The federal Opposition claims reactors are a certainty under a re-elected Howard government, despite a Government statement today that Australia may never turn to nuclear energy.

Environment Minister Malcolm Turnbull told reporters today that nuclear energy was not a certainty for Australia and if clean coal alternatives were found to be the cheaper option, nuclear power would not be used.

He also repeated Government assurances that a nuclear power industry was at least 10 to 15 years away.

But Opposition environment spokesman Peter Garrett issued a statement saying: "Just hours after the Prime Minister supported nuclear power in the national televised debate, Mr Turnbull is suddenly saying nuclear reactors may never be built in Australia.

"The fact is you cannot have nuclear power in Australia without 25 nuclear reactors.

"This is a clear case of Mr Turnbull trying to walk both sides of the street - one day nuclear and the next day not."

A report by a committee headed by nuclear physicist Ziggy Switkowski has suggested that up to 25 nuclear power stations could be built along the east coast to help provide for the nation's growing base load energy requirements.

"Only one thing has changed in the nuclear debate - that is an election is around the corner," Mr Garrett said.

"Nuclear power is guaranteed under a re-elected Howard government.

"Only a Rudd Labor government will say no to nuclear reactors and the waste dumps that go with them."

AAP