The unit, symbol Bq, of activity: one nucleus decaying per second. Because a becquerel is tiny, practical quantities run to kilo-, mega-, giga- and terabecquerels, and specific activity in foods, soils and waste is given in Bq per kilogram or Bq per gram. Activity says how much is decaying, not how much dose results; that depends on the radiation type, energy and where the material sits relative to people.
Resin sample is 4 megabecquerel per gram of cobalt-60, so it goes in the high-integrity container.
A becquerel count sounds alarming out of context: a banana carries roughly 15 becquerels of potassium-40 and an adult body several thousand.
Also heard as
- Bq
Related terms
Curie
The non-SI unit of radioactivity, equal to 37 billion decays per second.
Half-life
The time it takes for half the atoms of a radioactive isotope to decay, a fixed value for each nuclide.
Clearance
The release of materials with very low radioactivity from regulatory control, so they can be reused or disposed of normally.
Sealed source
Radioactive material permanently sealed in a capsule so it cannot escape under normal use.