Generating electricity using nuclear reactors carries high risk but offers large rewards. In operation, a very small amount of nuclear fuel will consistently generate a very large amount of electricity and generate very little polluting material. However, the financial costs of building and decommissioning a nuclear power station are very large, and the waste produced will remain radioactive - hazardous to humans and the environment - for thousands of years.
Fission reactors A fission reactor contains a number of different parts: Nuclear fuel - the uranium or plutonium isotope that will split when triggered by an incoming neutron. The fuel is held in rods so that the neutrons released will fly out and cause nuclear fission in other rods. Moderator - graphite core - a graphite core, for example, slows the neutrons down so that they are more likely to be absorbed into a nearby fuel rod.
Try these quick facts for starters. Nuclear energy protects air quality. Nuclear is a zero-emission clean energy source. A 25 megawatt solar power system in DeSoto County, Florida. Nuclear energy produces minimal waste.
According to the U. Nuclear Regulatory Commission :. The explosion and subsequent burnout of a large graphite-moderated, water-cooled reactor at Chernobyl in was easily the worst nuclear accident in history.
Twenty-nine disaster relief workers died of acute radiation exposure in the immediate aftermath of the accident. In the subsequent three decades, UNSCEAR — the United Nations Scientific Committee on the Effects of Atomic Radiation, composed of senior scientists from 27 member states — has observed and reported at regular intervals on the health effects of the Chernobyl accident. It has identified no long-term health consequences to populations exposed to Chernobyl fallout except for thyroid cancers in residents of Belarus, Ukraine and western Russia who were children or adolescents at the time of the accident, who drank milk contaminated with iodine, and who were not evacuated.
The occurrence of these cancers increased dramatically from to , which researchers attributed mostly to radiation exposure. No increase occurred in adults.
Pacific Gas and Electric. A full-body CT scan delivers about mSv. The statistics of Chernobyl irradiations cited here are so low that they must seem intentionally minimized to those who followed the extensive media coverage of the accident and its aftermath. Yet they are the peer-reviewed products of extensive investigation by an international scientific agency of the United Nations.
They indicate that even the worst possible accident at a nuclear power plant — the complete meltdown and burnup of its radioactive fuel — was yet far less destructive than other major industrial accidents across the past century. To name only two: Bhopal, in India, where at least 3, people died immediately and many thousands more were sickened when 40 tons of methyl isocyanate gas leaked from a pesticide plant; and Henan Province, in China, where at least 26, people drowned following the failure of a major hydroelectric dam in a typhoon.
For example, the Chernobyl rate is nine times lower than the death rate from liquefied gas… and 47 times lower than from hydroelectric stations. The accident in Japan at Fukushima Daiichi in March followed a major earthquake and tsunami.
The SIT technique is environmentally-friendly, and has proved an effective means of pest management even where mass application of pesticides had failed. At present, SIT is applied across six continents. Since its introduction, SIT has successfully controlled the populations of a number of high profile insects, including mosquitoes, moths, screwworm, tsetse fly, and various fruit flies Mediterranean fruit fly, Mexican fruit fly, oriental fruit fly, and melon fly.
The most recent high-profile application of SIT has been in the fight against the deadly Zika virus in Brazil and the broader Latin America and Caribbean region see also Insect control within the section on Medicine below. See also information paper on Radioisotopes in Consumer Products. The function of many common consumer products is dependent on the use of small amounts of radioactive material. One of the most common uses of radioisotopes today is in household smoke detectors.
These contain a small amount of americium which is a decay product of plutonium originating in nuclear reactors. The Am emits alpha particles which ionise the air and allow a current between two electrodes. If smoke enters the detector it absorbs the alpha particles and interrupts the current, setting off the alarm.
This problem is particularly prevalent in hot, humid countries. Food irradiation is the process of exposing foodstuffs to gamma rays to kill bacteria that can cause food-borne disease, and to increase shelf life. In all parts of the world there is growing use of irradiation technology to preserve food.
More than 60 countries worldwide have introduced regulations allowing the use of irradiation for food products. In addition to inhibiting spoilage, irradiation can delay ripening of fruits and vegetables to give them greater shelf life, and it also helps to control pests.
Its ability to control pests and reduce required quarantine periods has been the principal factor behind many countries adopting food irradiation practices.
See also information paper on Radioisotopes in Industry. Radioisotopes are used by manufacturers as tracers to monitor fluid flow and filtration, detect leaks, and gauge engine wear and corrosion of process equipment. Small concentrations of short-lived isotopes can be detected whilst no residues remain in the environment. By adding small amounts of radioactive substances to materials used in various processes it is possible to study the mixing and flow rates of a wide range of materials, including liquids, powders and gases, and to locate leaks.
Radioactive materials are used to inspect metal parts and the integrity of welds across a range of industries. For example, new oil and gas pipeline systems are checked by placing the radioactive source inside the pipe and the film outside the welds.
Gauges containing radioactive usually gamma sources are in wide use in all industries where levels of gases, liquids, and solids must be checked. They measure the amount of radiation from a source which has been absorbed in materials. These gauges are most useful where heat, pressure, or corrosive substances, such as molten glass or molten metal, make it impossible or difficult to use direct contact gauges. The ability to use radioisotopes to accurately measure thickness is widely utilised in the production of sheet materials, including metal, textiles, paper, plastics, and others.
Density gauges are used where automatic control of a liquid, powder, or solid is important, for example in detergent manufacture. Analysing the relative abundance of particular naturally-occurring radioisotopes is of vital importance in determining the age of rocks and other materials that are of interest to geologists, anthropologists, hydrologists, and archaeologists, among others. See also information paper on Nuclear Desalination.
Potable water is a major priority in sustainable development. Where it cannot be obtained from streams and aquifers, desalination of seawater, mineralised groundwater, or urban waste water is required. Most desalination today uses fossil fuels and thus contributes to increased levels of greenhouse gases. The feasibility of integrated nuclear desalination plants has been proven with over reactor-years of experience, chiefly in Kazakhstan, India, and Japan. Large-scale deployment of nuclear desalination on a commercial basis with reactors built primarily for that purpose will depend on economic factors.
See also information paper on Radioisotopes in Medicine. Many people are aware of the wide use of radiation and radioisotopes in medicine particularly for diagnosis identification and therapy treatment of various medical conditions.
In developed countries about one person in 50 uses diagnostic nuclear medicine each year, and the frequency of therapy with radioisotopes is about one-tenth of this. Diagnostic techniques in nuclear medicine use radiopharmaceuticals or radiotracers which emit gamma rays from within the body.
These tracers are generally short-lived isotopes linked to chemical compounds which permit specific physiological processes to be scrutinised.
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