EnCore to mine Gas Hills uranium

    Uranium is found in 20 of Wyoming’s 23 counties, but not in the concentrations found in the Gas Hills east of Riverton.

    The boom years of discovering the radioactive element in the 1950s led to large open pit mines dotting the area. Riverton grew exponentially with the development of the mines and Jeffrey City bloomed like a giant mushroom on the arid plains near the mine sites.

    That all vanished with the collapse of the uranium industry after Three Mile Island and Chornobyl.


    The uranium remains, an estimated 8,000,000 pounds of it, and American-owned development is returning to the hills with the announcement that EnCore, a Texas uranium producer.

    Traditional mining activities in the Gas Hills ceased with the dig sites reclaimed and the facilities sold off, but in-situ mining, a method of extracting uranium by leeching the element, and then pumping it out of the ground returned with a French-owned company a decade ago.

    EnCore will utilize the same in-situ method. High oxygenated water, mixed with bicarbonate of soda is pumped into the uranium-bearing strata under pressure and pumped out at another location after the water dissolves the uranium, creating a rich, radioactive slurry.

    EnCore owns another mine at Juniper Ridge near Rawlins.


    The Juniper Ridge site is a traditional mine and the underlying structure doesn’t lend itself well to in-situ processing. EnCore intends to sell the mine.

    The interest in Gas Hills uranium stems from several factors. The United States receives uranium from Russia and the unstable nature of Russia’s relationship with Western Nations could disrupt the supply.

    Small nuclear reactors are in the design and construction stage with one in development at Kemmerer. High-grade uranium is needed to operate these modern reactors and EnCore can deliver that product with uranium from Fremont County.


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