Atoms are the building blocks of all material. If atoms contain excess energy, they are unstable. Materials that are composed of unstable atoms will naturally emit radiation in order to release the excess energy and reach a stable state. The radiation is emitted in waves or particles of energy.
Radiation is not new or limited to nuclear power plants. Each of us is exposed to some radiation every moment of our lives from radioactive materials that exist in nature.
Natural radiation is a by-product of processes and materials created when the earth was formed. The sun on which we all depend for heat and light produces very highly charged particles called cosmic rays. We are exposed continuously to this radiation every day.
Not many people realize that we all have radiation sources within our own bodies, one example is potassium. Radioactive potassium occurs naturally in the earth and is therefore present in trace amounts in the food we eat and the water we drink.
Additionally, radioactivity from uranium and thorium is found in rocks and soil. For instance, radon gas is a source of radiation that results from the decay of uranium found in the earth. Radon gas has recently been identified as a concern because it can penetrate through the foundation of homes. Recent studies show that radon gas contributes more than half of our radiation exposure each year.
While our environment contains numerous sources of radiation, some radiation is man-made. For example, x-ray machines used for dental and medical purposes, our television sets and computer monitors, and the microwave ovens we use to cook foods are all sources of radiation. Nuclear power plants use the energy of radiation to convert water to steam, which is then used to generate electricity.
Each type of radiation has somewhat different characteristics. It is possible to measure the biological effects of the different types of radiation in terms of a unit of exposure called a "rem". This is a relatively large unit, so the biological effects of radiation are described in millirem, which are a thousand times smaller than a rem.
Radiation measurement techniques are highly advanced and can detect small changes in the environmental radiation level. Results of extensive environmental radiation monitoring confirm that routine nuclear power plant operation does not contribute a significant amount of radiation exposure.
People living near Fermi 2 receive less than one millirem of exposure a year due to that plant's operation. This compares to the 360 millirem of exposure a person typically receives annually from natural background radiation and other man-made sources.
Since every living thing on earth has been continuously exposed to radiation, such exposure is normal. The level of exposure from natural radiation and man-made sources is considered very low-level exposure. Scientists continue to study the risks associated with low-level radiation exposure to determine its effects on humans. The studies show that negative health effects caused by low-level exposures cannot be distinguished from those caused by other environmental hazards.
After more than 80 years of study, radiation is readily detected, understood and strictly regulated.