Nuclear waste could be stored in metropolitan Sydney within five years.

The waste is currently being processed in Europe and will be stored at the Lucas Heights facility in Sutherland upon it's return to Australia.

But Adi Paterson from the Australian Nuclear Science and Technology Organisation says Lucas Heights would only provide an interim solution until a national repository is built.

"It is not a permanent storage location.

"I think permanent storage at Lucas Heights would be out of line with international practice.

"A national waste unit deals with all sources of radiation including the medical and industrial sources that are used right around the country.

"International best practice suggests the longer term storage need to be in an integrated repository that is dedicated to that purpose; that has been selected for it's geological stability and for it's ability to take a long term store."