RIO Tinto chairman Jan du Plessis has sidestepped questions over the future of the Jabiluka uranium mine in the Northern Territory, with the traditional owners of the area wanting it merged into Kakadu National Park so it cannot be mined.

Jabiluka was mothballed midway through development in 1999 by Rio's 68.4 per cent-owned subsidiary Energy Resources of Australia after opposition from the local Mirarr people.

At Rio's London annual meeting, a Mirarr representative asked Rio to start good faith negotiations with the Mirarr people and the federal government to make the mine, which sits within the boundaries of Kakadu, part of the national park.

Despite Rio's control of ERA, Mr du Plessis said the issue was a separate matter for ERA.

"No doubt the board of that company will be looking at that issue and making its own decisions," he said.

Speaking after the ERA annual meeting on Wednesday, ERA chief executive Rob Atkinson told The Australian that ERA did not want Jabiluka -- one of the world's premier uranium resources -- to become part of Kakadu.

 

Under a 2005 agreement, the mine can be developed only with the agreement of the Mirarr.

If Rio approaches the Mirarr people about development and gets knocked back, it is unable to make another approach for four years.

After yesterday's AGM of Rio's other listed subsidiary, Coal & Allied, chief executive Bill Champion said the company's expansion plans were made uncertain by the Gillard government's plans to introduce a carbon tax.

While refusing to reveal the back-of-envelope studies Coal & Allied had done, Mr Champion said the major concern was over how coal gas released during mining was handled.

Mr Champion said the science around calculating these "fugitive emissions" was very uncertain, but that the eventual impact would depend on how emissions were handled.

Anglo American has called on the government to ringfence emissions from the planned carbon tax.