The board of uranium miner Energy Resources of Australia (ERA) has approved a A$57-million budget to conduct a prefeasibility study on the potential of the Ranger 3 Deeps mine, in the Northern Territory.

ERA said on Thursday that the prefeasibility study, which would be conducted between 2012 and 2014, would evaluate and confirm the scope for a possible Ranger 3 Deeps underground mine.

It would also include 16 000 m of drilling for resource definition, the extension of the decline and the installation of a ventilation shaft.

Earlier this year, ERA started construction of the Ranger 3 Deeps exploration decline project to conduct close-spaced underground exploration drilling to further define the orebody and explore areas adjacent to the resource. ERA said that the results of this underground exploration would be incorporated into the prefeasibility study.

"This is another positive and significant step towards determining the viability of an underground mine on the Ranger project area," said ERA CEO Rob Atkinson.

He noted that the company would continue discussions with the Aboriginal land holders and their representatives, as well as with the Commonwealth and state governments in relation to the project and the outcome of the study.

A decision on the viability of the Ranger 3 Deeps development was expected by late 2014.