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. 

Polonium - 210 (Po-210)

Polonium 210 (Po-210) is an Alpha Emitter with a Half-Life of around 138 days. Po-210 is all around us in the environment at low concentrations (e.g. water, cigarette smoke, NORM, Radon etc). It is also used in industry, primarily in static elimination devices where the alpha particle creates intense Ionisation which can neutralize positive and negative static charges. There is a move away from radioactive sources - with a preference towards electrically driven static elimination. Since it has a massive specific activity (166500 GBq/g) its alpha emission actually causes it to be hot in gram quantities - this property has been used for power sources in satellites. The death of Alexander Litvinenko from Po-210 poisoning on the 23/11/2006 has raised its profile.

The definition of 'safe' is not strictly an engineering term; it's a societal term. Does it mean absolutely no loss of life? Does it mean absolutely no contamination with radiation? What exactly does 'safe' mean?

– Henry Petroski -