URANIUM miner Energy Resources of Australia has revealed production has more than doubled this year as it recovers from the heavy flooding that hampered output in 2011.

The group's shares jumped almost 2 per cent yesterday after it declared it had produced almost 1250 tonnes of uranium oxide in the six months to June -- up 107 per cent on the same period last year.

But the company has warned it is the last hurrah for its key Ranger deposit, where mining is drawing to a close after 30 years.

ERA, which is majority owned by Rio Tinto, confirmed yesterday it would finish mining the open-cut Pit 3 in the Northern Territory at the end of this year.

And with new drilling around the site having failed to yield further uranium, it will begin concentrating on processing stockpiled ore.

"We will see a drop-off in production and earnings next year,'' Morningstar Equities analyst Mark Taylor said.

ERA is one of a handful of Australian uranium miners.

Although the group is likely to boost uranium production by 75 per cent between now and December, by 2016 it will see its output dwindle to less than 1700 tonnes a year.

Mr Taylor said production could fall even further, to as low as 500 tonnes a year, which would be just 15 per cent of its output now.

"Unless one of three things happens, ERA is going to be marking time over the next few years while spending hundreds of millions on new exploration and cleaning up after terminating Ranger,'' Mr Taylor said.

"But we could wake up one morning and find that the traditional owners of Jabiluka, which is near Ranger, have had a change of heart and grant permission for their deposit to be mined.''

Mr Taylor said ERA's other options included going ahead with underground mining near Ranger, where it had identified a 34,000-tonne deposit.

"They are spending nearly $200 million on studies to see how they can get to that uranium and if all goes to plan, they could begin mining it in 2015,'' he said.