A Model of Crud Particle/Wall Interaction and Deposition in a Pressurized Water Reactor Primary System

The relative importance of the soluble and particle fractions that take part in the transport of pressurized water reactor corrosion product is discussed in terms of modeling research. A model is proposed that considers the dominant role of the colloidal/particle fraction in the primary coolant system mass and radioactivity transfer. A new hypothesis for a two-stage sticking mechanism is used to quantify the thermal and water chemistry effects on particle/wall interaction. Analytical expressions for the deposition and release coefficients are derived. The results obtained by the MIGA computer code using this model are compared with observations.