Source term

A source term describes the composition and amount of radioactivity released in an accidental event such as an incident at a nuclear power plant.

Source term information includes information on the type and amount of radioactivity released as well as information on the location of the release (in the form of coordinate data and height above ground).

The source term is usually estimated based on the type of emergency - for example, in the case of a radiological emergency in German nuclear power plants, using mathematical models. After a release of radioactivity has occurred, the previously calculated source term can be checked and adjusted using measurement data.