THIS is the room at Royal Darwin Hospital where nuclear waste is kept.

The small lead-lined room leaked radiation a few years ago.

But the Health Department said it was regularly monitored by Environmental Health officers.

A hospital source said: "It would be interesting to go outside the room with a Geiger counter and test the radiation levels."

The room, which is below the pathology department, holds 2.3 cubic metres of radioactive waste.

It used to hold 16 cubic metres.

The Health Department said much of the waste was "disposed of" after it had "returned to normal background levels of radiation" several years ago.

But the hospital source said the waste "disappeared" only after checks showed that radiation had leaked to a room next door used by health workers.

"The stuff was gone overnight - don't know where to."

Meanwhile, Lingiari MHR Warren Snowdon yesterday confirmed he will vote for federal legislation overriding a Territory law banning the transport of nuclear waste through the NT.

"I'll be voting for it and it won't be difficult for me at all," he said.

But Mr Snowdon said he was disappointed traditional owners had offered Muckaty Station, 120kms north of Tennant Creek, as a site for the dump.

Solomon MHR Damian Hale said he would vote against.

"I'm against this waste dump and have told Caucus I won't support the federal legislation," he said.

Senator Nigel Scullion said he would support the legislation.

Senator Trish Crossin could not be contacted yesterday.

The Northern Land Council yesterday said its consultations with traditional owners over the dump were "comprehensive and to the letter of the law".

"The NLC consulted not only with the Ngapa traditional owners, but also with other interested and affected Aboriginal groups regarding both Muckaty Station and the general region," council head Kim Hill said.

"Senior representatives of other groups - including other Ngapa groups - supported the nomination, with only a few individuals in other groups expressing concerns."