There are far less negative effects of nuclear power than many other sources. The fact that nuclear reactors use uranium means there is some place in the world where uranium is being mined. In many respects uranium mining is much the same as any other mining. Projects must have environmental approvals prior to commencing, and must comply with all environmental, safety and occupational health conditions applicable. Increasingly, these are governed by international standards, with external audits.
Mining
the main type of uranium mining is open pit and underground mining. Solid waste products from the milling operation are tailings. They comprise most of the original ore and they contain most of the radioactivity in it. In particular they contain all the radium present in the original ore. At an underground mine they may be first cycloned to separate the coarse fraction which is used for underground fill. The balance is pumped as a slurry to a tailings dam, which may be a worked-out pit as at Ranger and McClean Lake.
When radium undergoes natural radioactive decay one of the products is radon gas. Because radon and its decay products (daughters) are radioactive and because the tailings are now on the surface, measures are taken to minimise the emission of radon gas. During the operational life of a mine the material in the tailings dam is often kept covered by water to reduce surface radioactivity and radon emission (though with lower-grade ores neither pose a hazard at these levels).Once approved, open pits or shafts and drives are dug, waste rock and overburden is placed in engineered dumps. Tailings from the ore processing must be placed in engineered dams or underground. Finally the whole site must be rehabilitated at the end of the project. Meanwhile air and water pollution must be avoided.
The uranium itself has a very low level of radioactivity, comparable with granite. Virtually all the radioactive material from the associated minerals in the ore processed ends up in the tailings dam.
Mining
the main type of uranium mining is open pit and underground mining. Solid waste products from the milling operation are tailings. They comprise most of the original ore and they contain most of the radioactivity in it. In particular they contain all the radium present in the original ore. At an underground mine they may be first cycloned to separate the coarse fraction which is used for underground fill. The balance is pumped as a slurry to a tailings dam, which may be a worked-out pit as at Ranger and McClean Lake.
When radium undergoes natural radioactive decay one of the products is radon gas. Because radon and its decay products (daughters) are radioactive and because the tailings are now on the surface, measures are taken to minimise the emission of radon gas. During the operational life of a mine the material in the tailings dam is often kept covered by water to reduce surface radioactivity and radon emission (though with lower-grade ores neither pose a hazard at these levels).Once approved, open pits or shafts and drives are dug, waste rock and overburden is placed in engineered dumps. Tailings from the ore processing must be placed in engineered dams or underground. Finally the whole site must be rehabilitated at the end of the project. Meanwhile air and water pollution must be avoided.
The uranium itself has a very low level of radioactivity, comparable with granite. Virtually all the radioactive material from the associated minerals in the ore processed ends up in the tailings dam.
Water specific
Mining:
Waste generated from uranium mining operations and rainwater runoff can contaminate groundwater and surface water resources with heavy metals and traces of radioactive uranium. Well-established environmental constraints apply in order to avoid any off-site pollution. Run-off from the mine stockpiles and waste liquors from the milling operation are collected in secure retention ponds for isolation and recovery of any heavy metals or other contaminants. The liquid portion is disposed of either by natural evaporation or recirculation to the milling operation. Most Australian and many other mines adopt a "zero discharge" policy for any pollutants.
Power Plant:
Heavy metals and salts build up in the water used in all power plant systems, including nuclear ones. These water pollutants, as well as the higher temperature of the water discharged from the power plant, can negatively affect water quality and aquatic life. Nuclear power plants sometimes discharge small amounts of tritium and other radioactive elements as allowed by their individual wastewater permits. Nuclear power plants use large quantities of water for steam production and for cooling. Some nuclear power plants remove large quantities of water from a lake or river, which could affect fish and other aquatic life.
Mining:
Waste generated from uranium mining operations and rainwater runoff can contaminate groundwater and surface water resources with heavy metals and traces of radioactive uranium. Well-established environmental constraints apply in order to avoid any off-site pollution. Run-off from the mine stockpiles and waste liquors from the milling operation are collected in secure retention ponds for isolation and recovery of any heavy metals or other contaminants. The liquid portion is disposed of either by natural evaporation or recirculation to the milling operation. Most Australian and many other mines adopt a "zero discharge" policy for any pollutants.
Power Plant:
Heavy metals and salts build up in the water used in all power plant systems, including nuclear ones. These water pollutants, as well as the higher temperature of the water discharged from the power plant, can negatively affect water quality and aquatic life. Nuclear power plants sometimes discharge small amounts of tritium and other radioactive elements as allowed by their individual wastewater permits. Nuclear power plants use large quantities of water for steam production and for cooling. Some nuclear power plants remove large quantities of water from a lake or river, which could affect fish and other aquatic life.
As shown by this diagram not all nuclear power plant release the cooling water back into the source from where they got it, but it is evaporated. Also the water that is used for cooling never actually comes in contact with the reactor but is cooling the steam generated by the reactor.
Health
Power Plant
Human health is not a problem with nuclear facility. The safety at a nuclear power plant is great because of all the regulation do to the nature of the work. Traditionally occupational health risks have been measured in terms of immediate accident, especially fatality, rates. However, today, and particularly in relation to nuclear power, there is an increased emphasis on less obvious or delayed effects of exposure to cancer-inducing substances and radiation. Many occupational accident statistics have been generated over the last 50 years of civil nuclear power in North America and Europe. These can be compared with those from coal-fired and other electricity generation. All show that nuclear is distinctly the safer means of electric power generation in this respect. A simple set of figures are quoted in Table 1. A major reason for coal showing up unfavourably is the huge amount of it which must be mined and transported to supply even a single large power station - some 20,000 times as much coal as uranium from the mine. Mining and multiple handling of so much material of any kind involves hazards, and these are reflected in the statistics.
Health
Power Plant
Human health is not a problem with nuclear facility. The safety at a nuclear power plant is great because of all the regulation do to the nature of the work. Traditionally occupational health risks have been measured in terms of immediate accident, especially fatality, rates. However, today, and particularly in relation to nuclear power, there is an increased emphasis on less obvious or delayed effects of exposure to cancer-inducing substances and radiation. Many occupational accident statistics have been generated over the last 50 years of civil nuclear power in North America and Europe. These can be compared with those from coal-fired and other electricity generation. All show that nuclear is distinctly the safer means of electric power generation in this respect. A simple set of figures are quoted in Table 1. A major reason for coal showing up unfavourably is the huge amount of it which must be mined and transported to supply even a single large power station - some 20,000 times as much coal as uranium from the mine. Mining and multiple handling of so much material of any kind involves hazards, and these are reflected in the statistics.
mining
In Australia all uranium mining and milling operations are undertaken under the Code of Practice and Safety Guide: Radiation Protection and Radioactive Waste Management in Mining and Mineral Processing, which sets strict health standards for radiation and radon gas exposure, for both workers and members of the public.
In Canada the Canadian Nuclear Safety Commission is responsible for regulating uranium mining as well as other aspects of the nuclear fuel cycle. In Saskatchewan, provincial regulations also apply concurrently, and set strict health standards for both miners and local people. Similar standards are set in other countries.
While uranium itself is only slightly radioactive, radon, a radioactive inert gas, is released to the atmosphere in very small quantities when the ore is mined and crushed. Radon is one of the decay products of uranium and radium, and occurs naturally in most rocks – minute traces of it are present in the air which we all breathe.
Australian uranium mines have mostly been open cut and therefore naturally well ventilated. The Olympic Dam and Canadian underground mines are ventilated with powerful fans. Radon levels are kept at a very low and certainly safe level in uranium mines. (Radon in non-uranium mines also may need control by ventilation.)
Gamma radiation may also be a hazard to those working close to high-grade ores. It comes principally from radium in the ore, so exposure to this is regulated as required. In particular, dust is suppressed, since this represents the main potential exposure to alpha radiation as well as a gamma radiation hazard.
At the concentrations associated with uranium (and some mineral sands) mining, radon is a potential health hazard, as is dust. Precautions taken during the mining and milling of uranium ores to protect the health of the workers include:
In Australia all uranium mining and milling operations are undertaken under the Code of Practice and Safety Guide: Radiation Protection and Radioactive Waste Management in Mining and Mineral Processing, which sets strict health standards for radiation and radon gas exposure, for both workers and members of the public.
In Canada the Canadian Nuclear Safety Commission is responsible for regulating uranium mining as well as other aspects of the nuclear fuel cycle. In Saskatchewan, provincial regulations also apply concurrently, and set strict health standards for both miners and local people. Similar standards are set in other countries.
While uranium itself is only slightly radioactive, radon, a radioactive inert gas, is released to the atmosphere in very small quantities when the ore is mined and crushed. Radon is one of the decay products of uranium and radium, and occurs naturally in most rocks – minute traces of it are present in the air which we all breathe.
Australian uranium mines have mostly been open cut and therefore naturally well ventilated. The Olympic Dam and Canadian underground mines are ventilated with powerful fans. Radon levels are kept at a very low and certainly safe level in uranium mines. (Radon in non-uranium mines also may need control by ventilation.)
Gamma radiation may also be a hazard to those working close to high-grade ores. It comes principally from radium in the ore, so exposure to this is regulated as required. In particular, dust is suppressed, since this represents the main potential exposure to alpha radiation as well as a gamma radiation hazard.
At the concentrations associated with uranium (and some mineral sands) mining, radon is a potential health hazard, as is dust. Precautions taken during the mining and milling of uranium ores to protect the health of the workers include:
- Good forced ventilation systems in underground mines to ensure that exposure to radon gas and its radioactive daughter products is as low as possible and does not exceed established safety levels.
- Efficient dust control, because the dust may contain radioactive constituents and emit radon gas.
- Limiting the radiation exposure of workers in mine, mill and tailings areas so that it is as low as possible, and in any event does not exceed the allowable dose limits set by the authorities. In Canada this means that mining in very high-grade ore is undertaken solely by remote control techniques and by fully containing the high-grade ore where practicable.
- The use of radiation detection equipment in all mines and plants.
- Imposition of strict personal hygiene standards for workers handling uranium oxide concentrate.