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How Uranium Mining Works


The Hunt for Uranium

Before companies can even think about putting miners on the job, they need to find ore deposits. How did novice prospectors, uranium boom opportunists such as Charlie Steen and seasoned experts find uranium to begin with?

Most mining sites stem from larger deposits, which vary in size and depth. Australia's Olympic Dam, one of the largest sites in the world, has explored and mined roughly 6.5 million feet (2,000 kilometers) of land [source: World Nuclear Association]. In recent years, surveyors have established that 1.1 million acres of land near the Grand Canyon may be suitable for mining, although U.S. President Obama announced a 20-year ban on uranium mining on 1 million acres of land near the Grand Canyon in 2012 [source: U.S. Natural Resources Committee].

This preliminary stage of the mining process is called exploration, where geoscience experts figure out which areas would be economically feasible to mine. Companies compare the estimated number of recoverable ore tons with the cost of extracting them. Because of financial constraints, landscape and access to a mining site dictate whether companies will invest in mining there. Even then, successes are rare. Among all minerals and metals, around one in every 1,000 exploration projects transitions into the mining stage [source: British Columbia Crown Land Administration Division].

But uranium's radioactivity makes finding it a bit easier. Geiger counters and scintillometers pick up on radiation and help survey uranium hot spots [source: Hunter]. Surveyors use hand-held Geiger counters to detect radioactivity closer to the ground, while larger devices called scintillometers can pick up gamma rays at greater distances. Geologists will also sample the soil and rock to find out the ratios of uranium hidden beneath the ground's surface. Several uranium isotopes occur together, including U-234, U-235 and U-238. Methods to detect them usually don't discriminate which is more abundant in a sample, but some devices that pick up U-235 may become more widely used.

Uranium's decay process also gives rise to byproducts called daughter elements such as radium and radon, which are both radioactive as well. Surveyors measure radiation carefully to make sure they're not mistaking other elements for uranium.

Once a company knows it wants to give uranium mining a shot, it must apply for permits from the local and federal government. The process differs by country, but most permits ensure that companies uphold standards that help protect the health of miners, nearby communities and the environment. In the United States, obtaining permits for mining, getting investors onboard and conducting resource assessments can take anywhere between three and 10 years [sources: Deery; Hunter].

Now that we know a bit about uranium's history and exploration phase, let's dig into the details of mining. Read more on the next page.