Production from world uranium mines now supplies only about 75% of the requirements of power utilities. Primary production from mines is supplemented by secondary supplies, principally by ex-military material and other inventories.
Uranium is a relatively common metal, found in rocks and seawater. Economic concentrations of it are not uncommon. Its availability to supply world energy needs is great both geologically and because of the technology for its use.
Uranium occurs in a number of different igneous, hydrothermal and sedimentary geological environments. The major primary ore mineral is uraninite or pitchblende, though a range of other uranium minerals exist.
Weapons-grade uranium and plutonium is being made available for use as civil fuel. Highly-enriched uranium from weapons stockpiles met about 13% of world reactor requirements through to 2013.
The basic fuel for a nuclear power reactor is uranium. Uranium occurs naturally in the Earth's crust and is mildly radioactive. Depleted uranium is a by-product from uranium enrichment.
Rock phosphate deposits contain many million tonnes of uranium, which may be extracted as a by-product of making fertilisers. The process because uneconomic in the 1990s, but process improvements and higher U prices may change this.
A large amount of uranium is in rare earths deposits, and may be extracted as a by-product. Higher uranium prices and geopolitical developments would enhance the economic potential for recovering these.
Geologists and geochemists have been studying the abundance, distribution and chronometric potential of the isotopes of uranium for more than a century. The Earth's uranium was produced in one or more supernovae over 6 billion years ago. Uranium later became enriched in the continental crust.