14. Glossary

Radionuclide; radionuclide

Isotope of a chemical element whose radioactive nucleus decays. Examples: tritium, noted ³ H, which is the radioactive isotope of hydrogen, or cesium 137 ( ¹³⁷ Cs), which is one of the radioactive isotopes of cesium, are radionuclides.

Activité; activity

A quantity representative of a radionuclide. It corresponds to the number of disintegrations of radionuclide nuclei per unit of time, expressed in becquerels (Bq): 1 Bq = 1 disintegration per second.

Activités massique et volumique; massic or volumic activity

Quantities representative of the concentration of a radionuclide; they are expressed in Bq.kg ^-1 ...