THE public has the right to know full details of a secret shipment of nuclear waste due to be trucked through Sydney streets in the next four months, the Greens say.

Five years' worth of spent nuclear fuel rods from the Lucas Heights nuclear reactor will be transported to the US by the middle of the year, the Australian Nuclear Science and Technology Organisation says.

But the organisation refuses to reveal the date or route of the operation, except that it will take place in the "Sydney/ Illawarra region".

"The shipment will be conducted under strict international and national security and safety standards," a spokeman said.

In 2003 and 2006 fuel rods were trucked in sealed casks from Lucas Heights to Port Botany before being sent overseas.

The Greens suspect the next consignment, which will comprise 159 spent nuclear fuel rods, will travel from Lucas Heights to Port Kembla.

Greens MP Lee Rhiannon said: "The safety of Sydney and Illawarra residents is now at risk through this covert operation ? The route and time that this transportation will occur must be immediately published."