The deluge of rain that has kept a large part of northern Australia waterlogged for months has resulted in the suspension of operations at one of the world's largest uranium mines - Ranger in the Alligator Rivers region of the Northern Territory.

Owner Energy Resources of Australia Ltd posted a presentation today that it had suspended the processing plant operations and now expects access to high grade ore in the bottom of the Ranger Pit to be restricted until at least late this year.

ERA said the plant operations suspension would now continue until late July to allow the total process water inventory at Ranger to reduce.

"This is highly dependent on future rainfall," the company said.

The company was commissioning additional pond water treatment capacity to expedite access to the bottom of Pit 3.

According to the Intierra Resource Intelligence Ranger produced 3,793 tonnes of U₃0₈ compared to 5,339t in 2009.

A recent upgraded reserves-resources statement by ERA put the December 30, 2009 proven-probable reserves in Pit 3 at 24.9 million tonnes grading 0.12% U₃0₈(including low grade stockpiles) while the measured-indicated resource was 131.27 Mt @ 0.06% U₃0₈.