Mining Uranium under Nebraska by Wayne Price
f you ask most Nebraskans about nuclear power in our state, they would probably mention the generating plants at Brownville and Fort Calhoun, along the Missouri River. Not many would mention another connection to nuclear power, the Crow Butte uranium mine in Dawes County in the northwest corner of Nebraska. Located near the town of Crawford, Neb. the uranium mine is the first step in the process of producing the fuel that powers a nuclear plant. Most Nebraskans don’t realize the Crow Butte uranium mine has been in operation for more than 20 years, and is in the process of expanding its mining field. Uranium is a silvery-white metal, roughly 70 percent denser than lead and is the only naturally-occurring fissile element on Earth. Uranium is more common than tin, about 40 times more common than silver and 500 times more common than gold. It’s found in very low concentrations almost everywhere on Earth in soil, rocks, water and even in your own back yard. Uranium at Crow Butte occurs in sandstone aquifers as coatings on sand grains at up to 300 meters underground. Uranium is removed
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using a grid of injection and production wells. The mining process at Crow Butte uses the in situ recovery (ISR) method. There are no large machines digging into the ground or any tunnels or open pits. Instead there are what appear to be overturned garbage cans dotting the hillside along with the occasional small metal building. Those cans are well-head covers, to keep exposed pipes from freezing in the harsh winters “We are basically a large water treatment plant,” said Larry Teahon, Manager Safety, Health, Environment & Quality. “This is essentially a closed-loop recirculation system.” The uranium is insoluble in the native groundwater. Small amounts of oxygen and bicarbonate (baking soda) are added to the injection stream to dissolve the uranium. Water from the production wells is reintroduced in the injection wells. Slightly less water is injected than withdrawn to ensure the fluids are
Resin beads are used to carry uranium to a processing plant for recovery. confined to the ore zones intended for extraction. The uranium solution, less than 1/10 of one percent uranium, is then pumped from a production well to a satellite facility where the uranium is transferred to ion exchange resin beads similar to the sand from which it was extracted. The uranium-bearing resin is then pumped to a processing Please turn to page 8
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