Beleaguered uranium miner Energy Resources Australia says its 2012 production remains highly dependent on the amount of rain in the Northern Territory during this year's wet season.

The majority Rio Tinto-owned company posted a $153.6 million loss for calendar 2011 compared to a $47 million profit in 2010.

The negative turnaround was driven mainly a four-month halt to processing at its sole producing mine, Ranger some 230 kilometres east of Darwin, because of heavier than usual wet season flooding.

Shares in the company plunged 13.64 per cent to $1.33, continuing a downward spiral started in 2009 when the share price nudged $18.

Options Xpress market analyst Ben Le Brun said the market was already expecting a poor result from ERA, given weather-related woes at Ranger.

Mr Le Brun said the company was obviously a victim of factors outside of its control and that the result was worse than expected.

He also said uncertainty remained regarding whether ERA would find enough uranium underneath the existing mine, known as the Ranger 3 Deeps resource, to continue production when the current open pit was exhausted.

"There are question marks over the life span of Ranger overall," Mr Le Brun said.

"They've really fallen from grace in recent years.

"Things aren't working too well for ERA at the moment, so hopefully things will turn around for them this year."

Typical dry season conditions from late April allowed the company to progressively re-start processing from mid-June, but significant volumes of water that remained in the mine hampered operations for the rest of the year, preventing access to high grade ore at the bottom of the pit.

A resulting 30 per cent fall in production forced ERA to buy uranium from other parties in order to meet its contractual obligations.

ERA late last year raised $500 million in a discounted share sale to fund exploration to extend the mine's life, two months after the company nearly halved its uranium reserve estimate that wiped $99 million of inventory value from its balance sheet.

The company said it expected uranium production within a range of 3,000 to 3,700 tonnes in 2012, up from 2,641 tonnes in 2011, depending on the weather.