Uranium is a naturally occurring radioactive element. While traces of uranium occur almost everywhere on Earth, the highest concentration is found in the Earth's crust. For example, there are about 3 milligrams of uranium per tonne of sea water, and up to 4 grams per tonne of Australian coal. The rocks that are mined for uranium in Australia contain about 3 kilograms of uranium per tonne. Large amounts of energy are obtained by splitting uranium atoms
Uranium has only become valuable since the explosion of the first atomic bomb in 1945, during World War II. This explosion confirmed the theory that energy could be released by splitting uranium atoms. The amount of energy released is calculated by using Einstein's famous equation, E = mc2 . Uranium is a very high-grade energy source. In practice, about 120,000 tonnes of black coal (350,000 of brown coal) would need to be burnt to get as much energy as could be obtained from 1 tonne of uranium fuel, of which 35 kilograms is fissionable. It takes 140 tonnes of uranium ore to make 27 tonnes of enriched uranium fuel, of which 1 tonne is fissionable. Electricity can be generated from uranium Most of the world's mined uranium (and all of Australia's) is used to generate electricity in nuclear power stations. A controlled atomic process produces heat, which converts water to steam to drive the turbines which generate electricity. Nuclear energy currently provides about 17 per cent of global electrical power, but in France it provides 75 per cent of electricity. Nuclear power: advantages and disadvantages Unlike coal-fired power stations, nuclear reactors do not generate carbon dioxide and atmospheric pollution. Every tonne of mined uranium used for fuel in place of coal saves the emission of 40,000 tonnes of carbon dioxide. However, there are disadvantages because of the danger of ionising radiation (Box 1: The danger of ionising radiation) that can come from mining and transporting uranium, accidents, and disposing of nuclear wastes. Australian uranium is exported Australia does not generate any nuclear power but does mine and export uranium. Australian mines provide about 22 per cent of the world's uranium, second only to Canada. In 2004-05 Australia produced more than 10,000 tonnes of uranium oxide, generating over $A475 million of export revenue. Australian uranium goes only to countries that undertake to use it solely for peaceful purposes. Many of these countries have insufficient supplies of coal or hydroelectricity or choose to use nuclear energy because it is more economical and it reduces atmospheric pollution. The three mines policy restricted uranium mining In 1984 the federal Labor government introduced their three mines policy. It confined Australia's uranium production to the three sites already being mined: Ranger, Nabarlek and Olympic Dam. At the time, the mining industry felt that this unnecessarily restricted uranium mining. Present government policy is to allow uranium to be mined and exported The three mines policy was abandoned when the Coalition government was elected in March 1996. The Coalition's policy is to develop the export potential of Australia's uranium industry by allowing mining and export of uranium under strict international agreements designed to prevent nuclear proliferation. Today the Ranger mine in the Northern Territory and the Olympic Dam mine in South Australia continue to operate, but the Nabarlek mine has closed. There is now a third uranium mine operating (Beverley), with approval given for a fourth mine (Honeymoon). Both of these mines are in South Australia. Uranium mining can have an impact on Aboriginal groups Mining in Australia's remote areas can be controversial when it is carried out in places that have great significance for Aboriginal people. The question of Aboriginal land rights is a complex one. Some areas in many States have now reverted to Aboriginal title, meaning that the Aboriginal people in the area are, as a group, the legal owners of the land, which they may then lease to governments, individuals or corporations. In September 2002 the company responsible for the Jabiluka mine site in the Northern Territory announced that the mine would not go ahead without the consent of the local Aboriginal people. Environmental effects of uranium mining Conservationists point out that the effects of mining can go far beyond the small area disturbed in the operation. A mine cannot operate in isolation. It requires the construction of roads, the transport of material and the disposal of wastes. Box 1. The danger of ionising radiation Related Nova topic: |
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Page updated September 2002.
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