The Government's own nuclear body, the Australian Nuclear Science and Technology Organisation, says it's time to give ''active consideration'' to nuclear power.

In a submission to the Government's white paper on energy, the organisation said nuclear power was safe, reliable, readily available and would become more cost-effective.

In a separate submission, mining giant Rio Tinto talked up nuclear power and called on the Government to make a decision about it by 2020.

Rio Tinto, the majority holder in Australia's biggest uranium mine, said nuclear power ''may provide the optimum clean, reliable and affordable energy option'' in some regions.

The pro-nuclear push has been buoyed by the expansion of Australia's uranium industry; two new mines have been approved, taking the total to five.

But Climate Change Minister Penny Wong does not want to lift the ban on nuclear power.

She said Australia was blessed for energy options, including solar, wind, wave and geothermal, and did not need nuclear power.

''Our focus as a government is on developing those resources,'' the minister said. AAP