Julia Gillard has ruled out the possibility of nuclear energy in Australia, defended her "cringeworthy" speech to American Congress and been questioned by WikiLeaks founder Julian Assange on the ABC's Q&A program.

One audience member raised concerns about nuclear power in Australia, given the current crisis in Japan following the earthquake and tsunami on Friday.

Three reactors at a quake-damaged nuclear power plant in northern Japan have lost their cooling capacity, raising fears of a meltdown.

But Ms Gillard said the Labor Party had not entertained the proposition of nuclear power in Australia.

"The Labor position is entirely clear, we don't think we need nuclear energy," she said.