Environmental Science 14th Edition by Tyler Miller ,Scott Spoolman

Exercise 2

Uranium (U) is a mineral resource obtained from uranium ore in various types of rock at different concentrations. It is used as a fuel in the reactors of nuclear power plants. A high-grade ore has 2% U and a low-grade ore has 0.1 % U. The estimated worldwide recoverable resources of uranium weigh 4,743,000 metric tons. The United States has about 7% of the world's uranium resources, which amounts to about 332,000 metric tons.
Assume that most U.S. ore deposits contain high-grade ore (2% U) and that the recovery rates of uranium from the ore (accounting for losses in mining, extraction, and refining) average 65%. How many metric tons of ore will have to be mined to meet U.S. needs