Safety assessment of water-cooled nuclear reactors encompasses potential severe accidents where, in particular, the behaviour of radionuclides released into the reactor coolant system is evaluated. The SOPHAEROS code, a module of the ASTEC integral code, models this behaviour. The code modelling is described here along with example calculations taken from the wide variety of validation studies (from highly analytical to integral experiments). Now a robust and relatively mature tool with a reasonable level of accuracy and an acceptable calculation time, SOPHAEROS constitutes a sound basis for completing modelling of the key phenomenology. Short-term improvements include implementing models for aerosol deposition in flow-geometry changes, retention in water volumes, and a more mechanistic model for mechanical resuspension.
(1) : IRSN
(2) : RMC-UV Canada.