Traditional owners have welcomed a deal over funding for rehabilitation of the Ranger uranium mine surrounded by Kakadu National Park.

Key points: Deal reached over Ranger mine rehabilitation with caveats

Deal reached over Ranger mine rehabilitation with caveats Traditional owners say deal eases uncertainty

Traditional owners say deal eases uncertainty Shareholder Rio Tinto puts in $100m loan

Rio Tinto, the major shareholder of the mine operator Energy Resources of Australia (ERA), has made a $100 million loan offer to cover any shortfall in rehabilitation funding.

But a condition of the deal is that mine operator ERA does not pursue the proposed lifeline for the mine — the underground Ranger 3 Deeps project.

Infrastructure will be put in the pits as part of the mine closure. ( ABC News: Sara Everingham )

Mirarr traditional owner Yvonne Margarula said the deal eased uncertainty over funding for the mine clean-up.

"I'm happy, ERA they listen to us Mirarr people. Thanks to ERA," she said.

It is estimated full rehabilitation of the site will cost about $509 million.

However, in December last year ERA said it only had $433 million in total cash resources.

ERA said it expected to have enough resources to cover the $509 million clean-up costs, but if there was a shortfall it would be able to draw on the $100 million credit facility.

Mine struggles after drop in uranium price

The Gundjeihmi Aboriginal Corporation, which represents the Mirarr traditional owners said the deal had been a long time coming, but was welcome.

"We are now given comfort by this to know that any shortfall, should there be one, will be met by Rio Tinto," CEO Justin O'Brien said.

Rehabilitation is being done at the uranium mine, surrounded by Kakadu National Park. ( ABC News: Sara Everingham )

But the agreement will be terminated if ERA pursues the proposed underground Ranger 3 deeps project.

The project was a proposed lifeline for the mine, which has struggled with the drop in the price of uranium.

Last year 3 Deeps lost the support of Rio Tinto and traditional owners but ERA has not officially closed the door on the proposal.

ERA may say more about its position on 3 Deeps at its AGM in Darwin next week.

Traditional owners want ERA to stick with the loan facility agreement with Rio Tinto.

"We think this provides the assurances we need to fully fund rehabilitation such that we can include this area in Kakadu National Park," Mr O'Brien said.

As it stands, ERA's lease on the mine is set to expire in 2021, the rehabilitation has to be done by 2026.

ERA said it began working on rehabilitation 20 years ago and was continuing a range of works to meet the 2026 deadline.

"We're very confident but we're certainly planned and resourced to meet our 2026 target," Ranger general operations manager Tim Eckersley said.

He said under agreements authorising the mine, ERA was required to rehabilitate the site so it could be brought into the world heritage listed Kakadu National Park.

"We want to see our country really clean so that we can put it into Kakadu National Park," Gudjeihmi Aboriginal Corporation chairwoman Annie Ngalmirama.

ERA stopped mining at Ranger in late 2012. It said its rehabilitation work included backfilling pits and dredging its tailings dam.

ERA said as part of the rehab, well over 100 million tonnes of rock would be put back into the pits.