Radiation Protection Glossary

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

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Gamma-ray Constant (Specific)

Published: Oct 12, 2018

The (specific) Gamma-ray Constant is a useful numerical quantity which is used to predict exposure in terms of Equivalent Dose per unit activity per unit distance. As the term is a constant, distance and activity values will vary in a linear fashion with distance and exposure, making approximate calculations of exposure (especially from Point Sources) very easy. For example, the gamma-ray constant for Cesium-137 is 76 micro Sv/h per GBq at 1m from a point source.

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