Radiation

Exposure to radiation | Medical exposure | Nuclear exposure | Consumer exposure | Radiation dose limits | Governmental standards | Programs to keep exposure down

Radiation is energy released from unstable atoms in the form of particles, waves or rays. An unstable atom ― one that has either too many protons in the nucleus or lacks a proper number of neutrons needed to keep the nucleus balanced ― naturally will tend to become stable by releasing energy, or radiation, from the nucleus.

There are many different forms of radiation. We also measure radiation in various ways that are easy to explain.

Exposure to radiation

Radiation from unstable atoms, has always been part of our environment. About 82 percent of the radiation to which the average person is exposed annually comes from natural sources, such as

• the sun
• space
• radioactive elements in soil
• food and
• water.

And levels of this natural, or background, radiation vary greatly from place to place.

Example: Exposure to cosmic radiation is twice as great at 5,000 feet as it is at sea level.

Medical exposure

The next largest source (about 15 percent) of radiation comes from medical diagnostic and therapy sources. Radiation is used to treat about half of all cancer patients and radioactive chemicals are routinely used for medical diagnosis, often replacing exploratory surgery.

Nuclear exposure

Of the remaining 3 percent of radiation to which humans are exposed, less than .5 percent comes from nuclear power plants and nuclear fuel-related industries (such as mining and fuel fabrication).

Consumer exposure

In fact, consumer products such as the following account for 3 times as much radiation exposure in the U.S. as the nuclear industry:

• television sets
• building materials
• smoke alarms
• natural gas
• tobacco and
• luminous dials on watches and clocks.

Radiation dose limits

The U.S. Nuclear Regulatory Commission (NRC) sets radiation dose limits as operating standards for all licensed nuclear activities.

NRC radiation exposure limits are designed so that occupational exposure to radiation should not produce adverse health effects. Additionally, the agency requires nuclear plants to keep exposure at levels that are as low as reasonably achievable. FPL has established even lower limits of worker exposure as a conservative measure.

Governmental standards

Nuclear power plants must meet very stringent government standards limiting the exposure to radiation of plant workers and the public. Nuclear power plants also are designed with multiple barriers of protection to "contain" radioactive materials to protect the public and the environment.

Programs to keep exposure down

A number of programs and procedures administered by a staff of health physics specialists keeps radiation exposure at or below these designated radiation limits.