The head of Northern Territory Unions says he will not be satisfied with Federal Government assurances that it is going to repeal the Radioactive Waste Management Act until it happens.

The legislation, as it stands, paves the way for the Federal Government to continue the former government's plan to site a radioactive waste dump somewhere in the Territory.

Unions NT secretary, Matthew Gardiner, says he will feel uncertain about the Act being changed until it happens.

"Actions do speak louder than words," he said.

"I would like to see the Act repealed and actually a scientific process put in place that actually does explore the best radioactive waste management ... not just in the Territory because it's a territory but an open and scientific process would allow that to continue."