Radioactives

Radioactives refer to substances that contain unstable atomic nuclei and emit ionizing radiation as they decay. The term covers radionuclides that can release alpha, beta, or gamma radiation. Each radionuclide has a characteristic half-life, the time needed for its activity to fall by half, which can range from fractions of a second to many millions of years. Decay can occur in chains, producing daughter nuclides that may themselves be radioactive.

Radioactives occur naturally or are produced artificially. Natural sources include uranium and thorium in rocks, as well as radon gas from soil and its decay products. Artificial radionuclides are created in nuclear reactors or particle accelerators and are used across medicine, industry, and science. Some radionuclides are short-lived and require careful handling; others persist for long times and need long-term containment.

Applications include diagnostic imaging and radiotherapy in medicine, non-destructive testing and industrial gauging in industry, and radiotracers in scientific research. In some contexts, nuclear fuel involves radioactive materials, but radioactives describe the materials themselves rather than the energy production process.

Safety and regulation address health risks from ionizing radiation, including effects on skin, eyes, and organs, as well as long-term cancer risk. Regulatory frameworks govern procurement, handling, storage, transport, use, and disposal, with shielding, containment, monitoring, and waste management requirements. International guidance from bodies such as the IAEA and ICRP is implemented by national authorities.