Uranium is a naturally-occurring radioactive element that has been mined and used for its chemical properties for more than a thousand years. It is now primarily used as fuel for nuclear reactors that make electricity. Uranium can be recovered in two ways: by conventional mining of the rock ore , or by using strong chemicals to dissolve uranium from the rock that is still in the ground and pumping it to the surface.
Industries in the United States recover uranium from the Earth through mining or chemical extraction. Once the uranium ore is extracted from the Earth, it must be processed to get the uranium from the ore. There are a few processes that can be used to recover uranium:.
Regardless of how uranium is extracted from rock, the processes leave behind radioactive waste. For example, the solid radioactive wastes that are left over from the milling processes are called tailings and the liquid wastes are called raffinates. Mill tailings and raffinates are stored in specially designed ponds called impoundments. The tailings remain radioactive and contain hazardous chemicals from the recovery process.
Uranium eventually decays to radium. Radium decays to release a radioactive gas called radon. Open pit uranium milling and in situ mining sites do not pose a significant radon risk to the public or to miners; the radon disperses into the atmosphere.
In the past, the waste rock produced by underground and open pit mining was piled up outside the mine. This practice has caused problems, including on Navajo lands where more than half of the small, abandoned uranium mines from the middle of the 20 th century and their wastes remain.
ERA has been recognised for its world-class environmental management, achieving ISO certification in Until tailings from the treatment plant were emplaced in an engineered dam on the lease, but they are now being deposited into the worked out pits.
No process or other contaminated water is released from the site. The Ranger mine is on a hectare lease which is surrounded by the World Heritage listed Kakadu National Park of 1. About hectares is actually disturbed by the mining and milling activities 0. Rainfall is monsoonal, with mm average mm falling in the wet season. The vegetation at Ranger is tropical open eucalypt forest, similar to much of the National Park. The project area is leased from the Aboriginal traditional owners, title to the land being held by the Kakadu Land Trust.
The Company contributes 4. The balance of royalty 1. Part of this environmental effort is directed to land management issues of relevance not simply to Ranger, but to the surrounding National Park and World Heritage area. These include maintenance of biodiversity, fire management including control burning which is very important and contentious in the region , terrestrial and aquatic weed control, feral animal control, mycorrhizal establishment, and rehabilitation of disturbed areas including rock waste dumps, etc.
Ranger is possibly the first mining operation deliberately to burn its own revegetated areas to assist the development of an appropriate vegetation community Eucalypts and Grevilleas instead of Acacia dominance. Related issues being studied include artificial wetland filters, soil formation from waste rock, and hydrology. Among Ranger's long term research priorities are projects which are relevant to eventual use of the land by its aboriginal owners.
The mine, smelter and infrastructure occupy about 7. The mine lease and the adjacent 11, hectare municipal lease have been destocked of sheep and cattle since Red Kangaroo numbers on the mine lease are about 20 per square kilometre, which is slightly higher than surrounding areas because of the access to water. In order to discourage wildlife from entering the tailings storage facility, alternative waterholes have been provided and deterrents installed on the dams and ponds.
The evaporation ponds have been fenced with fine mesh to exclude small mammals and reptiles. Foxes and cats are controlled on the lease by shooting and trapping. BHP Billiton Olympic Dam manages four pastoral stations in the area surrounding the mine and municipal leases with a total area of 1,, hectares.
These properties are conservatively stocked to maximise protection of sites of environmental or cultural significance. The Arid Recovery project, which covers an area of 8, hectares, is situated largely on the mine lease and BHP Billiton-operated pastoral stations, with the remaining area 6 hectares donated by local pastoralists.
Arid Recovery is an ecosystem restoration initiative working to restore Australia's arid lands. The reserve is surrounded by a unique cat, rabbit and fox-proof fence. Five locally extinct species have been reintroduced into the reserve. During this process, all significant slow-growing trees and shrubs and areas of cultural significance are identified. Efforts are made to minimise disturbance caused by operational activity on the leases, and rehabilitation is undertaken afterwards where practical.
Considerable attention has been given to rehabilitation of the hundreds of drill pads, some dating from initial exploration, so that many are now scarcely visible even on aerial photos. Rock waste and the coarse fraction of tailings are used as mine backfill. Fine tailings material, still containing potentially valuable minerals rare earths etc.
During seepage of contaminated water from the tailings dams was identified. This was of concern to the company, the regulators and the public because of the perceived threat to the quality of groundwater immediately below the tailings dams. Studies undertaken demonstrated that the pollutants in the seepage were quickly adsorbed on to clays and limestone in the soil and rock under the tailings dams, and, due to the low permeability and transmissivity of the rock, that there was no potential harm to the groundwater resource.
The level of the groundwater under the tailings dams is monitored and modelled on a quarterly basis. This comprehensive report covers all areas of potential environmental impact, including air emissions, site groundwater management, water supply and management of the Great Artesian Basin, flora and fauna monitoring and annual radiation dose to members of the public.
Reporting on progress with action items identified in the Environmental Management Program is provided, as well as involvement with community activities. Olympic Dam has a Rehabilitation and Closure Plan covering cost estimate basis, summary of closure requirements for the metallurgical facilities, pilot plant, mine, tailings dams, wellfields, exploration areas, town facilities, power line corridor and miscellaneous facilities , community consultation requirements, closure strategy including post operational land use objective and completion criteria and closure plan review requirements.
Demolition costs are budgeted based on quotations from a specialist demolition contractor and rehabilitation costs are estimated based on a quotation from a mining contractor with extensive rehabilitation experience. Progressive closure costs have been estimated for each year until actual closure of the site.
An Environmental Management and Monitoring Plan EMMP has been developed with the regulating authorities, who determined the requirements of it, including those for radiation protection. The Plan provides for ongoing management of every aspect of the operation. Monitoring to detect possible horizontal excursions from the mining zone or any vertical leakage into other aquifers is a fundamental facet of mine operations. In contrast to the main ISL operations in USA extracting uranium from aquifers with potable water, the groundwater quality at Beverley is very low, being fairly saline and orders of magnitude too high in radionuclides for any permitted use.
Fluids from mined areas are progressively moved to new mining areas, thus reducing the overall effect on the aquifer. In air it is coated by uranium oxide, tarnishing rapidly. It is attacked by steam and acids.
Uranium can form solids solutions and intermetallic compounds with many of the metals. Uranium gained importance with the development of practical uses of nuclear energy.
Depleted uranium is used as shelding to protect tanks, and also in bullets and missiles. The first atomic bomb used in warfare was an uranium bomb. This bomb contained enough of the uramium isotope to start a runaway chain reaction which in a fraction of a second caused a large number of the uranium atoms to undergo fission, there by releasing a fireball of energy.
The main use of uranium in the civilian sector is to fuel commercial nuclear power plants. This require uranium to be enriched with the uranium isotope and the chain reaction to be controlled so that the energy is released in a more manageable way. The isotope uranium is used to estimate the age of the earliest igneous rocks and for other types of radiometric dating.
Phosphate fertilizers are made from material typically high in uranium, so they usually contain high amounts of it. Although uranium is radioactive, it is not particularly rare. It is widely spread throughout the environment and so it is impossible to avoid uranium. Uranium can be found naturally in the environment in very small amounts in rocks, soil, air and water. Humans add uranium metals and compounds, because they are released during mining and milling processes.
In air the uranium concentrations are very low. Mining operations are currently being expanded and this will increase water use to million litres per day. To meet this demand a second borefield, Borefield B, has been developed for use until the year Even the table included in the Report shows this to be wrong. It is gross inaccuracies such as this in the majority Report which put its whole validity in doubt.
This spring system hosts unique ecosystems of flora and fauna as well as being a significant site to the Arabunna people who are the traditional owners.
Evidence presented to the Committee suggests that the demise of at least two spring complexes Priscilla and Venerable Springs may have already occurred and that 10 other spring complexes have been affected by reduced flows[ 2 ]. This environmental degradation requires urgent investigation by a fully independent scientific body with expertise in the environmental effects of uranium mining.
The risks of the tailings dams leaking translates into a risk to the environment through contamination of the Magela Creek system as well as the risk to members of the public, indigenous people and workers of exposure to radiation.
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