NUCLEAR waste is being stored in a room at Royal Darwin Hospital.

Other low-level waste is kept in shipping containers at mine sites.

The NT Health Department confirmed yesterday that 2.3 cubic metres of radioactive waste was stored "in a secure and appropriately lined facility" at Royal Darwin.

The Northern Territory News understands it is in a lead-lined safe in an unused room in the basement.

Health bosses refused to allow the NT News to see the waste or photograph it.

"As the waste exhibits low levels of radioactivity, it is maintained in a sealed room that is not accessible to unauthorised personnel, including the media," departmental spokesman Robin Osborne said. "The facility is regularly monitored by Environmental Health and strictly complies with legislated radioactive materials criteria."

The stored waste includes bore hole logging gauges, density and soil/moisture gauges, mineral samples and tracer radio-isotopes.

More than 16 cubic metres of waste was stored at Royal Darwin until 2004.

"When regular inspections indicated that the majority of this waste had returned to normal background levels of radiation, it was disposed of as medical waste," Mr Osborne said.

Medical waste is normally burnt in the hospital's incinerator at Tiwi.

The remaining waste is likely to be moved to a federal dump at Muckaty Station, 120kms north of Tennant Creek, in about four years.

Former federal MP Dave Tollner was ridiculed by some members of the media in 2004 when he said nuclear waste was kept in offices at hospitals and in shipping containers on mine sites.

The Muckaty proposal will go to the federal Environment Minister for assessment.

Consultants will then be employed to carry out an environmental impact study, open for public comment.

The dump is expected to be operational by late 2014.