Power Generation
Nuclear power plants are fuelled by uranium, a naturally occurring element found in the Rocky Mountains and in countries such as Canada, Australia and South Africa. The nearly infinite energy that is stored in uranium atoms makes nuclear power possible.
The interaction between three "heavy" elements - two types of uranium and a form of plutonium -- creates a chain reaction that can be harnessed to generate electricity. The nuclear reaction generates heat that is used to boil water to create steam to drive a turbine to generate electricity. Like fossil fuels, uranium is a finite non-renewable resource.
Some of the most serious impacts linked to the generation of electricity on land can be linked to nuclear plants. Where the amount of solid wastes generated at nuclear plants is small, these radioactive wastes pose health risks that are more than that of any other source of electricity. It is quite possible that these radioactive wastes will be stored for a century or more at existing nuclear plant sites, an idea that may stop any future re-uses of these contaminated lands.
A major failure in a nuclear power plant's cooling systems can create a nuclear meltdown, where fuel rods melt within a matter of seconds. The heat from the uncontrolled reaction can melt everything it comes into contact with. Catastrophic accidents could injure or kill thousands of people.
Sterilisation
Very small amounts of radioactive materials are components of some consumer products. For example, radioactive Americium-241 is a key component of some types of smoke detectors. Polonium-210 is a radioactive material used to prevent the build-up of static electricity in some photocopiers, and helps prevent paper jams.
More often, radioactive materials are involved in the production of goods. Radiation is used to kill bacteria and sterilise a number of products including baby powder, cosmetics, medical supplies, and contact lens solution. No chemicals are added to products when they are sterilised using radiation. Sterilisation by radiation can be performed after products have been sealed in packaging.
Irradiation is an alternative in the processing and sterilisation of some foods. Exposing foods like strawberries, onions, potatoes, and spices to radiation destroys moulds and other germs that can cause rotting. Radiation also kills insects in grains. The nutritional value of the food stays the same, and the food does not become radioactive just as a person doesn't become radioactive when teeth are x-rayed.
Thickness Measurement / Control
Industry frequently uses radiation for measurement and testing. For example, a source of radiation can be used to measure the thickness of paper during its production. In this process, a radioactive material is put on one side of the paper, and a radiation detection device is put on the other side. Thick paper blocks more radiation than thin paper. If the detector gets too much radiation, or too little, the operator knows the thickness is not correct and can adjust the paper manufacturing equipment. A similar detection system can be used to check the thickness of other materials such as sheet metal or padding in disposable diapers, or to determine the height of liquids in beverage containers. Radiation also is used for the curing of inks and coatings, and for pipeline, weld, and metal corrosion analysis.
Imaging
Nuclear medicine began around 50 years ago and has evolved into a medical specialty for both diagnosis and therapy of diseases. Over 10 million nuclear medical imaging and therapeutic procedures are done every year in the United States.
Nuclear medicine involves the use of small amounts of radioactive materials (or tracers) to help diagnose and treat a different types of diseases. Nuclear medicine determines the cause of a medical problem based on the function of the organ, tissue or bone. This is how nuclear medicine differs from an x-ray, ultrasound or other test that tells the presence of disease based on appearance.
Nuclear medicine tests (also known as scans, examinations, or procedures) are safe and painless. In a nuclear medicine test, the radioactive material is introduced into the body by injection, swallowing, or inhalation. Different tracers are used to study different parts of the body. The amount of tracer used is carefully selected to provide the least amount of radiation exposure to the patient but ensure an accurate test. A special camera (scintillation or gamma camera) is used to take pictures of your body. The camera does this by detecting the tracer in the organ, bone, or tissue being imaged and then records this information on a computer screen or on film. Generally, nuclear medicine tests are not recommended for pregnant women because unborn babies have a greater sensitivity to radiation than children or adults.
Nuclear medical imaging procedures often find abnormalities very early in the progression of a disease, long before some medical problems are seen with other diagnostic tests. This early detection allows a disease to be treated early when there may be a more successful prognosis.
