The Australian Conservation Foundation is urging the Federal Environment Minister, Robert Hill, not to approve the controversial Honeymoon uranium mine in South Australia's far north.
Senator Hill's office says the minister has not yet made a final decision, but an announcement is expected this week.
The ACF's Anti-nuclear Coordinator, Dave Sweeney, says the proposed acid leaching method of extracting uranium could lead to serious groundwater pollution, and another mine is not needed.
"What we have in Australia at the moment is governments approving technologies that are not used in any other developed nation because of the risks they pose and because of the environmental hazards they generate," he said.
"We are approving mining techniques which are increasingly discredited to mine a mineral of which is there is a glut of and which is inherently dangerous and a long lived problem."
A leading resource analyst, Peter Mangano, from Salomon, Smith, Barney, says spot prices for uranium are at all time low levels, and it is not a good time for new players to enter the international market...
"The market is quite weak at the moment and that's been caused by slower growth in nuclear power than I think people would have projected some years ago," he said.
"But most importantly it's been caused by a fairly significant oversupply of uranium into that fairly slow growing market."