Public comments on the proposed expansion are accepted until Oct. 29.
A uranium mine near the Fremont-Sweetwater County line is in line for a major expansion.
Colorado-based Ur-Energy plans to expand its Lost Creek in-situ mine in south-central Wyoming to an area covering some 15 square miles. Already one of the biggest uranium mines in Wyoming, Lost Creek would more than double in size under the plan.
Wyoming already is the nation's top uranium producer.
Production from the site would increase from around 800,000 pounds per year to as much 1.2 million pounds is the expansion goes forward. Total permitted production would increase from 1 million to 2.2 million pounds, which includes up to 1 million tons brought to Lost Creek from elsewhere for processing into yellowcake, the refined uranium concentrate used in energy production.
The proposed expansion must be approved by the U.S. Bureau of Land Management, which is now taking public comment.
Some 2.9 million of the 4.9 million pounds of uranium produced in the U.S. in 2014 came from Wyoming, home to four of the nation's eight operational in-situ uranium mines.
In-situ mining involves not digging tunnels or stripping an open pit, but drilling hundreds of injection and recovery wells across a wide area. Chemicals such as hydrogen peroxide or sodium bicarbonate are pumped underground to dissolve uranium from surrounding deposits.
Uranium-bearing solution is then pumped to the surface in solution form.
Spot prices for uranium, at around $37 per pound, are only half of where they were in early 2011 and one-third of their 2007 level. They could recover as Japan permanently restarts more of its 40 or so nuclear reactors, said Steve Hatten, Ur-Energy's vice president of operations.
"While the demand is still there, it's a very conservative market. We're waiting to see not only what the Europeans are doing but also the Asian markets are doing," Hatten said Tuesday.
"The rate of the restart, we believe, will have an effect on the pricing," he added.
The BLM will take public comments on the expansion until Oct. 29. If planning and permitting go smoothly, Hatten expects the expanded portion of the mine to go into operation in a year or two.
The new wells at Lost Creek, where production began in 2013, will target a formation about 500 feet down, or about 100 feet deeper than the existing wells, according to Hatten.
The mine 40 miles northwest of Rawlins covers a remote area of sagebrush and rock outcrops in the Great Divide Basin. About 50 people work there.