Industry and agriculture

Applications of radioactivity in industry and agriculture

The controlled applications of radiations in industry, which enter in the fabrication of many finished products of our daily lives, are largely unnoticed by the potential consumers. These radioactive processes involving sources and tracers, are a vital step in the quality control of numerous industrial techniques.

Gammadensimetry of a pile of wooden beams
This graph of comparative density, made using gamma ray imaging (a technique known as gammadensimetry), shows the areas of weakness (knots in the wood, beginnings of branches) in a plank.

The tests involved are part of a process known as non-destructive testing, wherein the final product is not damaged by the quality checks it undergoes.

A good example is the use of small amounts of argon 41 in oil refineries. This radioactive isotope is frequently injected into the catalytic cracking towers to better monitor the quality of oil produced.

Radioactive sources are also frequently used to supervise industrial processes. In the cement industry, for example, large wagons carrying raw material are passed in front of a neutron source. The nuclei in the sample absorb these neutrons, and release the excess energy by emitting high-energy gamma rays. The detection of these rays allows for a better understanding of the sample composition, which can then be altered to suit the factory standards.

Higher doses of radiations are frequently used to modify the chemical or mechanical properties of a given material. Industrial processes, similar to those used in the restoration of antique furniture, can transform soft woods into panelling as hard as marble. Many large walkways, such as those in airports, public spaces, large shops and museums will have floors treated in this way.

Eradication of insects, dangerous to man
Apart from the many programs to eradicate insects dangerous to agriculture, SIT has shown its success in the health field. The American department of agriculture has eliminated the screwworm in the United States and South America, a fly which feds itself on blood and attacked livestock and humans by infecting wounds. The IAEA has eradicated the tsetse fly in Zanzibar that also attacked the livestock and was the cause for the sleeping sickness in humans.

Irradiation by gamma rays has a number of applications in agriculture and food industry. While naturally-occurring rays do not have the energy needed to make atoms radioactive, they do have an impact on the sub-molecular world. The most common uses of radiations in the food-growing industry is to help remove insects and bacteria from fruits and vegetables. Either by killing them directly, or by sterilising the entire male population, insect-related problems can frequently be solved with no harm to the product involved.

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