on Friday that it was reviewing its options for the British Nuclear Group.
It has previously announced plans to sell its US-based nuclear power station building unit Westinghouse.
The UK's nuclear industry has a complicated structure.
In April 2005 the government set up the state-run Nuclear Decommissioning Agency to take ownership of the majority of civil nuclear sites in the UK, and control their current or future decommissioning.
These sites include the oldest Magnox reactors whose decommissioning is, or will be, carried out by British Nuclear Group, plus newer reactors and other nuclear facilities.
A completely separate private company - British Energy - owns and operates a further eight UK nuclear power stations.
British Nuclear Group is, or will be, carrying out the decommissioning at stations including Bradwell in Essex, Calder Hall in Cumbria, Chapelcross in Dumfries, Dungeness A in Kent, Hinkley Point A in Somerset, Oldbury in Gloucestershire, Sizewell A in Suffolk, Wylfa on Anglesey, and Trawsfynydd in Gwynedd.