Peak Uranium - Uranium Supply

Uranium Supply

Uranium occurs naturally in many rocks, and even in seawater. However, like other metals, it is seldom sufficiently concentrated to be economically recoverable. Like any resource, uranium cannot be mined at any desired concentration. No matter the technology, at some point it is too costly to mine lower grade ores. One highly critizied life cycle study by Jan Willem Storm van Leeuwen suggested that below 0.01–0.02% (100-200 ppm) in ore, the energy required to extract and process the ore to supply the fuel, operate reactors and dispose properly comes close to the energy gained by burning the uranium in the reactor. Researchers at the Paul Scherrer Institute who analyzed the Jan Willem Storm van Leeuwen paper however have detailed the number of incorrect assumptions of Jan Willem Storm van Leeuwen that led them to this evaluation, including their assumption that all the energy used in the mining of Olympic Dam is energy used in the mining of Uranium, when that mine is predominately a copper mine and uranium is produced only as a co-product, along with Gold and other metals.

The report by Jan Willem Storm van Leeuwen also assumes that all enrichment is done in the older and more energy intensive gaseous diffusion technology, however the less energy intensive gas centrifuge technology has produced the majority of the world's enriched uranium now for a number of decades.

An appraisal of nuclear power by a team at MIT in 2003, and updated in 2009, have stated that:

Most commentators conclude that a half century of unimpeded growth is possible, especially since resources costing several hundred dollars per kilogram (not estimated in the Red Book) would also be economically usable...We believe that the world-wide supply of uranium ore is sufficient to fuel the deployment of 1000 reactors over the next half century.

Mining companies usually consider concentrations greater than 0.075% (750 ppm) as ore, or rock economical to mine at current uranium market prices. There is around 40 trillion tons of uranium in Earth's crust, but most is distributed at low parts per million trace concentration over its 3 * 1019 ton mass. Estimates of the amount concentrated into ores affordable to extract for under $130 per kg can be less than a millionth of that total.

Uranium Grades

Source	Concentration
Very high-grade ore - 20% U	200,000 ppm U
High-grade ore - 2% U	20,000 ppm U
Low-grade ore - 0.1% U	1,000 ppm U
Very low-grade ore - 0.01% U	100 ppm U
Granite	4-5 ppm U
Sedimentary rock	2 ppm U
Earth's continental crust (av)	2.8 ppm U
Seawater	0.003 ppm U

According to the OECD Redbook, the world consumed 67 kilotonnes (150×10^6 lb) of uranium in 2002. Of that, 36 kilotonnes (79×10^6 lb) was produced from primary sources, with the balance coming from secondary sources, in particular stockpiles of natural and enriched uranium, decommissioned nuclear weapons, the reprocessing of natural and enriched uranium and the re-enrichment of depleted uranium tails.