An 113-member independent organization under the aegis of the United Nations. The Agency s programs concentrate on radioactive waste safety standards, safeguards for spent nuclear fuel storage and handling, and transportation regulations for hazardous waste. Used for medical purposes to destroy bacteria in milk or other foods and sterilize medical instruments and bandages or to induce the polymerization of monomers or vulcanization of rubber. Natural or engineered barriers designed to separate nuclear waste from workers, the public, or the environment. A different form of the same chemical element that differs only by the number of neutrons in its nucleus.
Most elements have more than one naturally occurring isotope.
Many isotopes have been produced in reactors and scientific laboratories.