URANIUM MINING
November 2006
This Fact Sheet covers the start of the nuclear industry chain – uranium mining. It aims to present a concise overview of the nature of uranium, its mining and milling, and the numerous environmental and radiological aspects associated with this heavy industrial endeavour. It is clear that uranium is a finite resource and that the environmental costs associated with mining are significant and must be taken into account in any truthful analysis of the nuclear debate.
Common Questions:
1. What is uranium and how is it mined?
2. Is uranium mining like any other mining?
3. Are there sufficient uranium resources for the future?
4. What are the environmental impacts of uranium mining?
5. How much radioactive waste does uranium mining produce?
6. What are the radioactivity releases from uranium mining?
7. Can uranium mines be operated safely?
8. Can uranium mines be satisfactorily rehabilitated?
Uranium Mining:
Australia and Globally
Author: Gavin M. Mudd energyscience.org.au
Uranium mining results in an environmental waste legacy. Significant resources are required, including energy, water and industrial chemicals.
fact sheet
06
Ranger Uranium Mine , Northern Territory , Australia : AAP Image/Mayu Kanamor
November 2006
What is Uranium and How is it Mined?
Uranium is the heaviest, naturally occurring element. It consists of two principal isotopes – uranium-238 ( 238 U) with 238 neutrons in its nucleus, and uranium-235 ( 235 U) with 235 neutrons. The 235 U isotope is the desired isotope for nuclear reactors or nuclear weapons due to its ability to fission or split apart and release vast quantities of energy in the process. Natural uranium consists of 99.3% 238 U and about 0.7% 235 U. Uranium is unstable – it decays into slightly lighter elements, which are also unstable and further decay. The process of decay releases energy and a small atomic particle, and is known as radioactivity. There are two principal types of radioactive decay – alpha decay, the release of a charged helium atom, and beta decay, the release of an electron. This decay chain progresses through until a stable isotope is achieved (i.e. lead-206 or 206 Pb from 238 U and 207 Pb from 235 U). The rate at which an isotope decays is a characteristic of that isotope, and the time taken for 50% of an isotope to decay is known as its ‘halflife'.
The various decay products from uranium have half-lives ranging from fractions of a second to billions of years, shown in Table 1. As uranium is mostly present in oxide form, it is commonly reported as either uranium (U) or its oxide ‘U 3 O 8 '. Average concentrations of uranium in typical soils and rocks are about 3 mg/kg U 3 O 8 or parts per million U 3 O 8 (ie. about 3 grams per tonne). This background uranium is partly responsible for natural background radiation. In order to mine uranium economically using existing technology, this concentration has to reach at least 300 mg/kg or 0.03% U 3 O 8 ,with most uranium mines historically ranging between 0.1 to 0.5% U 3 O 8 . Due to uranium's variable chemistry, it can be concentrated to mineable ore grades and deposits by numerous geologic processes. The most common types of mineable economic uranium ores are found in sandstone deposits, unconformity deposits, breccia complex deposits, intrusive deposits, metamorhpic deposits and surficial deposits.
Uranium is mined using traditional techniques such as open cut or underground mining, but sandstone deposits can also be mined by ‘in situ leaching' (also known as solution mining). Once the ore is mined it is finely ground and the uranium is chemically extracted through conventional processes involving leaching with acid or alkali, concentration and then purification to uranium oxide. Acid leaching is the most common. An oxidising chemical is commonly also used, such as pyrolusite (MnO 2 ) or hydrogen peroxide (H 2 O 2 ), to ensure the leaching is rapid. For in situ leaching, the acid or alkali is injected directly into the ore zone and pumped back to the surface (no ore is excavated). After leaching from the ore, the uranium is further concentrated using solvent extraction or ion exchange, followed by chemical precipitation to an impure oxide using ammonia (this product is ‘yellowcake'). Finally, the yellowcake is heated at high temperature to remove the ammonia and leave relatively pure uranium oxide (>97% U 3 O 8 ).
Australia faces an unprecedented increase in uranium mining. Uranium prices have increased by some 300% over the last six months. Western Mining Corporation is planning to triple the size of Roxby uranium mine. The nuclear industry is promotion nuclear power as the answer to climate change. With Australia having one third of the worlds uranium the pressure is on to open up to 28 new minesRoxby Downs Uranium: Death and Destruction
Roxby Downs Uranium: Death and Destruction
Campaign Against Nuclear Dumping
The planned expansion of the Roxby Downs uranium mine is shaping up as one of South Australia's major environmental issues.
The mine, located 500 kms north of Adelaide on Kokatha country, has been operating since 1988. Since then, it has produced a staggering amount of radioactive waste, which is simply dumped on site. The radioactive waste stockpile currently amounts to 60 million tonnes and is growing at a rate of 10 million tonnes annually. With the proposed doubling or tripling of the mine size, the waste dump will grow at a faster rate
WMC Resources (formerly known as Western Mining), the company which operates the mine, says it plans to manage the radioactive waste dump to "industry standards" - in other words, the company will be able to walk away from its toxic legacy not long after the mine's eventual closure, yet the waste will pose an environmental and public health threat for millenia.
Water is another key issue. The mine uses over 30 million litres of water per day, drawn from the Great Artesian Basin (GAB) and piped through Arabunna land. The precious mound springs - fragile, unique ecological systems supported by the GAB - have been adversely effected and in some cases destroyed. To accommodate the planned expansion, WMC wants to increase its water take from the GAB to up to 100 million litres per day, or to take water from the River Murray, or to desalinate water from the Spencer Gulf.
WMC has used outrageous divide-and-rule tactics against Aboriginal communities. As Jan Whyte and Ila Marks, from Friends of the Earth, noted in the July 1996 issue of 'Chain Reaction', "It appears that WMC has embarked on a course of side-stepping consultation with the Arabunna as the traditional custodians. It has also taken similar actions in regard to the Kokotha, the traditional custodians for the actual mine site. One method used by mining companies to side-step proper consultation processes is documented in North America and Canada as well as Australia. Mining companies incorporate small Aboriginal groups in areas under dispute and give them financial support. These groups are then regarded as the official representatives for that area and mining companies proceed to consult with them. Thus, it seems as if the companies are going through the correct legal processes whereas, in fact, they are ignoring parties who have legitimate interests." (<www.geocities.com/olympicdam/articles.html>)
Weapons proliferation is another crucial issue. WMC sells uranium to nuclear weapons states, such as the USA and France, which have no intention of fulfilling their disarmament obligations under the Nuclear Non-Proliferation Treaty (NPT) - this is a clear breach of the policy of successive Australian governments to prohibit uranium exports to NPT renegade states. It's impossible to be sure that uranium designated for use in peaceful nuclear energy programs is not diverted for weapons production - the international 'safeguards' system has been violated countless times and was described by Professor Jim Falk as "half blind, toothless and mute". Supposedly "peaceful" nuclear programs have been used in covert nuclear weapons programs in over 25 countries (<www.geocities.com/jimgreen3/rrweapons.html>).
There are numerous other issues which make Roxby Downs and the planned mine expansion crucial issues for the environmental movement:
* WMC is the single largest electricity user in SA and the single largest greenhouse gas polluter in SA.
* spills and leaks have been all too common; for example, in 2003, five spills resulted in the release of over 650,000 litres of radioactive and toxic liquids.
* WMC enjoys completely unjustifiable legal privileges under the Roxby Indenture Act; this Act overrides the Environment Protection Act, the Water Resources Act, the Aboriginal Heritage Act and also provides exemptions from the Freedom of Information Act.