Radiation Protection Glossary

A radiation protection glossary for Radiation Protection Supervisors (RPS), Radiation Protection Advisers (RPA) and anyone else interesting in radiation safety terms and definitions. The glossary is a mixture of health physics , phrases related to radiation protection legislation, transport, practical safety, technical terms and similar.

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For formal advice, see our Radiation Protection Adviser pages. 

Decay

Also known as Radioactive Decay. Radioactive substances undergo radioactive decay, the rate of which is determined by the properties of the radionuclide. As decay proceeds the resulting activity of the parent Nuclide reduces and will eventually disappear. The daughter product may be stable (inactive) or may itself be Radioactive and undergo further decay (i.e. as part of a decay series). The rate of decay can be expressed in terms of its Half-Life (the time taken for the activity to reduce by half).

If you start from nothing, it is very difficult to get anywhere

– Gerhard Herzberg -