The Australian Conservation Foundation (ACF) says it would be short-sighted to expand the Northern Territory's Ranger uranium mine now that another major potential deposit has been found.

Energy Resources of Australia says it has found a potential further 40,000 tonnes of uranium oxide near the Ranger mine in Kakadu National Park, which could extend the mine's life by seven years.

Dave Sweeny from the Conservation Foundation says focusing on the jobs it could bring will put the environment at a greater radioactive risk.

He says everyone at the Ranger mine could be employed for the rest of their working lives cleaning up the site.

"There is an obligation on Energy Resources Australia to clean up its mess, and its mess is considerable," he said.

"They've got a legal requirement to keep radioactive tailings, which there's a mountain of them out in Kakadu, to keep them out of the Kakadu environment for a period of not less than 10,000 years."

Expanding jobs

But the West Arnhem Shire says there is no need to worry about any possible environmental impacts from expanded uranium mining at Jabiru.

The Shire's chief executive, Mark Griffion, says an expanded mine would have to meet the same environmental conditions as the current operation.

And he says people in Jabiru would welcome the prospect the find, which could extend jobs at the mine.

"When Jabiru was first established obviously it was established for the purposes of the uranium mine," he said.

"There has been some divergence in relation to the activities taking place out in Jabiru with a lot of tourism occurring. But I'd say at least 50 per cent of the workforce in Jabiru would be related in some way, shape or form with the mine."

'No promises'

The Northern Territory Mines Minister is cautioning the potential expansion of the Ranger uranium mine is not guaranteed.

Kon Vatskalis says he is confident the health of Territorians and the environment will not be compromised.

"Any mine in the Territory to expand has to undergo a very strong assessment by our government departments, Mines and Environment and in the case of ERA from the Commonwealth Departments," he said.

"It's not just a fate accompli, it will happen.

"If it happens, it has to be assessed very strictly against the current environmental and mining legislation."