CASTEAUR (French acronym for simplified calculation of transfers to receptor waterways) is designed for use in studying the impact of accidental and routine releases from fuel cycle facilities.
It is used to compute the spatial and temporal evolution and the distribution of the radionuclides initially released.
This is done by considering the main physical (water, suspended matter, bottom sediments) and biological (phytoplankton, zooplankton, macrobenthos, and fish) compartments of a waterway; the transfer of radionuclides is assessed between and within these compartments.
Several types of source terms can be considered:
========> "Burst" release, representing an almost instantaneous contribution of a certain amount of pollutant at a particular point (accident situation).
========> "Sequence" release, representing a continuous though non-permanent contribution at a particular point.
========> "Linear" release, used to consider a continuous, non-permanent contribution over an entire section of the waterway. This type of release will make it possible to consider contributions due to run-off from drainage basins.
========> "Routine" release corresponding to a permanent contribution at a particular point.