A little makes a lot?

In comparison with the amount of coal burned for a given electrical generation, the nuclear proponents argue that the amount of uranium required for the same output from a nuclear power station is tiny. This leads to misleading statements intended to reassure the consumer that nuclear power is “home grown” or “indigenous”. In comparison with insecure supplies of oil and gas from politically unstable regions, it is claimed that it offers security of supply, because such a small quantity of fuel can be readily procured and stocked.

Natural uranium contains only 0.7% of the fissionable isotope U-235 and has to be enriched to around 3.6% to 4.5% for use in a modern reactor. This is a complex process involving the conversion of uranium, a heavy metal, into a gas (uranium hexafluoride) in which form the fissionable component can be increased by centrifuging or by diffusion. The gas is then re-converted into a solid oxide from which the nuclear fuel is manufactured. The enrichment process produces “tails” with a lowered U


Starting with 207 tonnes of natural uranium the process produces 30 tonnes of uranium dioxide (containing 25 tonnes of uranium of both kinds) from which sufficient fuel is manufactured to run a one GW (a gigawatt = thousand megawatts or a million kilowatts) nuclear power station for a year. The UK uranium requirement for 2007 amounts to 2158 tonnes of natural uranium equivalent, which at the current price of uranium of US $338/kg (US $130/lb U3O8) is valued at US $730 million, though probably acquired for less under current supply contracts. Thus 2,000 tonnes of natural uranium fuels just over 9 GW of electricity generation or 79 TWh (terawatthours).

Uranium is obtained from mines in a small number of countries, the principle ones being Canada, Australia, Kazakhstan, Niger, Russia and Namibia. To obtain 207 tonnes of natural uranium at the current world average uranium ore grade of 0.15% means the mining of 880,000 tonnes of rock and ore, which after enrichment produces the 25 tonnes needed in the fuel. But as ore grades decline and recourse is made to low ore grades of 0.045%, more than 3 million tonnes of rock and ore has to be mined for the same 207 tonnes of natural uranium. In addition 500,000 tonnes of mill tailings arise for disposal. The remaining deposits in Australia are characterised by these low ore grades and yet it claims to hold the world’s greatest reserves.

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